diff options
Diffstat (limited to 'axTLS/src/ssl/tls1_svr.c')
-rw-r--r-- | axTLS/src/ssl/tls1_svr.c | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/axTLS/src/ssl/tls1_svr.c b/axTLS/src/ssl/tls1_svr.c new file mode 100644 index 0000000..f374928 --- /dev/null +++ b/axTLS/src/ssl/tls1_svr.c @@ -0,0 +1,478 @@ +/* + * 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 <stdio.h> +#include "os_port.h" +#include "ssl.h" + +static const uint8_t g_hello_done[] = { HS_SERVER_HELLO_DONE, 0, 0, 0 }; + +static int process_client_hello(SSL *ssl); +static int send_server_hello_sequence(SSL *ssl); +static int send_server_hello(SSL *ssl); +static int send_server_hello_done(SSL *ssl); +static int process_client_key_xchg(SSL *ssl); +#ifdef CONFIG_SSL_CERT_VERIFICATION +static int send_certificate_request(SSL *ssl); +static int process_cert_verify(SSL *ssl); +#endif + +/* + * Establish a new SSL connection to an SSL client. + */ +EXP_FUNC SSL * STDCALL ssl_server_new(SSL_CTX *ssl_ctx, int client_fd) +{ + SSL *ssl; + + ssl = ssl_new(ssl_ctx, client_fd); + ssl->next_state = HS_CLIENT_HELLO; + +#ifdef CONFIG_SSL_FULL_MODE + if (ssl_ctx->chain_length == 0) + printf("Warning - no server certificate defined\n"); TTY_FLUSH(); +#endif + + return ssl; +} + +/* + * Process the handshake record. + */ +int do_svr_handshake(SSL *ssl, int handshake_type, uint8_t *buf, int hs_len) +{ + int ret = SSL_OK; + ssl->hs_status = SSL_NOT_OK; /* not connected */ + + /* To get here the state must be valid */ + switch (handshake_type) + { + case HS_CLIENT_HELLO: + if ((ret = process_client_hello(ssl)) == SSL_OK) + ret = send_server_hello_sequence(ssl); + break; + +#ifdef CONFIG_SSL_CERT_VERIFICATION + case HS_CERTIFICATE:/* the client sends its cert */ + ret = process_certificate(ssl, &ssl->x509_ctx); + + if (ret == SSL_OK) /* verify the cert */ + { + int cert_res; + cert_res = x509_verify( + ssl->ssl_ctx->ca_cert_ctx, ssl->x509_ctx); + ret = (cert_res == 0) ? SSL_OK : SSL_X509_ERROR(cert_res); + } + break; + + case HS_CERT_VERIFY: + ret = process_cert_verify(ssl); + add_packet(ssl, buf, hs_len); /* needs to be done after */ + break; +#endif + case HS_CLIENT_KEY_XCHG: + ret = process_client_key_xchg(ssl); + break; + + case HS_FINISHED: + ret = process_finished(ssl, buf, hs_len); + disposable_free(ssl); /* free up some memory */ + break; + } + + return ret; +} + +/* + * Process a client hello message. + */ +static int process_client_hello(SSL *ssl) +{ + uint8_t *buf = ssl->bm_data; + uint8_t *record_buf = ssl->hmac_header; + int pkt_size = ssl->bm_index; + int i, j, cs_len, id_len, offset = 6 + SSL_RANDOM_SIZE; + int ret = SSL_OK; + + uint8_t version = (record_buf[1] << 4) + record_buf[2]; + ssl->version = ssl->client_version = version; + + if (version > SSL_PROTOCOL_VERSION_MAX) + { + /* use client's version instead */ + ssl->version = SSL_PROTOCOL_VERSION_MAX; + } + else if (version < SSL_PROTOCOL_MIN_VERSION) /* old version supported? */ + { + ret = SSL_ERROR_INVALID_VERSION; + ssl_display_error(ret); + goto error; + } + + memcpy(ssl->dc->client_random, &buf[6], SSL_RANDOM_SIZE); + + /* process the session id */ + id_len = buf[offset++]; + if (id_len > SSL_SESSION_ID_SIZE) + { + return SSL_ERROR_INVALID_SESSION; + } + +#ifndef CONFIG_SSL_SKELETON_MODE + ssl->session = ssl_session_update(ssl->ssl_ctx->num_sessions, + ssl->ssl_ctx->ssl_sessions, ssl, id_len ? &buf[offset] : NULL); +#endif + + offset += id_len; + cs_len = (buf[offset]<<8) + buf[offset+1]; + offset += 3; /* add 1 due to all cipher suites being 8 bit */ + + PARANOIA_CHECK(pkt_size, offset); + + /* work out what cipher suite we are going to use - client defines + the preference */ + for (i = 0; i < cs_len; i += 2) + { + for (j = 0; j < NUM_PROTOCOLS; j++) + { + if (ssl_prot_prefs[j] == buf[offset+i]) /* got a match? */ + { + ssl->cipher = ssl_prot_prefs[j]; + goto do_state; + } + } + } + + /* ouch! protocol is not supported */ + ret = SSL_ERROR_NO_CIPHER; + +do_state: +error: + return ret; +} + +#ifdef CONFIG_SSL_ENABLE_V23_HANDSHAKE +/* + * Some browsers use a hybrid SSLv2 "client hello" + */ +int process_sslv23_client_hello(SSL *ssl) +{ + uint8_t *buf = ssl->bm_data; + int bytes_needed = ((buf[0] & 0x7f) << 8) + buf[1]; + int ret = SSL_OK; + + /* we have already read 3 extra bytes so far */ + int read_len = SOCKET_READ(ssl->client_fd, buf, bytes_needed-3); + int cs_len = buf[1]; + int id_len = buf[3]; + int ch_len = buf[5]; + int i, j, offset = 8; /* start at first cipher */ + int random_offset = 0; + + DISPLAY_BYTES(ssl, "received %d bytes", buf, read_len, read_len); + + add_packet(ssl, buf, read_len); + + /* connection has gone, so die */ + if (bytes_needed < 0) + { + return SSL_ERROR_CONN_LOST; + } + + /* now work out what cipher suite we are going to use */ + for (j = 0; j < NUM_PROTOCOLS; j++) + { + for (i = 0; i < cs_len; i += 3) + { + if (ssl_prot_prefs[j] == buf[offset+i]) + { + ssl->cipher = ssl_prot_prefs[j]; + goto server_hello; + } + } + } + + /* ouch! protocol is not supported */ + ret = SSL_ERROR_NO_CIPHER; + goto error; + +server_hello: + /* get the session id */ + offset += cs_len - 2; /* we've gone 2 bytes past the end */ +#ifndef CONFIG_SSL_SKELETON_MODE + ssl->session = ssl_session_update(ssl->ssl_ctx->num_sessions, + ssl->ssl_ctx->ssl_sessions, ssl, id_len ? &buf[offset] : NULL); +#endif + + /* get the client random data */ + offset += id_len; + + /* random can be anywhere between 16 and 32 bytes long - so it is padded + * with 0's to the left */ + if (ch_len == 0x10) + { + random_offset += 0x10; + } + + memcpy(&ssl->dc->client_random[random_offset], &buf[offset], ch_len); + ret = send_server_hello_sequence(ssl); + +error: + return ret; +} +#endif + +/* + * Send the entire server hello sequence + */ +static int send_server_hello_sequence(SSL *ssl) +{ + int ret; + + if ((ret = send_server_hello(ssl)) == SSL_OK) + { +#ifndef CONFIG_SSL_SKELETON_MODE + /* resume handshake? */ + if (IS_SET_SSL_FLAG(SSL_SESSION_RESUME)) + { + if ((ret = send_change_cipher_spec(ssl)) == SSL_OK) + { + ret = send_finished(ssl); + ssl->next_state = HS_FINISHED; + } + } + else +#endif + if ((ret = send_certificate(ssl)) == SSL_OK) + { +#ifdef CONFIG_SSL_CERT_VERIFICATION + /* ask the client for its certificate */ + if (IS_SET_SSL_FLAG(SSL_CLIENT_AUTHENTICATION)) + { + if ((ret = send_certificate_request(ssl)) == SSL_OK) + { + ret = send_server_hello_done(ssl); + ssl->next_state = HS_CERTIFICATE; + } + } + else +#endif + { + ret = send_server_hello_done(ssl); + ssl->next_state = HS_CLIENT_KEY_XCHG; + } + } + } + + return ret; +} + +/* + * Send a server hello message. + */ +static int send_server_hello(SSL *ssl) +{ + uint8_t *buf = ssl->bm_data; + int offset = 0; + + buf[0] = HS_SERVER_HELLO; + buf[1] = 0; + buf[2] = 0; + /* byte 3 is calculated later */ + buf[4] = 0x03; + buf[5] = ssl->version & 0x0f; + + /* server random value */ + get_random(SSL_RANDOM_SIZE, &buf[6]); + memcpy(ssl->dc->server_random, &buf[6], SSL_RANDOM_SIZE); + offset = 6 + SSL_RANDOM_SIZE; + +#ifndef CONFIG_SSL_SKELETON_MODE + if (IS_SET_SSL_FLAG(SSL_SESSION_RESUME)) + { + /* retrieve id from session cache */ + buf[offset++] = SSL_SESSION_ID_SIZE; + memcpy(&buf[offset], ssl->session->session_id, SSL_SESSION_ID_SIZE); + memcpy(ssl->session_id, ssl->session->session_id, SSL_SESSION_ID_SIZE); + ssl->sess_id_size = SSL_SESSION_ID_SIZE; + offset += SSL_SESSION_ID_SIZE; + } + else /* generate our own session id */ +#endif + { +#ifndef CONFIG_SSL_SKELETON_MODE + buf[offset++] = SSL_SESSION_ID_SIZE; + get_random(SSL_SESSION_ID_SIZE, &buf[offset]); + memcpy(ssl->session_id, &buf[offset], SSL_SESSION_ID_SIZE); + ssl->sess_id_size = SSL_SESSION_ID_SIZE; + + /* store id in session cache */ + if (ssl->ssl_ctx->num_sessions) + { + memcpy(ssl->session->session_id, + ssl->session_id, SSL_SESSION_ID_SIZE); + } + + offset += SSL_SESSION_ID_SIZE; +#else + buf[offset++] = 0; /* don't bother with session id in skelton mode */ +#endif + } + + buf[offset++] = 0; /* cipher we are using */ + buf[offset++] = ssl->cipher; + buf[offset++] = 0; /* no compression */ + buf[3] = offset - 4; /* handshake size */ + return send_packet(ssl, PT_HANDSHAKE_PROTOCOL, NULL, offset); +} + +/* + * Send the server hello done message. + */ +static int send_server_hello_done(SSL *ssl) +{ + return send_packet(ssl, PT_HANDSHAKE_PROTOCOL, + g_hello_done, sizeof(g_hello_done)); +} + +/* + * Pull apart a client key exchange message. Decrypt the pre-master key (using + * our RSA private key) and then work out the master key. Initialise the + * ciphers. + */ +static int process_client_key_xchg(SSL *ssl) +{ + uint8_t *buf = &ssl->bm_data[ssl->dc->bm_proc_index]; + int pkt_size = ssl->bm_index; + int premaster_size, secret_length = (buf[2] << 8) + buf[3]; + uint8_t premaster_secret[MAX_KEY_BYTE_SIZE]; + RSA_CTX *rsa_ctx = ssl->ssl_ctx->rsa_ctx; + int offset = 4; + int ret = SSL_OK; + + if (rsa_ctx == NULL) + { + ret = SSL_ERROR_NO_CERT_DEFINED; + goto error; + } + + /* is there an extra size field? */ + if ((secret_length - 2) == rsa_ctx->num_octets) + offset += 2; + + PARANOIA_CHECK(pkt_size, rsa_ctx->num_octets+offset); + + /* rsa_ctx->bi_ctx is not thread-safe */ + SSL_CTX_LOCK(ssl->ssl_ctx->mutex); + premaster_size = RSA_decrypt(rsa_ctx, &buf[offset], premaster_secret, 1); + SSL_CTX_UNLOCK(ssl->ssl_ctx->mutex); + + if (premaster_size != SSL_SECRET_SIZE || + premaster_secret[0] != 0x03 || /* must be the same as client + offered version */ + premaster_secret[1] != (ssl->client_version & 0x0f)) + { + /* guard against a Bleichenbacher attack */ + get_random(SSL_SECRET_SIZE, premaster_secret); + /* and continue - will die eventually when checking the mac */ + } + +#if 0 + print_blob("pre-master", premaster_secret, SSL_SECRET_SIZE); +#endif + + generate_master_secret(ssl, premaster_secret); + +#ifdef CONFIG_SSL_CERT_VERIFICATION + ssl->next_state = IS_SET_SSL_FLAG(SSL_CLIENT_AUTHENTICATION) ? + HS_CERT_VERIFY : HS_FINISHED; +#else + ssl->next_state = HS_FINISHED; +#endif + + ssl->dc->bm_proc_index += rsa_ctx->num_octets+offset; +error: + return ret; +} + +#ifdef CONFIG_SSL_CERT_VERIFICATION +static const uint8_t g_cert_request[] = { HS_CERT_REQ, 0, 0, 4, 1, 0, 0, 0 }; + +/* + * Send the certificate request message. + */ +static int send_certificate_request(SSL *ssl) +{ + return send_packet(ssl, PT_HANDSHAKE_PROTOCOL, + g_cert_request, sizeof(g_cert_request)); +} + +/* + * Ensure the client has the private key by first decrypting the packet and + * then checking the packet digests. + */ +static int process_cert_verify(SSL *ssl) +{ + uint8_t *buf = &ssl->bm_data[ssl->dc->bm_proc_index]; + int pkt_size = ssl->bm_index; + uint8_t dgst_buf[MAX_KEY_BYTE_SIZE]; + uint8_t dgst[MD5_SIZE+SHA1_SIZE]; + X509_CTX *x509_ctx = ssl->x509_ctx; + int ret = SSL_OK; + int n; + + PARANOIA_CHECK(pkt_size, x509_ctx->rsa_ctx->num_octets+6); + DISPLAY_RSA(ssl, x509_ctx->rsa_ctx); + + /* rsa_ctx->bi_ctx is not thread-safe */ + SSL_CTX_LOCK(ssl->ssl_ctx->mutex); + n = RSA_decrypt(x509_ctx->rsa_ctx, &buf[6], dgst_buf, 0); + SSL_CTX_UNLOCK(ssl->ssl_ctx->mutex); + + if (n != SHA1_SIZE + MD5_SIZE) + { + ret = SSL_ERROR_INVALID_KEY; + goto end_cert_vfy; + } + + finished_digest(ssl, NULL, dgst); /* calculate the digest */ + if (memcmp(dgst_buf, dgst, MD5_SIZE + SHA1_SIZE)) + { + ret = SSL_ERROR_INVALID_KEY; + } + +end_cert_vfy: + ssl->next_state = HS_FINISHED; +error: + return ret; +} + +#endif |