GcrCertificateChain: Gcr Library Reference Manual

## GcrCertificateChain GcrCertificateChain — A certificate chain |

## Functions

GcrCertificateChain * | gcr_certificate_chain_new ()
void | gcr_certificate_chain_add ()
GcrCertificate * | gcr_certificate_chain_get_certificate ()
GcrCertificateChainStatus | gcr_certificate_chain_get_status ()
GcrCertificate * | gcr_certificate_chain_get_anchor ()
GcrCertificate * | gcr_certificate_chain_get_endpoint ()
guint | gcr_certificate_chain_get_length ()
gboolean | gcr_certificate_chain_build ()
void | gcr_certificate_chain_build_async ()
gboolean | gcr_certificate_chain_build_finish ()

## Properties

guint | length | Read
GcrCertificateChainStatus | status | Read

## Types and Values

struct | GcrCertificateChain
struct | GcrCertificateChainClass
enum | GcrCertificateChainStatus
enum | GcrCertificateChainFlags
#define | GCR_TYPE_CERTIFICATE_CHAIN_FLAGS
#define | GCR_TYPE_CERTIFICATE_CHAIN_STATUS

## Object Hierarchy

        GObject
        ╰── GcrCertificateChain

## Description

GcrCertificateChain represents a chain of certificates, normally used to validate the trust in a certificate. An X.509 certificate chain has one endpoint certificate (the one for which trust is being verified) and then in turn the certificate that issued each previous certificate in the chain.

This functionality is for building of certificate chains not for validating them. Use your favorite crypto library to validate trust in a certificate chain once its built.

The order of certificates in the chain should be first the endpoint certificates and then the signing certificates.

Create a new certificate chain with `gcr_certificate_chain_new()` and then add the certificates with `gcr_certificate_chain_add()`.

You can then use `gcr_certificate_chain_build()` to build the remainder of the chain. This will lookup missing certificates in PKCS#11 modules and also check that each certificate in the chain is the signer of the previous one. If a trust anchor, pinned certificate, or self-signed certificate is found, then the chain is considered built. Any extra certificates are removed from the chain.

Once the certificate chain has been built, you can access its status through `gcr_certificate_chain_get_status()`. The status signifies whether the chain is anchored on a trust root, self-signed, incomplete etc. See GcrCertificateChainStatus for information on the various statuses.

It's important to understand that the building of a certificate chain is merely the first step towards verifying trust in a certificate.

## Functions

### gcr_certificate_chain_new ()

    GcrCertificateChain *
    gcr_certificate_chain_new (void);

Create a new GcrCertificateChain.

#### Returns

a newly allocated certificate chain.

[transfer full]

### gcr_certificate_chain_add ()

    void
    gcr_certificate_chain_add (GcrCertificateChain *self,
                               GcrCertificate *certificate);

Add `certificate` to the chain. The order of certificates in the chain are important. The first certificate should be the endpoint certificate, and then come the signers (certificate authorities) each in turn. If a root certificate authority is present, it should come last.

Adding a certificate an already built chain (see `gcr_certificate_chain_build()`) resets the type of the certificate chain to `GCR_CERTIFICATE_CHAIN_UNKNOWN`

#### Parameters

self | the GcrCertificateChain |
certificate | a GcrCertificate to add to the chain |

### gcr_certificate_chain_get_certificate ()

    GcrCertificate *
    gcr_certificate_chain_get_certificate (GcrCertificateChain *self,
                                           guint index);

Get a certificate in the chain. It is an error to call this function with an invalid index.

#### Parameters

self | the GcrCertificateChain |
index | index of the certificate to get |

#### Returns

the certificate.

[transfer none]

### gcr_certificate_chain_get_status ()

    GcrCertificateChainStatus
    gcr_certificate_chain_get_status (GcrCertificateChain *self);

Get the status of a certificate chain. If the certificate chain has not been built, then the status will be `GCR_CERTIFICATE_CHAIN_UNKNOWN`.

A status of `GCR_CERTIFICATE_CHAIN_ANCHORED` does not mean that the certificate chain has been verified, but merely that an anchor has been found.

#### Parameters

self | the GcrCertificateChain |

#### Returns

the status of the certificate chain.

### gcr_certificate_chain_get_anchor ()

    GcrCertificate *
    gcr_certificate_chain_get_anchor (GcrCertificateChain *self);

If the certificate chain has been built and is of status `GCR_CERTIFICATE_CHAIN_ANCHORED`, then this will return the anchor certificate that was found. This is not necessarily a root certificate authority. If an intermediate certificate authority in the chain was found to be anchored, then that certificate will be returned.

If an anchor is returned it does not mean that the certificate chain has been verified, but merely that an anchor has been found.

#### Parameters

self | the GcrCertificateChain |

#### Returns

the anchor certificate, or NULL if not anchored.

[transfer none]

### gcr_certificate_chain_get_endpoint ()

    GcrCertificate *
    gcr_certificate_chain_get_endpoint (GcrCertificateChain *self);

Get the endpoint certificate in the chain. This is always the first certificate in the chain. The endpoint certificate cannot be anchored.

#### Parameters

self | the GcrCertificateChain |

#### Returns

the endpoint certificate, or `NULL` if the chain is empty.

[transfer none]

### gcr_certificate_chain_get_length ()

    guint
    gcr_certificate_chain_get_length (GcrCertificateChain *self);

Get the length of the certificate chain.

#### Parameters

self | the GcrCertificateChain |

#### Returns

the length of the certificate chain

### gcr_certificate_chain_build ()

    gboolean
    gcr_certificate_chain_build (GcrCertificateChain *self,
                                 const gchar *purpose,
                                 const gchar *peer,
                                 GcrCertificateChainFlags flags,
                                 GCancellable *cancellable,
                                 GError **error);

Complete a certificate chain. Once a certificate chain has been built its status can be examined.

This operation will lookup missing certificates in PKCS#11 modules and also that each certificate in the chain is the signer of the previous one. If a trust anchor, pinned certificate, or self-signed certificate is found, then the chain is considered built. Any extra certificates are removed from the chain.

It's important to understand that building of a certificate chain does not constitute verifying that chain. This is merely the first step towards trust verification.

The `purpose` is a string like `GCR_PURPOSE_CLIENT_AUTH` and is the purpose for which the certificate chain will be used. Trust anchors are looked up for this purpose. This argument is required.

The `peer` is usually the host name of the peer whith which this certificate chain is being used. It is used to look up pinned certificates that have been stored for this peer. If `NULL` then no pinned certificates will be considered.

If the `GCR_CERTIFICATE_CHAIN_NO_LOOKUPS` flag is specified then no lookups for anchors or pinned certificates are done, and the resulting chain will be neither anchored or pinned. Additionally no missing certificate authorities are looked up in PKCS#11

This call will block, see `gcr_certificate_chain_build_async()` for the asynchronous version.

#### Parameters

self | the GcrCertificateChain |
purpose | the purpose the certificate chain will be used for |
peer | the peer the certificate chain will be used with, or `NULL`. | [allow-none]
flags | chain completion flags |
cancellable | a GCancellable or `NULL` |
error | a GError or `NULL` |

#### Returns

whether the operation completed successfully

### gcr_certificate_chain_build_async ()

    void
    gcr_certificate_chain_build_async (GcrCertificateChain *self,
                                       const gchar *purpose,
                                       const gchar *peer,
                                       GcrCertificateChainFlags flags,
                                       GCancellable *cancellable,
                                       GAsyncReadyCallback callback,
                                       gpointer user_data);

Complete a certificate chain. Once a certificate chain has been built its status can be examined.

This will lookup missing certificates in PKCS#11 modules and also that each certificate in the chain is the signer of the previous one. If a trust anchor, pinned certificate, or self-signed certificate is found, then the chain is considered built. Any extra certificates are removed from the chain.

It's important to understand that building of a certificate chain does not constitute verifying that chain. This is merely the first step towards trust verification.

The `purpose` is a string like `GCR_PURPOSE_CLIENT_AUTH` and is the purpose for which the certificate chain will be used. Trust anchors are looked up for this purpose. This argument is required.

The `peer` is usually the host name of the peer whith which this certificate chain is being used. It is used to look up pinned certificates that have been stored for this peer. If `NULL` then no pinned certificates will be considered.

If the `GCR_CERTIFICATE_CHAIN_NO_LOOKUPS` flag is specified then no lookups for anchors or pinned certificates are done, and the resulting chain will be neither anchored or pinned. Additionally no missing certificate authorities are looked up in PKCS#11

When the operation is finished, `callback` will be called. You can then call `gcr_certificate_chain_build_finish()` to get the result of the operation.

#### Parameters

self | the GcrCertificateChain |
purpose | the purpose the certificate chain will be used for |
peer | the peer the certificate chain will be used with, or `NULL`. | [allow-none]
flags | chain completion flags |
cancellable | a GCancellable or `NULL` |
callback | this will be called when the operation completes. |
user_data | data to pass to the callback |

### gcr_certificate_chain_build_finish ()

    gboolean
    gcr_certificate_chain_build_finish (GcrCertificateChain *self,
                                        GAsyncResult *result,
                                        GError **error);

Finishes an asynchronous operation started by `gcr_certificate_chain_build_async()`.

#### Parameters

self | the GcrCertificateChain |
result | the GAsyncResult passed to the callback |
error | a GError, or NULL |

#### Returns

whether the operation succeeded

## Types and Values

### struct GcrCertificateChain

    struct GcrCertificateChain;

A chain of certificates.

### struct GcrCertificateChainClass

    struct GcrCertificateChainClass {
    	GObjectClass parent_class;
    };

The class for GcrCertificateChain.

#### Members

### enum GcrCertificateChainStatus

The status of a built certificate chain. Will be set to `GCR_CERTIFICATE_CHAIN_UNKNOWN` for certificate chains that have not been built.

#### Members

GCR_CERTIFICATE_CHAIN_UNKNOWN | The certificate chain's status is unknown. When a chain is not yet built it has this status. If a chain is modified after being built, it has this status. |
GCR_CERTIFICATE_CHAIN_INCOMPLETE | A full chain could not be loaded. The chain does not end with a self-signed certificate, a trusted anchor, or a pinned certificate. |
GCR_CERTIFICATE_CHAIN_DISTRUSTED | The certificate chain contains a revoked or otherwise explicitly distrusted certificate. The entire chain should be distrusted. |
GCR_CERTIFICATE_CHAIN_SELFSIGNED | The chain ends with a self-signed certificate. No trust anchor was found. |
GCR_CERTIFICATE_CHAIN_PINNED | The chain represents a pinned certificate. A pinned certificate is an exception which trusts a given certificate explicitly for a purpose and communication with a certain peer. |
GCR_CERTIFICATE_CHAIN_ANCHORED | The chain ends with an anchored certificate. The anchored certificate is not necessarily self-signed. |

### enum GcrCertificateChainFlags

Flags to be used with the `gcr_certificate_chain_build()` operation.

#### Members

GCR_CERTIFICATE_CHAIN_NONE | no flags |
GCR_CERTIFICATE_CHAIN_NO_LOOKUPS | If this flag is specified then no lookups for anchors or pinned certificates are done, and the resulting chain will be neither anchored or pinned. Additionally no missing certificate authorities are looked up in PKCS#11. |

### GCR_TYPE_CERTIFICATE_CHAIN_FLAGS

    #define GCR_TYPE_CERTIFICATE_CHAIN_FLAGS (gcr_certificate_chain_flags_get_type ())

The flags GType for GcrCertificateChainFlags.

### GCR_TYPE_CERTIFICATE_CHAIN_STATUS

    #define GCR_TYPE_CERTIFICATE_CHAIN_STATUS (gcr_certificate_chain_status_get_type ())

The enum GType for GcrCertificateChainStatus.

## Property Details

### The `“length”` property

      “length”                   guint

The length of the certificate chain.

Flags: Read

Default value: 0

### The `“status”` property

      “status”                   GcrCertificateChainStatus

The certificate chain status. See GcrCertificateChainStatus

Flags: Read

Default value: GCR_CERTIFICATE_CHAIN_UNKNOWN