SSL_get_verify_result - get result of peer certificate verification
#include <openssl/ssl.h> long SSL_get_verify_result(const SSL *ssl);
SSL_get_verify_result() returns the result of the verification of the X509 certificate presented by the peer, if any.
SSL_get_verify_result() can only return one error code while the verification of a certificate can fail because of many reasons at the same time. Only the last verification error that occurred during the processing is available from SSL_get_verify_result().
Sometimes there can be a sequence of errors leading to the verification failure as reported by SSL_get_verify_result(). To get the errors, it is necessary to setup a verify callback via SSL_CTX_set_verify(3) or SSL_set_verify(3) and retrieve the errors from the error stack there, because once SSL_connect(3) returns, these errors may no longer be available.
The verification result is part of the established session and is restored when a session is reused.
If no peer certificate was presented, the returned result code is X509_V_OK. This is because no verification error occurred, it does however not indicate success. SSL_get_verify_result() is only useful in connection with SSL_get_peer_certificate(3).
The following return values can currently occur:
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