NAME

       SSL_get_peer_cert_chain, SSL_get0_verified_chain - get the X509 certificate chain of the
       peer

SYNOPSIS

        #include <openssl/ssl.h>

        STACK_OF(X509) *SSL_get_peer_cert_chain(const SSL *ssl);
        STACK_OF(X509) *SSL_get0_verified_chain(const SSL *ssl);

DESCRIPTION

       SSL_get_peer_cert_chain() returns a pointer to STACK_OF(X509) certificates forming the
       certificate chain sent by the peer. If called on the client side, the stack also contains
       the peer's certificate; if called on the server side, the peer's certificate must be
       obtained separately using SSL_get_peer_certificate(3).  If the peer did not present a
       certificate, NULL is returned.

       NB: SSL_get_peer_cert_chain() returns the peer chain as sent by the peer: it only consists
       of certificates the peer has sent (in the order the peer has sent them) it is not a
       verified chain.

       SSL_get0_verified_chain() returns the verified certificate chain of the peer including the
       peer's end entity certificate. It must be called after a session has been successfully
       established. If peer verification was not successful (as indicated by
       SSL_get_verify_result() not returning X509_V_OK) the chain may be incomplete or invalid.

NOTES

       If the session is resumed peers do not send certificates so a NULL pointer is returned by
       these functions. Applications can call SSL_session_reused() to determine whether a session
       is resumed.

       The reference count of each certificate in the returned STACK_OF(X509) object is not
       incremented and the returned stack may be invalidated by renegotiation.  If applications
       wish to use any certificates in the returned chain indefinitely they must increase the
       reference counts using X509_up_ref() or obtain a copy of the whole chain with
       X509_chain_up_ref().

RETURN VALUES

       The following return values can occur:

       NULL
           No certificate was presented by the peer or no connection was established or the
           certificate chain is no longer available when a session is reused.

       Pointer to a STACK_OF(X509)
           The return value points to the certificate chain presented by the peer.

SEE ALSO

       ssl(7), SSL_get_peer_certificate(3), X509_up_ref(3), X509_chain_up_ref(3)

COPYRIGHT

       Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (the "License").  You may not use this file except
       in compliance with the License.  You can obtain a copy in the file LICENSE in the source
       distribution or at <https://www.openssl.org/source/license.html>.