diff options
Diffstat (limited to 'lib/tls.c')
| -rw-r--r-- | lib/tls.c | 157 |
1 files changed, 156 insertions, 1 deletions
@@ -8,6 +8,8 @@ #include <assert.h> #include <openssl/ssl.h> #include <openssl/err.h> +#include <openssl/bn.h> +#include <openssl/x509v3.h> #include <radsec/radsec.h> #include <radsec/radsec-impl.h> @@ -41,6 +43,74 @@ _get_tlsconf (struct rs_connection *conn, const struct rs_realm *realm) return c; } +#if defined RS_ENABLE_TLS_PSK +static unsigned int +psk_client_cb (SSL *ssl, + const char *hint, + char *identity, + unsigned int max_identity_len, + unsigned char *psk, + unsigned int max_psk_len) +{ + struct rs_connection *conn = NULL; + struct rs_credentials *cred = NULL; + + conn = SSL_get_ex_data (ssl, 0); + assert (conn != NULL); + cred = conn->active_peer->realm->transport_cred; + assert (cred != NULL); + /* NOTE: Ignoring identity hint from server. */ + + if (strlen (cred->identity) + 1 > max_identity_len) + { + rs_err_conn_push (conn, RSE_CRED, "PSK identity longer than max %d", + max_identity_len - 1); + return 0; + } + strcpy (identity, cred->identity); + + switch (cred->secret_encoding) + { + case RS_KEY_ENCODING_UTF8: + cred->secret_len = strlen (cred->secret); + if (cred->secret_len > max_psk_len) + { + rs_err_conn_push (conn, RSE_CRED, "PSK secret longer than max %d", + max_psk_len); + return 0; + } + memcpy (psk, cred->secret, cred->secret_len); + break; + case RS_KEY_ENCODING_ASCII_HEX: + { + BIGNUM *bn = NULL; + + if (BN_hex2bn (&bn, cred->secret) == 0) + { + rs_err_conn_push (conn, RSE_CRED, "Unable to convert pskhexstr"); + if (bn != NULL) + BN_clear_free (bn); + return 0; + } + if ((unsigned int) BN_num_bytes (bn) > max_psk_len) + { + rs_err_conn_push (conn, RSE_CRED, "PSK secret longer than max %d", + max_psk_len); + BN_clear_free (bn); + return 0; + } + cred->secret_len = BN_bn2bin (bn, psk); + BN_clear_free (bn); + } + break; + default: + assert (!"unknown psk encoding"); + } + + return cred->secret_len; +} +#endif /* RS_ENABLE_TLS_PSK */ + int rs_tls_init (struct rs_connection *conn) { @@ -56,7 +126,7 @@ rs_tls_init (struct rs_connection *conn) tlsconf = _get_tlsconf (conn, conn->active_peer->realm); if (!tlsconf) return -1; - ssl_ctx = tlsgetctx (RADPROT_TLS, tlsconf); + ssl_ctx = tlsgetctx (RAD_TLS, tlsconf); if (!ssl_ctx) { for (sslerr = ERR_get_error (); sslerr; sslerr = ERR_get_error ()) @@ -73,8 +143,93 @@ rs_tls_init (struct rs_connection *conn) return -1; } +#if defined RS_ENABLE_TLS_PSK + if (conn->active_peer->realm->transport_cred != NULL) + { + SSL_set_psk_client_callback (ssl, psk_client_cb); + SSL_set_ex_data (ssl, 0, conn); + } +#endif /* RS_ENABLE_TLS_PSK */ + conn->tls_ctx = ssl_ctx; conn->tls_ssl = ssl; rs_free (ctx, tlsconf); return RSE_OK; } + +/* 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 (!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; +} |