| /* |
| * SSLv3/TLSv1 server-side functions |
| * |
| * Based on XySSL: Copyright (C) 2006-2008 Christophe Devine |
| * |
| * Copyright (C) 2009 Paul Bakker <polarssl_maintainer at polarssl dot org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| */ |
| |
| #include "polarssl/config.h" |
| |
| #if defined(POLARSSL_SSL_SRV_C) |
| |
| #include "polarssl/debug.h" |
| #include "polarssl/ssl.h" |
| |
| #include <string.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <time.h> |
| |
| static int ssl_parse_client_hello( ssl_context *ssl ) |
| { |
| int ret, i, j, n; |
| int ciph_len, sess_len; |
| int chal_len, comp_len; |
| unsigned char *buf, *p; |
| |
| SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) ); |
| |
| if( ( ret = ssl_fetch_input( ssl, 5 ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); |
| return( ret ); |
| } |
| |
| buf = ssl->in_hdr; |
| |
| if( ( buf[0] & 0x80 ) != 0 ) |
| { |
| SSL_DEBUG_BUF( 4, "record header", buf, 5 ); |
| |
| SSL_DEBUG_MSG( 3, ( "client hello v2, message type: %d", |
| buf[2] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v2, message len.: %d", |
| ( ( buf[0] & 0x7F ) << 8 ) | buf[1] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v2, max. version: [%d:%d]", |
| buf[3], buf[4] ) ); |
| |
| /* |
| * SSLv2 Client Hello |
| * |
| * Record layer: |
| * 0 . 1 message length |
| * |
| * SSL layer: |
| * 2 . 2 message type |
| * 3 . 4 protocol version |
| */ |
| if( buf[2] != SSL_HS_CLIENT_HELLO || |
| buf[3] != SSL_MAJOR_VERSION_3 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| n = ( ( buf[0] << 8 ) | buf[1] ) & 0x7FFF; |
| |
| if( n < 17 || n > 512 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->max_major_ver = buf[3]; |
| ssl->max_minor_ver = buf[4]; |
| |
| ssl->major_ver = SSL_MAJOR_VERSION_3; |
| ssl->minor_ver = ( buf[4] <= SSL_MINOR_VERSION_1 ) |
| ? buf[4] : SSL_MINOR_VERSION_1; |
| |
| if( ( ret = ssl_fetch_input( ssl, 2 + n ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); |
| return( ret ); |
| } |
| |
| md5_update( &ssl->fin_md5 , buf + 2, n ); |
| sha1_update( &ssl->fin_sha1, buf + 2, n ); |
| |
| buf = ssl->in_msg; |
| n = ssl->in_left - 5; |
| |
| /* |
| * 0 . 1 cipherlist length |
| * 2 . 3 session id length |
| * 4 . 5 challenge length |
| * 6 . .. cipherlist |
| * .. . .. session id |
| * .. . .. challenge |
| */ |
| SSL_DEBUG_BUF( 4, "record contents", buf, n ); |
| |
| ciph_len = ( buf[0] << 8 ) | buf[1]; |
| sess_len = ( buf[2] << 8 ) | buf[3]; |
| chal_len = ( buf[4] << 8 ) | buf[5]; |
| |
| SSL_DEBUG_MSG( 3, ( "ciph_len: %d, sess_len: %d, chal_len: %d", |
| ciph_len, sess_len, chal_len ) ); |
| |
| /* |
| * Make sure each parameter length is valid |
| */ |
| if( ciph_len < 3 || ( ciph_len % 3 ) != 0 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( sess_len < 0 || sess_len > 32 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( chal_len < 8 || chal_len > 32 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( n != 6 + ciph_len + sess_len + chal_len ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| SSL_DEBUG_BUF( 3, "client hello, cipherlist", |
| buf + 6, ciph_len ); |
| SSL_DEBUG_BUF( 3, "client hello, session id", |
| buf + 6 + ciph_len, sess_len ); |
| SSL_DEBUG_BUF( 3, "client hello, challenge", |
| buf + 6 + ciph_len + sess_len, chal_len ); |
| |
| p = buf + 6 + ciph_len; |
| ssl->session->length = sess_len; |
| memset( ssl->session->id, 0, sizeof( ssl->session->id ) ); |
| memcpy( ssl->session->id, p, ssl->session->length ); |
| |
| p += sess_len; |
| memset( ssl->randbytes, 0, 64 ); |
| memcpy( ssl->randbytes + 32 - chal_len, p, chal_len ); |
| |
| for( i = 0; ssl->ciphers[i] != 0; i++ ) |
| { |
| for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 ) |
| { |
| if( p[0] == 0 && |
| p[1] == 0 && |
| p[2] == ssl->ciphers[i] ) |
| goto have_cipher; |
| } |
| } |
| } |
| else |
| { |
| SSL_DEBUG_BUF( 4, "record header", buf, 5 ); |
| |
| SSL_DEBUG_MSG( 3, ( "client hello v3, message type: %d", |
| buf[0] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v3, message len.: %d", |
| ( buf[3] << 8 ) | buf[4] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v3, protocol ver: [%d:%d]", |
| buf[1], buf[2] ) ); |
| |
| /* |
| * SSLv3 Client Hello |
| * |
| * Record layer: |
| * 0 . 0 message type |
| * 1 . 2 protocol version |
| * 3 . 4 message length |
| */ |
| if( buf[0] != SSL_MSG_HANDSHAKE || |
| buf[1] != SSL_MAJOR_VERSION_3 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| n = ( buf[3] << 8 ) | buf[4]; |
| |
| if( n < 45 || n > 512 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( ( ret = ssl_fetch_input( ssl, 5 + n ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); |
| return( ret ); |
| } |
| |
| buf = ssl->in_msg; |
| n = ssl->in_left - 5; |
| |
| md5_update( &ssl->fin_md5 , buf, n ); |
| sha1_update( &ssl->fin_sha1, buf, n ); |
| |
| /* |
| * SSL layer: |
| * 0 . 0 handshake type |
| * 1 . 3 handshake length |
| * 4 . 5 protocol version |
| * 6 . 9 UNIX time() |
| * 10 . 37 random bytes |
| * 38 . 38 session id length |
| * 39 . 38+x session id |
| * 39+x . 40+x cipherlist length |
| * 41+x . .. cipherlist |
| * .. . .. compression alg. |
| * .. . .. extensions |
| */ |
| SSL_DEBUG_BUF( 4, "record contents", buf, n ); |
| |
| SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d", |
| buf[0] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d", |
| ( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v3, max. version: [%d:%d]", |
| buf[4], buf[5] ) ); |
| |
| /* |
| * Check the handshake type and protocol version |
| */ |
| if( buf[0] != SSL_HS_CLIENT_HELLO || |
| buf[4] != SSL_MAJOR_VERSION_3 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->major_ver = SSL_MAJOR_VERSION_3; |
| ssl->minor_ver = ( buf[5] <= SSL_MINOR_VERSION_1 ) |
| ? buf[5] : SSL_MINOR_VERSION_1; |
| |
| ssl->max_major_ver = buf[4]; |
| ssl->max_minor_ver = buf[5]; |
| |
| memcpy( ssl->randbytes, buf + 6, 32 ); |
| |
| /* |
| * Check the handshake message length |
| */ |
| if( buf[1] != 0 || n != 4 + ( ( buf[2] << 8 ) | buf[3] ) ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* |
| * Check the session length |
| */ |
| sess_len = buf[38]; |
| |
| if( sess_len < 0 || sess_len > 32 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->session->length = sess_len; |
| memset( ssl->session->id, 0, sizeof( ssl->session->id ) ); |
| memcpy( ssl->session->id, buf + 39 , ssl->session->length ); |
| |
| /* |
| * Check the cipherlist length |
| */ |
| ciph_len = ( buf[39 + sess_len] << 8 ) |
| | ( buf[40 + sess_len] ); |
| |
| if( ciph_len < 2 || ciph_len > 256 || ( ciph_len % 2 ) != 0 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* |
| * Check the compression algorithms length |
| */ |
| comp_len = buf[41 + sess_len + ciph_len]; |
| |
| if( comp_len < 1 || comp_len > 16 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| SSL_DEBUG_BUF( 3, "client hello, random bytes", |
| buf + 6, 32 ); |
| SSL_DEBUG_BUF( 3, "client hello, session id", |
| buf + 38, sess_len ); |
| SSL_DEBUG_BUF( 3, "client hello, cipherlist", |
| buf + 41 + sess_len, ciph_len ); |
| SSL_DEBUG_BUF( 3, "client hello, compression", |
| buf + 42 + sess_len + ciph_len, comp_len ); |
| |
| /* |
| * Search for a matching cipher |
| */ |
| for( i = 0; ssl->ciphers[i] != 0; i++ ) |
| { |
| for( j = 0, p = buf + 41 + sess_len; j < ciph_len; |
| j += 2, p += 2 ) |
| { |
| if( p[0] == 0 && p[1] == ssl->ciphers[i] ) |
| goto have_cipher; |
| } |
| } |
| } |
| |
| SSL_DEBUG_MSG( 1, ( "got no ciphers in common" ) ); |
| |
| return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN ); |
| |
| have_cipher: |
| |
| ssl->session->cipher = ssl->ciphers[i]; |
| ssl->in_left = 0; |
| ssl->state++; |
| |
| SSL_DEBUG_MSG( 2, ( "<= parse client hello" ) ); |
| |
| return( 0 ); |
| } |
| |
| static int ssl_write_server_hello( ssl_context *ssl ) |
| { |
| time_t t; |
| int ret, i, n; |
| unsigned char *buf, *p; |
| |
| SSL_DEBUG_MSG( 2, ( "=> write server hello" ) ); |
| |
| /* |
| * 0 . 0 handshake type |
| * 1 . 3 handshake length |
| * 4 . 5 protocol version |
| * 6 . 9 UNIX time() |
| * 10 . 37 random bytes |
| */ |
| buf = ssl->out_msg; |
| p = buf + 4; |
| |
| *p++ = (unsigned char) ssl->major_ver; |
| *p++ = (unsigned char) ssl->minor_ver; |
| |
| SSL_DEBUG_MSG( 3, ( "server hello, chosen version: [%d:%d]", |
| buf[4], buf[5] ) ); |
| |
| t = time( NULL ); |
| *p++ = (unsigned char)( t >> 24 ); |
| *p++ = (unsigned char)( t >> 16 ); |
| *p++ = (unsigned char)( t >> 8 ); |
| *p++ = (unsigned char)( t ); |
| |
| SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", t ) ); |
| |
| for( i = 28; i > 0; i-- ) |
| *p++ = (unsigned char) ssl->f_rng( ssl->p_rng ); |
| |
| memcpy( ssl->randbytes + 32, buf + 6, 32 ); |
| |
| SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 ); |
| |
| /* |
| * 38 . 38 session id length |
| * 39 . 38+n session id |
| * 39+n . 40+n chosen cipher |
| * 41+n . 41+n chosen compression alg. |
| */ |
| ssl->session->length = n = 32; |
| *p++ = (unsigned char) ssl->session->length; |
| |
| if( ssl->s_get == NULL || |
| ssl->s_get( ssl ) != 0 ) |
| { |
| /* |
| * Not found, create a new session id |
| */ |
| ssl->resume = 0; |
| ssl->state++; |
| |
| for( i = 0; i < n; i++ ) |
| ssl->session->id[i] = |
| (unsigned char) ssl->f_rng( ssl->p_rng ); |
| } |
| else |
| { |
| /* |
| * Found a matching session, resume it |
| */ |
| ssl->resume = 1; |
| ssl->state = SSL_SERVER_CHANGE_CIPHER_SPEC; |
| ssl_derive_keys( ssl ); |
| } |
| |
| memcpy( p, ssl->session->id, ssl->session->length ); |
| p += ssl->session->length; |
| |
| SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) ); |
| SSL_DEBUG_BUF( 3, "server hello, session id", buf + 39, n ); |
| SSL_DEBUG_MSG( 3, ( "%s session has been resumed", |
| ssl->resume ? "a" : "no" ) ); |
| |
| *p++ = (unsigned char)( ssl->session->cipher >> 8 ); |
| *p++ = (unsigned char)( ssl->session->cipher ); |
| *p++ = SSL_COMPRESS_NULL; |
| |
| SSL_DEBUG_MSG( 3, ( "server hello, chosen cipher: %d", |
| ssl->session->cipher ) ); |
| SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", 0 ) ); |
| |
| ssl->out_msglen = p - buf; |
| ssl->out_msgtype = SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = SSL_HS_SERVER_HELLO; |
| |
| ret = ssl_write_record( ssl ); |
| |
| SSL_DEBUG_MSG( 2, ( "<= write server hello" ) ); |
| |
| return( ret ); |
| } |
| |
| static int ssl_write_certificate_request( ssl_context *ssl ) |
| { |
| int ret, n; |
| unsigned char *buf, *p; |
| x509_cert *crt; |
| |
| SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) ); |
| |
| ssl->state++; |
| |
| if( ssl->authmode == SSL_VERIFY_NONE ) |
| { |
| SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) ); |
| return( 0 ); |
| } |
| |
| /* |
| * 0 . 0 handshake type |
| * 1 . 3 handshake length |
| * 4 . 4 cert type count |
| * 5 .. n-1 cert types |
| * n .. n+1 length of all DNs |
| * n+2 .. n+3 length of DN 1 |
| * n+4 .. ... Distinguished Name #1 |
| * ... .. ... length of DN 2, etc. |
| */ |
| buf = ssl->out_msg; |
| p = buf + 4; |
| |
| /* |
| * At the moment, only RSA certificates are supported |
| */ |
| *p++ = 1; |
| *p++ = 1; |
| |
| p += 2; |
| crt = ssl->ca_chain; |
| |
| while( crt != NULL && crt->next != NULL ) |
| { |
| if( p - buf > 4096 ) |
| break; |
| |
| n = crt->subject_raw.len; |
| *p++ = (unsigned char)( n >> 8 ); |
| *p++ = (unsigned char)( n ); |
| memcpy( p, crt->subject_raw.p, n ); |
| |
| SSL_DEBUG_BUF( 3, "requested DN", p, n ); |
| p += n; crt = crt->next; |
| } |
| |
| ssl->out_msglen = n = p - buf; |
| ssl->out_msgtype = SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = SSL_HS_CERTIFICATE_REQUEST; |
| ssl->out_msg[6] = (unsigned char)( ( n - 8 ) >> 8 ); |
| ssl->out_msg[7] = (unsigned char)( ( n - 8 ) ); |
| |
| ret = ssl_write_record( ssl ); |
| |
| SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) ); |
| |
| return( ret ); |
| } |
| |
| static int ssl_write_server_key_exchange( ssl_context *ssl ) |
| { |
| int ret, n; |
| unsigned char hash[36]; |
| md5_context md5; |
| sha1_context sha1; |
| |
| SSL_DEBUG_MSG( 2, ( "=> write server key exchange" ) ); |
| |
| if( ssl->session->cipher != SSL_EDH_RSA_DES_168_SHA && |
| ssl->session->cipher != SSL_EDH_RSA_AES_256_SHA && |
| ssl->session->cipher != SSL_EDH_RSA_CAMELLIA_256_SHA) |
| { |
| SSL_DEBUG_MSG( 2, ( "<= skip write server key exchange" ) ); |
| ssl->state++; |
| return( 0 ); |
| } |
| |
| #if !defined(POLARSSL_DHM_C) |
| SSL_DEBUG_MSG( 1, ( "support for dhm is not available" ) ); |
| return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); |
| #else |
| /* |
| * Ephemeral DH parameters: |
| * |
| * struct { |
| * opaque dh_p<1..2^16-1>; |
| * opaque dh_g<1..2^16-1>; |
| * opaque dh_Ys<1..2^16-1>; |
| * } ServerDHParams; |
| */ |
| if( ( ret = dhm_make_params( &ssl->dhm_ctx, 256, ssl->out_msg + 4, |
| &n, ssl->f_rng, ssl->p_rng ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "dhm_make_params", ret ); |
| return( ret ); |
| } |
| |
| SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->dhm_ctx.X ); |
| SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->dhm_ctx.P ); |
| SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->dhm_ctx.G ); |
| SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->dhm_ctx.GX ); |
| |
| /* |
| * digitally-signed struct { |
| * opaque md5_hash[16]; |
| * opaque sha_hash[20]; |
| * }; |
| * |
| * md5_hash |
| * MD5(ClientHello.random + ServerHello.random |
| * + ServerParams); |
| * sha_hash |
| * SHA(ClientHello.random + ServerHello.random |
| * + ServerParams); |
| */ |
| md5_starts( &md5 ); |
| md5_update( &md5, ssl->randbytes, 64 ); |
| md5_update( &md5, ssl->out_msg + 4, n ); |
| md5_finish( &md5, hash ); |
| |
| sha1_starts( &sha1 ); |
| sha1_update( &sha1, ssl->randbytes, 64 ); |
| sha1_update( &sha1, ssl->out_msg + 4, n ); |
| sha1_finish( &sha1, hash + 16 ); |
| |
| SSL_DEBUG_BUF( 3, "parameters hash", hash, 36 ); |
| |
| ssl->out_msg[4 + n] = (unsigned char)( ssl->rsa_key->len >> 8 ); |
| ssl->out_msg[5 + n] = (unsigned char)( ssl->rsa_key->len ); |
| |
| ret = rsa_pkcs1_sign( ssl->rsa_key, RSA_PRIVATE, |
| RSA_RAW, 36, hash, ssl->out_msg + 6 + n ); |
| if( ret != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "rsa_pkcs1_sign", ret ); |
| return( ret ); |
| } |
| |
| SSL_DEBUG_BUF( 3, "my RSA sig", ssl->out_msg + 6 + n, |
| ssl->rsa_key->len ); |
| |
| ssl->out_msglen = 6 + n + ssl->rsa_key->len; |
| ssl->out_msgtype = SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = SSL_HS_SERVER_KEY_EXCHANGE; |
| |
| ssl->state++; |
| |
| if( ( ret = ssl_write_record( ssl ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_write_record", ret ); |
| return( ret ); |
| } |
| |
| SSL_DEBUG_MSG( 2, ( "<= write server key exchange" ) ); |
| |
| return( 0 ); |
| #endif |
| } |
| |
| static int ssl_write_server_hello_done( ssl_context *ssl ) |
| { |
| int ret; |
| |
| SSL_DEBUG_MSG( 2, ( "=> write server hello done" ) ); |
| |
| ssl->out_msglen = 4; |
| ssl->out_msgtype = SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = SSL_HS_SERVER_HELLO_DONE; |
| |
| ssl->state++; |
| |
| if( ( ret = ssl_write_record( ssl ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_write_record", ret ); |
| return( ret ); |
| } |
| |
| SSL_DEBUG_MSG( 2, ( "<= write server hello done" ) ); |
| |
| return( 0 ); |
| } |
| |
| static int ssl_parse_client_key_exchange( ssl_context *ssl ) |
| { |
| int ret, i, n; |
| |
| SSL_DEBUG_MSG( 2, ( "=> parse client key exchange" ) ); |
| |
| if( ( ret = ssl_read_record( ssl ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_read_record", ret ); |
| return( ret ); |
| } |
| |
| if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| |
| if( ssl->in_msg[0] != SSL_HS_CLIENT_KEY_EXCHANGE ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| |
| if( ssl->session->cipher == SSL_EDH_RSA_DES_168_SHA || |
| ssl->session->cipher == SSL_EDH_RSA_AES_256_SHA || |
| ssl->session->cipher == SSL_EDH_RSA_CAMELLIA_256_SHA) |
| { |
| #if !defined(POLARSSL_DHM_C) |
| SSL_DEBUG_MSG( 1, ( "support for dhm is not available" ) ); |
| return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); |
| #else |
| /* |
| * Receive G^Y mod P, premaster = (G^Y)^X mod P |
| */ |
| n = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5]; |
| |
| if( n < 1 || n > ssl->dhm_ctx.len || |
| n + 6 != ssl->in_hslen ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| |
| if( ( ret = dhm_read_public( &ssl->dhm_ctx, |
| ssl->in_msg + 6, n ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "dhm_read_public", ret ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE | ret ); |
| } |
| |
| SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->dhm_ctx.GY ); |
| |
| ssl->pmslen = ssl->dhm_ctx.len; |
| |
| if( ( ret = dhm_calc_secret( &ssl->dhm_ctx, |
| ssl->premaster, &ssl->pmslen ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "dhm_calc_secret", ret ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE | ret ); |
| } |
| |
| SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->dhm_ctx.K ); |
| #endif |
| } |
| else |
| { |
| /* |
| * Decrypt the premaster using own private RSA key |
| */ |
| i = 4; |
| n = ssl->rsa_key->len; |
| ssl->pmslen = 48; |
| |
| if( ssl->minor_ver != SSL_MINOR_VERSION_0 ) |
| { |
| i += 2; |
| if( ssl->in_msg[4] != ( ( n >> 8 ) & 0xFF ) || |
| ssl->in_msg[5] != ( ( n ) & 0xFF ) ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| } |
| |
| if( ssl->in_hslen != i + n ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| |
| ret = rsa_pkcs1_decrypt( ssl->rsa_key, RSA_PRIVATE, &ssl->pmslen, |
| ssl->in_msg + i, ssl->premaster, |
| sizeof(ssl->premaster) ); |
| |
| if( ret != 0 || ssl->pmslen != 48 || |
| ssl->premaster[0] != ssl->max_major_ver || |
| ssl->premaster[1] != ssl->max_minor_ver ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| |
| /* |
| * Protection against Bleichenbacher's attack: |
| * invalid PKCS#1 v1.5 padding must not cause |
| * the connection to end immediately; instead, |
| * send a bad_record_mac later in the handshake. |
| */ |
| ssl->pmslen = 48; |
| |
| for( i = 0; i < ssl->pmslen; i++ ) |
| ssl->premaster[i] = (unsigned char) ssl->f_rng( ssl->p_rng ); |
| } |
| } |
| |
| ssl_derive_keys( ssl ); |
| |
| if( ssl->s_set != NULL ) |
| ssl->s_set( ssl ); |
| |
| ssl->state++; |
| |
| SSL_DEBUG_MSG( 2, ( "<= parse client key exchange" ) ); |
| |
| return( 0 ); |
| } |
| |
| static int ssl_parse_certificate_verify( ssl_context *ssl ) |
| { |
| int n1, n2, ret; |
| unsigned char hash[36]; |
| |
| SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) ); |
| |
| if( ssl->peer_cert == NULL ) |
| { |
| SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) ); |
| ssl->state++; |
| return( 0 ); |
| } |
| |
| ssl_calc_verify( ssl, hash ); |
| |
| if( ( ret = ssl_read_record( ssl ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_read_record", ret ); |
| return( ret ); |
| } |
| |
| ssl->state++; |
| |
| if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); |
| } |
| |
| if( ssl->in_msg[0] != SSL_HS_CERTIFICATE_VERIFY ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); |
| } |
| |
| n1 = ssl->peer_cert->rsa.len; |
| n2 = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5]; |
| |
| if( n1 + 6 != ssl->in_hslen || n1 != n2 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); |
| } |
| |
| ret = rsa_pkcs1_verify( &ssl->peer_cert->rsa, RSA_PUBLIC, |
| RSA_RAW, 36, hash, ssl->in_msg + 6 ); |
| if( ret != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "rsa_pkcs1_verify", ret ); |
| return( ret ); |
| } |
| |
| SSL_DEBUG_MSG( 2, ( "<= parse certificate verify" ) ); |
| |
| return( 0 ); |
| } |
| |
| /* |
| * SSL handshake -- server side |
| */ |
| int ssl_handshake_server( ssl_context *ssl ) |
| { |
| int ret = 0; |
| |
| SSL_DEBUG_MSG( 2, ( "=> handshake server" ) ); |
| |
| while( ssl->state != SSL_HANDSHAKE_OVER ) |
| { |
| SSL_DEBUG_MSG( 2, ( "server state: %d", ssl->state ) ); |
| |
| if( ( ret = ssl_flush_output( ssl ) ) != 0 ) |
| break; |
| |
| switch( ssl->state ) |
| { |
| case SSL_HELLO_REQUEST: |
| ssl->state = SSL_CLIENT_HELLO; |
| break; |
| |
| /* |
| * <== ClientHello |
| */ |
| case SSL_CLIENT_HELLO: |
| ret = ssl_parse_client_hello( ssl ); |
| break; |
| |
| /* |
| * ==> ServerHello |
| * Certificate |
| * ( ServerKeyExchange ) |
| * ( CertificateRequest ) |
| * ServerHelloDone |
| */ |
| case SSL_SERVER_HELLO: |
| ret = ssl_write_server_hello( ssl ); |
| break; |
| |
| case SSL_SERVER_CERTIFICATE: |
| ret = ssl_write_certificate( ssl ); |
| break; |
| |
| case SSL_SERVER_KEY_EXCHANGE: |
| ret = ssl_write_server_key_exchange( ssl ); |
| break; |
| |
| case SSL_CERTIFICATE_REQUEST: |
| ret = ssl_write_certificate_request( ssl ); |
| break; |
| |
| case SSL_SERVER_HELLO_DONE: |
| ret = ssl_write_server_hello_done( ssl ); |
| break; |
| |
| /* |
| * <== ( Certificate/Alert ) |
| * ClientKeyExchange |
| * ( CertificateVerify ) |
| * ChangeCipherSpec |
| * Finished |
| */ |
| case SSL_CLIENT_CERTIFICATE: |
| ret = ssl_parse_certificate( ssl ); |
| break; |
| |
| case SSL_CLIENT_KEY_EXCHANGE: |
| ret = ssl_parse_client_key_exchange( ssl ); |
| break; |
| |
| case SSL_CERTIFICATE_VERIFY: |
| ret = ssl_parse_certificate_verify( ssl ); |
| break; |
| |
| case SSL_CLIENT_CHANGE_CIPHER_SPEC: |
| ret = ssl_parse_change_cipher_spec( ssl ); |
| break; |
| |
| case SSL_CLIENT_FINISHED: |
| ret = ssl_parse_finished( ssl ); |
| break; |
| |
| /* |
| * ==> ChangeCipherSpec |
| * Finished |
| */ |
| case SSL_SERVER_CHANGE_CIPHER_SPEC: |
| ret = ssl_write_change_cipher_spec( ssl ); |
| break; |
| |
| case SSL_SERVER_FINISHED: |
| ret = ssl_write_finished( ssl ); |
| break; |
| |
| case SSL_FLUSH_BUFFERS: |
| SSL_DEBUG_MSG( 2, ( "handshake: done" ) ); |
| ssl->state = SSL_HANDSHAKE_OVER; |
| break; |
| |
| default: |
| SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) ); |
| return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); |
| } |
| |
| if( ret != 0 ) |
| break; |
| } |
| |
| SSL_DEBUG_MSG( 2, ( "<= handshake server" ) ); |
| |
| return( ret ); |
| } |
| |
| #endif |
