openpgp: GnuTLS API Reference Manual

## openpgp openpgp |

## Functions

int | gnutls_certificate_set_openpgp_key ()
int | gnutls_certificate_set_openpgp_key_file ()
int | gnutls_certificate_set_openpgp_key_file2 ()
int | gnutls_certificate_set_openpgp_key_mem ()
int | gnutls_certificate_set_openpgp_key_mem2 ()
int | gnutls_certificate_set_openpgp_keyring_file ()
int | gnutls_certificate_set_openpgp_keyring_mem ()
int | gnutls_openpgp_crt_check_hostname ()
void | gnutls_openpgp_crt_deinit ()
int | gnutls_openpgp_crt_export ()
int | gnutls_openpgp_crt_export2 ()
int | gnutls_openpgp_crt_get_auth_subkey ()
time_t | gnutls_openpgp_crt_get_creation_time ()
time_t | gnutls_openpgp_crt_get_expiration_time ()
int | gnutls_openpgp_crt_get_fingerprint ()
int | gnutls_openpgp_crt_get_key_id ()
int | gnutls_openpgp_crt_get_key_usage ()
int | gnutls_openpgp_crt_get_name ()
gnutls_pk_algorithm_t | gnutls_openpgp_crt_get_pk_algorithm ()
int | gnutls_openpgp_crt_get_pk_dsa_raw ()
int | gnutls_openpgp_crt_get_pk_rsa_raw ()
int | gnutls_openpgp_crt_get_preferred_key_id ()
int | gnutls_openpgp_crt_get_revoked_status ()
int | gnutls_openpgp_crt_get_subkey_count ()
time_t | gnutls_openpgp_crt_get_subkey_creation_time ()
time_t | gnutls_openpgp_crt_get_subkey_expiration_time ()
int | gnutls_openpgp_crt_get_subkey_fingerprint ()
int | gnutls_openpgp_crt_get_subkey_id ()
int | gnutls_openpgp_crt_get_subkey_idx ()
gnutls_pk_algorithm_t | gnutls_openpgp_crt_get_subkey_pk_algorithm ()
int | gnutls_openpgp_crt_get_subkey_pk_dsa_raw ()
int | gnutls_openpgp_crt_get_subkey_pk_rsa_raw ()
int | gnutls_openpgp_crt_get_subkey_revoked_status ()
int | gnutls_openpgp_crt_get_subkey_usage ()
int | gnutls_openpgp_crt_get_version ()
int | gnutls_openpgp_crt_import ()
int | gnutls_openpgp_crt_init ()
int | gnutls_openpgp_crt_print ()
int | gnutls_openpgp_crt_set_preferred_key_id ()
int | gnutls_openpgp_crt_verify_ring ()
int | gnutls_openpgp_crt_verify_self ()
int | gnutls_openpgp_keyring_check_id ()
void | gnutls_openpgp_keyring_deinit ()
int | gnutls_openpgp_keyring_get_crt ()
int | gnutls_openpgp_keyring_get_crt_count ()
int | gnutls_openpgp_keyring_import ()
int | gnutls_openpgp_keyring_init ()
void | gnutls_openpgp_privkey_deinit ()
int | gnutls_openpgp_privkey_export ()
int | gnutls_openpgp_privkey_export2 ()
int | gnutls_openpgp_privkey_export_dsa_raw ()
int | gnutls_openpgp_privkey_export_rsa_raw ()
int | gnutls_openpgp_privkey_export_subkey_dsa_raw ()
int | gnutls_openpgp_privkey_export_subkey_rsa_raw ()
int | gnutls_openpgp_privkey_get_fingerprint ()
int | gnutls_openpgp_privkey_get_key_id ()
gnutls_pk_algorithm_t | gnutls_openpgp_privkey_get_pk_algorithm ()
int | gnutls_openpgp_privkey_get_preferred_key_id ()
int | gnutls_openpgp_privkey_get_revoked_status ()
int | gnutls_openpgp_privkey_get_subkey_count ()
time_t | gnutls_openpgp_privkey_get_subkey_creation_time ()
time_t | gnutls_openpgp_privkey_get_subkey_expiration_time ()
int | gnutls_openpgp_privkey_get_subkey_fingerprint ()
int | gnutls_openpgp_privkey_get_subkey_id ()
int | gnutls_openpgp_privkey_get_subkey_idx ()
gnutls_pk_algorithm_t | gnutls_openpgp_privkey_get_subkey_pk_algorithm ()
int | gnutls_openpgp_privkey_get_subkey_revoked_status ()
int | gnutls_openpgp_privkey_import ()
int | gnutls_openpgp_privkey_init ()
gnutls_sec_param_t | gnutls_openpgp_privkey_sec_param ()
int | gnutls_openpgp_privkey_set_preferred_key_id ()
int | (*gnutls_openpgp_recv_key_func) ()
void | gnutls_openpgp_set_recv_key_function ()

## Types and Values

#define | GNUTLS_OPENPGP_KEYID_SIZE
#define | GNUTLS_OPENPGP_MASTER_KEYID_IDX
enum | gnutls_openpgp_crt_fmt_t

## Description

## Functions

### gnutls_certificate_set_openpgp_key ()

    int
    gnutls_certificate_set_openpgp_key (gnutls_certificate_credentials_t res,
                                        gnutls_openpgp_crt_t crt,
                                        gnutls_openpgp_privkey_t pkey);

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.

#### Parameters

res | is a gnutls_certificate_credentials_t type. |
crt | contains an openpgp public key |
pkey | is an openpgp private key |

#### Returns

On success, `GNUTLS_E_SUCCESS` (0) is returned, otherwise a negative error code is returned.

### gnutls_certificate_set_openpgp_key_file ()

    int
    gnutls_certificate_set_openpgp_key_file
                                   (gnutls_certificate_credentials_t res,
                                    const char *certfile,
                                    const char *keyfile,
                                    gnutls_openpgp_crt_fmt_t format);

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

#### Parameters

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 |

#### Returns

On success, `GNUTLS_E_SUCCESS` (0) is returned, otherwise a negative error value.

### gnutls_certificate_set_openpgp_key_file2 ()

    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);

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.

#### Parameters

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 |

#### Returns

On success, `GNUTLS_E_SUCCESS` (0) is returned, otherwise a negative error value.

Since: 2.4.0

### gnutls_certificate_set_openpgp_key_mem ()

    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);

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

#### Parameters

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 |

#### Returns

On success, `GNUTLS_E_SUCCESS` (0) is returned, otherwise a negative error value.

### gnutls_certificate_set_openpgp_key_mem2 ()

    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);

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.

#### Parameters

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 |

#### Returns

On success, `GNUTLS_E_SUCCESS` (0) is returned, otherwise a negative error value.

Since: 2.4.0

### gnutls_certificate_set_openpgp_keyring_file ()

    int
    gnutls_certificate_set_openpgp_keyring_file
                                   (gnutls_certificate_credentials_t c,
                                    const char *file,
                                    gnutls_openpgp_crt_fmt_t format);

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.

#### Parameters

c | A certificate credentials structure |
file | filename of the keyring. |
format | format of keyring. |

#### Returns

On success, `GNUTLS_E_SUCCESS` (0) is returned, otherwise a negative error value.

### gnutls_certificate_set_openpgp_keyring_mem ()

    int
    gnutls_certificate_set_openpgp_keyring_mem
                                   (gnutls_certificate_credentials_t c,
                                    const unsigned char *data,
                                    size_t dlen,
                                    gnutls_openpgp_crt_fmt_t format);

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.

#### Parameters

c | A certificate credentials structure |
data | buffer with keyring data. |
dlen | length of data buffer. |
format | the format of the keyring |

#### Returns

On success, `GNUTLS_E_SUCCESS` (0) is returned, otherwise a negative error value.

### gnutls_openpgp_crt_check_hostname ()

    int
    gnutls_openpgp_crt_check_hostname (gnutls_openpgp_crt_t key,
                                       const char *hostname);

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.

#### Parameters

key | should contain a gnutls_openpgp_crt_t type |
hostname | A null terminated string that contains a DNS name |

#### Returns

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

### gnutls_openpgp_crt_deinit ()

    void
    gnutls_openpgp_crt_deinit (gnutls_openpgp_crt_t key);

This function will deinitialize a key structure.

#### Parameters

key | A pointer to the type to be initialized |

### gnutls_openpgp_crt_export ()

    int
    gnutls_openpgp_crt_export (gnutls_openpgp_crt_t key,
                               gnutls_openpgp_crt_fmt_t format,
                               void *output_data,
                               size_t *output_data_size);

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.

#### Parameters

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) |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_crt_export2 ()

    int
    gnutls_openpgp_crt_export2 (gnutls_openpgp_crt_t key,
                                gnutls_openpgp_crt_fmt_t format,
                                gnutls_datum_t *out);

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

#### Parameters

key | Holds the key. |
format | One of gnutls_openpgp_crt_fmt_t elements. |
out | will contain the raw or base64 encoded key |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

Since: 3.1.3

### gnutls_openpgp_crt_get_auth_subkey ()

    int
    gnutls_openpgp_crt_get_auth_subkey (gnutls_openpgp_crt_t crt,
                                        gnutls_openpgp_keyid_t keyid,
                                        unsigned int flag);

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.

#### Parameters

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

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_crt_get_creation_time ()

    time_t
    gnutls_openpgp_crt_get_creation_time (gnutls_openpgp_crt_t key);

Get key creation time.

#### Parameters

key | the structure that contains the OpenPGP public key. |

#### Returns

the timestamp when the OpenPGP key was created.

### gnutls_openpgp_crt_get_expiration_time ()

    time_t
    gnutls_openpgp_crt_get_expiration_time
                                   (gnutls_openpgp_crt_t key);

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

#### Parameters

key | the structure that contains the OpenPGP public key. |

#### Returns

the time when the OpenPGP key expires.

### gnutls_openpgp_crt_get_fingerprint ()

    int
    gnutls_openpgp_crt_get_fingerprint (gnutls_openpgp_crt_t key,
                                        void *fpr,
                                        size_t *fprlen);

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

#### Parameters

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. |

#### Returns

On success, 0 is returned. Otherwise, an error code.

### gnutls_openpgp_crt_get_key_id ()

    int
    gnutls_openpgp_crt_get_key_id (gnutls_openpgp_crt_t key,
                                   gnutls_openpgp_keyid_t keyid);

Get key id string.

#### Parameters

key | the structure that contains the OpenPGP public key. |
keyid | the buffer to save the keyid. |

#### Returns

the 64-bit keyID of the OpenPGP key.

Since: 2.4.0

### gnutls_openpgp_crt_get_key_usage ()

    int
    gnutls_openpgp_crt_get_key_usage (gnutls_openpgp_crt_t key,
                                      unsigned int *key_usage);

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`.

#### Parameters

key | should contain a gnutls_openpgp_crt_t type |
key_usage | where the key usage bits will be stored |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_crt_get_name ()

    int
    gnutls_openpgp_crt_get_name (gnutls_openpgp_crt_t key,
                                 int idx,
                                 char *buf,
                                 size_t *sizeof_buf);

Extracts the userID from the parsed OpenPGP key.

#### Parameters

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` . |

#### 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 ()

    gnutls_pk_algorithm_t
    gnutls_openpgp_crt_get_pk_algorithm (gnutls_openpgp_crt_t key,
                                         unsigned int *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.

#### Parameters

key | is an OpenPGP key |
bits | if bits is non null it will hold the size of the parameters' in bits |

#### 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 ()

    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);

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.

#### Parameters

crt | Holds the certificate |
p | will hold the p |
q | will hold the q |
g | will hold the g |
y | will hold the y |

#### Returns

`GNUTLS_E_SUCCESS` on success, otherwise a negative error code.

Since: 2.4.0

### gnutls_openpgp_crt_get_pk_rsa_raw ()

    int
    gnutls_openpgp_crt_get_pk_rsa_raw (gnutls_openpgp_crt_t crt,
                                       gnutls_datum_t *m,
                                       gnutls_datum_t *e);

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.

#### Parameters

crt | Holds the certificate |
m | will hold the modulus |
e | will hold the public exponent |

#### Returns

`GNUTLS_E_SUCCESS` on success, otherwise a negative error code.

Since: 2.4.0

### gnutls_openpgp_crt_get_preferred_key_id ()

    int
    gnutls_openpgp_crt_get_preferred_key_id
                                   (gnutls_openpgp_crt_t key,
                                    gnutls_openpgp_keyid_t keyid);

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

#### Parameters

key | the structure that contains the OpenPGP public key. |
keyid | the struct to save the keyid. |

#### Returns

the 64-bit preferred keyID of the OpenPGP key.

### gnutls_openpgp_crt_get_revoked_status ()

    int
    gnutls_openpgp_crt_get_revoked_status (gnutls_openpgp_crt_t key);

Get revocation status of key.

#### Parameters

key | the structure that contains the OpenPGP public 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 ()

    int
    gnutls_openpgp_crt_get_subkey_count (gnutls_openpgp_crt_t key);

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

#### Parameters

key | is an OpenPGP key |

#### Returns

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

Since: 2.4.0

### gnutls_openpgp_crt_get_subkey_creation_time ()

    time_t
    gnutls_openpgp_crt_get_subkey_creation_time
                                   (gnutls_openpgp_crt_t key,
                                    unsigned int idx);

Get subkey creation time.

#### Parameters

key | the structure that contains the OpenPGP public key. |
idx | the subkey index |

#### Returns

the timestamp when the OpenPGP sub-key was created.

Since: 2.4.0

### gnutls_openpgp_crt_get_subkey_expiration_time ()

    time_t
    gnutls_openpgp_crt_get_subkey_expiration_time
                                   (gnutls_openpgp_crt_t key,
                                    unsigned int idx);

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

#### Parameters

key | the structure that contains the OpenPGP public key. |
idx | the subkey index |

#### Returns

the time when the OpenPGP key expires.

Since: 2.4.0

### gnutls_openpgp_crt_get_subkey_fingerprint ()

    int
    gnutls_openpgp_crt_get_subkey_fingerprint
                                   (gnutls_openpgp_crt_t key,
                                    unsigned int idx,
                                    void *fpr,
                                    size_t *fprlen);

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

#### Parameters

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. |

#### Returns

On success, 0 is returned. Otherwise, an error code.

Since: 2.4.0

### gnutls_openpgp_crt_get_subkey_id ()

    int
    gnutls_openpgp_crt_get_subkey_id (gnutls_openpgp_crt_t key,
                                      unsigned int idx,
                                      gnutls_openpgp_keyid_t keyid);

Get the subkey's key-id.

#### Parameters

key | the structure that contains the OpenPGP public key. |
idx | the subkey index |
keyid | the buffer to save the keyid. |

#### Returns

the 64-bit keyID of the OpenPGP key.

### gnutls_openpgp_crt_get_subkey_idx ()

    int
    gnutls_openpgp_crt_get_subkey_idx (gnutls_openpgp_crt_t key,
                                       const gnutls_openpgp_keyid_t keyid);

Get subkey's index.

#### Parameters

key | the structure that contains the OpenPGP public key. |
keyid | the keyid. |

#### Returns

the index of the subkey or a negative error value.

Since: 2.4.0

### gnutls_openpgp_crt_get_subkey_pk_algorithm ()

    gnutls_pk_algorithm_t
    gnutls_openpgp_crt_get_subkey_pk_algorithm
                                   (gnutls_openpgp_crt_t key,
                                    unsigned int idx,
                                    unsigned int *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.

#### Parameters

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 |

#### 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 ()

    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);

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.

#### Parameters

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 |

#### Returns

`GNUTLS_E_SUCCESS` on success, otherwise a negative error code.

Since: 2.4.0

### gnutls_openpgp_crt_get_subkey_pk_rsa_raw ()

    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);

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.

#### Parameters

crt | Holds the certificate |
idx | Is the subkey index |
m | will hold the modulus |
e | will hold the public exponent |

#### Returns

`GNUTLS_E_SUCCESS` on success, otherwise a negative error code.

Since: 2.4.0

### gnutls_openpgp_crt_get_subkey_revoked_status ()

    int
    gnutls_openpgp_crt_get_subkey_revoked_status
                                   (gnutls_openpgp_crt_t key,
                                    unsigned int idx);

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

#### Parameters

key | the structure that contains the OpenPGP public key. |
idx | is the subkey index |

#### 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 ()

    int
    gnutls_openpgp_crt_get_subkey_usage (gnutls_openpgp_crt_t key,
                                         unsigned int idx,
                                         unsigned int *key_usage);

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.

#### Parameters

key | should contain a gnutls_openpgp_crt_t type |
idx | the subkey index |
key_usage | where the key usage bits will be stored |

#### Returns

key usage value.

Since: 2.4.0

### gnutls_openpgp_crt_get_version ()

    int
    gnutls_openpgp_crt_get_version (gnutls_openpgp_crt_t key);

Extract the version of the OpenPGP key.

#### Parameters

key | the structure that contains the OpenPGP public key. |

#### Returns

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

### gnutls_openpgp_crt_import ()

    int
    gnutls_openpgp_crt_import (gnutls_openpgp_crt_t key,
                               const gnutls_datum_t *data,
                               gnutls_openpgp_crt_fmt_t format);

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'.

#### Parameters

key | The structure to store the parsed key. |
data | The RAW or BASE64 encoded key. |
format | One of gnutls_openpgp_crt_fmt_t elements. |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_crt_init ()

    int
    gnutls_openpgp_crt_init (gnutls_openpgp_crt_t *key);

This function will initialize an OpenPGP key structure.

#### Parameters

key | A pointer to the type to be initialized |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_crt_print ()

    int
    gnutls_openpgp_crt_print (gnutls_openpgp_crt_t cert,
                              gnutls_certificate_print_formats_t format,
                              gnutls_datum_t *out);

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()`.

#### Parameters

cert | The structure to be printed |
format | Indicate the format to use |
out | Newly allocated datum with (0) terminated string. |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_crt_set_preferred_key_id ()

    int
    gnutls_openpgp_crt_set_preferred_key_id
                                   (gnutls_openpgp_crt_t key,
                                    const gnutls_openpgp_keyid_t 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.

#### Parameters

key | the structure that contains the OpenPGP public key. |
keyid | the selected keyid |

#### Returns

On success, `GNUTLS_E_SUCCESS` (0) is returned, otherwise a negative error code is returned.

### gnutls_openpgp_crt_verify_ring ()

    int
    gnutls_openpgp_crt_verify_ring (gnutls_openpgp_crt_t key,
                                    gnutls_openpgp_keyring_t keyring,
                                    unsigned int flags,
                                    unsigned int *verify);

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.

#### Parameters

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. |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_crt_verify_self ()

    int
    gnutls_openpgp_crt_verify_self (gnutls_openpgp_crt_t key,
                                    unsigned int flags,
                                    unsigned int *verify);

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.

#### Parameters

key | the structure that holds the key. |
flags | unused (should be 0) |
verify | will hold the key verification output. |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_keyring_check_id ()

    int
    gnutls_openpgp_keyring_check_id (gnutls_openpgp_keyring_t ring,
                                     const gnutls_openpgp_keyid_t keyid,
                                     unsigned int flags);

Check if a given key ID exists in the keyring.

#### Parameters

ring | holds the keyring to check against |
keyid | will hold the keyid to check for. |
flags | unused (should be 0) |

#### Returns

`GNUTLS_E_SUCCESS` on success (if keyid exists) and a negative error code on failure.

### gnutls_openpgp_keyring_deinit ()

    void
    gnutls_openpgp_keyring_deinit (gnutls_openpgp_keyring_t keyring);

This function will deinitialize a keyring structure.

#### Parameters

keyring | A pointer to the type to be initialized |

### gnutls_openpgp_keyring_get_crt ()

    int
    gnutls_openpgp_keyring_get_crt (gnutls_openpgp_keyring_t ring,
                                    unsigned int idx,
                                    gnutls_openpgp_crt_t *cert);

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.

#### Parameters

ring | Holds the keyring. |
idx | the index of the certificate to export |
cert | An uninitialized gnutls_openpgp_crt_t type |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_keyring_get_crt_count ()

    int
    gnutls_openpgp_keyring_get_crt_count (gnutls_openpgp_keyring_t ring);

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

#### Parameters

ring | is an OpenPGP key ring |

#### Returns

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

### gnutls_openpgp_keyring_import ()

    int
    gnutls_openpgp_keyring_import (gnutls_openpgp_keyring_t keyring,
                                   const gnutls_datum_t *data,
                                   gnutls_openpgp_crt_fmt_t format);

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'.

#### Parameters

keyring | The structure to store the parsed key. |
data | The RAW or BASE64 encoded keyring. |
format | One of gnutls_openpgp_keyring_fmt elements. |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_keyring_init ()

    int
    gnutls_openpgp_keyring_init (gnutls_openpgp_keyring_t *keyring);

This function will initialize an keyring structure.

#### Parameters

keyring | A pointer to the type to be initialized |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_privkey_deinit ()

    void
    gnutls_openpgp_privkey_deinit (gnutls_openpgp_privkey_t key);

This function will deinitialize a key structure.

#### Parameters

key | A pointer to the type to be initialized |

### gnutls_openpgp_privkey_export ()

    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);

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.

#### Parameters

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) |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

Since: 2.4.0

### gnutls_openpgp_privkey_export2 ()

    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);

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

#### Parameters

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 |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

Since: 3.1.3

### gnutls_openpgp_privkey_export_dsa_raw ()

    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);

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.

#### Parameters

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 |

#### Returns

`GNUTLS_E_SUCCESS` on success, otherwise a negative error code.

Since: 2.4.0

### gnutls_openpgp_privkey_export_rsa_raw ()

    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);

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.

#### Parameters

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 |

#### Returns

`GNUTLS_E_SUCCESS` on success, otherwise a negative error code.

Since: 2.4.0

### gnutls_openpgp_privkey_export_subkey_dsa_raw ()

    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);

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.

#### Parameters

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 |

#### Returns

`GNUTLS_E_SUCCESS` on success, otherwise a negative error code.

Since: 2.4.0

### gnutls_openpgp_privkey_export_subkey_rsa_raw ()

    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);

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.

#### Parameters

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 |

#### Returns

`GNUTLS_E_SUCCESS` on success, otherwise a negative error code.

Since: 2.4.0

### gnutls_openpgp_privkey_get_fingerprint ()

    int
    gnutls_openpgp_privkey_get_fingerprint
                                   (gnutls_openpgp_privkey_t key,
                                    void *fpr,
                                    size_t *fprlen);

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

#### Parameters

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. |

#### Returns

On success, 0 is returned, or an error code.

Since: 2.4.0

### gnutls_openpgp_privkey_get_key_id ()

    int
    gnutls_openpgp_privkey_get_key_id (gnutls_openpgp_privkey_t key,
                                       gnutls_openpgp_keyid_t keyid);

Get key-id.

#### Parameters

key | the structure that contains the OpenPGP secret key. |
keyid | the buffer to save the keyid. |

#### Returns

the 64-bit keyID of the OpenPGP key.

Since: 2.4.0

### gnutls_openpgp_privkey_get_pk_algorithm ()

    gnutls_pk_algorithm_t
    gnutls_openpgp_privkey_get_pk_algorithm
                                   (gnutls_openpgp_privkey_t key,
                                    unsigned int *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.

#### Parameters

key | is an OpenPGP key |
bits | if bits is non null it will hold the size of the parameters' in bits |

#### 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 ()

    int
    gnutls_openpgp_privkey_get_preferred_key_id
                                   (gnutls_openpgp_privkey_t key,
                                    gnutls_openpgp_keyid_t keyid);

Get the preferred key-id for the key.

#### Parameters

key | the structure that contains the OpenPGP public key. |
keyid | the struct to save the keyid. |

#### 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 ()

    int
    gnutls_openpgp_privkey_get_revoked_status
                                   (gnutls_openpgp_privkey_t key);

Get revocation status of key.

#### Parameters

key | the structure that contains the OpenPGP private 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 ()

    int
    gnutls_openpgp_privkey_get_subkey_count
                                   (gnutls_openpgp_privkey_t key);

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

#### Parameters

key | is an OpenPGP key |

#### Returns

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

Since: 2.4.0

### gnutls_openpgp_privkey_get_subkey_creation_time ()

    time_t
    gnutls_openpgp_privkey_get_subkey_creation_time
                                   (gnutls_openpgp_privkey_t key,
                                    unsigned int idx);

Get subkey creation time.

#### Parameters

key | the structure that contains the OpenPGP private key. |
idx | the subkey index |

#### Returns

the timestamp when the OpenPGP key was created.

Since: 2.4.0

### gnutls_openpgp_privkey_get_subkey_expiration_time ()

    time_t
    gnutls_openpgp_privkey_get_subkey_expiration_time
                                   (gnutls_openpgp_privkey_t key,
                                    unsigned int idx);

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

#### Parameters

key | the structure that contains the OpenPGP private key. |
idx | the subkey index |

#### Returns

the time when the OpenPGP key expires.

Since: 2.4.0

### gnutls_openpgp_privkey_get_subkey_fingerprint ()

    int
    gnutls_openpgp_privkey_get_subkey_fingerprint
                                   (gnutls_openpgp_privkey_t key,
                                    unsigned int idx,
                                    void *fpr,
                                    size_t *fprlen);

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

#### Parameters

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. |

#### Returns

On success, 0 is returned, or an error code.

Since: 2.4.0

### gnutls_openpgp_privkey_get_subkey_id ()

    int
    gnutls_openpgp_privkey_get_subkey_id (gnutls_openpgp_privkey_t key,
                                          unsigned int idx,
                                          gnutls_openpgp_keyid_t keyid);

Get the key-id for the subkey.

#### Parameters

key | the structure that contains the OpenPGP secret key. |
idx | the subkey index |
keyid | the buffer to save the keyid. |

#### Returns

the 64-bit keyID of the OpenPGP key.

Since: 2.4.0

### gnutls_openpgp_privkey_get_subkey_idx ()

    int
    gnutls_openpgp_privkey_get_subkey_idx (gnutls_openpgp_privkey_t key,
                                           const gnutls_openpgp_keyid_t keyid);

Get index of subkey.

#### Parameters

key | the structure that contains the OpenPGP private key. |
keyid | the keyid. |

#### Returns

the index of the subkey or a negative error value.

Since: 2.4.0

### gnutls_openpgp_privkey_get_subkey_pk_algorithm ()

    gnutls_pk_algorithm_t
    gnutls_openpgp_privkey_get_subkey_pk_algorithm
                                   (gnutls_openpgp_privkey_t key,
                                    unsigned int idx,
                                    unsigned int *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.

#### Parameters

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 |

#### 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 ()

    int
    gnutls_openpgp_privkey_get_subkey_revoked_status
                                   (gnutls_openpgp_privkey_t key,
                                    unsigned int idx);

Get revocation status of key.

#### Parameters

key | the structure that contains the OpenPGP private key. |
idx | is the subkey index |

#### 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 ()

    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);

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'.

#### Parameters

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) |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_privkey_init ()

    int
    gnutls_openpgp_privkey_init (gnutls_openpgp_privkey_t *key);

This function will initialize an OpenPGP key structure.

#### Parameters

key | A pointer to the type to be initialized |

#### Returns

`GNUTLS_E_SUCCESS` on success, or an error code.

### gnutls_openpgp_privkey_sec_param ()

    gnutls_sec_param_t
    gnutls_openpgp_privkey_sec_param (gnutls_openpgp_privkey_t key);

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

#### Parameters

key | a key structure |

#### 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 ()

    int
    gnutls_openpgp_privkey_set_preferred_key_id
                                   (gnutls_openpgp_privkey_t key,
                                    const gnutls_openpgp_keyid_t 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.

#### Parameters

key | the structure that contains the OpenPGP public key. |
keyid | the selected keyid |

#### Returns

On success, `GNUTLS_E_SUCCESS` (0) is returned, otherwise a negative error code is returned.

### gnutls_openpgp_recv_key_func ()

    int
    (*gnutls_openpgp_recv_key_func) (gnutls_session_t session,
                                     const unsigned char *keyfpr,
                                     unsigned int keyfpr_length,
                                     gnutls_datum_t *key);

A callback of this type is used to retrieve OpenPGP keys. Only useful on the server, and will only be used if the peer send a key fingerprint instead of a full key. See also `gnutls_openpgp_set_recv_key_function()`.

The variable `key` must be allocated using `gnutls_malloc()`.

#### Parameters

session | a TLS session |
keyfpr | key fingerprint |
keyfpr_length | length of key fingerprint |
key | output key. |

#### Returns

On success, `GNUTLS_E_SUCCESS` (zero) is returned, otherwise an error code is returned.

### gnutls_openpgp_set_recv_key_function ()

    void
    gnutls_openpgp_set_recv_key_function (gnutls_session_t session,
                                          gnutls_openpgp_recv_key_func func);

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()`.

#### Parameters

session | a TLS session |
func | the callback |

## Types and Values

### GNUTLS_OPENPGP_KEYID_SIZE

    #define GNUTLS_OPENPGP_KEYID_SIZE 8

### GNUTLS_OPENPGP_MASTER_KEYID_IDX

    #define GNUTLS_OPENPGP_MASTER_KEYID_IDX INT_MAX

### enum gnutls_openpgp_crt_fmt_t

Enumeration of different OpenPGP key formats.

#### Members

GNUTLS_OPENPGP_FMT_RAW | OpenPGP certificate in raw format. |
GNUTLS_OPENPGP_FMT_BASE64 | OpenPGP certificate in base64 format. |