/* Copyright 2010-2013 NORDUnet A/S. All rights reserved. See LICENSE for licensing information. */ #if defined HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #if defined HAVE_PTHREAD_H #include #endif #include #include #include #include #include #include #include #include #include #include "radsecproxy/list.h" #include "radsecproxy/radsecproxy.h" #include "tls.h" static struct tls * _get_tlsconf (struct rs_connection *conn, const struct rs_realm *realm) { struct tls *c = rs_malloc (conn->ctx, sizeof (struct tls)); if (c) { memset (c, 0, sizeof (struct tls)); /* TODO: Make sure old radsecproxy code doesn't free these all of a sudden, or strdup them. */ c->name = realm->name; c->cacertfile = realm->cacertfile; c->cacertpath = NULL; /* NYI */ c->certfile = realm->certfile; c->certkeyfile = realm->certkeyfile; c->certkeypwd = NULL; /* NYI */ c->cacheexpiry = 0; /* NYI */ c->crlcheck = 0; /* NYI */ c->policyoids = (char **) NULL; /* NYI */ } else rs_err_conn_push_fl (conn, RSE_NOMEM, __FILE__, __LINE__, NULL); 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 */ /** Read \a buf_len bytes from one of the random devices into \a buf. Return 0 on success and -1 on failure. */ static int load_rand_ (uint8_t *buf, size_t buf_len) { static const char *fns[] = {"/dev/urandom", "/dev/random", NULL}; int i; if (buf_len > SSIZE_MAX) return -1; for (i = 0; fns[i] != NULL; i++) { size_t nread = 0; int fd = open (fns[i], O_RDONLY); if (fd < 0) continue; while (nread != buf_len) { ssize_t r = read (fd, buf + nread, buf_len - nread); if (r < 0) return -1; if (r == 0) break; nread += r; } close (fd); if (nread != buf_len) return -1; return 0; } return -1; } /** Initialise OpenSSL's PRNG by possibly invoking RAND_poll() and by feeding RAND_seed() data from one of the random devices. If either succeeds, we're happy and return 0. */ static int init_openssl_rand_ (void) { long openssl_version = 0; int openssl_random_init_flag = 0; int our_random_init_flag = 0; uint8_t buf[32]; /* Older OpenSSL has a crash bug in RAND_poll (when a file it opens gets a file descriptor with a number higher than FD_SETSIZE) so use it only for newer versions. */ openssl_version = SSLeay (); if (openssl_version >= OPENSSL_V (0,9,8,'c')) openssl_random_init_flag = RAND_poll (); our_random_init_flag = !load_rand_ (buf, sizeof(buf)); if (our_random_init_flag) RAND_seed (buf, sizeof(buf)); memset (buf, 0, sizeof(buf)); /* FIXME: What if memset() is optimised out? */ if (!openssl_random_init_flag && !our_random_init_flag) return -1; if (!RAND_bytes (buf, sizeof(buf))) return -1; return 0; } #if defined HAVE_PTHREADS /** Array of pthread_mutex_t for OpenSSL. Allocated and initialised in \a init_locking_ and never freed. */ static pthread_mutex_t *s_openssl_mutexes = NULL; /** Number of pthread_mutex_t's allocated at s_openssl_mutexes. */ static int s_openssl_mutexes_count = 0; /** Callback for OpenSSL when a lock is to be held or released. */ __attribute__((unused)) static void openssl_locking_cb_ (int mode, int i, const char *file, int line) { if (s_openssl_mutexes == NULL || i >= s_openssl_mutexes_count) return; if (mode & CRYPTO_LOCK) pthread_mutex_lock (&s_openssl_mutexes[i]); else pthread_mutex_unlock (&s_openssl_mutexes[i]); } /** Initialise any locking needed for being thread safe. Libradsec has all its own state in one or more struct rs_context and doesn't need locks but libraries used by libradsec may need protection. */ static int init_locking_ () { int i, n; n = CRYPTO_num_locks (); s_openssl_mutexes = calloc (n, sizeof(pthread_mutex_t)); if (s_openssl_mutexes == NULL) return -RSE_NOMEM; for (i = 0; i < n; i++) pthread_mutex_init (&s_openssl_mutexes[i], NULL); s_openssl_mutexes_count = n; return 0; } #endif /* HAVE_PTHREADS */ /** Initialise the TLS library. Return 0 on success, -1 on failure. */ int tls_init () { SSL_load_error_strings (); #if defined HAVE_PTHREADS if (CRYPTO_get_locking_callback () == NULL) { assert (s_openssl_mutexes_count == 0); /* Allocate and initialise mutexes. We will never free these. FIXME: Is there a portable way of having a function invoked when a solib is unloaded? -ln */ if (init_locking_ ()) return -1; CRYPTO_set_locking_callback (openssl_locking_cb_); } #endif /* HAVE_PTHREADS */ SSL_library_init (); return init_openssl_rand_ (); } int tls_init_conn (struct rs_connection *conn) { struct rs_context *ctx = NULL; struct tls *tlsconf = NULL; SSL_CTX *ssl_ctx = NULL; SSL *ssl = NULL; unsigned long sslerr = 0; assert (conn->ctx); ctx = conn->ctx; tlsconf = _get_tlsconf (conn, conn->active_peer->realm); if (!tlsconf) return -1; ssl_ctx = tlsgetctx (RAD_TLS, tlsconf); if (!ssl_ctx) { for (sslerr = ERR_get_error (); sslerr; sslerr = ERR_get_error ()) rs_err_conn_push_fl (conn, RSE_SSLERR, __FILE__, __LINE__, ERR_error_string (sslerr, NULL)); return -1; } ssl = SSL_new (ssl_ctx); if (!ssl) { for (sslerr = ERR_get_error (); sslerr; sslerr = ERR_get_error ()) rs_err_conn_push_fl (conn, RSE_SSLERR, __FILE__, __LINE__, ERR_error_string (sslerr, NULL)); 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 (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; }