387 lines
11 KiB
Plaintext
387 lines
11 KiB
Plaintext
![]() |
/*
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* Copyright (c) 2007, Cameron Rich
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*
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* * Neither the name of the axTLS project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <stdio.h>
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#include "ssl.h"
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#ifdef CONFIG_SSL_ENABLE_CLIENT /* all commented out if no client */
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static int send_client_hello(SSL *ssl);
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static int process_server_hello(SSL *ssl);
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static int process_server_hello_done(SSL *ssl);
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static int send_client_key_xchg(SSL *ssl);
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static int process_cert_req(SSL *ssl);
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static int send_cert_verify(SSL *ssl);
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/*
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* Establish a new SSL connection to an SSL server.
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*/
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EXP_FUNC SSL * STDCALL ssl_client_new(SSL_CTX *ssl_ctx, int client_fd, const
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uint8_t *session_id, uint8_t sess_id_size)
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{
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SSL *ssl;
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int ret;
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SOCKET_BLOCK(client_fd); /* ensure blocking mode */
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ssl = ssl_new(ssl_ctx, client_fd);
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if (session_id && ssl_ctx->num_sessions)
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{
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if (sess_id_size > SSL_SESSION_ID_SIZE) /* validity check */
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{
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ssl_free(ssl);
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return NULL;
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}
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memcpy(ssl->session_id, session_id, sess_id_size);
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ssl->sess_id_size = sess_id_size;
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SET_SSL_FLAG(SSL_SESSION_RESUME); /* just flag for later */
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}
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SET_SSL_FLAG(SSL_IS_CLIENT);
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ret = do_client_connect(ssl);
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return ssl;
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}
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/*
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* Process the handshake record.
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*/
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int do_clnt_handshake(SSL *ssl, int handshake_type, uint8_t *buf, int hs_len)
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{
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int ret = SSL_OK;
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/* To get here the state must be valid */
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switch (handshake_type)
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{
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case HS_SERVER_HELLO:
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ret = process_server_hello(ssl);
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break;
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case HS_CERTIFICATE:
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ret = process_certificate(ssl, &ssl->x509_ctx);
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break;
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case HS_SERVER_HELLO_DONE:
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if ((ret = process_server_hello_done(ssl)) == SSL_OK)
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{
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if (IS_SET_SSL_FLAG(SSL_HAS_CERT_REQ))
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{
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if ((ret = send_certificate(ssl)) == SSL_OK &&
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(ret = send_client_key_xchg(ssl)) == SSL_OK)
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{
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send_cert_verify(ssl);
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}
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}
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else
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{
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ret = send_client_key_xchg(ssl);
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}
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if (ret == SSL_OK &&
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(ret = send_change_cipher_spec(ssl)) == SSL_OK)
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{
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ret = send_finished(ssl);
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}
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}
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break;
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case HS_CERT_REQ:
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ret = process_cert_req(ssl);
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break;
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case HS_FINISHED:
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ret = process_finished(ssl, hs_len);
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disposable_free(ssl); /* free up some memory */
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break;
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case HS_HELLO_REQUEST:
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disposable_new(ssl);
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ret = do_client_connect(ssl);
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break;
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}
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return ret;
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}
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/*
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* Do the handshaking from the beginning.
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*/
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int do_client_connect(SSL *ssl)
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{
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int ret = SSL_OK;
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send_client_hello(ssl); /* send the client hello */
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ssl->bm_read_index = 0;
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ssl->next_state = HS_SERVER_HELLO;
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ssl->hs_status = SSL_NOT_OK; /* not connected */
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x509_free(ssl->x509_ctx);
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/* sit in a loop until it all looks good */
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while (ssl->hs_status != SSL_OK)
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{
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ret = basic_read(ssl, NULL);
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if (ret < SSL_OK)
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{
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if (ret != SSL_ERROR_CONN_LOST)
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{
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/* let the server know we are dying and why */
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if (send_alert(ssl, ret))
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{
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/* something nasty happened, so get rid of it */
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kill_ssl_session(ssl->ssl_ctx->ssl_sessions, ssl);
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}
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}
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break;
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}
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}
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ssl->hs_status = ret; /* connected? */
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return ret;
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}
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/*
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* Send the initial client hello.
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*/
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static int send_client_hello(SSL *ssl)
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{
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uint8_t *buf = ssl->bm_data;
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time_t tm = time(NULL);
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uint8_t *tm_ptr = &buf[6]; /* time will go here */
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int i, offset;
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buf[0] = HS_CLIENT_HELLO;
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buf[1] = 0;
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buf[2] = 0;
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/* byte 3 is calculated later */
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buf[4] = 0x03;
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buf[5] = 0x01;
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/* client random value - spec says that 1st 4 bytes are big endian time */
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*tm_ptr++ = (uint8_t)(((long)tm & 0xff000000) >> 24);
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*tm_ptr++ = (uint8_t)(((long)tm & 0x00ff0000) >> 16);
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*tm_ptr++ = (uint8_t)(((long)tm & 0x0000ff00) >> 8);
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*tm_ptr++ = (uint8_t)(((long)tm & 0x000000ff));
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get_random(SSL_RANDOM_SIZE-4, &buf[10]);
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memcpy(ssl->dc->client_random, &buf[6], SSL_RANDOM_SIZE);
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offset = 6 + SSL_RANDOM_SIZE;
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/* give session resumption a go */
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if (IS_SET_SSL_FLAG(SSL_SESSION_RESUME)) /* set initially by user */
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{
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buf[offset++] = ssl->sess_id_size;
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memcpy(&buf[offset], ssl->session_id, ssl->sess_id_size);
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offset += ssl->sess_id_size;
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CLR_SSL_FLAG(SSL_SESSION_RESUME); /* clear so we can set later */
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}
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else
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{
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/* no session id - because no session resumption just yet */
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buf[offset++] = 0;
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}
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buf[offset++] = 0; /* number of ciphers */
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buf[offset++] = NUM_PROTOCOLS*2;/* number of ciphers */
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/* put all our supported protocols in our request */
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for (i = 0; i < NUM_PROTOCOLS; i++)
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{
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buf[offset++] = 0; /* cipher we are using */
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buf[offset++] = ssl_prot_prefs[i];
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}
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buf[offset++] = 1; /* no compression */
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buf[offset++] = 0;
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buf[3] = offset - 4; /* handshake size */
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return send_packet(ssl, PT_HANDSHAKE_PROTOCOL, NULL, offset);
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}
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/*
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* Process the server hello.
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*/
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static int process_server_hello(SSL *ssl)
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{
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uint8_t *buf = ssl->bm_data;
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int pkt_size = ssl->bm_index;
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int version = (buf[4] << 4) + buf[5];
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int num_sessions = ssl->ssl_ctx->num_sessions;
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uint8_t sess_id_size;
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int offset, ret = SSL_OK;
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/* check that we are talking to a TLSv1 server */
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if (version != 0x31)
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return SSL_ERROR_INVALID_VERSION;
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/* get the server random value */
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memcpy(ssl->dc->server_random, &buf[6], SSL_RANDOM_SIZE);
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offset = 6 + SSL_RANDOM_SIZE; /* skip of session id size */
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sess_id_size = buf[offset++];
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if (num_sessions)
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{
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ssl->session = ssl_session_update(num_sessions,
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ssl->ssl_ctx->ssl_sessions, ssl, &buf[offset]);
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memcpy(ssl->session->session_id, &buf[offset], sess_id_size);
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/* pad the rest with 0's */
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if (sess_id_size < SSL_SESSION_ID_SIZE)
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{
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memset(&ssl->session->session_id[sess_id_size], 0,
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SSL_SESSION_ID_SIZE-sess_id_size);
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}
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}
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memcpy(ssl->session_id, &buf[offset], sess_id_size);
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ssl->sess_id_size = sess_id_size;
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offset += sess_id_size;
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/* get the real cipher we are using */
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ssl->cipher = buf[++offset];
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ssl->next_state = IS_SET_SSL_FLAG(SSL_SESSION_RESUME) ?
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HS_FINISHED : HS_CERTIFICATE;
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offset++; // skip the compr
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PARANOIA_CHECK(pkt_size, offset);
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ssl->dc->bm_proc_index = offset+1;
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error:
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return ret;
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}
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/**
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* Process the server hello done message.
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*/
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static int process_server_hello_done(SSL *ssl)
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{
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ssl->next_state = HS_FINISHED;
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return SSL_OK;
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}
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/*
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* Send a client key exchange message.
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*/
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static int send_client_key_xchg(SSL *ssl)
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{
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uint8_t *buf = ssl->bm_data;
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uint8_t premaster_secret[SSL_SECRET_SIZE];
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int enc_secret_size = -1;
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buf[0] = HS_CLIENT_KEY_XCHG;
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buf[1] = 0;
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premaster_secret[0] = 0x03; /* encode the version number */
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premaster_secret[1] = 0x01;
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get_random(SSL_SECRET_SIZE-2, &premaster_secret[2]);
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DISPLAY_RSA(ssl, ssl->x509_ctx->rsa_ctx);
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/* rsa_ctx->bi_ctx is not thread-safe */
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SSL_CTX_LOCK(ssl->ssl_ctx->mutex);
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enc_secret_size = RSA_encrypt(ssl->x509_ctx->rsa_ctx, premaster_secret,
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SSL_SECRET_SIZE, &buf[6], 0);
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SSL_CTX_UNLOCK(ssl->ssl_ctx->mutex);
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buf[2] = (enc_secret_size + 2) >> 8;
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buf[3] = (enc_secret_size + 2) & 0xff;
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buf[4] = enc_secret_size >> 8;
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buf[5] = enc_secret_size & 0xff;
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generate_master_secret(ssl, premaster_secret);
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return send_packet(ssl, PT_HANDSHAKE_PROTOCOL, NULL, enc_secret_size+6);
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}
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/*
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* Process the certificate request.
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*/
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static int process_cert_req(SSL *ssl)
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{
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uint8_t *buf = &ssl->bm_data[ssl->dc->bm_proc_index];
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int ret = SSL_OK;
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int offset = (buf[2] << 4) + buf[3];
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int pkt_size = ssl->bm_index;
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/* don't do any processing - we will send back an RSA certificate anyway */
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ssl->next_state = HS_SERVER_HELLO_DONE;
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SET_SSL_FLAG(SSL_HAS_CERT_REQ);
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ssl->dc->bm_proc_index += offset;
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PARANOIA_CHECK(pkt_size, offset);
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error:
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return ret;
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}
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/*
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* Send a certificate verify message.
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*/
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static int send_cert_verify(SSL *ssl)
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{
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uint8_t *buf = ssl->bm_data;
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uint8_t dgst[MD5_SIZE+SHA1_SIZE];
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RSA_CTX *rsa_ctx = ssl->ssl_ctx->rsa_ctx;
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int n = 0, ret;
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DISPLAY_RSA(ssl, rsa_ctx);
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buf[0] = HS_CERT_VERIFY;
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buf[1] = 0;
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finished_digest(ssl, NULL, dgst); /* calculate the digest */
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/* rsa_ctx->bi_ctx is not thread-safe */
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if (rsa_ctx)
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{
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SSL_CTX_LOCK(ssl->ssl_ctx->mutex);
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n = RSA_encrypt(rsa_ctx, dgst, sizeof(dgst), &buf[6], 1);
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SSL_CTX_UNLOCK(ssl->ssl_ctx->mutex);
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if (n == 0)
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{
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ret = SSL_ERROR_INVALID_KEY;
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goto error;
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}
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}
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buf[4] = n >> 8; /* add the RSA size (not officially documented) */
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buf[5] = n & 0xff;
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n += 2;
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buf[2] = n >> 8;
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buf[3] = n & 0xff;
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ret = send_packet(ssl, PT_HANDSHAKE_PROTOCOL, NULL, n+4);
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error:
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return ret;
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}
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#endif /* CONFIG_SSL_ENABLE_CLIENT */
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