PACKET: simplify ServerHello parsing (fc5ce51d) · Commits · CYBER - Cyber Security / TS 103 523 MSP / ETS / ETS OpenSSL

ssl/s3_clnt.c

+35 −38

Original line number	Diff line number	Diff line
		@@ -928,10 +928,11 @@ int ssl3_get_server_hello(SSL *s)
		{
		STACK_OF(SSL_CIPHER) *sk;
		const SSL_CIPHER *c;
		PACKET pkt;
		unsigned char session_id, cipherchars;
		PACKET pkt, session_id;
		size_t session_id_len;
		unsigned char *cipherchars;
		int i, al = SSL_AD_INTERNAL_ERROR, ok;
		unsigned int j;
		unsigned int compression;
		long n;
		#ifndef OPENSSL_NO_COMP
		SSL_COMP *comp;
		@@ -1075,15 +1076,26 @@ int ssl3_get_server_hello(SSL *s)

		s->hit = 0;

		/* get the session-id length */
		if (!PACKET_get_1(&pkt, &j)
		\|\| (j > sizeof s->session->session_id)
		\|\| (j > SSL3_SESSION_ID_SIZE)) {
		/* Get the session-id. */
		if (!PACKET_get_length_prefixed_1(&pkt, &session_id)) {
		al = SSL_AD_DECODE_ERROR;
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
		goto f_err;
		}
		session_id_len = PACKET_remaining(&session_id);
		if (session_id_len > sizeof s->session->session_id
		\|\| session_id_len > SSL3_SESSION_ID_SIZE) {
		al = SSL_AD_ILLEGAL_PARAMETER;
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_SSL3_SESSION_ID_TOO_LONG);
		goto f_err;
		}

		if (!PACKET_get_bytes(&pkt, &cipherchars, TLS_CIPHER_LEN)) {
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
		al = SSL_AD_DECODE_ERROR;
		goto f_err;
		}

		/*
		* Check if we can resume the session based on external pre-shared secret.
		* EAP-FAST (RFC 4851) supports two types of session resumption.
		@@ -1099,13 +1111,6 @@ int ssl3_get_server_hello(SSL *s)
		if (s->version >= TLS1_VERSION && s->tls_session_secret_cb &&
		s->session->tlsext_tick) {
		SSL_CIPHER *pref_cipher = NULL;
		PACKET bookmark = pkt;
		if (!PACKET_forward(&pkt, j)
		\|\| !PACKET_get_bytes(&pkt, &cipherchars, TLS_CIPHER_LEN)) {
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
		al = SSL_AD_DECODE_ERROR;
		goto f_err;
		}
		s->session->master_key_length = sizeof(s->session->master_key);
		if (s->tls_session_secret_cb(s, s->session->master_key,
		&s->session->master_key_length,
		@@ -1118,18 +1123,11 @@ int ssl3_get_server_hello(SSL *s)
		al = SSL_AD_INTERNAL_ERROR;
		goto f_err;
		}
		pkt = bookmark;
		}

		/* Get the session id */
		if (!PACKET_get_bytes(&pkt, &session_id, j)) {
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
		al = SSL_AD_DECODE_ERROR;
		goto f_err;
		}

		if (j != 0 && j == s->session->session_id_length
		&& memcmp(session_id, s->session->session_id, j) == 0) {
		if (session_id_len != 0 && session_id_len == s->session->session_id_length
		&& memcmp(PACKET_data(&session_id), s->session->session_id,
		session_id_len) == 0) {
		if (s->sid_ctx_length != s->session->sid_ctx_length
		\|\| memcmp(s->session->sid_ctx, s->sid_ctx, s->sid_ctx_length)) {
		/* actually a client application bug */
		@@ -1152,15 +1150,13 @@ int ssl3_get_server_hello(SSL *s)
		goto f_err;
		}
		}
		s->session->session_id_length = j;
		memcpy(s->session->session_id, session_id, j); /* j could be 0 */
		}

		if (!PACKET_get_bytes(&pkt, &cipherchars, TLS_CIPHER_LEN)) {
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
		al = SSL_AD_DECODE_ERROR;
		goto f_err;
		s->session->session_id_length = session_id_len;
		/* session_id_len could be 0 */
		memcpy(s->session->session_id, PACKET_data(&session_id),
		session_id_len);
		}

		c = ssl_get_cipher_by_char(s, cipherchars);
		if (c == NULL) {
		/* unknown cipher */
		@@ -1214,13 +1210,13 @@ int ssl3_get_server_hello(SSL *s)
		goto f_err;
		/* lets get the compression algorithm */
		/* COMPRESSION */
		if (!PACKET_get_1(&pkt, &j)) {
		if (!PACKET_get_1(&pkt, &compression)) {
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_LENGTH_MISMATCH);
		al = SSL_AD_DECODE_ERROR;
		goto f_err;
		}
		#ifdef OPENSSL_NO_COMP
		if (j != 0) {
		if (compression != 0) {
		al = SSL_AD_ILLEGAL_PARAMETER;
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,
		SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
		@@ -1235,22 +1231,23 @@ int ssl3_get_server_hello(SSL *s)
		goto f_err;
		}
		#else
		if (s->hit && j != s->session->compress_meth) {
		if (s->hit && compression != s->session->compress_meth) {
		al = SSL_AD_ILLEGAL_PARAMETER;
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,
		SSL_R_OLD_SESSION_COMPRESSION_ALGORITHM_NOT_RETURNED);
		goto f_err;
		}
		if (j == 0)
		if (compression == 0)
		comp = NULL;
		else if (!ssl_allow_compression(s)) {
		al = SSL_AD_ILLEGAL_PARAMETER;
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO, SSL_R_COMPRESSION_DISABLED);
		goto f_err;
		} else
		comp = ssl3_comp_find(s->ctx->comp_methods, j);
		} else {
		comp = ssl3_comp_find(s->ctx->comp_methods, compression);
		}

		if ((j != 0) && (comp == NULL)) {
		if (compression != 0 && comp == NULL) {
		al = SSL_AD_ILLEGAL_PARAMETER;
		SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,
		SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);