This is gnutls.info, produced by makeinfo version 6.0 from gnutls.texi.

This manual is last updated 4 March 2015 for version 3.4.4 of GnuTLS.

Copyright (C) 2001-2015 Free Software Foundation, Inc.\\ Copyright (C)
2001-2015 Nikos Mavrogiannopoulos

     Permission is granted to copy, distribute and/or modify this
     document under the terms of the GNU Free Documentation License,
     Version 1.3 or any later version published by the Free Software
     Foundation; with no Invariant Sections, no Front-Cover Texts, and
     no Back-Cover Texts.  A copy of the license is included in the
     section entitled "GNU Free Documentation License".
INFO-DIR-SECTION Software libraries
START-INFO-DIR-ENTRY
* GnuTLS: (gnutls).		GNU Transport Layer Security Library.
END-INFO-DIR-ENTRY

INFO-DIR-SECTION System Administration
START-INFO-DIR-ENTRY
* certtool: (gnutls)Invoking certtool.	Manipulate certificates and keys.
* gnutls-serv: (gnutls)Invoking gnutls-serv.	GnuTLS test server.
* gnutls-cli: (gnutls)Invoking gnutls-cli.	GnuTLS test client.
* gnutls-cli-debug: (gnutls)Invoking gnutls-cli-debug.	GnuTLS debug client.
* psktool: (gnutls)Invoking psktool.	Simple TLS-Pre-Shared-Keys manager.
* srptool: (gnutls)Invoking srptool.	Simple SRP password tool.
END-INFO-DIR-ENTRY


File: gnutls.info,  Node: PKCS 7 API,  Next: OCSP API,  Prev: X509 certificate API,  Up: API reference

E.4 PKCS 7 API
==============

The following functions are to be used for PKCS 7 structures handling.
Their prototypes lie in 'gnutls/pkcs7.h'.

gnutls_pkcs7_add_attr
---------------------

 -- Function: int gnutls_pkcs7_add_attr (gnutls_pkcs7_attrs_t * LIST,
          const char * OID, gnutls_datum_t * DATA, unsigned FLAGS)
     LIST: A list of existing attributes or pointer to 'NULL' for the
     first one

     OID: the OID of the attribute to be set

     DATA: the raw (DER-encoded) data of the attribute to be set

     FLAGS: zero or 'GNUTLS_PKCS7_ATTR_ENCODE_OCTET_STRING'

     This function will set a PKCS '7' attribute in the provided list.
     If this function fails, the previous list would be deallocated.

     Note that any attributes set with this function must either be DER
     or BER encoded, unless a special flag is present.

     *Returns:* On success, the new list head, otherwise 'NULL' .

     *Since:* 3.4.2

gnutls_pkcs7_attrs_deinit
-------------------------

 -- Function: void gnutls_pkcs7_attrs_deinit (gnutls_pkcs7_attrs_t LIST)
     LIST: A list of existing attributes

     This function will clear a PKCS '7' attribute list.

     *Since:* 3.4.2

gnutls_pkcs7_deinit
-------------------

 -- Function: void gnutls_pkcs7_deinit (gnutls_pkcs7_t PKCS7)
     PKCS7: the type to be deinitialized

     This function will deinitialize a PKCS7 type.

gnutls_pkcs7_delete_crl
-----------------------

 -- Function: int gnutls_pkcs7_delete_crl (gnutls_pkcs7_t PKCS7, int
          INDX)
     PKCS7: The pkcs7 type

     INDX: the index of the crl to delete

     This function will delete a crl from a PKCS7 or RFC2630 crl set.
     Index starts from 0.  Returns 0 on success.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_delete_crt
-----------------------

 -- Function: int gnutls_pkcs7_delete_crt (gnutls_pkcs7_t PKCS7, int
          INDX)
     PKCS7: The pkcs7 type

     INDX: the index of the certificate to delete

     This function will delete a certificate from a PKCS7 or RFC2630
     certificate set.  Index starts from 0.  Returns 0 on success.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_export
-------------------

 -- Function: int gnutls_pkcs7_export (gnutls_pkcs7_t PKCS7,
          gnutls_x509_crt_fmt_t FORMAT, void * OUTPUT_DATA, size_t *
          OUTPUT_DATA_SIZE)
     PKCS7: The pkcs7 type

     FORMAT: the format of output params.  One of PEM or DER.

     OUTPUT_DATA: will contain a structure PEM or DER encoded

     OUTPUT_DATA_SIZE: holds the size of output_data (and will be
     replaced by the actual size of parameters)

     This function will export the pkcs7 structure to DER or PEM format.

     If the buffer provided is not long enough to hold the output, then
     * 'output_data_size' is updated and 'GNUTLS_E_SHORT_MEMORY_BUFFER'
     will be returned.

     If the structure is PEM encoded, it will have a header of "BEGIN
     PKCS7".

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_export2
--------------------

 -- Function: int gnutls_pkcs7_export2 (gnutls_pkcs7_t PKCS7,
          gnutls_x509_crt_fmt_t FORMAT, gnutls_datum_t * OUT)
     PKCS7: The pkcs7 type

     FORMAT: the format of output params.  One of PEM or DER.

     OUT: will contain a structure PEM or DER encoded

     This function will export the pkcs7 structure to DER or PEM format.

     The output buffer is allocated using 'gnutls_malloc()' .

     If the structure is PEM encoded, it will have a header of "BEGIN
     PKCS7".

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

     *Since:* 3.1.3

gnutls_pkcs7_get_attr
---------------------

 -- Function: int gnutls_pkcs7_get_attr (gnutls_pkcs7_attrs_t LIST,
          unsigned IDX, char ** OID, gnutls_datum_t * DATA, unsigned
          FLAGS)
     LIST: A list of existing attributes or 'NULL' for the first one

     IDX: the index of the attribute to get

     OID: the OID of the attribute (read-only)

     DATA: the raw data of the attribute

     FLAGS: zero or 'GNUTLS_PKCS7_ATTR_ENCODE_OCTET_STRING'

     This function will get a PKCS '7' attribute from the provided list.
     The OID is a constant string, but data will be allocated and must
     be deinitialized by the caller.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' is returned if there are no
     data in the current index.

     *Since:* 3.4.2

gnutls_pkcs7_get_crl_count
--------------------------

 -- Function: int gnutls_pkcs7_get_crl_count (gnutls_pkcs7_t PKCS7)
     PKCS7: The pkcs7 type

     This function will return the number of certifcates in the PKCS7 or
     RFC2630 crl set.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_get_crl_raw
------------------------

 -- Function: int gnutls_pkcs7_get_crl_raw (gnutls_pkcs7_t PKCS7, int
          INDX, void * CRL, size_t * CRL_SIZE)
     PKCS7: The pkcs7 type

     INDX: contains the index of the crl to extract

     CRL: the contents of the crl will be copied there (may be null)

     CRL_SIZE: should hold the size of the crl

     This function will return a crl of the PKCS7 or RFC2630 crl set.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.  If the provided buffer is not
     long enough, then 'crl_size' is updated and
     'GNUTLS_E_SHORT_MEMORY_BUFFER' is returned.  After the last crl has
     been read 'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' will be returned.

gnutls_pkcs7_get_crl_raw2
-------------------------

 -- Function: int gnutls_pkcs7_get_crl_raw2 (gnutls_pkcs7_t PKCS7, int
          INDX, gnutls_datum_t * CRL)
     PKCS7: The pkcs7 type

     INDX: contains the index of the crl to extract

     CRL: will contain the contents of the CRL in an allocated buffer

     This function will return a DER encoded CRL of the PKCS7 or RFC2630
     crl set.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.  After the last crl has been read
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' will be returned.

     *Since:* 3.4.2

gnutls_pkcs7_get_crt_count
--------------------------

 -- Function: int gnutls_pkcs7_get_crt_count (gnutls_pkcs7_t PKCS7)
     PKCS7: should contain a 'gnutls_pkcs7_t' type

     This function will return the number of certifcates in the PKCS7 or
     RFC2630 certificate set.

     *Returns:* On success, a positive number is returned, otherwise a
     negative error value.

gnutls_pkcs7_get_crt_raw
------------------------

 -- Function: int gnutls_pkcs7_get_crt_raw (gnutls_pkcs7_t PKCS7, int
          INDX, void * CERTIFICATE, size_t * CERTIFICATE_SIZE)
     PKCS7: should contain a gnutls_pkcs7_t type

     INDX: contains the index of the certificate to extract

     CERTIFICATE: the contents of the certificate will be copied there
     (may be null)

     CERTIFICATE_SIZE: should hold the size of the certificate

     This function will return a certificate of the PKCS7 or RFC2630
     certificate set.

     After the last certificate has been read
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' will be returned.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.  If the provided buffer is not
     long enough, then 'certificate_size' is updated and
     'GNUTLS_E_SHORT_MEMORY_BUFFER' is returned.

gnutls_pkcs7_get_crt_raw2
-------------------------

 -- Function: int gnutls_pkcs7_get_crt_raw2 (gnutls_pkcs7_t PKCS7, int
          INDX, gnutls_datum_t * CERT)
     PKCS7: should contain a gnutls_pkcs7_t type

     INDX: contains the index of the certificate to extract

     CERT: will hold the contents of the certificate; must be
     deallocated with 'gnutls_free()'

     This function will return a certificate of the PKCS7 or RFC2630
     certificate set.

     After the last certificate has been read
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' will be returned.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.  If the provided buffer is not
     long enough, then 'certificate_size' is updated and
     'GNUTLS_E_SHORT_MEMORY_BUFFER' is returned.

     *Since:* 3.4.2

gnutls_pkcs7_get_signature_count
--------------------------------

 -- Function: int gnutls_pkcs7_get_signature_count (gnutls_pkcs7_t
          PKCS7)
     PKCS7: should contain a 'gnutls_pkcs7_t' type

     This function will return the number of signatures in the PKCS7
     structure.

     *Returns:* On success, a positive number is returned, otherwise a
     negative error value.

     *Since:* 3.4.3

gnutls_pkcs7_get_signature_info
-------------------------------

 -- Function: int gnutls_pkcs7_get_signature_info (gnutls_pkcs7_t PKCS7,
          unsigned IDX, gnutls_pkcs7_signature_info_st * INFO)
     PKCS7: should contain a 'gnutls_pkcs7_t' type

     IDX: the index of the signature info to check

     INFO: will contain the output signature

     This function will return information about the signature
     identified by idx in the provided PKCS '7' structure.  The
     information should be deinitialized using
     'gnutls_pkcs7_signature_info_deinit()' .

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

     *Since:* 3.4.2

gnutls_pkcs7_import
-------------------

 -- Function: int gnutls_pkcs7_import (gnutls_pkcs7_t PKCS7, const
          gnutls_datum_t * DATA, gnutls_x509_crt_fmt_t FORMAT)
     PKCS7: The data to store the parsed PKCS7.

     DATA: The DER or PEM encoded PKCS7.

     FORMAT: One of DER or PEM

     This function will convert the given DER or PEM encoded PKCS7 to
     the native 'gnutls_pkcs7_t' format.  The output will be stored in
     'pkcs7' .

     If the PKCS7 is PEM encoded it should have a header of "PKCS7".

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_init
-----------------

 -- Function: int gnutls_pkcs7_init (gnutls_pkcs7_t * PKCS7)
     PKCS7: A pointer to the type to be initialized

     This function will initialize a PKCS7 structure.  PKCS7 structures
     usually contain lists of X.509 Certificates and X.509 Certificate
     revocation lists.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_print
------------------

 -- Function: int gnutls_pkcs7_print (gnutls_pkcs7_t PKCS7,
          gnutls_certificate_print_formats_t FORMAT, gnutls_datum_t *
          OUT)
     PKCS7: The PKCS7 struct to be printed

     FORMAT: Indicate the format to use

     OUT: Newly allocated datum with null terminated string.

     This function will pretty print a signed PKCS '7' structure,
     suitable for display to a human.

     Currently the supported formats are 'GNUTLS_CRT_PRINT_FULL' and
     'GNUTLS_CRT_PRINT_COMPACT' .

     The output 'out' needs to be deallocated using 'gnutls_free()' .

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_set_crl
--------------------

 -- Function: int gnutls_pkcs7_set_crl (gnutls_pkcs7_t PKCS7,
          gnutls_x509_crl_t CRL)
     PKCS7: The pkcs7 type

     CRL: the DER encoded crl to be added

     This function will add a parsed CRL to the PKCS7 or RFC2630 crl
     set.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_set_crl_raw
------------------------

 -- Function: int gnutls_pkcs7_set_crl_raw (gnutls_pkcs7_t PKCS7, const
          gnutls_datum_t * CRL)
     PKCS7: The pkcs7 type

     CRL: the DER encoded crl to be added

     This function will add a crl to the PKCS7 or RFC2630 crl set.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_set_crt
--------------------

 -- Function: int gnutls_pkcs7_set_crt (gnutls_pkcs7_t PKCS7,
          gnutls_x509_crt_t CRT)
     PKCS7: The pkcs7 type

     CRT: the certificate to be copied.

     This function will add a parsed certificate to the PKCS7 or RFC2630
     certificate set.  This is a wrapper function over
     'gnutls_pkcs7_set_crt_raw()' .

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_set_crt_raw
------------------------

 -- Function: int gnutls_pkcs7_set_crt_raw (gnutls_pkcs7_t PKCS7, const
          gnutls_datum_t * CRT)
     PKCS7: The pkcs7 type

     CRT: the DER encoded certificate to be added

     This function will add a certificate to the PKCS7 or RFC2630
     certificate set.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_pkcs7_sign
-----------------

 -- Function: int gnutls_pkcs7_sign (gnutls_pkcs7_t PKCS7,
          gnutls_x509_crt_t SIGNER, gnutls_privkey_t SIGNER_KEY, const
          gnutls_datum_t * DATA, gnutls_pkcs7_attrs_t SIGNED_ATTRS,
          gnutls_pkcs7_attrs_t UNSIGNED_ATTRS, gnutls_digest_algorithm_t
          DIG, unsigned FLAGS)
     PKCS7: should contain a 'gnutls_pkcs7_t' type

     SIGNER: the certificate to sign the structure

     SIGNER_KEY: the key to sign the structure

     DATA: The data to be signed or 'NULL' if the data are already
     embedded

     SIGNED_ATTRS: Any additional attributes to be included in the
     signed ones (or 'NULL' )

     UNSIGNED_ATTRS: Any additional attributes to be included in the
     unsigned ones (or 'NULL' )

     DIG: The digest algorithm to use for signing

     FLAGS: Should be zero or one of 'GNUTLS_PKCS7' flags

     This function will add a signature in the provided PKCS '7'
     structure for the provided data.  Multiple signatures can be made
     with different signers.

     The available flags are: - 'GNUTLS_PKCS7_EMBED_DATA' : the data
     will be embedded in the structure - 'GNUTLS_PKCS7_INCLUDE_TIME' :
     the signing time will be included - 'GNUTLS_PKCS7_INCLUDE_CERT' :
     the signer's certificate will be included in the cert list -
     'GNUTLS_PKCS7_WRITE_SPKI' : store the issuer's ID instead of name

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

     *Since:* 3.4.2

gnutls_pkcs7_signature_info_deinit
----------------------------------

 -- Function: void gnutls_pkcs7_signature_info_deinit
          (gnutls_pkcs7_signature_info_st * INFO)
     INFO: should point to a 'gnutls_pkcs7_signature_info_st' structure

     This function will deinitialize any allocated value in the provided
     'gnutls_pkcs7_signature_info_st' .

     *Since:* 3.4.2

gnutls_pkcs7_verify
-------------------

 -- Function: int gnutls_pkcs7_verify (gnutls_pkcs7_t PKCS7,
          gnutls_x509_trust_list_t TL, gnutls_typed_vdata_st * VDATA,
          unsigned int VDATA_SIZE, unsigned IDX, const gnutls_datum_t *
          DATA, unsigned FLAGS)
     PKCS7: should contain a 'gnutls_pkcs7_t' type

     TL: A list of trusted certificates

     VDATA: an array of typed data

     VDATA_SIZE: the number of data elements

     IDX: the index of the signature info to check

     DATA: The data to be verified or 'NULL'

     FLAGS: Zero or an OR list of 'gnutls_certificate_verify_flags'

     This function will verify the provided data against the signature
     present in the SignedData of the PKCS '7' structure.  If the data
     provided are NULL then the data in the encapsulatedContent field
     will be used instead.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.  A verification error results to
     a 'GNUTLS_E_PK_SIG_VERIFY_FAILED' and the lack of encapsulated data
     to verify to a 'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' .

     *Since:* 3.4.2

gnutls_pkcs7_verify_direct
--------------------------

 -- Function: int gnutls_pkcs7_verify_direct (gnutls_pkcs7_t PKCS7,
          gnutls_x509_crt_t SIGNER, unsigned IDX, const gnutls_datum_t *
          DATA, unsigned FLAGS)
     PKCS7: should contain a 'gnutls_pkcs7_t' type

     SIGNER: the certificate believed to have signed the structure

     IDX: the index of the signature info to check

     DATA: The data to be verified or 'NULL'

     FLAGS: Zero or an OR list of 'gnutls_certificate_verify_flags'

     This function will verify the provided data against the signature
     present in the SignedData of the PKCS '7' structure.  If the data
     provided are NULL then the data in the encapsulatedContent field
     will be used instead.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.  A verification error results to
     a 'GNUTLS_E_PK_SIG_VERIFY_FAILED' and the lack of encapsulated data
     to verify to a 'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' .

     *Since:* 3.4.2


File: gnutls.info,  Node: OCSP API,  Next: OpenPGP API,  Prev: PKCS 7 API,  Up: API reference

E.5 OCSP API
============

The following functions are for OCSP certificate status checking.  Their
prototypes lie in 'gnutls/ocsp.h'.

gnutls_ocsp_req_add_cert
------------------------

 -- Function: int gnutls_ocsp_req_add_cert (gnutls_ocsp_req_t REQ,
          gnutls_digest_algorithm_t DIGEST, gnutls_x509_crt_t ISSUER,
          gnutls_x509_crt_t CERT)
     REQ: should contain a 'gnutls_ocsp_req_t' type

     DIGEST: hash algorithm, a 'gnutls_digest_algorithm_t' value

     ISSUER: issuer of 'subject' certificate

     CERT: certificate to request status for

     This function will add another request to the OCSP request for a
     particular certificate.  The issuer name hash, issuer key hash, and
     serial number fields is populated as follows.  The issuer name and
     the serial number is taken from 'cert' .  The issuer key is taken
     from 'issuer' .  The hashed values will be hashed using the
     'digest' algorithm, normally 'GNUTLS_DIG_SHA1' .

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_ocsp_req_add_cert_id
---------------------------

 -- Function: int gnutls_ocsp_req_add_cert_id (gnutls_ocsp_req_t REQ,
          gnutls_digest_algorithm_t DIGEST, const gnutls_datum_t *
          ISSUER_NAME_HASH, const gnutls_datum_t * ISSUER_KEY_HASH,
          const gnutls_datum_t * SERIAL_NUMBER)
     REQ: should contain a 'gnutls_ocsp_req_t' type

     DIGEST: hash algorithm, a 'gnutls_digest_algorithm_t' value

     ISSUER_NAME_HASH: hash of issuer's DN

     ISSUER_KEY_HASH: hash of issuer's public key

     SERIAL_NUMBER: serial number of certificate to check

     This function will add another request to the OCSP request for a
     particular certificate having the issuer name hash of
     'issuer_name_hash' and issuer key hash of 'issuer_key_hash' (both
     hashed using 'digest' ) and serial number 'serial_number' .

     The information needed corresponds to the CertID structure:

     <informalexample><programlisting> CertID ::= SEQUENCE {
     hashAlgorithm AlgorithmIdentifier, issuerNameHash OCTET STRING, -
     Hash of Issuer's DN issuerKeyHash OCTET STRING, - Hash of Issuers
     public key serialNumber CertificateSerialNumber }
     </programlisting></informalexample>

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_ocsp_req_deinit
----------------------

 -- Function: void gnutls_ocsp_req_deinit (gnutls_ocsp_req_t REQ)
     REQ: The data to be deinitialized

     This function will deinitialize a OCSP request structure.

gnutls_ocsp_req_export
----------------------

 -- Function: int gnutls_ocsp_req_export (gnutls_ocsp_req_t REQ,
          gnutls_datum_t * DATA)
     REQ: Holds the OCSP request

     DATA: newly allocate buffer holding DER encoded OCSP request

     This function will export the OCSP request to DER format.

     *Returns:* In case of failure a negative error code will be
     returned, and 0 on success.

gnutls_ocsp_req_get_cert_id
---------------------------

 -- Function: int gnutls_ocsp_req_get_cert_id (gnutls_ocsp_req_t REQ,
          unsigned INDX, gnutls_digest_algorithm_t * DIGEST,
          gnutls_datum_t * ISSUER_NAME_HASH, gnutls_datum_t *
          ISSUER_KEY_HASH, gnutls_datum_t * SERIAL_NUMBER)
     REQ: should contain a 'gnutls_ocsp_req_t' type

     INDX: Specifies which extension OID to get.  Use (0) to get the
     first one.

     DIGEST: output variable with 'gnutls_digest_algorithm_t' hash
     algorithm

     ISSUER_NAME_HASH: output buffer with hash of issuer's DN

     ISSUER_KEY_HASH: output buffer with hash of issuer's public key

     SERIAL_NUMBER: output buffer with serial number of certificate to
     check

     This function will return the certificate information of the 'indx'
     'ed request in the OCSP request.  The information returned
     corresponds to the CertID structure:

     <informalexample><programlisting> CertID ::= SEQUENCE {
     hashAlgorithm AlgorithmIdentifier, issuerNameHash OCTET STRING, -
     Hash of Issuer's DN issuerKeyHash OCTET STRING, - Hash of Issuers
     public key serialNumber CertificateSerialNumber }
     </programlisting></informalexample>

     Each of the pointers to output variables may be NULL to indicate
     that the caller is not interested in that value.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.  If you have reached
     the last CertID available 'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE'
     will be returned.

gnutls_ocsp_req_get_extension
-----------------------------

 -- Function: int gnutls_ocsp_req_get_extension (gnutls_ocsp_req_t REQ,
          unsigned INDX, gnutls_datum_t * OID, unsigned int * CRITICAL,
          gnutls_datum_t * DATA)
     REQ: should contain a 'gnutls_ocsp_req_t' type

     INDX: Specifies which extension OID to get.  Use (0) to get the
     first one.

     OID: will hold newly allocated buffer with OID of extension, may be
     NULL

     CRITICAL: output variable with critical flag, may be NULL.

     DATA: will hold newly allocated buffer with extension data, may be
     NULL

     This function will return all information about the requested
     extension in the OCSP request.  The information returned is the
     OID, the critical flag, and the data itself.  The extension OID
     will be stored as a string.  Any of 'oid' , 'critical' , and 'data'
     may be NULL which means that the caller is not interested in
     getting that information back.

     The caller needs to deallocate memory by calling 'gnutls_free()' on
     'oid' ->data and 'data' ->data.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.  If you have reached
     the last extension available
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' will be returned.

gnutls_ocsp_req_get_nonce
-------------------------

 -- Function: int gnutls_ocsp_req_get_nonce (gnutls_ocsp_req_t REQ,
          unsigned int * CRITICAL, gnutls_datum_t * NONCE)
     REQ: should contain a 'gnutls_ocsp_req_t' type

     CRITICAL: whether nonce extension is marked critical, or NULL

     NONCE: will hold newly allocated buffer with nonce data

     This function will return the OCSP request nonce extension data.

     The caller needs to deallocate memory by calling 'gnutls_free()' on
     'nonce' ->data.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_ocsp_req_get_version
---------------------------

 -- Function: int gnutls_ocsp_req_get_version (gnutls_ocsp_req_t REQ)
     REQ: should contain a 'gnutls_ocsp_req_t' type

     This function will return the version of the OCSP request.
     Typically this is always 1 indicating version 1.

     *Returns:* version of OCSP request, or a negative error code on
     error.

gnutls_ocsp_req_import
----------------------

 -- Function: int gnutls_ocsp_req_import (gnutls_ocsp_req_t REQ, const
          gnutls_datum_t * DATA)
     REQ: The data to store the parsed request.

     DATA: DER encoded OCSP request.

     This function will convert the given DER encoded OCSP request to
     the native 'gnutls_ocsp_req_t' format.  The output will be stored
     in 'req' .

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_req_init
--------------------

 -- Function: int gnutls_ocsp_req_init (gnutls_ocsp_req_t * REQ)
     REQ: A pointer to the type to be initialized

     This function will initialize an OCSP request structure.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_req_print
---------------------

 -- Function: int gnutls_ocsp_req_print (gnutls_ocsp_req_t REQ,
          gnutls_ocsp_print_formats_t FORMAT, gnutls_datum_t * OUT)
     REQ: The data to be printed

     FORMAT: Indicate the format to use

     OUT: Newly allocated datum with (0) terminated string.

     This function will pretty print a OCSP request, suitable for
     display to a human.

     If the format is 'GNUTLS_OCSP_PRINT_FULL' then all fields of the
     request will be output, on multiple lines.

     The output 'out' ->data needs to be deallocate using
     'gnutls_free()' .

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_req_randomize_nonce
-------------------------------

 -- Function: int gnutls_ocsp_req_randomize_nonce (gnutls_ocsp_req_t
          REQ)
     REQ: should contain a 'gnutls_ocsp_req_t' type

     This function will add or update an nonce extension to the OCSP
     request with a newly generated random value.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_ocsp_req_set_extension
-----------------------------

 -- Function: int gnutls_ocsp_req_set_extension (gnutls_ocsp_req_t REQ,
          const char * OID, unsigned int CRITICAL, const gnutls_datum_t
          * DATA)
     REQ: should contain a 'gnutls_ocsp_req_t' type

     OID: buffer with OID of extension as a string.

     CRITICAL: critical flag, normally false.

     DATA: the extension data

     This function will add an extension to the OCSP request.  Calling
     this function multiple times for the same OID will overwrite values
     from earlier calls.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_ocsp_req_set_nonce
-------------------------

 -- Function: int gnutls_ocsp_req_set_nonce (gnutls_ocsp_req_t REQ,
          unsigned int CRITICAL, const gnutls_datum_t * NONCE)
     REQ: should contain a 'gnutls_ocsp_req_t' type

     CRITICAL: critical flag, normally false.

     NONCE: the nonce data

     This function will add an nonce extension to the OCSP request.
     Calling this function multiple times will overwrite values from
     earlier calls.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_ocsp_resp_check_crt
--------------------------

 -- Function: int gnutls_ocsp_resp_check_crt (gnutls_ocsp_resp_t RESP,
          unsigned int INDX, gnutls_x509_crt_t CRT)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     INDX: Specifies response number to get.  Use (0) to get the first
     one.

     CRT: The certificate to check

     This function will check whether the OCSP response is about the
     provided certificate.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

     *Since:* 3.1.3

gnutls_ocsp_resp_deinit
-----------------------

 -- Function: void gnutls_ocsp_resp_deinit (gnutls_ocsp_resp_t RESP)
     RESP: The data to be deinitialized

     This function will deinitialize a OCSP response structure.

gnutls_ocsp_resp_export
-----------------------

 -- Function: int gnutls_ocsp_resp_export (gnutls_ocsp_resp_t RESP,
          gnutls_datum_t * DATA)
     RESP: Holds the OCSP response

     DATA: newly allocate buffer holding DER encoded OCSP response

     This function will export the OCSP response to DER format.

     *Returns:* In case of failure a negative error code will be
     returned, and 0 on success.

gnutls_ocsp_resp_get_certs
--------------------------

 -- Function: int gnutls_ocsp_resp_get_certs (gnutls_ocsp_resp_t RESP,
          gnutls_x509_crt_t ** CERTS, size_t * NCERTS)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     CERTS: newly allocated array with 'gnutls_x509_crt_t' certificates

     NCERTS: output variable with number of allocated certs.

     This function will extract the X.509 certificates found in the
     Basic OCSP Response.  The 'certs' output variable will hold a newly
     allocated zero-terminated array with X.509 certificates.

     Every certificate in the array needs to be de-allocated with
     'gnutls_x509_crt_deinit()' and the array itself must be freed using
     'gnutls_free()' .

     Both the 'certs' and 'ncerts' variables may be NULL. Then the
     function will work as normal but will not return the NULL:d
     information.  This can be used to get the number of certificates
     only, or to just get the certificate array without its size.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_resp_get_extension
------------------------------

 -- Function: int gnutls_ocsp_resp_get_extension (gnutls_ocsp_resp_t
          RESP, unsigned INDX, gnutls_datum_t * OID, unsigned int *
          CRITICAL, gnutls_datum_t * DATA)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     INDX: Specifies which extension OID to get.  Use (0) to get the
     first one.

     OID: will hold newly allocated buffer with OID of extension, may be
     NULL

     CRITICAL: output variable with critical flag, may be NULL.

     DATA: will hold newly allocated buffer with extension data, may be
     NULL

     This function will return all information about the requested
     extension in the OCSP response.  The information returned is the
     OID, the critical flag, and the data itself.  The extension OID
     will be stored as a string.  Any of 'oid' , 'critical' , and 'data'
     may be NULL which means that the caller is not interested in
     getting that information back.

     The caller needs to deallocate memory by calling 'gnutls_free()' on
     'oid' ->data and 'data' ->data.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.  If you have reached
     the last extension available
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' will be returned.

gnutls_ocsp_resp_get_nonce
--------------------------

 -- Function: int gnutls_ocsp_resp_get_nonce (gnutls_ocsp_resp_t RESP,
          unsigned int * CRITICAL, gnutls_datum_t * NONCE)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     CRITICAL: whether nonce extension is marked critical

     NONCE: will hold newly allocated buffer with nonce data

     This function will return the Basic OCSP Response nonce extension
     data.

     The caller needs to deallocate memory by calling 'gnutls_free()' on
     'nonce' ->data.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_ocsp_resp_get_produced
-----------------------------

 -- Function: time_t gnutls_ocsp_resp_get_produced (gnutls_ocsp_resp_t
          RESP)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     This function will return the time when the OCSP response was
     signed.

     *Returns:* signing time, or (time_t)-1 on error.

gnutls_ocsp_resp_get_responder
------------------------------

 -- Function: int gnutls_ocsp_resp_get_responder (gnutls_ocsp_resp_t
          RESP, gnutls_datum_t * DN)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     DN: newly allocated buffer with name

     This function will extract the name of the Basic OCSP Response in
     the provided buffer.  The name will be in the form
     "C=xxxx,O=yyyy,CN=zzzz" as described in RFC2253.  The output string
     will be ASCII or UTF-8 encoded, depending on the certificate data.

     If the responder ID is not a name but a hash, this function will
     return zero and the 'dn' elements will be set to 'NULL' .

     The caller needs to deallocate memory by calling 'gnutls_free()' on
     'dn' ->data.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_ocsp_resp_get_responder_raw_id
-------------------------------------

 -- Function: int gnutls_ocsp_resp_get_responder_raw_id
          (gnutls_ocsp_resp_t RESP, unsigned TYPE, gnutls_datum_t * RAW)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     TYPE: should be 'GNUTLS_OCSP_RESP_ID_KEY' or
     'GNUTLS_OCSP_RESP_ID_DN'

     RAW: newly allocated buffer with the raw ID

     This function will extract the raw key (or DN) ID of the Basic OCSP
     Response in the provided buffer.  If the responder ID is not a key
     ID then this function will return
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' .

     The caller needs to deallocate memory by calling 'gnutls_free()' on
     'dn' ->data.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_ocsp_resp_get_response
-----------------------------

 -- Function: int gnutls_ocsp_resp_get_response (gnutls_ocsp_resp_t
          RESP, gnutls_datum_t * RESPONSE_TYPE_OID, gnutls_datum_t *
          RESPONSE)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     RESPONSE_TYPE_OID: newly allocated output buffer with response type
     OID

     RESPONSE: newly allocated output buffer with DER encoded response

     This function will extract the response type OID in and the
     response data from an OCSP response.  Normally the
     'response_type_oid' is always "1.3.6.1.5.5.7.48.1.1" which means
     the 'response' should be decoded as a Basic OCSP Response, but
     technically other response types could be used.

     This function is typically only useful when you want to extract the
     response type OID of an response for diagnostic purposes.
     Otherwise 'gnutls_ocsp_resp_import()' will decode the basic OCSP
     response part and the caller need not worry about that aspect.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_resp_get_signature
------------------------------

 -- Function: int gnutls_ocsp_resp_get_signature (gnutls_ocsp_resp_t
          RESP, gnutls_datum_t * SIG)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     SIG: newly allocated output buffer with signature data

     This function will extract the signature field of a OCSP response.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_resp_get_signature_algorithm
----------------------------------------

 -- Function: int gnutls_ocsp_resp_get_signature_algorithm
          (gnutls_ocsp_resp_t RESP)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     This function will return a value of the 'gnutls_sign_algorithm_t'
     enumeration that is the signature algorithm that has been used to
     sign the OCSP response.

     *Returns:* a 'gnutls_sign_algorithm_t' value, or a negative error
     code on error.

gnutls_ocsp_resp_get_single
---------------------------

 -- Function: int gnutls_ocsp_resp_get_single (gnutls_ocsp_resp_t RESP,
          unsigned INDX, gnutls_digest_algorithm_t * DIGEST,
          gnutls_datum_t * ISSUER_NAME_HASH, gnutls_datum_t *
          ISSUER_KEY_HASH, gnutls_datum_t * SERIAL_NUMBER, unsigned int
          * CERT_STATUS, time_t * THIS_UPDATE, time_t * NEXT_UPDATE,
          time_t * REVOCATION_TIME, unsigned int * REVOCATION_REASON)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     INDX: Specifies response number to get.  Use (0) to get the first
     one.

     DIGEST: output variable with 'gnutls_digest_algorithm_t' hash
     algorithm

     ISSUER_NAME_HASH: output buffer with hash of issuer's DN

     ISSUER_KEY_HASH: output buffer with hash of issuer's public key

     SERIAL_NUMBER: output buffer with serial number of certificate to
     check

     CERT_STATUS: a certificate status, a 'gnutls_ocsp_cert_status_t'
     enum.

     THIS_UPDATE: time at which the status is known to be correct.

     NEXT_UPDATE: when newer information will be available, or
     (time_t)-1 if unspecified

     REVOCATION_TIME: when 'cert_status' is 'GNUTLS_OCSP_CERT_REVOKED' ,
     holds time of revocation.

     REVOCATION_REASON: revocation reason, a 'gnutls_x509_crl_reason_t'
     enum.

     This function will return the certificate information of the 'indx'
     'ed response in the Basic OCSP Response 'resp' .  The information
     returned corresponds to the OCSP SingleResponse structure except
     the final singleExtensions.

     Each of the pointers to output variables may be NULL to indicate
     that the caller is not interested in that value.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.  If you have reached
     the last CertID available 'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE'
     will be returned.

gnutls_ocsp_resp_get_status
---------------------------

 -- Function: int gnutls_ocsp_resp_get_status (gnutls_ocsp_resp_t RESP)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     This function will return the status of a OCSP response, an
     'gnutls_ocsp_resp_status_t' enumeration.

     *Returns:* status of OCSP request as a 'gnutls_ocsp_resp_status_t'
     , or a negative error code on error.

gnutls_ocsp_resp_get_version
----------------------------

 -- Function: int gnutls_ocsp_resp_get_version (gnutls_ocsp_resp_t RESP)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     This function will return the version of the Basic OCSP Response.
     Typically this is always 1 indicating version 1.

     *Returns:* version of Basic OCSP response, or a negative error code
     on error.

gnutls_ocsp_resp_import
-----------------------

 -- Function: int gnutls_ocsp_resp_import (gnutls_ocsp_resp_t RESP,
          const gnutls_datum_t * DATA)
     RESP: The data to store the parsed response.

     DATA: DER encoded OCSP response.

     This function will convert the given DER encoded OCSP response to
     the native 'gnutls_ocsp_resp_t' format.  It also decodes the Basic
     OCSP Response part, if any.  The output will be stored in 'resp' .

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_resp_init
---------------------

 -- Function: int gnutls_ocsp_resp_init (gnutls_ocsp_resp_t * RESP)
     RESP: A pointer to the type to be initialized

     This function will initialize an OCSP response structure.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_resp_print
----------------------

 -- Function: int gnutls_ocsp_resp_print (gnutls_ocsp_resp_t RESP,
          gnutls_ocsp_print_formats_t FORMAT, gnutls_datum_t * OUT)
     RESP: The data to be printed

     FORMAT: Indicate the format to use

     OUT: Newly allocated datum with (0) terminated string.

     This function will pretty print a OCSP response, suitable for
     display to a human.

     If the format is 'GNUTLS_OCSP_PRINT_FULL' then all fields of the
     response will be output, on multiple lines.

     The output 'out' ->data needs to be deallocate using
     'gnutls_free()' .

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_resp_verify
-----------------------

 -- Function: int gnutls_ocsp_resp_verify (gnutls_ocsp_resp_t RESP,
          gnutls_x509_trust_list_t TRUSTLIST, unsigned int * VERIFY,
          unsigned int FLAGS)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     TRUSTLIST: trust anchors as a 'gnutls_x509_trust_list_t' type

     VERIFY: output variable with verification status, an
     'gnutls_ocsp_verify_reason_t'

     FLAGS: verification flags, 0 for now.

     Verify signature of the Basic OCSP Response against the public key
     in the certificate of a trusted signer.  The 'trustlist' should be
     populated with trust anchors.  The function will extract the signer
     certificate from the Basic OCSP Response and will verify it against
     the 'trustlist' .  A trusted signer is a certificate that is either
     in 'trustlist' , or it is signed directly by a certificate in
     'trustlist' and has the id-ad-ocspSigning Extended Key Usage bit
     set.

     The output 'verify' variable will hold verification status codes
     (e.g., 'GNUTLS_OCSP_VERIFY_SIGNER_NOT_FOUND' ,
     'GNUTLS_OCSP_VERIFY_INSECURE_ALGORITHM' ) which are only valid if
     the function returned 'GNUTLS_E_SUCCESS' .

     Note that the function returns 'GNUTLS_E_SUCCESS' even when
     verification failed.  The caller must always inspect the 'verify'
     variable to find out the verification status.

     The 'flags' variable should be 0 for now.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_ocsp_resp_verify_direct
------------------------------

 -- Function: int gnutls_ocsp_resp_verify_direct (gnutls_ocsp_resp_t
          RESP, gnutls_x509_crt_t ISSUER, unsigned int * VERIFY,
          unsigned int FLAGS)
     RESP: should contain a 'gnutls_ocsp_resp_t' type

     ISSUER: certificate believed to have signed the response

     VERIFY: output variable with verification status, an
     'gnutls_ocsp_verify_reason_t'

     FLAGS: verification flags, 0 for now.

     Verify signature of the Basic OCSP Response against the public key
     in the 'issuer' certificate.

     The output 'verify' variable will hold verification status codes
     (e.g., 'GNUTLS_OCSP_VERIFY_SIGNER_NOT_FOUND' ,
     'GNUTLS_OCSP_VERIFY_INSECURE_ALGORITHM' ) which are only valid if
     the function returned 'GNUTLS_E_SUCCESS' .

     Note that the function returns 'GNUTLS_E_SUCCESS' even when
     verification failed.  The caller must always inspect the 'verify'
     variable to find out the verification status.

     The 'flags' variable should be 0 for now.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.


File: gnutls.info,  Node: OpenPGP API,  Next: PKCS 12 API,  Prev: OCSP API,  Up: API reference

E.6 OpenPGP API
===============

The following functions are to be used for OpenPGP certificate handling.
Their prototypes lie in 'gnutls/openpgp.h'.

gnutls_certificate_get_openpgp_crt
----------------------------------

 -- Function: int gnutls_certificate_get_openpgp_crt
          (gnutls_certificate_credentials_t RES, unsigned INDEX,
          gnutls_openpgp_crt_t ** CRT_LIST, unsigned * CRT_LIST_SIZE)
     RES: is a 'gnutls_certificate_credentials_t' type.

     INDEX: The index of the certificate list to obtain.

     CRT_LIST: Where to store the certificate list.

     CRT_LIST_SIZE: - undescribed -

     Obtains a X.509 certificate list that has been stored in 'res' with
     one of 'gnutls_certificate_set_openpgp_key()' ,
     'gnutls_certificate_set_openpgp_key_file()' ,
     'gnutls_certificate_set_openpgp_key_file2()' ,
     'gnutls_certificate_set_openpgp_key_mem()' , or
     'gnutls_certificate_set_openpgp_key_mem2()' .  Each certificate in
     the returned certificate list must be deallocated with
     'gnutls_openpgp_crt_deinit()' , and the list itself must be freed
     with 'gnutls_free()' .

     If there is no certificate with the given index,
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' is returned.  If the
     certificate with the given index is not a X.509 certificate,
     'GNUTLS_E_INVALID_REQUEST' is returned.

     *Returns:* 'GNUTLS_E_SUCCESS' (0) on success, or a negative error
     code.

     *Since:* 3.4.0

gnutls_certificate_get_openpgp_key
----------------------------------

 -- Function: int gnutls_certificate_get_openpgp_key
          (gnutls_certificate_credentials_t RES, unsigned INDEX,
          gnutls_openpgp_privkey_t * KEY)
     RES: is a 'gnutls_certificate_credentials_t' type.

     INDEX: The index of the key to obtain.

     KEY: Location to store the key.

     Obtains a OpenPGP private key that has been stored in 'res' with
     one of 'gnutls_certificate_set_openpgp_key()' ,
     'gnutls_certificate_set_openpgp_key_file()' ,
     'gnutls_certificate_set_openpgp_key_file2()' ,
     'gnutls_certificate_set_openpgp_key_mem()' , or
     'gnutls_certificate_set_openpgp_key_mem2()' .  The returned key
     must be deallocated with 'gnutls_openpgp_privkey_deinit()' when no
     longer needed.

     If there is no key with the given index,
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' is returned.  If the key
     with the given index is not a X.509 key, 'GNUTLS_E_INVALID_REQUEST'
     is returned.

     *Returns:* 'GNUTLS_E_SUCCESS' (0) on success, or a negative error
     code.

     *Since:* 3.4.0

gnutls_certificate_set_openpgp_key
----------------------------------

 -- Function: int gnutls_certificate_set_openpgp_key
          (gnutls_certificate_credentials_t RES, gnutls_openpgp_crt_t
          CRT, gnutls_openpgp_privkey_t PKEY)
     RES: is a 'gnutls_certificate_credentials_t' type.

     CRT: contains an openpgp public key

     PKEY: is an openpgp private key

     This function sets a certificate/private key pair in the
     gnutls_certificate_credentials_t type.  This function may be called
     more than once (in case multiple keys/certificates exist for the
     server).

     Note that this function requires that the preferred key ids have
     been set and be used.  See
     'gnutls_openpgp_crt_set_preferred_key_id()' .  Otherwise the master
     key will be used.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_certificate_set_openpgp_key_file
---------------------------------------

 -- Function: int gnutls_certificate_set_openpgp_key_file
          (gnutls_certificate_credentials_t RES, const char * CERTFILE,
          const char * KEYFILE, gnutls_openpgp_crt_fmt_t FORMAT)
     RES: the destination context to save the data.

     CERTFILE: the file that contains the public key.

     KEYFILE: the file that contains the secret key.

     FORMAT: the format of the keys

     This funtion is used to load OpenPGP keys into the GnuTLS
     credentials structure.  The file should contain at least one valid
     non encrypted subkey.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_certificate_set_openpgp_key_file2
----------------------------------------

 -- Function: int gnutls_certificate_set_openpgp_key_file2
          (gnutls_certificate_credentials_t RES, const char * CERTFILE,
          const char * KEYFILE, const char * SUBKEY_ID,
          gnutls_openpgp_crt_fmt_t FORMAT)
     RES: the destination context to save the data.

     CERTFILE: the file that contains the public key.

     KEYFILE: the file that contains the secret key.

     SUBKEY_ID: a hex encoded subkey id

     FORMAT: the format of the keys

     This funtion is used to load OpenPGP keys into the GnuTLS
     credential structure.  The file should contain at least one valid
     non encrypted subkey.

     The special keyword "auto" is also accepted as 'subkey_id' .  In
     that case the 'gnutls_openpgp_crt_get_auth_subkey()' will be used
     to retrieve the subkey.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

     *Since:* 2.4.0

gnutls_certificate_set_openpgp_key_mem
--------------------------------------

 -- Function: int gnutls_certificate_set_openpgp_key_mem
          (gnutls_certificate_credentials_t RES, const gnutls_datum_t *
          CERT, const gnutls_datum_t * KEY, gnutls_openpgp_crt_fmt_t
          FORMAT)
     RES: the destination context to save the data.

     CERT: the datum that contains the public key.

     KEY: the datum that contains the secret key.

     FORMAT: the format of the keys

     This funtion is used to load OpenPGP keys into the GnuTLS
     credential structure.  The datum should contain at least one valid
     non encrypted subkey.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_certificate_set_openpgp_key_mem2
---------------------------------------

 -- Function: int gnutls_certificate_set_openpgp_key_mem2
          (gnutls_certificate_credentials_t RES, const gnutls_datum_t *
          CERT, const gnutls_datum_t * KEY, const char * SUBKEY_ID,
          gnutls_openpgp_crt_fmt_t FORMAT)
     RES: the destination context to save the data.

     CERT: the datum that contains the public key.

     KEY: the datum that contains the secret key.

     SUBKEY_ID: a hex encoded subkey id

     FORMAT: the format of the keys

     This funtion is used to load OpenPGP keys into the GnuTLS
     credentials structure.  The datum should contain at least one valid
     non encrypted subkey.

     The special keyword "auto" is also accepted as 'subkey_id' .  In
     that case the 'gnutls_openpgp_crt_get_auth_subkey()' will be used
     to retrieve the subkey.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

     *Since:* 2.4.0

gnutls_certificate_set_openpgp_keyring_file
-------------------------------------------

 -- Function: int gnutls_certificate_set_openpgp_keyring_file
          (gnutls_certificate_credentials_t C, const char * FILE,
          gnutls_openpgp_crt_fmt_t FORMAT)
     C: A certificate credentials structure

     FILE: filename of the keyring.

     FORMAT: format of keyring.

     The function is used to set keyrings that will be used internally
     by various OpenPGP functions.  For example to find a key when it is
     needed for an operations.  The keyring will also be used at the
     verification functions.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_certificate_set_openpgp_keyring_mem
------------------------------------------

 -- Function: int gnutls_certificate_set_openpgp_keyring_mem
          (gnutls_certificate_credentials_t C, const uint8_t * DATA,
          size_t DLEN, gnutls_openpgp_crt_fmt_t FORMAT)
     C: A certificate credentials structure

     DATA: buffer with keyring data.

     DLEN: length of data buffer.

     FORMAT: the format of the keyring

     The function is used to set keyrings that will be used internally
     by various OpenPGP functions.  For example to find a key when it is
     needed for an operations.  The keyring will also be used at the
     verification functions.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error value.

gnutls_openpgp_crt_check_email
------------------------------

 -- Function: int gnutls_openpgp_crt_check_email (gnutls_openpgp_crt_t
          KEY, const char * EMAIL, unsigned FLAGS)
     KEY: should contain a 'gnutls_openpgp_crt_t' type

     EMAIL: A null terminated string that contains an RFC822 address
     (email)

     FLAGS: gnutls_certificate_verify_flags

     This function will check if the given key's owner matches the given
     email address.

     *Returns:* non-zero for a successful match, and zero on failure.

gnutls_openpgp_crt_check_hostname
---------------------------------

 -- Function: int gnutls_openpgp_crt_check_hostname
          (gnutls_openpgp_crt_t KEY, const char * HOSTNAME)
     KEY: should contain a 'gnutls_openpgp_crt_t' type

     HOSTNAME: A null terminated string that contains a DNS name

     This function will check if the given key's owner matches the given
     hostname.  This is a basic implementation of the matching described
     in RFC2818 (HTTPS), which takes into account wildcards.

     *Returns:* non-zero for a successful match, and zero on failure.

gnutls_openpgp_crt_check_hostname2
----------------------------------

 -- Function: int gnutls_openpgp_crt_check_hostname2
          (gnutls_openpgp_crt_t KEY, const char * HOSTNAME, unsigned
          FLAGS)
     KEY: should contain a 'gnutls_openpgp_crt_t' type

     HOSTNAME: A null terminated string that contains a DNS name

     FLAGS: gnutls_certificate_verify_flags

     This function will check if the given key's owner matches the given
     hostname.

     Unless, the flag 'GNUTLS_VERIFY_DO_NOT_ALLOW_WILDCARDS' is
     specified, wildcards are only considered if the domain name
     consists of three components or more, and the wildcard starts at
     the leftmost position.

     *Returns:* non-zero for a successful match, and zero on failure.

gnutls_openpgp_crt_deinit
-------------------------

 -- Function: void gnutls_openpgp_crt_deinit (gnutls_openpgp_crt_t KEY)
     KEY: A pointer to the type to be initialized

     This function will deinitialize a key structure.

gnutls_openpgp_crt_export
-------------------------

 -- Function: int gnutls_openpgp_crt_export (gnutls_openpgp_crt_t KEY,
          gnutls_openpgp_crt_fmt_t FORMAT, void * OUTPUT_DATA, size_t *
          OUTPUT_DATA_SIZE)
     KEY: Holds the key.

     FORMAT: One of gnutls_openpgp_crt_fmt_t elements.

     OUTPUT_DATA: will contain the raw or base64 encoded key

     OUTPUT_DATA_SIZE: holds the size of output_data (and will be
     replaced by the actual size of parameters)

     This function will convert the given key to RAW or Base64 format.
     If the buffer provided is not long enough to hold the output, then
     'GNUTLS_E_SHORT_MEMORY_BUFFER' will be returned.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_crt_export2
--------------------------

 -- Function: int gnutls_openpgp_crt_export2 (gnutls_openpgp_crt_t KEY,
          gnutls_openpgp_crt_fmt_t FORMAT, gnutls_datum_t * OUT)
     KEY: Holds the key.

     FORMAT: One of gnutls_openpgp_crt_fmt_t elements.

     OUT: will contain the raw or base64 encoded key

     This function will convert the given key to RAW or Base64 format.
     The output buffer is allocated using 'gnutls_malloc()' .

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

     *Since:* 3.1.3

gnutls_openpgp_crt_get_auth_subkey
----------------------------------

 -- Function: int gnutls_openpgp_crt_get_auth_subkey
          (gnutls_openpgp_crt_t CRT, gnutls_openpgp_keyid_t KEYID,
          unsigned int FLAG)
     CRT: the structure that contains the OpenPGP public key.

     KEYID: the struct to save the keyid.

     FLAG: Non-zero indicates that a valid subkey is always returned.

     Returns the 64-bit keyID of the first valid OpenPGP subkey marked
     for authentication.  If flag is non-zero and no authentication
     subkey exists, then a valid subkey will be returned even if it is
     not marked for authentication.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_crt_get_creation_time
------------------------------------

 -- Function: time_t gnutls_openpgp_crt_get_creation_time
          (gnutls_openpgp_crt_t KEY)
     KEY: the structure that contains the OpenPGP public key.

     Get key creation time.

     *Returns:* the timestamp when the OpenPGP key was created.

gnutls_openpgp_crt_get_expiration_time
--------------------------------------

 -- Function: time_t gnutls_openpgp_crt_get_expiration_time
          (gnutls_openpgp_crt_t KEY)
     KEY: the structure that contains the OpenPGP public key.

     Get key expiration time.  A value of '0' means that the key doesn't
     expire at all.

     *Returns:* the time when the OpenPGP key expires.

gnutls_openpgp_crt_get_fingerprint
----------------------------------

 -- Function: int gnutls_openpgp_crt_get_fingerprint
          (gnutls_openpgp_crt_t KEY, void * FPR, size_t * FPRLEN)
     KEY: the raw data that contains the OpenPGP public key.

     FPR: the buffer to save the fingerprint, must hold at least 20
     bytes.

     FPRLEN: the integer to save the length of the fingerprint.

     Get key fingerprint.  Depending on the algorithm, the fingerprint
     can be 16 or 20 bytes.

     *Returns:* On success, 0 is returned.  Otherwise, an error code.

gnutls_openpgp_crt_get_key_id
-----------------------------

 -- Function: int gnutls_openpgp_crt_get_key_id (gnutls_openpgp_crt_t
          KEY, gnutls_openpgp_keyid_t KEYID)
     KEY: the structure that contains the OpenPGP public key.

     KEYID: the buffer to save the keyid.

     Get key id string.

     *Returns:* the 64-bit keyID of the OpenPGP key.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_key_usage
--------------------------------

 -- Function: int gnutls_openpgp_crt_get_key_usage (gnutls_openpgp_crt_t
          KEY, unsigned int * KEY_USAGE)
     KEY: should contain a gnutls_openpgp_crt_t type

     KEY_USAGE: where the key usage bits will be stored

     This function will return certificate's key usage, by checking the
     key algorithm.  The key usage value will ORed values of the:
     'GNUTLS_KEY_DIGITAL_SIGNATURE' , 'GNUTLS_KEY_KEY_ENCIPHERMENT' .

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_crt_get_name
---------------------------

 -- Function: int gnutls_openpgp_crt_get_name (gnutls_openpgp_crt_t KEY,
          int IDX, char * BUF, size_t * SIZEOF_BUF)
     KEY: the structure that contains the OpenPGP public key.

     IDX: the index of the ID to extract

     BUF: a pointer to a structure to hold the name, may be 'NULL' to
     only get the 'sizeof_buf' .

     SIZEOF_BUF: holds the maximum size of 'buf' , on return hold the
     actual/required size of 'buf' .

     Extracts the userID from the parsed OpenPGP key.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, and if the index of the
     ID does not exist 'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' , or an
     error code.

gnutls_openpgp_crt_get_pk_algorithm
-----------------------------------

 -- Function: gnutls_pk_algorithm_t gnutls_openpgp_crt_get_pk_algorithm
          (gnutls_openpgp_crt_t KEY, unsigned int * BITS)
     KEY: is an OpenPGP key

     BITS: if bits is non null it will hold the size of the parameters'
     in bits

     This function will return the public key algorithm of an OpenPGP
     certificate.

     If bits is non null, it should have enough size to hold the
     parameters size in bits.  For RSA the bits returned is the modulus.
     For DSA the bits returned are of the public exponent.

     *Returns:* a member of the 'gnutls_pk_algorithm_t' enumeration on
     success, or GNUTLS_PK_UNKNOWN on error.

gnutls_openpgp_crt_get_pk_dsa_raw
---------------------------------

 -- Function: int gnutls_openpgp_crt_get_pk_dsa_raw
          (gnutls_openpgp_crt_t CRT, gnutls_datum_t * P, gnutls_datum_t
          * Q, gnutls_datum_t * G, gnutls_datum_t * Y)
     CRT: Holds the certificate

     P: will hold the p

     Q: will hold the q

     G: will hold the g

     Y: will hold the y

     This function will export the DSA public key's parameters found in
     the given certificate.  The new parameters will be allocated using
     'gnutls_malloc()' and will be stored in the appropriate datum.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, otherwise a negative
     error code.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_pk_rsa_raw
---------------------------------

 -- Function: int gnutls_openpgp_crt_get_pk_rsa_raw
          (gnutls_openpgp_crt_t CRT, gnutls_datum_t * M, gnutls_datum_t
          * E)
     CRT: Holds the certificate

     M: will hold the modulus

     E: will hold the public exponent

     This function will export the RSA public key's parameters found in
     the given structure.  The new parameters will be allocated using
     'gnutls_malloc()' and will be stored in the appropriate datum.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, otherwise a negative
     error code.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_preferred_key_id
---------------------------------------

 -- Function: int gnutls_openpgp_crt_get_preferred_key_id
          (gnutls_openpgp_crt_t KEY, gnutls_openpgp_keyid_t KEYID)
     KEY: the structure that contains the OpenPGP public key.

     KEYID: the struct to save the keyid.

     Get preferred key id.  If it hasn't been set it returns
     'GNUTLS_E_INVALID_REQUEST' .

     *Returns:* the 64-bit preferred keyID of the OpenPGP key.

gnutls_openpgp_crt_get_revoked_status
-------------------------------------

 -- Function: int gnutls_openpgp_crt_get_revoked_status
          (gnutls_openpgp_crt_t KEY)
     KEY: the structure that contains the OpenPGP public key.

     Get revocation status of key.

     *Returns:* true (1) if the key has been revoked, or false (0) if it
     has not.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_count
-----------------------------------

 -- Function: int gnutls_openpgp_crt_get_subkey_count
          (gnutls_openpgp_crt_t KEY)
     KEY: is an OpenPGP key

     This function will return the number of subkeys present in the
     given OpenPGP certificate.

     *Returns:* the number of subkeys, or a negative error code on
     error.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_creation_time
-------------------------------------------

 -- Function: time_t gnutls_openpgp_crt_get_subkey_creation_time
          (gnutls_openpgp_crt_t KEY, unsigned int IDX)
     KEY: the structure that contains the OpenPGP public key.

     IDX: the subkey index

     Get subkey creation time.

     *Returns:* the timestamp when the OpenPGP sub-key was created.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_expiration_time
---------------------------------------------

 -- Function: time_t gnutls_openpgp_crt_get_subkey_expiration_time
          (gnutls_openpgp_crt_t KEY, unsigned int IDX)
     KEY: the structure that contains the OpenPGP public key.

     IDX: the subkey index

     Get subkey expiration time.  A value of '0' means that the key
     doesn't expire at all.

     *Returns:* the time when the OpenPGP key expires.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_fingerprint
-----------------------------------------

 -- Function: int gnutls_openpgp_crt_get_subkey_fingerprint
          (gnutls_openpgp_crt_t KEY, unsigned int IDX, void * FPR,
          size_t * FPRLEN)
     KEY: the raw data that contains the OpenPGP public key.

     IDX: the subkey index

     FPR: the buffer to save the fingerprint, must hold at least 20
     bytes.

     FPRLEN: the integer to save the length of the fingerprint.

     Get key fingerprint of a subkey.  Depending on the algorithm, the
     fingerprint can be 16 or 20 bytes.

     *Returns:* On success, 0 is returned.  Otherwise, an error code.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_id
--------------------------------

 -- Function: int gnutls_openpgp_crt_get_subkey_id (gnutls_openpgp_crt_t
          KEY, unsigned int IDX, gnutls_openpgp_keyid_t KEYID)
     KEY: the structure that contains the OpenPGP public key.

     IDX: the subkey index

     KEYID: the buffer to save the keyid.

     Get the subkey's key-id.

     *Returns:* the 64-bit keyID of the OpenPGP key.

gnutls_openpgp_crt_get_subkey_idx
---------------------------------

 -- Function: int gnutls_openpgp_crt_get_subkey_idx
          (gnutls_openpgp_crt_t KEY, const gnutls_openpgp_keyid_t KEYID)
     KEY: the structure that contains the OpenPGP public key.

     KEYID: the keyid.

     Get subkey's index.

     *Returns:* the index of the subkey or a negative error value.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_pk_algorithm
------------------------------------------

 -- Function: gnutls_pk_algorithm_t
          gnutls_openpgp_crt_get_subkey_pk_algorithm
          (gnutls_openpgp_crt_t KEY, unsigned int IDX, unsigned int *
          BITS)
     KEY: is an OpenPGP key

     IDX: is the subkey index

     BITS: if bits is non null it will hold the size of the parameters'
     in bits

     This function will return the public key algorithm of a subkey of
     an OpenPGP certificate.

     If bits is non null, it should have enough size to hold the
     parameters size in bits.  For RSA the bits returned is the modulus.
     For DSA the bits returned are of the public exponent.

     *Returns:* a member of the 'gnutls_pk_algorithm_t' enumeration on
     success, or GNUTLS_PK_UNKNOWN on error.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_pk_dsa_raw
----------------------------------------

 -- Function: int gnutls_openpgp_crt_get_subkey_pk_dsa_raw
          (gnutls_openpgp_crt_t CRT, unsigned int IDX, gnutls_datum_t *
          P, gnutls_datum_t * Q, gnutls_datum_t * G, gnutls_datum_t * Y)
     CRT: Holds the certificate

     IDX: Is the subkey index

     P: will hold the p

     Q: will hold the q

     G: will hold the g

     Y: will hold the y

     This function will export the DSA public key's parameters found in
     the given certificate.  The new parameters will be allocated using
     'gnutls_malloc()' and will be stored in the appropriate datum.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, otherwise a negative
     error code.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_pk_rsa_raw
----------------------------------------

 -- Function: int gnutls_openpgp_crt_get_subkey_pk_rsa_raw
          (gnutls_openpgp_crt_t CRT, unsigned int IDX, gnutls_datum_t *
          M, gnutls_datum_t * E)
     CRT: Holds the certificate

     IDX: Is the subkey index

     M: will hold the modulus

     E: will hold the public exponent

     This function will export the RSA public key's parameters found in
     the given structure.  The new parameters will be allocated using
     'gnutls_malloc()' and will be stored in the appropriate datum.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, otherwise a negative
     error code.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_revoked_status
--------------------------------------------

 -- Function: int gnutls_openpgp_crt_get_subkey_revoked_status
          (gnutls_openpgp_crt_t KEY, unsigned int IDX)
     KEY: the structure that contains the OpenPGP public key.

     IDX: is the subkey index

     Get subkey revocation status.  A negative error code indicates an
     error.

     *Returns:* true (1) if the key has been revoked, or false (0) if it
     has not.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_subkey_usage
-----------------------------------

 -- Function: int gnutls_openpgp_crt_get_subkey_usage
          (gnutls_openpgp_crt_t KEY, unsigned int IDX, unsigned int *
          KEY_USAGE)
     KEY: should contain a gnutls_openpgp_crt_t type

     IDX: the subkey index

     KEY_USAGE: where the key usage bits will be stored

     This function will return certificate's key usage, by checking the
     key algorithm.  The key usage value will ORed values of
     'GNUTLS_KEY_DIGITAL_SIGNATURE' or 'GNUTLS_KEY_KEY_ENCIPHERMENT' .

     A negative error code may be returned in case of parsing error.

     *Returns:* key usage value.

     *Since:* 2.4.0

gnutls_openpgp_crt_get_version
------------------------------

 -- Function: int gnutls_openpgp_crt_get_version (gnutls_openpgp_crt_t
          KEY)
     KEY: the structure that contains the OpenPGP public key.

     Extract the version of the OpenPGP key.

     *Returns:* the version number is returned, or a negative error code
     on errors.

gnutls_openpgp_crt_import
-------------------------

 -- Function: int gnutls_openpgp_crt_import (gnutls_openpgp_crt_t KEY,
          const gnutls_datum_t * DATA, gnutls_openpgp_crt_fmt_t FORMAT)
     KEY: The structure to store the parsed key.

     DATA: The RAW or BASE64 encoded key.

     FORMAT: One of gnutls_openpgp_crt_fmt_t elements.

     This function will convert the given RAW or Base64 encoded key to
     the native 'gnutls_openpgp_crt_t' format.  The output will be
     stored in 'key'.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_crt_init
-----------------------

 -- Function: int gnutls_openpgp_crt_init (gnutls_openpgp_crt_t * KEY)
     KEY: A pointer to the type to be initialized

     This function will initialize an OpenPGP key structure.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_crt_print
------------------------

 -- Function: int gnutls_openpgp_crt_print (gnutls_openpgp_crt_t CERT,
          gnutls_certificate_print_formats_t FORMAT, gnutls_datum_t *
          OUT)
     CERT: The structure to be printed

     FORMAT: Indicate the format to use

     OUT: Newly allocated datum with (0) terminated string.

     This function will pretty print an OpenPGP certificate, suitable
     for display to a human.

     The format should be (0) for future compatibility.

     The output 'out' needs to be deallocate using 'gnutls_free()' .

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_crt_set_preferred_key_id
---------------------------------------

 -- Function: int gnutls_openpgp_crt_set_preferred_key_id
          (gnutls_openpgp_crt_t KEY, const gnutls_openpgp_keyid_t KEYID)
     KEY: the structure that contains the OpenPGP public key.

     KEYID: the selected keyid

     This allows setting a preferred key id for the given certificate.
     This key will be used by functions that involve key handling.

     If the provided 'keyid' is 'NULL' then the master key is set as
     preferred.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_openpgp_crt_verify_ring
------------------------------

 -- Function: int gnutls_openpgp_crt_verify_ring (gnutls_openpgp_crt_t
          KEY, gnutls_openpgp_keyring_t KEYRING, unsigned int FLAGS,
          unsigned int * VERIFY)
     KEY: the structure that holds the key.

     KEYRING: holds the keyring to check against

     FLAGS: unused (should be 0)

     VERIFY: will hold the certificate verification output.

     Verify all signatures in the key, using the given set of keys
     (keyring).

     The key verification output will be put in 'verify' and will be one
     or more of the 'gnutls_certificate_status_t' enumerated elements
     bitwise or'd.

     Note that this function does not verify using any "web of trust".
     You may use GnuPG for that purpose, or any other external PGP
     application.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_crt_verify_self
------------------------------

 -- Function: int gnutls_openpgp_crt_verify_self (gnutls_openpgp_crt_t
          KEY, unsigned int FLAGS, unsigned int * VERIFY)
     KEY: the structure that holds the key.

     FLAGS: unused (should be 0)

     VERIFY: will hold the key verification output.

     Verifies the self signature in the key.  The key verification
     output will be put in 'verify' and will be one or more of the
     gnutls_certificate_status_t enumerated elements bitwise or'd.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_keyring_check_id
-------------------------------

 -- Function: int gnutls_openpgp_keyring_check_id
          (gnutls_openpgp_keyring_t RING, const gnutls_openpgp_keyid_t
          KEYID, unsigned int FLAGS)
     RING: holds the keyring to check against

     KEYID: will hold the keyid to check for.

     FLAGS: unused (should be 0)

     Check if a given key ID exists in the keyring.

     *Returns:* 'GNUTLS_E_SUCCESS' on success (if keyid exists) and a
     negative error code on failure.

gnutls_openpgp_keyring_deinit
-----------------------------

 -- Function: void gnutls_openpgp_keyring_deinit
          (gnutls_openpgp_keyring_t KEYRING)
     KEYRING: A pointer to the type to be initialized

     This function will deinitialize a keyring structure.

gnutls_openpgp_keyring_get_crt
------------------------------

 -- Function: int gnutls_openpgp_keyring_get_crt
          (gnutls_openpgp_keyring_t RING, unsigned int IDX,
          gnutls_openpgp_crt_t * CERT)
     RING: Holds the keyring.

     IDX: the index of the certificate to export

     CERT: An uninitialized 'gnutls_openpgp_crt_t' type

     This function will extract an OpenPGP certificate from the given
     keyring.  If the index given is out of range
     'GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE' will be returned.  The
     returned structure needs to be deinited.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_keyring_get_crt_count
------------------------------------

 -- Function: int gnutls_openpgp_keyring_get_crt_count
          (gnutls_openpgp_keyring_t RING)
     RING: is an OpenPGP key ring

     This function will return the number of OpenPGP certificates
     present in the given keyring.

     *Returns:* the number of subkeys, or a negative error code on
     error.

gnutls_openpgp_keyring_import
-----------------------------

 -- Function: int gnutls_openpgp_keyring_import
          (gnutls_openpgp_keyring_t KEYRING, const gnutls_datum_t *
          DATA, gnutls_openpgp_crt_fmt_t FORMAT)
     KEYRING: The structure to store the parsed key.

     DATA: The RAW or BASE64 encoded keyring.

     FORMAT: One of 'gnutls_openpgp_keyring_fmt' elements.

     This function will convert the given RAW or Base64 encoded keyring
     to the native 'gnutls_openpgp_keyring_t' format.  The output will
     be stored in 'keyring'.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_keyring_init
---------------------------

 -- Function: int gnutls_openpgp_keyring_init (gnutls_openpgp_keyring_t
          * KEYRING)
     KEYRING: A pointer to the type to be initialized

     This function will initialize an keyring structure.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_privkey_deinit
-----------------------------

 -- Function: void gnutls_openpgp_privkey_deinit
          (gnutls_openpgp_privkey_t KEY)
     KEY: A pointer to the type to be initialized

     This function will deinitialize a key structure.

gnutls_openpgp_privkey_export
-----------------------------

 -- Function: int gnutls_openpgp_privkey_export
          (gnutls_openpgp_privkey_t KEY, gnutls_openpgp_crt_fmt_t
          FORMAT, const char * PASSWORD, unsigned int FLAGS, void *
          OUTPUT_DATA, size_t * OUTPUT_DATA_SIZE)
     KEY: Holds the key.

     FORMAT: One of gnutls_openpgp_crt_fmt_t elements.

     PASSWORD: the password that will be used to encrypt the key.
     (unused for now)

     FLAGS: (0) for future compatibility

     OUTPUT_DATA: will contain the key base64 encoded or raw

     OUTPUT_DATA_SIZE: holds the size of output_data (and will be
     replaced by the actual size of parameters)

     This function will convert the given key to RAW or Base64 format.
     If the buffer provided is not long enough to hold the output, then
     GNUTLS_E_SHORT_MEMORY_BUFFER will be returned.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

     *Since:* 2.4.0

gnutls_openpgp_privkey_export2
------------------------------

 -- Function: int gnutls_openpgp_privkey_export2
          (gnutls_openpgp_privkey_t KEY, gnutls_openpgp_crt_fmt_t
          FORMAT, const char * PASSWORD, unsigned int FLAGS,
          gnutls_datum_t * OUT)
     KEY: Holds the key.

     FORMAT: One of gnutls_openpgp_crt_fmt_t elements.

     PASSWORD: the password that will be used to encrypt the key.
     (unused for now)

     FLAGS: (0) for future compatibility

     OUT: will contain the raw or based64 encoded key

     This function will convert the given key to RAW or Base64 format.
     The output buffer is allocated using 'gnutls_malloc()' .

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

     *Since:* 3.1.3

gnutls_openpgp_privkey_export_dsa_raw
-------------------------------------

 -- Function: int gnutls_openpgp_privkey_export_dsa_raw
          (gnutls_openpgp_privkey_t PKEY, gnutls_datum_t * P,
          gnutls_datum_t * Q, gnutls_datum_t * G, gnutls_datum_t * Y,
          gnutls_datum_t * X)
     PKEY: Holds the certificate

     P: will hold the p

     Q: will hold the q

     G: will hold the g

     Y: will hold the y

     X: will hold the x

     This function will export the DSA private key's parameters found in
     the given certificate.  The new parameters will be allocated using
     'gnutls_malloc()' and will be stored in the appropriate datum.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, otherwise a negative
     error code.

     *Since:* 2.4.0

gnutls_openpgp_privkey_export_rsa_raw
-------------------------------------

 -- Function: int gnutls_openpgp_privkey_export_rsa_raw
          (gnutls_openpgp_privkey_t PKEY, gnutls_datum_t * M,
          gnutls_datum_t * E, gnutls_datum_t * D, gnutls_datum_t * P,
          gnutls_datum_t * Q, gnutls_datum_t * U)
     PKEY: Holds the certificate

     M: will hold the modulus

     E: will hold the public exponent

     D: will hold the private exponent

     P: will hold the first prime (p)

     Q: will hold the second prime (q)

     U: will hold the coefficient

     This function will export the RSA private key's parameters found in
     the given structure.  The new parameters will be allocated using
     'gnutls_malloc()' and will be stored in the appropriate datum.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, otherwise a negative
     error code.

     *Since:* 2.4.0

gnutls_openpgp_privkey_export_subkey_dsa_raw
--------------------------------------------

 -- Function: int gnutls_openpgp_privkey_export_subkey_dsa_raw
          (gnutls_openpgp_privkey_t PKEY, unsigned int IDX,
          gnutls_datum_t * P, gnutls_datum_t * Q, gnutls_datum_t * G,
          gnutls_datum_t * Y, gnutls_datum_t * X)
     PKEY: Holds the certificate

     IDX: Is the subkey index

     P: will hold the p

     Q: will hold the q

     G: will hold the g

     Y: will hold the y

     X: will hold the x

     This function will export the DSA private key's parameters found in
     the given certificate.  The new parameters will be allocated using
     'gnutls_malloc()' and will be stored in the appropriate datum.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, otherwise a negative
     error code.

     *Since:* 2.4.0

gnutls_openpgp_privkey_export_subkey_rsa_raw
--------------------------------------------

 -- Function: int gnutls_openpgp_privkey_export_subkey_rsa_raw
          (gnutls_openpgp_privkey_t PKEY, unsigned int IDX,
          gnutls_datum_t * M, gnutls_datum_t * E, gnutls_datum_t * D,
          gnutls_datum_t * P, gnutls_datum_t * Q, gnutls_datum_t * U)
     PKEY: Holds the certificate

     IDX: Is the subkey index

     M: will hold the modulus

     E: will hold the public exponent

     D: will hold the private exponent

     P: will hold the first prime (p)

     Q: will hold the second prime (q)

     U: will hold the coefficient

     This function will export the RSA private key's parameters found in
     the given structure.  The new parameters will be allocated using
     'gnutls_malloc()' and will be stored in the appropriate datum.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, otherwise a negative
     error code.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_fingerprint
--------------------------------------

 -- Function: int gnutls_openpgp_privkey_get_fingerprint
          (gnutls_openpgp_privkey_t KEY, void * FPR, size_t * FPRLEN)
     KEY: the raw data that contains the OpenPGP secret key.

     FPR: the buffer to save the fingerprint, must hold at least 20
     bytes.

     FPRLEN: the integer to save the length of the fingerprint.

     Get the fingerprint of the OpenPGP key.  Depends on the algorithm,
     the fingerprint can be 16 or 20 bytes.

     *Returns:* On success, 0 is returned, or an error code.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_key_id
---------------------------------

 -- Function: int gnutls_openpgp_privkey_get_key_id
          (gnutls_openpgp_privkey_t KEY, gnutls_openpgp_keyid_t KEYID)
     KEY: the structure that contains the OpenPGP secret key.

     KEYID: the buffer to save the keyid.

     Get key-id.

     *Returns:* the 64-bit keyID of the OpenPGP key.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_pk_algorithm
---------------------------------------

 -- Function: gnutls_pk_algorithm_t
          gnutls_openpgp_privkey_get_pk_algorithm
          (gnutls_openpgp_privkey_t KEY, unsigned int * BITS)
     KEY: is an OpenPGP key

     BITS: if bits is non null it will hold the size of the parameters'
     in bits

     This function will return the public key algorithm of an OpenPGP
     certificate.

     If bits is non null, it should have enough size to hold the
     parameters size in bits.  For RSA the bits returned is the modulus.
     For DSA the bits returned are of the public exponent.

     *Returns:* a member of the 'gnutls_pk_algorithm_t' enumeration on
     success, or a negative error code on error.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_preferred_key_id
-------------------------------------------

 -- Function: int gnutls_openpgp_privkey_get_preferred_key_id
          (gnutls_openpgp_privkey_t KEY, gnutls_openpgp_keyid_t KEYID)
     KEY: the structure that contains the OpenPGP public key.

     KEYID: the struct to save the keyid.

     Get the preferred key-id for the key.

     *Returns:* the 64-bit preferred keyID of the OpenPGP key, or if it
     hasn't been set it returns 'GNUTLS_E_INVALID_REQUEST' .

gnutls_openpgp_privkey_get_revoked_status
-----------------------------------------

 -- Function: int gnutls_openpgp_privkey_get_revoked_status
          (gnutls_openpgp_privkey_t KEY)
     KEY: the structure that contains the OpenPGP private key.

     Get revocation status of key.

     *Returns:* true (1) if the key has been revoked, or false (0) if it
     has not, or a negative error code indicates an error.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_subkey_count
---------------------------------------

 -- Function: int gnutls_openpgp_privkey_get_subkey_count
          (gnutls_openpgp_privkey_t KEY)
     KEY: is an OpenPGP key

     This function will return the number of subkeys present in the
     given OpenPGP certificate.

     *Returns:* the number of subkeys, or a negative error code on
     error.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_subkey_creation_time
-----------------------------------------------

 -- Function: time_t gnutls_openpgp_privkey_get_subkey_creation_time
          (gnutls_openpgp_privkey_t KEY, unsigned int IDX)
     KEY: the structure that contains the OpenPGP private key.

     IDX: the subkey index

     Get subkey creation time.

     *Returns:* the timestamp when the OpenPGP key was created.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_subkey_expiration_time
-------------------------------------------------

 -- Function: time_t gnutls_openpgp_privkey_get_subkey_expiration_time
          (gnutls_openpgp_privkey_t KEY, unsigned int IDX)
     KEY: the structure that contains the OpenPGP private key.

     IDX: the subkey index

     Get subkey expiration time.  A value of '0' means that the key
     doesn't expire at all.

     *Returns:* the time when the OpenPGP key expires.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_subkey_fingerprint
---------------------------------------------

 -- Function: int gnutls_openpgp_privkey_get_subkey_fingerprint
          (gnutls_openpgp_privkey_t KEY, unsigned int IDX, void * FPR,
          size_t * FPRLEN)
     KEY: the raw data that contains the OpenPGP secret key.

     IDX: the subkey index

     FPR: the buffer to save the fingerprint, must hold at least 20
     bytes.

     FPRLEN: the integer to save the length of the fingerprint.

     Get the fingerprint of an OpenPGP subkey.  Depends on the
     algorithm, the fingerprint can be 16 or 20 bytes.

     *Returns:* On success, 0 is returned, or an error code.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_subkey_id
------------------------------------

 -- Function: int gnutls_openpgp_privkey_get_subkey_id
          (gnutls_openpgp_privkey_t KEY, unsigned int IDX,
          gnutls_openpgp_keyid_t KEYID)
     KEY: the structure that contains the OpenPGP secret key.

     IDX: the subkey index

     KEYID: the buffer to save the keyid.

     Get the key-id for the subkey.

     *Returns:* the 64-bit keyID of the OpenPGP key.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_subkey_idx
-------------------------------------

 -- Function: int gnutls_openpgp_privkey_get_subkey_idx
          (gnutls_openpgp_privkey_t KEY, const gnutls_openpgp_keyid_t
          KEYID)
     KEY: the structure that contains the OpenPGP private key.

     KEYID: the keyid.

     Get index of subkey.

     *Returns:* the index of the subkey or a negative error value.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_subkey_pk_algorithm
----------------------------------------------

 -- Function: gnutls_pk_algorithm_t
          gnutls_openpgp_privkey_get_subkey_pk_algorithm
          (gnutls_openpgp_privkey_t KEY, unsigned int IDX, unsigned int
          * BITS)
     KEY: is an OpenPGP key

     IDX: is the subkey index

     BITS: if bits is non null it will hold the size of the parameters'
     in bits

     This function will return the public key algorithm of a subkey of
     an OpenPGP certificate.

     If bits is non null, it should have enough size to hold the
     parameters size in bits.  For RSA the bits returned is the modulus.
     For DSA the bits returned are of the public exponent.

     *Returns:* a member of the 'gnutls_pk_algorithm_t' enumeration on
     success, or a negative error code on error.

     *Since:* 2.4.0

gnutls_openpgp_privkey_get_subkey_revoked_status
------------------------------------------------

 -- Function: int gnutls_openpgp_privkey_get_subkey_revoked_status
          (gnutls_openpgp_privkey_t KEY, unsigned int IDX)
     KEY: the structure that contains the OpenPGP private key.

     IDX: is the subkey index

     Get revocation status of key.

     *Returns:* true (1) if the key has been revoked, or false (0) if it
     has not, or a negative error code indicates an error.

     *Since:* 2.4.0

gnutls_openpgp_privkey_import
-----------------------------

 -- Function: int gnutls_openpgp_privkey_import
          (gnutls_openpgp_privkey_t KEY, const gnutls_datum_t * DATA,
          gnutls_openpgp_crt_fmt_t FORMAT, const char * PASSWORD,
          unsigned int FLAGS)
     KEY: The structure to store the parsed key.

     DATA: The RAW or BASE64 encoded key.

     FORMAT: One of 'gnutls_openpgp_crt_fmt_t' elements.

     PASSWORD: not used for now

     FLAGS: should be (0)

     This function will convert the given RAW or Base64 encoded key to
     the native gnutls_openpgp_privkey_t format.  The output will be
     stored in 'key'.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_privkey_init
---------------------------

 -- Function: int gnutls_openpgp_privkey_init (gnutls_openpgp_privkey_t
          * KEY)
     KEY: A pointer to the type to be initialized

     This function will initialize an OpenPGP key structure.

     *Returns:* 'GNUTLS_E_SUCCESS' on success, or an error code.

gnutls_openpgp_privkey_sec_param
--------------------------------

 -- Function: gnutls_sec_param_t gnutls_openpgp_privkey_sec_param
          (gnutls_openpgp_privkey_t KEY)
     KEY: a key structure

     This function will return the security parameter appropriate with
     this private key.

     *Returns:* On success, a valid security parameter is returned
     otherwise 'GNUTLS_SEC_PARAM_UNKNOWN' is returned.

     *Since:* 2.12.0

gnutls_openpgp_privkey_set_preferred_key_id
-------------------------------------------

 -- Function: int gnutls_openpgp_privkey_set_preferred_key_id
          (gnutls_openpgp_privkey_t KEY, const gnutls_openpgp_keyid_t
          KEYID)
     KEY: the structure that contains the OpenPGP public key.

     KEYID: the selected keyid

     This allows setting a preferred key id for the given certificate.
     This key will be used by functions that involve key handling.

     If the provided 'keyid' is 'NULL' then the master key is set as
     preferred.

     *Returns:* On success, 'GNUTLS_E_SUCCESS' (0) is returned,
     otherwise a negative error code is returned.

gnutls_openpgp_set_recv_key_function
------------------------------------

 -- Function: void gnutls_openpgp_set_recv_key_function
          (gnutls_session_t SESSION, gnutls_openpgp_recv_key_func FUNC)
     SESSION: a TLS session

     FUNC: the callback

     This funtion will set a key retrieval function for OpenPGP keys.
     This callback is only useful in server side, and will be used if
     the peer sent a key fingerprint instead of a full key.

     The retrieved key must be allocated using 'gnutls_malloc()' .

