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