Commit c636c1c4 authored by Viktor Dukhovni's avatar Viktor Dukhovni
Browse files

Fix client verify mode to check SSL_VERIFY_PEER 



The original check for != SSL_VERIFY_NONE can give surprising results
when flags SSL_VERIFY_PEER is not set, but other flags are.  Note
that SSL_VERIFY_NONE (0) is not a flag bit, it is rather the absense
of all other flag bits.

Signed-off-by: default avatarRob Percival <robpercival@google.com>
Reviewed-by: default avatarEmilia Käsper <emilia@openssl.org>
parent 6afef8b1

doc/ssl/SSL_CTX_set_verify.pod

+1 −14
Original line number Diff line number Diff line
@@ -89,8 +89,7 @@ B<Client mode:> ignored 


=back



Exactly one of the B<mode> flags SSL_VERIFY_NONE and SSL_VERIFY_PEER must be

set at any time.

If the B<mode> is SSL_VERIFY_NONE none of the other flags may be set.



The actual verification procedure is performed either using the built-in

verification procedure or using another application provided verification
@@ -146,18 +145,6 @@ Its return value is identical to B<preverify_ok>, so that any verification 
failure will lead to a termination of the TLS/SSL handshake with an

alert message, if SSL_VERIFY_PEER is set.



=head1 BUGS



In client mode, it is not checked whether the SSL_VERIFY_PEER flag

is set, but whether SSL_VERIFY_NONE is not set. This can lead to

unexpected behaviour, if the SSL_VERIFY_PEER and SSL_VERIFY_NONE are not

used as required (exactly one must be set at any time).



The certificate verification depth set with SSL[_CTX]_verify_depth()

stops the verification at a certain depth. The error message produced

will be that of an incomplete certificate chain and not

X509_V_ERR_CERT_CHAIN_TOO_LONG as may be expected.



=head1 RETURN VALUES



The SSL*_set_verify*() functions do not provide diagnostic information.

ssl/statem/statem_clnt.c

+1 −1
Original line number Diff line number Diff line
@@ -1334,7 +1334,7 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt) 
    }



    i = ssl_verify_cert_chain(s, sk);

    if (s->verify_mode != SSL_VERIFY_NONE && i <= 0) {

    if ((s->verify_mode & SSL_VERIFY_PEER) && i <= 0) {

        al = ssl_verify_alarm_type(s->verify_result);

        SSLerr(SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,

               SSL_R_CERTIFICATE_VERIFY_FAILED);