+
+/* draft-ietf-radext-radsec-11.txt
+
+ * Certificate validation MUST include the verification rules as
+ per [RFC5280].
+
+ * Implementations SHOULD indicate their acceptable Certification
+ Authorities as per section 7.4.4 (server side) and x.y.z
+ ["Trusted CA Indication"] (client side) of [RFC5246] (see
+ Section 3.2)
+
+ * Implementations SHOULD allow to configure a list of acceptable
+ certificates, identified via certificate fingerprint. When a
+ fingerprint configured, the fingerprint is prepended with an
+ ASCII label identifying the hash function followed by a colon.
+ Implementations MUST support SHA-1 as the hash algorithm and
+ use the ASCII label "sha-1" to identify the SHA-1 algorithm.
+ The length of a SHA-1 hash is 20 bytes and the length of the
+ corresponding fingerprint string is 65 characters. An example
+ certificate fingerprint is: sha-
+ 1:E1:2D:53:2B:7C:6B:8A:29:A2:76:C8:64:36:0B:08:4B:7A:F1:9E:9D
+
+ * Peer validation always includes a check on whether the locally
+ configured expected DNS name or IP address of the server that
+ is contacted matches its presented certificate. DNS names and
+ IP addresses can be contained in the Common Name (CN) or
+ subjectAltName entries. For verification, only one of these
+ entries is to be considered. The following precedence
+ applies: for DNS name validation, subjectAltName:DNS has
+ precedence over CN; for IP address validation, subjectAltName:
+ iPAddr has precedence over CN.
+
+ * Implementations SHOULD allow to configure a set of acceptable
+ values for subjectAltName:URI.
+ */
+int
+tls_verify_cert (struct rs_connection *conn)
+{
+ int err = 0;
+ int success = 0;
+ X509 *peer_cert = NULL;
+ struct in6_addr addr;
+ const char *hostname = NULL;
+
+ assert (conn->active_peer->conn == conn);
+ assert (conn->active_peer->hostname != NULL);
+ hostname = conn->active_peer->hostname;
+
+ /* verifytlscert() performs basic verification as described by
+ OpenSSL VERIFY(1), i.e. verification of the certificate chain. */
+ peer_cert = verifytlscert (conn->tls_ssl);
+ if (peer_cert == NULL)
+ {
+ err = rs_err_conn_push (conn, RSE_SSLERR,
+ "basic certificate validation failed");
+ goto out;
+ }
+
+ if (inet_pton (AF_INET, hostname, &addr))
+ success = (subjectaltnameaddr (peer_cert, AF_INET, &addr) == 1);
+ else if (inet_pton (AF_INET6, hostname, &addr))
+ success = (subjectaltnameaddr (peer_cert, AF_INET6, &addr) == 1);
+ else
+ success = (subjectaltnameregexp (peer_cert, GEN_DNS, hostname, NULL) == 1);
+
+ if (!success)
+ success = (cnregexp (peer_cert, hostname, NULL) == 1);
+
+ if (conn->realm->disable_hostname_check)
+ success = 1;
+ if (!success)
+ err = rs_err_conn_push (conn, RSE_CERT, "server certificate doesn't "
+ "match configured hostname \"%s\"", hostname);
+
+ out:
+ if (peer_cert != NULL)
+ X509_free (peer_cert);
+ return err;
+}