| /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
| * All rights reserved. |
| * |
| * This package is an SSL implementation written |
| * by Eric Young (eay@cryptsoft.com). |
| * The implementation was written so as to conform with Netscapes SSL. |
| * |
| * This library is free for commercial and non-commercial use as long as |
| * the following conditions are aheared to. The following conditions |
| * apply to all code found in this distribution, be it the RC4, RSA, |
| * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
| * included with this distribution is covered by the same copyright terms |
| * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
| * |
| * Copyright remains Eric Young's, and as such any Copyright notices in |
| * the code are not to be removed. |
| * If this package is used in a product, Eric Young should be given attribution |
| * as the author of the parts of the library used. |
| * This can be in the form of a textual message at program startup or |
| * in documentation (online or textual) provided with the package. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. All advertising materials mentioning features or use of this software |
| * must display the following acknowledgement: |
| * "This product includes cryptographic software written by |
| * Eric Young (eay@cryptsoft.com)" |
| * The word 'cryptographic' can be left out if the rouines from the library |
| * being used are not cryptographic related :-). |
| * 4. If you include any Windows specific code (or a derivative thereof) from |
| * the apps directory (application code) you must include an acknowledgement: |
| * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
| * |
| * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * |
| * The licence and distribution terms for any publically available version or |
| * derivative of this code cannot be changed. i.e. this code cannot simply be |
| * copied and put under another distribution licence |
| * [including the GNU Public Licence.] |
| */ |
| /* ==================================================================== |
| * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. All advertising materials mentioning features or use of this |
| * software must display the following acknowledgment: |
| * "This product includes software developed by the OpenSSL Project |
| * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" |
| * |
| * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
| * endorse or promote products derived from this software without |
| * prior written permission. For written permission, please contact |
| * openssl-core@openssl.org. |
| * |
| * 5. Products derived from this software may not be called "OpenSSL" |
| * nor may "OpenSSL" appear in their names without prior written |
| * permission of the OpenSSL Project. |
| * |
| * 6. Redistributions of any form whatsoever must retain the following |
| * acknowledgment: |
| * "This product includes software developed by the OpenSSL Project |
| * for use in the OpenSSL Toolkit (http://www.openssl.org/)" |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
| * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| * OF THE POSSIBILITY OF SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This product includes cryptographic software written by Eric Young |
| * (eay@cryptsoft.com). This product includes software written by Tim |
| * Hudson (tjh@cryptsoft.com). */ |
| /* ==================================================================== |
| * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. |
| * ECC cipher suite support in OpenSSL originally developed by |
| * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project. */ |
| |
| #include <openssl/ssl.h> |
| |
| #include <assert.h> |
| #include <limits.h> |
| #include <string.h> |
| |
| #include <tuple> |
| |
| #include <openssl/buf.h> |
| #include <openssl/bytestring.h> |
| #include <openssl/err.h> |
| #include <openssl/evp.h> |
| #include <openssl/mem.h> |
| #include <openssl/md5.h> |
| #include <openssl/nid.h> |
| #include <openssl/rand.h> |
| #include <openssl/sha.h> |
| |
| #include "../crypto/internal.h" |
| #include "internal.h" |
| |
| |
| BSSL_NAMESPACE_BEGIN |
| |
| static bool add_record_to_flight(SSL *ssl, uint8_t type, |
| Span<const uint8_t> in) { |
| // The caller should have flushed |pending_hs_data| first. |
| assert(!ssl->s3->pending_hs_data); |
| // We'll never add a flight while in the process of writing it out. |
| assert(ssl->s3->pending_flight_offset == 0); |
| |
| if (ssl->s3->pending_flight == nullptr) { |
| ssl->s3->pending_flight.reset(BUF_MEM_new()); |
| if (ssl->s3->pending_flight == nullptr) { |
| return false; |
| } |
| } |
| |
| size_t max_out = in.size() + SSL_max_seal_overhead(ssl); |
| size_t new_cap = ssl->s3->pending_flight->length + max_out; |
| if (max_out < in.size() || new_cap < max_out) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW); |
| return false; |
| } |
| |
| size_t len; |
| if (!BUF_MEM_reserve(ssl->s3->pending_flight.get(), new_cap) || |
| !tls_seal_record(ssl, |
| (uint8_t *)ssl->s3->pending_flight->data + |
| ssl->s3->pending_flight->length, |
| &len, max_out, type, in.data(), in.size())) { |
| return false; |
| } |
| |
| ssl->s3->pending_flight->length += len; |
| return true; |
| } |
| |
| bool tls_init_message(const SSL *ssl, CBB *cbb, CBB *body, uint8_t type) { |
| // Pick a modest size hint to save most of the |realloc| calls. |
| if (!CBB_init(cbb, 64) || |
| !CBB_add_u8(cbb, type) || |
| !CBB_add_u24_length_prefixed(cbb, body)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| CBB_cleanup(cbb); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool tls_finish_message(const SSL *ssl, CBB *cbb, Array<uint8_t> *out_msg) { |
| return CBBFinishArray(cbb, out_msg); |
| } |
| |
| bool tls_add_message(SSL *ssl, Array<uint8_t> msg) { |
| // Pack handshake data into the minimal number of records. This avoids |
| // unnecessary encryption overhead, notably in TLS 1.3 where we send several |
| // encrypted messages in a row. For now, we do not do this for the null |
| // cipher. The benefit is smaller and there is a risk of breaking buggy |
| // implementations. |
| // |
| // TODO(davidben): See if we can do this uniformly. |
| Span<const uint8_t> rest = msg; |
| if (ssl->quic_method == nullptr && |
| ssl->s3->aead_write_ctx->is_null_cipher()) { |
| while (!rest.empty()) { |
| Span<const uint8_t> chunk = rest.subspan(0, ssl->max_send_fragment); |
| rest = rest.subspan(chunk.size()); |
| |
| if (!add_record_to_flight(ssl, SSL3_RT_HANDSHAKE, chunk)) { |
| return false; |
| } |
| } |
| } else { |
| while (!rest.empty()) { |
| // Flush if |pending_hs_data| is full. |
| if (ssl->s3->pending_hs_data && |
| ssl->s3->pending_hs_data->length >= ssl->max_send_fragment && |
| !tls_flush_pending_hs_data(ssl)) { |
| return false; |
| } |
| |
| size_t pending_len = |
| ssl->s3->pending_hs_data ? ssl->s3->pending_hs_data->length : 0; |
| Span<const uint8_t> chunk = |
| rest.subspan(0, ssl->max_send_fragment - pending_len); |
| assert(!chunk.empty()); |
| rest = rest.subspan(chunk.size()); |
| |
| if (!ssl->s3->pending_hs_data) { |
| ssl->s3->pending_hs_data.reset(BUF_MEM_new()); |
| } |
| if (!ssl->s3->pending_hs_data || |
| !BUF_MEM_append(ssl->s3->pending_hs_data.get(), chunk.data(), |
| chunk.size())) { |
| return false; |
| } |
| } |
| } |
| |
| ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_HANDSHAKE, msg); |
| // TODO(svaldez): Move this up a layer to fix abstraction for SSLTranscript on |
| // hs. |
| if (ssl->s3->hs != NULL && |
| !ssl->s3->hs->transcript.Update(msg)) { |
| return false; |
| } |
| return true; |
| } |
| |
| bool tls_flush_pending_hs_data(SSL *ssl) { |
| if (!ssl->s3->pending_hs_data || ssl->s3->pending_hs_data->length == 0) { |
| return true; |
| } |
| |
| UniquePtr<BUF_MEM> pending_hs_data = std::move(ssl->s3->pending_hs_data); |
| auto data = |
| MakeConstSpan(reinterpret_cast<const uint8_t *>(pending_hs_data->data), |
| pending_hs_data->length); |
| if (ssl->quic_method) { |
| if ((ssl->s3->hs == nullptr || !ssl->s3->hs->hints_requested) && |
| !ssl->quic_method->add_handshake_data(ssl, ssl->s3->write_level, |
| data.data(), data.size())) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_QUIC_INTERNAL_ERROR); |
| return false; |
| } |
| return true; |
| } |
| |
| return add_record_to_flight(ssl, SSL3_RT_HANDSHAKE, data); |
| } |
| |
| bool tls_add_change_cipher_spec(SSL *ssl) { |
| static const uint8_t kChangeCipherSpec[1] = {SSL3_MT_CCS}; |
| |
| if (!tls_flush_pending_hs_data(ssl)) { |
| return false; |
| } |
| |
| if (!ssl->quic_method && |
| !add_record_to_flight(ssl, SSL3_RT_CHANGE_CIPHER_SPEC, |
| kChangeCipherSpec)) { |
| return false; |
| } |
| |
| ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_CHANGE_CIPHER_SPEC, |
| kChangeCipherSpec); |
| return true; |
| } |
| |
| int tls_flush_flight(SSL *ssl) { |
| if (!tls_flush_pending_hs_data(ssl)) { |
| return -1; |
| } |
| |
| if (ssl->quic_method) { |
| if (ssl->s3->write_shutdown != ssl_shutdown_none) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_PROTOCOL_IS_SHUTDOWN); |
| return -1; |
| } |
| |
| if (!ssl->quic_method->flush_flight(ssl)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_QUIC_INTERNAL_ERROR); |
| return -1; |
| } |
| } |
| |
| if (ssl->s3->pending_flight == nullptr) { |
| return 1; |
| } |
| |
| if (ssl->s3->write_shutdown != ssl_shutdown_none) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_PROTOCOL_IS_SHUTDOWN); |
| return -1; |
| } |
| |
| static_assert(INT_MAX <= 0xffffffff, "int is larger than 32 bits"); |
| if (ssl->s3->pending_flight->length > INT_MAX) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return -1; |
| } |
| |
| // If there is pending data in the write buffer, it must be flushed out before |
| // any new data in pending_flight. |
| if (!ssl->s3->write_buffer.empty()) { |
| int ret = ssl_write_buffer_flush(ssl); |
| if (ret <= 0) { |
| ssl->s3->rwstate = SSL_ERROR_WANT_WRITE; |
| return ret; |
| } |
| } |
| |
| if (ssl->wbio == nullptr) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_BIO_NOT_SET); |
| return -1; |
| } |
| |
| // Write the pending flight. |
| while (ssl->s3->pending_flight_offset < ssl->s3->pending_flight->length) { |
| int ret = BIO_write( |
| ssl->wbio.get(), |
| ssl->s3->pending_flight->data + ssl->s3->pending_flight_offset, |
| ssl->s3->pending_flight->length - ssl->s3->pending_flight_offset); |
| if (ret <= 0) { |
| ssl->s3->rwstate = SSL_ERROR_WANT_WRITE; |
| return ret; |
| } |
| |
| ssl->s3->pending_flight_offset += ret; |
| } |
| |
| if (BIO_flush(ssl->wbio.get()) <= 0) { |
| ssl->s3->rwstate = SSL_ERROR_WANT_WRITE; |
| return -1; |
| } |
| |
| ssl->s3->pending_flight.reset(); |
| ssl->s3->pending_flight_offset = 0; |
| return 1; |
| } |
| |
| static ssl_open_record_t read_v2_client_hello(SSL *ssl, size_t *out_consumed, |
| Span<const uint8_t> in) { |
| *out_consumed = 0; |
| assert(in.size() >= SSL3_RT_HEADER_LENGTH); |
| // Determine the length of the V2ClientHello. |
| size_t msg_length = ((in[0] & 0x7f) << 8) | in[1]; |
| if (msg_length > (1024 * 4)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE); |
| return ssl_open_record_error; |
| } |
| if (msg_length < SSL3_RT_HEADER_LENGTH - 2) { |
| // Reject lengths that are too short early. We have already read |
| // |SSL3_RT_HEADER_LENGTH| bytes, so we should not attempt to process an |
| // (invalid) V2ClientHello which would be shorter than that. |
| OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_LENGTH_MISMATCH); |
| return ssl_open_record_error; |
| } |
| |
| // Ask for the remainder of the V2ClientHello. |
| if (in.size() < 2 + msg_length) { |
| *out_consumed = 2 + msg_length; |
| return ssl_open_record_partial; |
| } |
| |
| CBS v2_client_hello = CBS(ssl->s3->read_buffer.span().subspan(2, msg_length)); |
| // The V2ClientHello without the length is incorporated into the handshake |
| // hash. This is only ever called at the start of the handshake, so hs is |
| // guaranteed to be non-NULL. |
| if (!ssl->s3->hs->transcript.Update(v2_client_hello)) { |
| return ssl_open_record_error; |
| } |
| |
| ssl_do_msg_callback(ssl, 0 /* read */, 0 /* V2ClientHello */, |
| v2_client_hello); |
| |
| uint8_t msg_type; |
| uint16_t version, cipher_spec_length, session_id_length, challenge_length; |
| CBS cipher_specs, session_id, challenge; |
| if (!CBS_get_u8(&v2_client_hello, &msg_type) || |
| !CBS_get_u16(&v2_client_hello, &version) || |
| !CBS_get_u16(&v2_client_hello, &cipher_spec_length) || |
| !CBS_get_u16(&v2_client_hello, &session_id_length) || |
| !CBS_get_u16(&v2_client_hello, &challenge_length) || |
| !CBS_get_bytes(&v2_client_hello, &cipher_specs, cipher_spec_length) || |
| !CBS_get_bytes(&v2_client_hello, &session_id, session_id_length) || |
| !CBS_get_bytes(&v2_client_hello, &challenge, challenge_length) || |
| CBS_len(&v2_client_hello) != 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| return ssl_open_record_error; |
| } |
| |
| // msg_type has already been checked. |
| assert(msg_type == SSL2_MT_CLIENT_HELLO); |
| |
| // The client_random is the V2ClientHello challenge. Truncate or left-pad with |
| // zeros as needed. |
| size_t rand_len = CBS_len(&challenge); |
| if (rand_len > SSL3_RANDOM_SIZE) { |
| rand_len = SSL3_RANDOM_SIZE; |
| } |
| uint8_t random[SSL3_RANDOM_SIZE]; |
| OPENSSL_memset(random, 0, SSL3_RANDOM_SIZE); |
| OPENSSL_memcpy(random + (SSL3_RANDOM_SIZE - rand_len), CBS_data(&challenge), |
| rand_len); |
| |
| // Write out an equivalent TLS ClientHello directly to the handshake buffer. |
| size_t max_v3_client_hello = SSL3_HM_HEADER_LENGTH + 2 /* version */ + |
| SSL3_RANDOM_SIZE + 1 /* session ID length */ + |
| 2 /* cipher list length */ + |
| CBS_len(&cipher_specs) / 3 * 2 + |
| 1 /* compression length */ + 1 /* compression */; |
| ScopedCBB client_hello; |
| CBB hello_body, cipher_suites; |
| if (!ssl->s3->hs_buf) { |
| ssl->s3->hs_buf.reset(BUF_MEM_new()); |
| } |
| if (!ssl->s3->hs_buf || |
| !BUF_MEM_reserve(ssl->s3->hs_buf.get(), max_v3_client_hello) || |
| !CBB_init_fixed(client_hello.get(), (uint8_t *)ssl->s3->hs_buf->data, |
| ssl->s3->hs_buf->max) || |
| !CBB_add_u8(client_hello.get(), SSL3_MT_CLIENT_HELLO) || |
| !CBB_add_u24_length_prefixed(client_hello.get(), &hello_body) || |
| !CBB_add_u16(&hello_body, version) || |
| !CBB_add_bytes(&hello_body, random, SSL3_RANDOM_SIZE) || |
| // No session id. |
| !CBB_add_u8(&hello_body, 0) || |
| !CBB_add_u16_length_prefixed(&hello_body, &cipher_suites)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); |
| return ssl_open_record_error; |
| } |
| |
| // Copy the cipher suites. |
| while (CBS_len(&cipher_specs) > 0) { |
| uint32_t cipher_spec; |
| if (!CBS_get_u24(&cipher_specs, &cipher_spec)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| return ssl_open_record_error; |
| } |
| |
| // Skip SSLv2 ciphers. |
| if ((cipher_spec & 0xff0000) != 0) { |
| continue; |
| } |
| if (!CBB_add_u16(&cipher_suites, cipher_spec)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return ssl_open_record_error; |
| } |
| } |
| |
| // Add the null compression scheme and finish. |
| if (!CBB_add_u8(&hello_body, 1) || |
| !CBB_add_u8(&hello_body, 0) || |
| !CBB_finish(client_hello.get(), NULL, &ssl->s3->hs_buf->length)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return ssl_open_record_error; |
| } |
| |
| *out_consumed = 2 + msg_length; |
| ssl->s3->is_v2_hello = true; |
| return ssl_open_record_success; |
| } |
| |
| static bool parse_message(const SSL *ssl, SSLMessage *out, |
| size_t *out_bytes_needed) { |
| if (!ssl->s3->hs_buf) { |
| *out_bytes_needed = 4; |
| return false; |
| } |
| |
| CBS cbs; |
| uint32_t len; |
| CBS_init(&cbs, reinterpret_cast<const uint8_t *>(ssl->s3->hs_buf->data), |
| ssl->s3->hs_buf->length); |
| if (!CBS_get_u8(&cbs, &out->type) || |
| !CBS_get_u24(&cbs, &len)) { |
| *out_bytes_needed = 4; |
| return false; |
| } |
| |
| if (!CBS_get_bytes(&cbs, &out->body, len)) { |
| *out_bytes_needed = 4 + len; |
| return false; |
| } |
| |
| CBS_init(&out->raw, reinterpret_cast<const uint8_t *>(ssl->s3->hs_buf->data), |
| 4 + len); |
| out->is_v2_hello = ssl->s3->is_v2_hello; |
| return true; |
| } |
| |
| bool tls_get_message(const SSL *ssl, SSLMessage *out) { |
| size_t unused; |
| if (!parse_message(ssl, out, &unused)) { |
| return false; |
| } |
| if (!ssl->s3->has_message) { |
| if (!out->is_v2_hello) { |
| ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_HANDSHAKE, out->raw); |
| } |
| ssl->s3->has_message = true; |
| } |
| return true; |
| } |
| |
| bool tls_can_accept_handshake_data(const SSL *ssl, uint8_t *out_alert) { |
| // If there is a complete message, the caller must have consumed it first. |
| SSLMessage msg; |
| size_t bytes_needed; |
| if (parse_message(ssl, &msg, &bytes_needed)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| *out_alert = SSL_AD_INTERNAL_ERROR; |
| return false; |
| } |
| |
| // Enforce the limit so the peer cannot force us to buffer 16MB. |
| if (bytes_needed > 4 + ssl_max_handshake_message_len(ssl)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESSIVE_MESSAGE_SIZE); |
| *out_alert = SSL_AD_ILLEGAL_PARAMETER; |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool tls_has_unprocessed_handshake_data(const SSL *ssl) { |
| size_t msg_len = 0; |
| if (ssl->s3->has_message) { |
| SSLMessage msg; |
| size_t unused; |
| if (parse_message(ssl, &msg, &unused)) { |
| msg_len = CBS_len(&msg.raw); |
| } |
| } |
| |
| return ssl->s3->hs_buf && ssl->s3->hs_buf->length > msg_len; |
| } |
| |
| bool tls_append_handshake_data(SSL *ssl, Span<const uint8_t> data) { |
| // Re-create the handshake buffer if needed. |
| if (!ssl->s3->hs_buf) { |
| ssl->s3->hs_buf.reset(BUF_MEM_new()); |
| } |
| return ssl->s3->hs_buf && |
| BUF_MEM_append(ssl->s3->hs_buf.get(), data.data(), data.size()); |
| } |
| |
| ssl_open_record_t tls_open_handshake(SSL *ssl, size_t *out_consumed, |
| uint8_t *out_alert, Span<uint8_t> in) { |
| *out_consumed = 0; |
| // Bypass the record layer for the first message to handle V2ClientHello. |
| if (ssl->server && !ssl->s3->v2_hello_done) { |
| // Ask for the first 5 bytes, the size of the TLS record header. This is |
| // sufficient to detect a V2ClientHello and ensures that we never read |
| // beyond the first record. |
| if (in.size() < SSL3_RT_HEADER_LENGTH) { |
| *out_consumed = SSL3_RT_HEADER_LENGTH; |
| return ssl_open_record_partial; |
| } |
| |
| // Some dedicated error codes for protocol mixups should the application |
| // wish to interpret them differently. (These do not overlap with |
| // ClientHello or V2ClientHello.) |
| const char *str = reinterpret_cast<const char*>(in.data()); |
| if (strncmp("GET ", str, 4) == 0 || |
| strncmp("POST ", str, 5) == 0 || |
| strncmp("HEAD ", str, 5) == 0 || |
| strncmp("PUT ", str, 4) == 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_HTTP_REQUEST); |
| *out_alert = 0; |
| return ssl_open_record_error; |
| } |
| if (strncmp("CONNE", str, 5) == 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_HTTPS_PROXY_REQUEST); |
| *out_alert = 0; |
| return ssl_open_record_error; |
| } |
| |
| // Check for a V2ClientHello. |
| if ((in[0] & 0x80) != 0 && in[2] == SSL2_MT_CLIENT_HELLO && |
| in[3] == SSL3_VERSION_MAJOR) { |
| auto ret = read_v2_client_hello(ssl, out_consumed, in); |
| if (ret == ssl_open_record_error) { |
| *out_alert = 0; |
| } else if (ret == ssl_open_record_success) { |
| ssl->s3->v2_hello_done = true; |
| } |
| return ret; |
| } |
| |
| ssl->s3->v2_hello_done = true; |
| } |
| |
| uint8_t type; |
| Span<uint8_t> body; |
| auto ret = tls_open_record(ssl, &type, &body, out_consumed, out_alert, in); |
| if (ret != ssl_open_record_success) { |
| return ret; |
| } |
| |
| // WatchGuard's TLS 1.3 interference bug is very distinctive: they drop the |
| // ServerHello and send the remaining encrypted application data records |
| // as-is. This manifests as an application data record when we expect |
| // handshake. Report a dedicated error code for this case. |
| if (!ssl->server && type == SSL3_RT_APPLICATION_DATA && |
| ssl->s3->aead_read_ctx->is_null_cipher()) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_APPLICATION_DATA_INSTEAD_OF_HANDSHAKE); |
| *out_alert = SSL_AD_UNEXPECTED_MESSAGE; |
| return ssl_open_record_error; |
| } |
| |
| if (type != SSL3_RT_HANDSHAKE) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD); |
| *out_alert = SSL_AD_UNEXPECTED_MESSAGE; |
| return ssl_open_record_error; |
| } |
| |
| // Append the entire handshake record to the buffer. |
| if (!tls_append_handshake_data(ssl, body)) { |
| *out_alert = SSL_AD_INTERNAL_ERROR; |
| return ssl_open_record_error; |
| } |
| |
| return ssl_open_record_success; |
| } |
| |
| void tls_next_message(SSL *ssl) { |
| SSLMessage msg; |
| if (!tls_get_message(ssl, &msg) || |
| !ssl->s3->hs_buf || |
| ssl->s3->hs_buf->length < CBS_len(&msg.raw)) { |
| assert(0); |
| return; |
| } |
| |
| OPENSSL_memmove(ssl->s3->hs_buf->data, |
| ssl->s3->hs_buf->data + CBS_len(&msg.raw), |
| ssl->s3->hs_buf->length - CBS_len(&msg.raw)); |
| ssl->s3->hs_buf->length -= CBS_len(&msg.raw); |
| ssl->s3->is_v2_hello = false; |
| ssl->s3->has_message = false; |
| |
| // Post-handshake messages are rare, so release the buffer after every |
| // message. During the handshake, |on_handshake_complete| will release it. |
| if (!SSL_in_init(ssl) && ssl->s3->hs_buf->length == 0) { |
| ssl->s3->hs_buf.reset(); |
| } |
| } |
| |
| // CipherScorer produces a "score" for each possible cipher suite offered by |
| // the client. |
| class CipherScorer { |
| public: |
| CipherScorer() : aes_is_fine_(EVP_has_aes_hardware()) {} |
| |
| typedef std::tuple<bool, bool> Score; |
| |
| // MinScore returns a |Score| that will compare less than the score of all |
| // cipher suites. |
| Score MinScore() const { |
| return Score(false, false); |
| } |
| |
| Score Evaluate(const SSL_CIPHER *a) const { |
| return Score( |
| // Something is always preferable to nothing. |
| true, |
| // Either AES is fine, or else ChaCha20 is preferred. |
| aes_is_fine_ || a->algorithm_enc == SSL_CHACHA20POLY1305); |
| } |
| |
| private: |
| const bool aes_is_fine_; |
| }; |
| |
| bool ssl_tls13_cipher_meets_policy(uint16_t cipher_id, bool only_fips) { |
| if (!only_fips) { |
| return true; |
| } |
| |
| switch (cipher_id) { |
| case TLS1_3_CK_AES_128_GCM_SHA256 & 0xffff: |
| case TLS1_3_CK_AES_256_GCM_SHA384 & 0xffff: |
| return true; |
| case TLS1_3_CK_CHACHA20_POLY1305_SHA256 & 0xffff: |
| return false; |
| default: |
| assert(false); |
| return false; |
| } |
| } |
| |
| const SSL_CIPHER *ssl_choose_tls13_cipher(CBS cipher_suites, uint16_t version, |
| uint16_t group_id, bool only_fips) { |
| if (CBS_len(&cipher_suites) % 2 != 0) { |
| return nullptr; |
| } |
| |
| const SSL_CIPHER *best = nullptr; |
| CipherScorer scorer; |
| CipherScorer::Score best_score = scorer.MinScore(); |
| |
| while (CBS_len(&cipher_suites) > 0) { |
| uint16_t cipher_suite; |
| if (!CBS_get_u16(&cipher_suites, &cipher_suite)) { |
| return nullptr; |
| } |
| |
| // Limit to TLS 1.3 ciphers we know about. |
| const SSL_CIPHER *candidate = SSL_get_cipher_by_value(cipher_suite); |
| if (candidate == nullptr || |
| SSL_CIPHER_get_min_version(candidate) > version || |
| SSL_CIPHER_get_max_version(candidate) < version) { |
| continue; |
| } |
| |
| if (!ssl_tls13_cipher_meets_policy(SSL_CIPHER_get_protocol_id(candidate), |
| only_fips)) { |
| continue; |
| } |
| |
| const CipherScorer::Score candidate_score = scorer.Evaluate(candidate); |
| // |candidate_score| must be larger to displace the current choice. That way |
| // the client's order controls between ciphers with an equal score. |
| if (candidate_score > best_score) { |
| best = candidate; |
| best_score = candidate_score; |
| } |
| } |
| |
| return best; |
| } |
| |
| BSSL_NAMESPACE_END |