+/*
+ * Size of the to-be-signed TLS13 data, without the hash size itself:
+ * 64 bytes of value 32, 33 context bytes, 1 byte separator
+ */
+#define TLS13_TBS_START_SIZE 64
+#define TLS13_TBS_PREAMBLE_SIZE (TLS13_TBS_START_SIZE + 33 + 1)
+
+static int get_cert_verify_tbs_data(SSL *s, unsigned char *tls13tbs,
+ void **hdata, size_t *hdatalen)
+{
+ static const char *servercontext = "TLS 1.3, server CertificateVerify";
+ static const char *clientcontext = "TLS 1.3, client CertificateVerify";
+
+ if (SSL_IS_TLS13(s)) {
+ size_t hashlen;
+
+ /* Set the first 64 bytes of to-be-signed data to octet 32 */
+ memset(tls13tbs, 32, TLS13_TBS_START_SIZE);
+ /* This copies the 33 bytes of context plus the 0 separator byte */
+ if (s->statem.hand_state == TLS_ST_CR_CERT_VRFY
+ || s->statem.hand_state == TLS_ST_SW_CERT_VRFY)
+ strcpy((char *)tls13tbs + TLS13_TBS_START_SIZE, servercontext);
+ else
+ strcpy((char *)tls13tbs + TLS13_TBS_START_SIZE, clientcontext);
+
+ /*
+ * If we're currently reading then we need to use the saved handshake
+ * hash value. We can't use the current handshake hash state because
+ * that includes the CertVerify itself.
+ */
+ if (s->statem.hand_state == TLS_ST_CR_CERT_VRFY
+ || s->statem.hand_state == TLS_ST_SR_CERT_VRFY) {
+ memcpy(tls13tbs + TLS13_TBS_PREAMBLE_SIZE, s->cert_verify_hash,
+ s->cert_verify_hash_len);
+ hashlen = s->cert_verify_hash_len;
+ } else if (!ssl_handshake_hash(s, tls13tbs + TLS13_TBS_PREAMBLE_SIZE,
+ EVP_MAX_MD_SIZE, &hashlen)) {
+ return 0;
+ }
+
+ *hdata = tls13tbs;
+ *hdatalen = TLS13_TBS_PREAMBLE_SIZE + hashlen;
+ } else {
+ size_t retlen;
+
+ retlen = BIO_get_mem_data(s->s3->handshake_buffer, hdata);
+ if (retlen <= 0)
+ return 0;
+ *hdatalen = retlen;
+ }
+
+ return 1;
+}
+
+int tls_construct_cert_verify(SSL *s, WPACKET *pkt)
+{
+ EVP_PKEY *pkey;
+ const EVP_MD *md;
+ EVP_MD_CTX *mctx = NULL;
+ EVP_PKEY_CTX *pctx = NULL;
+ size_t hdatalen = 0, siglen = 0;
+ void *hdata;
+ unsigned char *sig = NULL;
+ unsigned char tls13tbs[TLS13_TBS_PREAMBLE_SIZE + EVP_MAX_MD_SIZE];
+ int pktype, ispss = 0;
+
+ if (s->server) {
+ /* Only happens in TLSv1.3 */
+ /*
+ * TODO(TLS1.3): This needs to change. We should not get this from the
+ * cipher. However, for now, we have not done the work to separate the
+ * certificate type from the ciphersuite
+ */
+ pkey = ssl_get_sign_pkey(s, s->s3->tmp.new_cipher, &md);
+ if (pkey == NULL)
+ goto err;
+ } else {
+ md = s->s3->tmp.md[s->cert->key - s->cert->pkeys];
+ pkey = s->cert->key->privatekey;
+ }
+ pktype = EVP_PKEY_id(pkey);
+
+ mctx = EVP_MD_CTX_new();
+ if (mctx == NULL) {
+ SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+
+ /* Get the data to be signed */
+ if (!get_cert_verify_tbs_data(s, tls13tbs, &hdata, &hdatalen)) {
+ SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ if (SSL_USE_SIGALGS(s) && !tls12_get_sigandhash(s, pkt, pkey, md, &ispss)) {
+ SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+#ifdef SSL_DEBUG
+ fprintf(stderr, "Using client alg %s\n", EVP_MD_name(md));
+#endif
+ siglen = EVP_PKEY_size(pkey);
+ sig = OPENSSL_malloc(siglen);
+ if (sig == NULL) {
+ SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+
+ if (EVP_DigestSignInit(mctx, &pctx, md, NULL, pkey) <= 0
+ || EVP_DigestSignUpdate(mctx, hdata, hdatalen) <= 0) {
+ SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_EVP_LIB);
+ goto err;
+ }
+
+ if (ispss) {
+ if (EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) <= 0
+ /* -1 here means set saltlen to the digest len */
+ || EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1) <= 0) {
+ SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_EVP_LIB);
+ goto err;
+ }
+ } else if (s->version == SSL3_VERSION) {
+ if (!EVP_MD_CTX_ctrl(mctx, EVP_CTRL_SSL3_MASTER_SECRET,
+ (int)s->session->master_key_length,
+ s->session->master_key)) {
+ SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_EVP_LIB);
+ goto err;
+ }
+ }
+
+ if (EVP_DigestSignFinal(mctx, sig, &siglen) <= 0) {
+ SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_EVP_LIB);
+ goto err;
+ }
+
+#ifndef OPENSSL_NO_GOST
+ {
+ if (pktype == NID_id_GostR3410_2001
+ || pktype == NID_id_GostR3410_2012_256
+ || pktype == NID_id_GostR3410_2012_512)
+ BUF_reverse(sig, NULL, siglen);
+ }
+#endif
+
+ if (!WPACKET_sub_memcpy_u16(pkt, sig, siglen)) {
+ SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ /* Digest cached records and discard handshake buffer */
+ if (!ssl3_digest_cached_records(s, 0))
+ goto err;
+
+ OPENSSL_free(sig);
+ EVP_MD_CTX_free(mctx);
+ return 1;
+ err:
+ OPENSSL_free(sig);
+ EVP_MD_CTX_free(mctx);
+ ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+ return 0;
+}
+
+MSG_PROCESS_RETURN tls_process_cert_verify(SSL *s, PACKET *pkt)
+{
+ EVP_PKEY *pkey = NULL;
+ const unsigned char *data;
+#ifndef OPENSSL_NO_GOST
+ unsigned char *gost_data = NULL;
+#endif
+ int al = SSL_AD_INTERNAL_ERROR, ret = MSG_PROCESS_ERROR;
+ int type = 0, j, pktype, ispss = 0;
+ unsigned int len;
+ X509 *peer;
+ const EVP_MD *md = NULL;
+ size_t hdatalen = 0;
+ void *hdata;
+ unsigned char tls13tbs[TLS13_TBS_PREAMBLE_SIZE + EVP_MAX_MD_SIZE];
+ EVP_MD_CTX *mctx = EVP_MD_CTX_new();
+ EVP_PKEY_CTX *pctx = NULL;
+
+ if (mctx == NULL) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
+ goto f_err;
+ }
+
+ peer = s->session->peer;
+ pkey = X509_get0_pubkey(peer);
+ pktype = EVP_PKEY_id(pkey);
+ type = X509_certificate_type(peer, pkey);
+
+ if (!(type & EVP_PKT_SIGN)) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY,
+ SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE);
+ al = SSL_AD_ILLEGAL_PARAMETER;
+ goto f_err;
+ }
+
+ /* Check for broken implementations of GOST ciphersuites */
+ /*
+ * If key is GOST and n is exactly 64, it is bare signature without
+ * length field (CryptoPro implementations at least till CSP 4.0)
+ */
+#ifndef OPENSSL_NO_GOST
+ if (PACKET_remaining(pkt) == 64
+ && EVP_PKEY_id(pkey) == NID_id_GostR3410_2001) {
+ len = 64;
+ } else
+#endif
+ {
+ if (SSL_USE_SIGALGS(s)) {
+ int rv;
+ unsigned int sigalg;
+
+ if (!PACKET_get_net_2(pkt, &sigalg)) {
+ al = SSL_AD_DECODE_ERROR;
+ goto f_err;
+ }
+ rv = tls12_check_peer_sigalg(&md, s, sigalg, pkey);
+ if (rv == -1) {
+ goto f_err;
+ } else if (rv == 0) {
+ al = SSL_AD_DECODE_ERROR;
+ goto f_err;
+ }
+ ispss = SIGID_IS_PSS(sigalg);
+#ifdef SSL_DEBUG
+ fprintf(stderr, "USING TLSv1.2 HASH %s\n", EVP_MD_name(md));
+#endif
+ } else {
+ /* Use default digest for this key type */
+ int idx = ssl_cert_type(NULL, pkey);
+ if (idx >= 0)
+ md = s->s3->tmp.md[idx];
+ if (md == NULL) {
+ al = SSL_AD_INTERNAL_ERROR;
+ goto f_err;
+ }
+ }
+
+ if (!PACKET_get_net_2(pkt, &len)) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_LENGTH_MISMATCH);
+ al = SSL_AD_DECODE_ERROR;
+ goto f_err;
+ }
+ }
+ j = EVP_PKEY_size(pkey);
+ if (((int)len > j) || ((int)PACKET_remaining(pkt) > j)
+ || (PACKET_remaining(pkt) == 0)) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_WRONG_SIGNATURE_SIZE);
+ al = SSL_AD_DECODE_ERROR;
+ goto f_err;
+ }
+ if (!PACKET_get_bytes(pkt, &data, len)) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_LENGTH_MISMATCH);
+ al = SSL_AD_DECODE_ERROR;
+ goto f_err;
+ }
+
+ if (!get_cert_verify_tbs_data(s, tls13tbs, &hdata, &hdatalen)) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
+ goto f_err;
+ }
+
+#ifdef SSL_DEBUG
+ fprintf(stderr, "Using client verify alg %s\n", EVP_MD_name(md));
+#endif
+ if (EVP_DigestVerifyInit(mctx, &pctx, md, NULL, pkey) <= 0
+ || EVP_DigestVerifyUpdate(mctx, hdata, hdatalen) <= 0) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_EVP_LIB);
+ goto f_err;
+ }
+#ifndef OPENSSL_NO_GOST
+ {
+ if (pktype == NID_id_GostR3410_2001
+ || pktype == NID_id_GostR3410_2012_256
+ || pktype == NID_id_GostR3410_2012_512) {
+ if ((gost_data = OPENSSL_malloc(len)) == NULL) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
+ goto f_err;
+ }
+ BUF_reverse(gost_data, data, len);
+ data = gost_data;
+ }
+ }
+#endif
+
+ if (ispss) {
+ if (EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) <= 0
+ /* -1 here means set saltlen to the digest len */
+ || EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1) <= 0) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_EVP_LIB);
+ goto f_err;
+ }
+ } else if (s->version == SSL3_VERSION
+ && !EVP_MD_CTX_ctrl(mctx, EVP_CTRL_SSL3_MASTER_SECRET,
+ (int)s->session->master_key_length,
+ s->session->master_key)) {
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_EVP_LIB);
+ goto f_err;
+ }
+
+ if (EVP_DigestVerifyFinal(mctx, data, len) <= 0) {
+ al = SSL_AD_DECRYPT_ERROR;
+ SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_SIGNATURE);
+ goto f_err;
+ }
+
+ if (SSL_IS_TLS13(s))
+ ret = MSG_PROCESS_CONTINUE_READING;
+ else
+ ret = MSG_PROCESS_CONTINUE_PROCESSING;
+ if (0) {
+ f_err:
+ ssl3_send_alert(s, SSL3_AL_FATAL, al);
+ ossl_statem_set_error(s);
+ }
+ BIO_free(s->s3->handshake_buffer);
+ s->s3->handshake_buffer = NULL;
+ EVP_MD_CTX_free(mctx);
+#ifndef OPENSSL_NO_GOST
+ OPENSSL_free(gost_data);
+#endif
+ return ret;
+}
+