/* * SSLv3/TLSv1 server-side functions * * Copyright (C) 2006-2012, Brainspark B.V. * * This file is part of PolarSSL (http://www.polarssl.org) * Lead Maintainer: Paul Bakker * * All rights reserved. * * 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" #if defined(POLARSSL_PKCS11_C) #include "polarssl/pkcs11.h" #endif /* defined(POLARSSL_PKCS11_C) */ #include #include #include static int ssl_parse_client_hello( ssl_context *ssl ) { int ret; unsigned int i, j; size_t n; unsigned int ciph_len, sess_len; unsigned 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_3 ) ? buf[4] : SSL_MINOR_VERSION_3; if( ( ret = ssl_fetch_input( ssl, 2 + n ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); return( ret ); } ssl->update_checksum( ssl, buf + 2, n ); buf = ssl->in_msg; n = ssl->in_left - 5; /* * 0 . 1 ciphersuitelist length * 2 . 3 session id length * 4 . 5 challenge length * 6 . .. ciphersuitelist * .. . .. 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 > 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, ciphersuitelist", 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->ciphersuites[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->ciphersuites[i] ) goto have_ciphersuite; } } } 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; ssl->update_checksum( ssl, 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 ciphersuitelist length * 41+x . .. ciphersuitelist * .. . .. 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_3 ) ? buf[5] : SSL_MINOR_VERSION_3; 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 != (unsigned int) 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 > 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 ciphersuitelist 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->session->compression = SSL_COMPRESS_NULL; #if defined(POLARSSL_ZLIB_SUPPORT) for( i = 0; i < comp_len; ++i ) { if( buf[41 + sess_len + ciph_len + i] == SSL_COMPRESS_DEFLATE ) { ssl->session->compression = SSL_COMPRESS_DEFLATE; break; } } #endif 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, ciphersuitelist", 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 ciphersuite */ for( i = 0; ssl->ciphersuites[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->ciphersuites[i] ) goto have_ciphersuite; } } } SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) ); return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN ); have_ciphersuite: ssl->session->ciphersuite = ssl->ciphersuites[i]; ssl_kickstart_checksum( ssl, ssl->session->ciphersuite, buf, n ); 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, 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 ) ); if( ( ret = ssl->f_rng( ssl->p_rng, p, 28 ) ) != 0 ) return( ret ); p += 28; 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 ciphersuite * 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++; if( ssl->session == NULL ) { SSL_DEBUG_MSG( 1, ( "No session struct set" ) ); return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); } if( ( ret = ssl->f_rng( ssl->p_rng, ssl->session->id, n ) ) != 0 ) return( ret ); } else { /* * Found a matching session, resume it */ ssl->resume = 1; ssl->state = SSL_SERVER_CHANGE_CIPHER_SPEC; if( ( ret = ssl_derive_keys( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_derive_keys", ret ); return( ret ); } } 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->ciphersuite >> 8 ); *p++ = (unsigned char)( ssl->session->ciphersuite ); *p++ = (unsigned char)( ssl->session->compression ); SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %d", ssl->session->ciphersuite ) ); SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", ssl->session->compression ) ); 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; size_t n; unsigned char *buf, *p; const 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 ) { 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 ) { #if defined(POLARSSL_DHM_C) int ret; size_t n, rsa_key_len = 0; unsigned char hash[48]; md5_context md5; sha1_context sha1; int hash_id; unsigned int hashlen; #endif SSL_DEBUG_MSG( 2, ( "=> write server key exchange" ) ); if( ssl->session->ciphersuite != SSL_EDH_RSA_DES_SHA && ssl->session->ciphersuite != SSL_EDH_RSA_DES_168_SHA && ssl->session->ciphersuite != SSL_EDH_RSA_AES_128_SHA && ssl->session->ciphersuite != SSL_EDH_RSA_AES_256_SHA && ssl->session->ciphersuite != SSL_EDH_RSA_AES_128_SHA256 && ssl->session->ciphersuite != SSL_EDH_RSA_AES_256_SHA256 && ssl->session->ciphersuite != SSL_EDH_RSA_CAMELLIA_128_SHA && ssl->session->ciphersuite != SSL_EDH_RSA_CAMELLIA_256_SHA && ssl->session->ciphersuite != SSL_EDH_RSA_CAMELLIA_128_SHA256 && ssl->session->ciphersuite != SSL_EDH_RSA_CAMELLIA_256_SHA256 && ssl->session->ciphersuite != SSL_EDH_RSA_AES_128_GCM_SHA256 && ssl->session->ciphersuite != SSL_EDH_RSA_AES_256_GCM_SHA384 ) { 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 if( ssl->rsa_key == NULL ) { #if defined(POLARSSL_PKCS11_C) if( ssl->pkcs11_key == NULL ) { #endif /* defined(POLARSSL_PKCS11_C) */ SSL_DEBUG_MSG( 1, ( "got no private key" ) ); return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED ); #if defined(POLARSSL_PKCS11_C) } #endif /* defined(POLARSSL_PKCS11_C) */ } /* * 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 ); if( ssl->minor_ver != SSL_MINOR_VERSION_3 ) { /* * 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 ); hashlen = 36; hash_id = SIG_RSA_RAW; } else { /* * digitally-signed struct { * opaque client_random[32]; * opaque server_random[32]; * ServerDHParams params; * }; */ /* TODO TLS1.2 Get a supported hash algorithm from the * signature_algorithms extension, Otherwise SHA1 + RSA! */ sha1_starts( &sha1 ); sha1_update( &sha1, ssl->randbytes, 64 ); sha1_update( &sha1, ssl->out_msg + 4, n ); sha1_finish( &sha1, hash ); hashlen = 20; hash_id = SIG_RSA_SHA1; } SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen ); if ( ssl->rsa_key ) rsa_key_len = ssl->rsa_key->len; #if defined(POLARSSL_PKCS11_C) else rsa_key_len = ssl->pkcs11_key->len; #endif /* defined(POLARSSL_PKCS11_C) */ if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) { // TODO TLS1.2 Base on selection above (SHA1 + RSA is default choice) ssl->out_msg[4 + n] = SSL_HASH_SHA1; ssl->out_msg[5 + n] = SSL_SIG_RSA; n += 2; } ssl->out_msg[4 + n] = (unsigned char)( rsa_key_len >> 8 ); ssl->out_msg[5 + n] = (unsigned char)( rsa_key_len ); if ( ssl->rsa_key ) { ret = rsa_pkcs1_sign( ssl->rsa_key, ssl->f_rng, ssl->p_rng, RSA_PRIVATE, hash_id, hashlen, hash, ssl->out_msg + 6 + n ); } #if defined(POLARSSL_PKCS11_C) else { ret = pkcs11_sign( ssl->pkcs11_key, RSA_PRIVATE, hash_id, hashlen, hash, ssl->out_msg + 6 + n ); } #endif /* defined(POLARSSL_PKCS11_C) */ if( ret != 0 ) { SSL_DEBUG_RET( 1, "pkcs1_sign", ret ); return( ret ); } SSL_DEBUG_BUF( 3, "my RSA sig", ssl->out_msg + 6 + n, rsa_key_len ); ssl->out_msglen = 6 + n + 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; size_t i, n = 0; 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->ciphersuite == SSL_EDH_RSA_DES_SHA || ssl->session->ciphersuite == SSL_EDH_RSA_DES_168_SHA || ssl->session->ciphersuite == SSL_EDH_RSA_AES_128_SHA || ssl->session->ciphersuite == SSL_EDH_RSA_AES_256_SHA || ssl->session->ciphersuite == SSL_EDH_RSA_AES_128_SHA256 || ssl->session->ciphersuite == SSL_EDH_RSA_AES_256_SHA256 || ssl->session->ciphersuite == SSL_EDH_RSA_CAMELLIA_128_SHA || ssl->session->ciphersuite == SSL_EDH_RSA_CAMELLIA_256_SHA || ssl->session->ciphersuite == SSL_EDH_RSA_CAMELLIA_128_SHA256 || ssl->session->ciphersuite == SSL_EDH_RSA_CAMELLIA_256_SHA256 || ssl->session->ciphersuite == SSL_EDH_RSA_AES_128_GCM_SHA256 || ssl->session->ciphersuite == SSL_EDH_RSA_AES_256_GCM_SHA384 ) { #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_DHM_RP ); } 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_DHM_CS ); } SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->dhm_ctx.K ); #endif } else { if( ssl->rsa_key == NULL ) { #if defined(POLARSSL_PKCS11_C) if( ssl->pkcs11_key == NULL ) { #endif SSL_DEBUG_MSG( 1, ( "got no private key" ) ); return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED ); #if defined(POLARSSL_PKCS11_C) } #endif } /* * Decrypt the premaster using own private RSA key */ i = 4; if( ssl->rsa_key ) n = ssl->rsa_key->len; #if defined(POLARSSL_PKCS11_C) else n = ssl->pkcs11_key->len; #endif 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 ); } if( ssl->rsa_key ) { ret = rsa_pkcs1_decrypt( ssl->rsa_key, RSA_PRIVATE, &ssl->pmslen, ssl->in_msg + i, ssl->premaster, sizeof(ssl->premaster) ); } #if defined(POLARSSL_PKCS11_C) else { ret = pkcs11_decrypt( ssl->pkcs11_key, RSA_PRIVATE, &ssl->pmslen, ssl->in_msg + i, ssl->premaster, sizeof(ssl->premaster) ); } #endif /* defined(POLARSSL_PKCS11_C) */ 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; ret = ssl->f_rng( ssl->p_rng, ssl->premaster, ssl->pmslen ); if( ret != 0 ) return( ret ); } } if( ( ret = ssl_derive_keys( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_derive_keys", ret ); return( ret ); } 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 ret; size_t n1, n2; unsigned char hash[48]; 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, SIG_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