/* based on verify_extract_name from tls_client.c in postfix */
static gboolean irssi_ssl_verify_hostname(X509 *cert, const char *hostname)
{
int gen_index, gen_count;
gboolean matched = FALSE, has_dns_name = FALSE;
const char *cert_dns_name;
char *cert_subject_cn;
const GENERAL_NAME *gn;
STACK_OF(GENERAL_NAME) * gens;
GString *alt_names;
alt_names = g_string_new("");
/* Verify the dNSName(s) in the peer certificate against the hostname. */
gens = X509_get_ext_d2i(cert, NID_subject_alt_name, 0, 0);
if (gens) {
gen_count = sk_GENERAL_NAME_num(gens);
for (gen_index = 0; gen_index < gen_count && !matched; ++gen_index) {
gn = sk_GENERAL_NAME_value(gens, gen_index);
if (gn->type != GEN_DNS)
continue;
/* Even if we have an invalid DNS name, we still ultimately
ignore the CommonName, because subjectAltName:DNS is
present (though malformed). */
has_dns_name = TRUE;
cert_dns_name = tls_dns_name(gn);
if (cert_dns_name && *cert_dns_name) {
g_string_append_printf(alt_names, " '%s'", cert_dns_name);
matched = match_hostname(cert_dns_name, hostname);
}
}
/* Free stack *and* member GENERAL_NAME objects */
sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
}
if (has_dns_name) {
if (! matched) {
/* The CommonName in the issuer DN is obsolete when SubjectAltName is available. */
g_warning("None of the Subject Alt Names%s in the certificate match hostname '%s'", alt_names->str, hostname);
}
g_string_free(alt_names, TRUE);
return matched;
} else { /* No subjectAltNames, look at CommonName */
g_string_free(alt_names, TRUE);
cert_subject_cn = tls_text_name(X509_get_subject_name(cert), NID_commonName);
if (cert_subject_cn && *cert_subject_cn) {
matched = match_hostname(cert_subject_cn, hostname);
if (! matched) {
g_warning("SSL certificate common name '%s' doesn't match host name '%s'", cert_subject_cn, hostname);
}
} else {
g_warning("No subjectAltNames and no valid common name in certificate");
}
free(cert_subject_cn);
}
return matched;
}
static void verify_extract_name(TLS_SESS_STATE *TLScontext, X509 *peercert,
const TLS_CLIENT_START_PROPS *props)
{
int i;
int r;
int matched = 0;
int dnsname_match;
int verify_peername = 0;
int log_certmatch;
int verbose;
const char *dnsname;
const GENERAL_NAME *gn;
general_name_stack_t *gens;
/*
* On exit both peer_CN and issuer_CN should be set.
*/
TLScontext->issuer_CN = tls_issuer_CN(peercert, TLScontext);
/*
* Is the certificate trust chain valid and trusted?
*/
if (SSL_get_verify_result(TLScontext->con) == X509_V_OK)
TLScontext->peer_status |= TLS_CERT_FLAG_TRUSTED;
/*
* With fingerprint or dane we may already be done. Otherwise, verify the
* peername if using traditional PKI or DANE with trust-anchors.
*/
if (!TLS_CERT_IS_MATCHED(TLScontext)
&& TLS_CERT_IS_TRUSTED(TLScontext)
&& TLS_MUST_TRUST(props->tls_level))
verify_peername = 1;
/* Force cert processing so we can log the data? */
log_certmatch = TLScontext->log_mask & TLS_LOG_CERTMATCH;
/* Log cert details when processing? */
verbose = log_certmatch || (TLScontext->log_mask & TLS_LOG_VERBOSE);
if (verify_peername || log_certmatch) {
/*
* Verify the dNSName(s) in the peer certificate against the nexthop
* and hostname.
*
* If DNS names are present, we use the first matching (or else simply
* the first) DNS name as the subject CN. The CommonName in the
* issuer DN is obsolete when SubjectAltName is available. This
* yields much less surprising logs, because we log the name we
* verified or a name we checked and failed to match.
*
* XXX: The nexthop and host name may both be the same network address
* rather than a DNS name. In this case we really should be looking
* for GEN_IPADD entries, not GEN_DNS entries.
*
* XXX: In ideal world the caller who used the address to build the
* connection would tell us that the nexthop is the connection
* address, but if that is not practical, we can parse the nexthop
* again here.
*/
gens = X509_get_ext_d2i(peercert, NID_subject_alt_name, 0, 0);
if (gens) {
r = sk_GENERAL_NAME_num(gens);
for (i = 0; i < r; ++i) {
gn = sk_GENERAL_NAME_value(gens, i);
if (gn->type != GEN_DNS)
continue;
/*
* Even if we have an invalid DNS name, we still ultimately
* ignore the CommonName, because subjectAltName:DNS is
* present (though malformed). Replace any previous peer_CN
* if empty or we get a match.
*
* We always set at least an empty peer_CN if the ALTNAME cert
* flag is set. If not, we set peer_CN from the cert
* CommonName below, so peer_CN is always non-null on return.
*/
TLScontext->peer_status |= TLS_CERT_FLAG_ALTNAME;
dnsname = tls_dns_name(gn, TLScontext);
if (dnsname && *dnsname) {
if ((dnsname_match = match_servername(dnsname, props)) != 0)
matched++;
/* Keep the first matched name. */
if (TLScontext->peer_CN
&& ((dnsname_match && matched == 1)
|| *TLScontext->peer_CN == 0)) {
myfree(TLScontext->peer_CN);
TLScontext->peer_CN = 0;
}
if (verbose)
msg_info("%s: %ssubjectAltName: %s", props->namaddr,
dnsname_match ? "Matched " : "", dnsname);
}
if (TLScontext->peer_CN == 0)
TLScontext->peer_CN = mystrdup(dnsname ? dnsname : "");
if (matched && !log_certmatch)
break;
}
if (verify_peername && matched)
TLScontext->peer_status |= TLS_CERT_FLAG_MATCHED;
/*
* (Sam Rushing, Ironport) Free stack *and* member GENERAL_NAME
* objects
*/
sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
}
/*
* No subjectAltNames, peer_CN is taken from CommonName.
*/
if (TLScontext->peer_CN == 0) {
TLScontext->peer_CN = tls_peer_CN(peercert, TLScontext);
if (*TLScontext->peer_CN)
matched = match_servername(TLScontext->peer_CN, props);
if (verify_peername && matched)
TLScontext->peer_status |= TLS_CERT_FLAG_MATCHED;
if (verbose)
msg_info("%s %sCommonName %s", props->namaddr,
matched ? "Matched " : "", TLScontext->peer_CN);
} else if (verbose) {
char *tmpcn = tls_peer_CN(peercert, TLScontext);
/*
* Though the CommonName was superceded by a subjectAltName, log
* it when certificate match debugging was requested.
*/
msg_info("%s CommonName %s", TLScontext->namaddr, tmpcn);
myfree(tmpcn);
}
} else
TLScontext->peer_CN = tls_peer_CN(peercert, TLScontext);
/*
* Give them a clue. Problems with trust chain verification are logged
* when the session is first negotiated, before the session is stored
* into the cache. We don't want mystery failures, so log the fact the
* real problem is to be found in the past.
*/
if (!TLS_CERT_IS_TRUSTED(TLScontext)
&& (TLScontext->log_mask & TLS_LOG_UNTRUSTED)) {
if (TLScontext->session_reused == 0)
tls_log_verify_error(TLScontext);
else
msg_info("%s: re-using session with untrusted certificate, "
"look for details earlier in the log", props->namaddr);
}
}
static void verify_extract_name(TLS_SESS_STATE *TLScontext, X509 *peercert,
const TLS_CLIENT_START_PROPS *props)
{
int i;
int r;
int matched = 0;
const char *dnsname;
const GENERAL_NAME *gn;
STACK_OF(GENERAL_NAME) * gens;
/*
* On exit both peer_CN and issuer_CN should be set.
*/
TLScontext->issuer_CN = tls_issuer_CN(peercert, TLScontext);
/*
* Is the certificate trust chain valid and trusted?
*/
if (SSL_get_verify_result(TLScontext->con) == X509_V_OK)
TLScontext->peer_status |= TLS_CERT_FLAG_TRUSTED;
if (TLS_CERT_IS_TRUSTED(TLScontext) && props->tls_level >= TLS_LEV_VERIFY) {
/*
* Verify the dNSName(s) in the peer certificate against the nexthop
* and hostname.
*
* If DNS names are present, we use the first matching (or else simply
* the first) DNS name as the subject CN. The CommonName in the
* issuer DN is obsolete when SubjectAltName is available. This
* yields much less surprising logs, because we log the name we
* verified or a name we checked and failed to match.
*
* XXX: The nexthop and host name may both be the same network address
* rather than a DNS name. In this case we really should be looking
* for GEN_IPADD entries, not GEN_DNS entries.
*
* XXX: In ideal world the caller who used the address to build the
* connection would tell us that the nexthop is the connection
* address, but if that is not practical, we can parse the nexthop
* again here.
*/
gens = X509_get_ext_d2i(peercert, NID_subject_alt_name, 0, 0);
if (gens) {
r = sk_GENERAL_NAME_num(gens);
for (i = 0; i < r && !matched; ++i) {
gn = sk_GENERAL_NAME_value(gens, i);
if (gn->type != GEN_DNS)
continue;
/*
* Even if we have an invalid DNS name, we still ultimately
* ignore the CommonName, because subjectAltName:DNS is
* present (though malformed). Replace any previous peer_CN
* if empty or we get a match.
*
* We always set at least an empty peer_CN if the ALTNAME cert
* flag is set. If not, we set peer_CN from the cert
* CommonName below, so peer_CN is always non-null on return.
*/
TLScontext->peer_status |= TLS_CERT_FLAG_ALTNAME;
dnsname = tls_dns_name(gn, TLScontext);
if (dnsname && *dnsname) {
matched = match_hostname(dnsname, props);
if (TLScontext->peer_CN
&& (matched || *TLScontext->peer_CN == 0)) {
acl_myfree(TLScontext->peer_CN);
TLScontext->peer_CN = 0;
}
}
if (TLScontext->peer_CN == 0)
TLScontext->peer_CN = acl_mystrdup(dnsname ? dnsname : "");
}
/*
* (Sam Rushing, Ironport) Free stack *and* member GENERAL_NAME
* objects
*/
sk_GENERAL_NAME_pop_free(gens, GENERAL_NAME_free);
}
/*
* No subjectAltNames, peer_CN is taken from CommonName.
*/
if (TLScontext->peer_CN == 0) {
TLScontext->peer_CN = tls_peer_CN(peercert, TLScontext);
if (*TLScontext->peer_CN)
matched = match_hostname(TLScontext->peer_CN, props);
}
if (matched)
TLScontext->peer_status |= TLS_CERT_FLAG_MATCHED;
/*
* - Matched: Trusted and peername matches - Trusted: Signed by
* trusted CA(s), but peername not matched - Untrusted: Can't verify
* the trust chain, reason already logged.
*/
if (TLScontext->log_level >= 2)
acl_msg_info("%s: %s subject_CN=%s, issuer_CN=%s", props->namaddr,
TLS_CERT_IS_MATCHED(TLScontext) ? "Matched" :
TLS_CERT_IS_TRUSTED(TLScontext) ? "Trusted" : "Untrusted",
TLScontext->peer_CN, TLScontext->issuer_CN);
} else
TLScontext->peer_CN = tls_peer_CN(peercert, TLScontext);
/*
* Give them a clue. Problems with trust chain verification were logged
* when the session was first negotiated, before the session was stored
* into the cache. We don't want mystery failures, so log the fact the
* real problem is to be found in the past.
*/
if (TLScontext->session_reused
&& !TLS_CERT_IS_TRUSTED(TLScontext)
&& TLScontext->log_level >= 1)
acl_msg_info("%s: re-using session with untrusted certificate, "
"look for details earlier in the log", props->namaddr);
}
