/* * SSLv3/TLSv1 shared functions * * Based on XySSL: Copyright (C) 2006-2008 Christophe Devine * * Copyright (C) 2009 Paul Bakker * * 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. */ /* * The SSL 3.0 specification was drafted by Netscape in 1996, * and became an IETF standard in 1999. * * http://wp.netscape.com/eng/ssl3/ * http://www.ietf.org/rfc/rfc2246.txt * http://www.ietf.org/rfc/rfc4346.txt */ #include "polarssl/config.h" #if defined(POLARSSL_SSL_TLS_C) #include "polarssl/aes.h" #include "polarssl/arc4.h" #include "polarssl/camellia.h" #include "polarssl/des.h" #include "polarssl/debug.h" #include "polarssl/ssl.h" #include #include #include /* * Key material generation */ static int tls1_prf( unsigned char *secret, int slen, char *label, unsigned char *random, int rlen, unsigned char *dstbuf, int dlen ) { int nb, hs; int i, j, k; unsigned char *S1, *S2; unsigned char tmp[128]; unsigned char h_i[20]; if( sizeof( tmp ) < 20 + strlen( label ) + rlen ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); hs = ( slen + 1 ) / 2; S1 = secret; S2 = secret + slen - hs; nb = strlen( label ); memcpy( tmp + 20, label, nb ); memcpy( tmp + 20 + nb, random, rlen ); nb += rlen; /* * First compute P_md5(secret,label+random)[0..dlen] */ md5_hmac( S1, hs, tmp + 20, nb, 4 + tmp ); for( i = 0; i < dlen; i += 16 ) { md5_hmac( S1, hs, 4 + tmp, 16 + nb, h_i ); md5_hmac( S1, hs, 4 + tmp, 16, 4 + tmp ); k = ( i + 16 > dlen ) ? dlen % 16 : 16; for( j = 0; j < k; j++ ) dstbuf[i + j] = h_i[j]; } /* * XOR out with P_sha1(secret,label+random)[0..dlen] */ sha1_hmac( S2, hs, tmp + 20, nb, tmp ); for( i = 0; i < dlen; i += 20 ) { sha1_hmac( S2, hs, tmp, 20 + nb, h_i ); sha1_hmac( S2, hs, tmp, 20, tmp ); k = ( i + 20 > dlen ) ? dlen % 20 : 20; for( j = 0; j < k; j++ ) dstbuf[i + j] = (unsigned char)( dstbuf[i + j] ^ h_i[j] ); } memset( tmp, 0, sizeof( tmp ) ); memset( h_i, 0, sizeof( h_i ) ); return( 0 ); } int ssl_derive_keys( ssl_context *ssl ) { int i; md5_context md5; sha1_context sha1; unsigned char tmp[64]; unsigned char padding[16]; unsigned char sha1sum[20]; unsigned char keyblk[256]; unsigned char *key1; unsigned char *key2; SSL_DEBUG_MSG( 2, ( "=> derive keys" ) ); /* * SSLv3: * master = * MD5( premaster + SHA1( 'A' + premaster + randbytes ) ) + * MD5( premaster + SHA1( 'BB' + premaster + randbytes ) ) + * MD5( premaster + SHA1( 'CCC' + premaster + randbytes ) ) * * TLSv1: * master = PRF( premaster, "master secret", randbytes )[0..47] */ if( ssl->resume == 0 ) { int len = ssl->pmslen; SSL_DEBUG_BUF( 3, "premaster secret", ssl->premaster, len ); if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { for( i = 0; i < 3; i++ ) { memset( padding, 'A' + i, 1 + i ); sha1_starts( &sha1 ); sha1_update( &sha1, padding, 1 + i ); sha1_update( &sha1, ssl->premaster, len ); sha1_update( &sha1, ssl->randbytes, 64 ); sha1_finish( &sha1, sha1sum ); md5_starts( &md5 ); md5_update( &md5, ssl->premaster, len ); md5_update( &md5, sha1sum, 20 ); md5_finish( &md5, ssl->session->master + i * 16 ); } } else tls1_prf( ssl->premaster, len, "master secret", ssl->randbytes, 64, ssl->session->master, 48 ); memset( ssl->premaster, 0, sizeof( ssl->premaster ) ); } else SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) ); /* * Swap the client and server random values. */ memcpy( tmp, ssl->randbytes, 64 ); memcpy( ssl->randbytes, tmp + 32, 32 ); memcpy( ssl->randbytes + 32, tmp, 32 ); memset( tmp, 0, sizeof( tmp ) ); /* * SSLv3: * key block = * MD5( master + SHA1( 'A' + master + randbytes ) ) + * MD5( master + SHA1( 'BB' + master + randbytes ) ) + * MD5( master + SHA1( 'CCC' + master + randbytes ) ) + * MD5( master + SHA1( 'DDDD' + master + randbytes ) ) + * ... * * TLSv1: * key block = PRF( master, "key expansion", randbytes ) */ if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { for( i = 0; i < 16; i++ ) { memset( padding, 'A' + i, 1 + i ); sha1_starts( &sha1 ); sha1_update( &sha1, padding, 1 + i ); sha1_update( &sha1, ssl->session->master, 48 ); sha1_update( &sha1, ssl->randbytes, 64 ); sha1_finish( &sha1, sha1sum ); md5_starts( &md5 ); md5_update( &md5, ssl->session->master, 48 ); md5_update( &md5, sha1sum, 20 ); md5_finish( &md5, keyblk + i * 16 ); } memset( &md5, 0, sizeof( md5 ) ); memset( &sha1, 0, sizeof( sha1 ) ); memset( padding, 0, sizeof( padding ) ); memset( sha1sum, 0, sizeof( sha1sum ) ); } else tls1_prf( ssl->session->master, 48, "key expansion", ssl->randbytes, 64, keyblk, 256 ); SSL_DEBUG_MSG( 3, ( "cipher = %s", ssl_get_cipher( ssl ) ) ); SSL_DEBUG_BUF( 3, "master secret", ssl->session->master, 48 ); SSL_DEBUG_BUF( 4, "random bytes", ssl->randbytes, 64 ); SSL_DEBUG_BUF( 4, "key block", keyblk, 256 ); memset( ssl->randbytes, 0, sizeof( ssl->randbytes ) ); /* * Determine the appropriate key, IV and MAC length. */ switch( ssl->session->cipher ) { #if defined(POLARSSL_ARC4_C) case SSL_RSA_RC4_128_MD5: ssl->keylen = 16; ssl->minlen = 16; ssl->ivlen = 0; ssl->maclen = 16; break; case SSL_RSA_RC4_128_SHA: ssl->keylen = 16; ssl->minlen = 20; ssl->ivlen = 0; ssl->maclen = 20; break; #endif #if defined(POLARSSL_DES_C) case SSL_RSA_DES_168_SHA: case SSL_EDH_RSA_DES_168_SHA: ssl->keylen = 24; ssl->minlen = 24; ssl->ivlen = 8; ssl->maclen = 20; break; #endif #if defined(POLARSSL_AES_C) case SSL_RSA_AES_128_SHA: ssl->keylen = 16; ssl->minlen = 32; ssl->ivlen = 16; ssl->maclen = 20; break; case SSL_RSA_AES_256_SHA: case SSL_EDH_RSA_AES_256_SHA: ssl->keylen = 32; ssl->minlen = 32; ssl->ivlen = 16; ssl->maclen = 20; break; #endif #if defined(POLARSSL_CAMELLIA_C) case SSL_RSA_CAMELLIA_128_SHA: ssl->keylen = 16; ssl->minlen = 32; ssl->ivlen = 16; ssl->maclen = 20; break; case SSL_RSA_CAMELLIA_256_SHA: case SSL_EDH_RSA_CAMELLIA_256_SHA: ssl->keylen = 32; ssl->minlen = 32; ssl->ivlen = 16; ssl->maclen = 20; break; #endif default: SSL_DEBUG_MSG( 1, ( "cipher %s is not available", ssl_get_cipher( ssl ) ) ); return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); } SSL_DEBUG_MSG( 3, ( "keylen: %d, minlen: %d, ivlen: %d, maclen: %d", ssl->keylen, ssl->minlen, ssl->ivlen, ssl->maclen ) ); /* * Finally setup the cipher contexts, IVs and MAC secrets. */ if( ssl->endpoint == SSL_IS_CLIENT ) { key1 = keyblk + ssl->maclen * 2; key2 = keyblk + ssl->maclen * 2 + ssl->keylen; memcpy( ssl->mac_enc, keyblk, ssl->maclen ); memcpy( ssl->mac_dec, keyblk + ssl->maclen, ssl->maclen ); memcpy( ssl->iv_enc, key2 + ssl->keylen, ssl->ivlen ); memcpy( ssl->iv_dec, key2 + ssl->keylen + ssl->ivlen, ssl->ivlen ); } else { key1 = keyblk + ssl->maclen * 2 + ssl->keylen; key2 = keyblk + ssl->maclen * 2; memcpy( ssl->mac_dec, keyblk, ssl->maclen ); memcpy( ssl->mac_enc, keyblk + ssl->maclen, ssl->maclen ); memcpy( ssl->iv_dec, key1 + ssl->keylen, ssl->ivlen ); memcpy( ssl->iv_enc, key1 + ssl->keylen + ssl->ivlen, ssl->ivlen ); } switch( ssl->session->cipher ) { #if defined(POLARSSL_ARC4_C) case SSL_RSA_RC4_128_MD5: case SSL_RSA_RC4_128_SHA: arc4_setup( (arc4_context *) ssl->ctx_enc, key1, ssl->keylen ); arc4_setup( (arc4_context *) ssl->ctx_dec, key2, ssl->keylen ); break; #endif #if defined(POLARSSL_DES_C) case SSL_RSA_DES_168_SHA: case SSL_EDH_RSA_DES_168_SHA: des3_set3key_enc( (des3_context *) ssl->ctx_enc, key1 ); des3_set3key_dec( (des3_context *) ssl->ctx_dec, key2 ); break; #endif #if defined(POLARSSL_AES_C) case SSL_RSA_AES_128_SHA: aes_setkey_enc( (aes_context *) ssl->ctx_enc, key1, 128 ); aes_setkey_dec( (aes_context *) ssl->ctx_dec, key2, 128 ); break; case SSL_RSA_AES_256_SHA: case SSL_EDH_RSA_AES_256_SHA: aes_setkey_enc( (aes_context *) ssl->ctx_enc, key1, 256 ); aes_setkey_dec( (aes_context *) ssl->ctx_dec, key2, 256 ); break; #endif #if defined(POLARSSL_CAMELLIA_C) case SSL_RSA_CAMELLIA_128_SHA: camellia_setkey_enc( (camellia_context *) ssl->ctx_enc, key1, 128 ); camellia_setkey_dec( (camellia_context *) ssl->ctx_dec, key2, 128 ); break; case SSL_RSA_CAMELLIA_256_SHA: case SSL_EDH_RSA_CAMELLIA_256_SHA: camellia_setkey_enc( (camellia_context *) ssl->ctx_enc, key1, 256 ); camellia_setkey_dec( (camellia_context *) ssl->ctx_dec, key2, 256 ); break; #endif default: return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); } memset( keyblk, 0, sizeof( keyblk ) ); SSL_DEBUG_MSG( 2, ( "<= derive keys" ) ); return( 0 ); } void ssl_calc_verify( ssl_context *ssl, unsigned char hash[36] ) { md5_context md5; sha1_context sha1; unsigned char pad_1[48]; unsigned char pad_2[48]; SSL_DEBUG_MSG( 2, ( "=> calc verify" ) ); memcpy( &md5 , &ssl->fin_md5 , sizeof( md5_context ) ); memcpy( &sha1, &ssl->fin_sha1, sizeof( sha1_context ) ); if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { memset( pad_1, 0x36, 48 ); memset( pad_2, 0x5C, 48 ); md5_update( &md5, ssl->session->master, 48 ); md5_update( &md5, pad_1, 48 ); md5_finish( &md5, hash ); md5_starts( &md5 ); md5_update( &md5, ssl->session->master, 48 ); md5_update( &md5, pad_2, 48 ); md5_update( &md5, hash, 16 ); md5_finish( &md5, hash ); sha1_update( &sha1, ssl->session->master, 48 ); sha1_update( &sha1, pad_1, 40 ); sha1_finish( &sha1, hash + 16 ); sha1_starts( &sha1 ); sha1_update( &sha1, ssl->session->master, 48 ); sha1_update( &sha1, pad_2, 40 ); sha1_update( &sha1, hash + 16, 20 ); sha1_finish( &sha1, hash + 16 ); } else /* TLSv1 */ { md5_finish( &md5, hash ); sha1_finish( &sha1, hash + 16 ); } SSL_DEBUG_BUF( 3, "calculated verify result", hash, 36 ); SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); return; } /* * SSLv3.0 MAC functions */ static void ssl_mac_md5( unsigned char *secret, unsigned char *buf, int len, unsigned char *ctr, int type ) { unsigned char header[11]; unsigned char padding[48]; md5_context md5; memcpy( header, ctr, 8 ); header[ 8] = (unsigned char) type; header[ 9] = (unsigned char)( len >> 8 ); header[10] = (unsigned char)( len ); memset( padding, 0x36, 48 ); md5_starts( &md5 ); md5_update( &md5, secret, 16 ); md5_update( &md5, padding, 48 ); md5_update( &md5, header, 11 ); md5_update( &md5, buf, len ); md5_finish( &md5, buf + len ); memset( padding, 0x5C, 48 ); md5_starts( &md5 ); md5_update( &md5, secret, 16 ); md5_update( &md5, padding, 48 ); md5_update( &md5, buf + len, 16 ); md5_finish( &md5, buf + len ); } static void ssl_mac_sha1( unsigned char *secret, unsigned char *buf, int len, unsigned char *ctr, int type ) { unsigned char header[11]; unsigned char padding[40]; sha1_context sha1; memcpy( header, ctr, 8 ); header[ 8] = (unsigned char) type; header[ 9] = (unsigned char)( len >> 8 ); header[10] = (unsigned char)( len ); memset( padding, 0x36, 40 ); sha1_starts( &sha1 ); sha1_update( &sha1, secret, 20 ); sha1_update( &sha1, padding, 40 ); sha1_update( &sha1, header, 11 ); sha1_update( &sha1, buf, len ); sha1_finish( &sha1, buf + len ); memset( padding, 0x5C, 40 ); sha1_starts( &sha1 ); sha1_update( &sha1, secret, 20 ); sha1_update( &sha1, padding, 40 ); sha1_update( &sha1, buf + len, 20 ); sha1_finish( &sha1, buf + len ); } /* * Encryption/decryption functions */ static int ssl_encrypt_buf( ssl_context *ssl ) { int i, padlen; SSL_DEBUG_MSG( 2, ( "=> encrypt buf" ) ); /* * Add MAC then encrypt */ if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { if( ssl->maclen == 16 ) ssl_mac_md5( ssl->mac_enc, ssl->out_msg, ssl->out_msglen, ssl->out_ctr, ssl->out_msgtype ); if( ssl->maclen == 20 ) ssl_mac_sha1( ssl->mac_enc, ssl->out_msg, ssl->out_msglen, ssl->out_ctr, ssl->out_msgtype ); } else { if( ssl->maclen == 16 ) md5_hmac( ssl->mac_enc, 16, ssl->out_ctr, ssl->out_msglen + 13, ssl->out_msg + ssl->out_msglen ); if( ssl->maclen == 20 ) sha1_hmac( ssl->mac_enc, 20, ssl->out_ctr, ssl->out_msglen + 13, ssl->out_msg + ssl->out_msglen ); } SSL_DEBUG_BUF( 4, "computed mac", ssl->out_msg + ssl->out_msglen, ssl->maclen ); ssl->out_msglen += ssl->maclen; for( i = 7; i >= 0; i-- ) if( ++ssl->out_ctr[i] != 0 ) break; if( ssl->ivlen == 0 ) { #if defined(POLARSSL_ARC4_C) padlen = 0; SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, " "including %d bytes of padding", ssl->out_msglen, 0 ) ); SSL_DEBUG_BUF( 4, "before encrypt: output payload", ssl->out_msg, ssl->out_msglen ); arc4_crypt( (arc4_context *) ssl->ctx_enc, ssl->out_msg, ssl->out_msglen ); #else return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); #endif } else { padlen = ssl->ivlen - ( ssl->out_msglen + 1 ) % ssl->ivlen; if( padlen == ssl->ivlen ) padlen = 0; for( i = 0; i <= padlen; i++ ) ssl->out_msg[ssl->out_msglen + i] = (unsigned char) padlen; ssl->out_msglen += padlen + 1; SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, " "including %d bytes of padding", ssl->out_msglen, padlen + 1 ) ); SSL_DEBUG_BUF( 4, "before encrypt: output payload", ssl->out_msg, ssl->out_msglen ); switch( ssl->ivlen ) { case 8: #if defined(POLARSSL_DES_C) des3_crypt_cbc( (des3_context *) ssl->ctx_enc, DES_ENCRYPT, ssl->out_msglen, ssl->iv_enc, ssl->out_msg, ssl->out_msg ); break; #endif case 16: #if defined(POLARSSL_AES_C) if ( ssl->session->cipher == SSL_RSA_AES_128_SHA || ssl->session->cipher == SSL_RSA_AES_256_SHA || ssl->session->cipher == SSL_EDH_RSA_AES_256_SHA) { aes_crypt_cbc( (aes_context *) ssl->ctx_enc, AES_ENCRYPT, ssl->out_msglen, ssl->iv_enc, ssl->out_msg, ssl->out_msg ); break; } #endif #if defined(POLARSSL_CAMELLIA_C) if ( ssl->session->cipher == SSL_RSA_CAMELLIA_128_SHA || ssl->session->cipher == SSL_RSA_CAMELLIA_256_SHA || ssl->session->cipher == SSL_EDH_RSA_CAMELLIA_256_SHA) { camellia_crypt_cbc( (camellia_context *) ssl->ctx_enc, CAMELLIA_ENCRYPT, ssl->out_msglen, ssl->iv_enc, ssl->out_msg, ssl->out_msg ); break; } #endif default: return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); } } SSL_DEBUG_MSG( 2, ( "<= encrypt buf" ) ); return( 0 ); } static int ssl_decrypt_buf( ssl_context *ssl ) { int i, padlen; unsigned char tmp[20]; SSL_DEBUG_MSG( 2, ( "=> decrypt buf" ) ); if( ssl->in_msglen < ssl->minlen ) { SSL_DEBUG_MSG( 1, ( "in_msglen (%d) < minlen (%d)", ssl->in_msglen, ssl->minlen ) ); return( POLARSSL_ERR_SSL_INVALID_MAC ); } if( ssl->ivlen == 0 ) { #if defined(POLARSSL_ARC4_C) padlen = 0; arc4_crypt( (arc4_context *) ssl->ctx_dec, ssl->in_msg, ssl->in_msglen ); #else return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); #endif } else { /* * Decrypt and check the padding */ if( ssl->in_msglen % ssl->ivlen != 0 ) { SSL_DEBUG_MSG( 1, ( "msglen (%d) %% ivlen (%d) != 0", ssl->in_msglen, ssl->ivlen ) ); return( POLARSSL_ERR_SSL_INVALID_MAC ); } switch( ssl->ivlen ) { #if defined(POLARSSL_DES_C) case 8: des3_crypt_cbc( (des3_context *) ssl->ctx_dec, DES_DECRYPT, ssl->in_msglen, ssl->iv_dec, ssl->in_msg, ssl->in_msg ); break; #endif case 16: #if defined(POLARSSL_AES_C) if ( ssl->session->cipher == SSL_RSA_AES_128_SHA || ssl->session->cipher == SSL_RSA_AES_256_SHA || ssl->session->cipher == SSL_EDH_RSA_AES_256_SHA) { aes_crypt_cbc( (aes_context *) ssl->ctx_dec, AES_DECRYPT, ssl->in_msglen, ssl->iv_dec, ssl->in_msg, ssl->in_msg ); break; } #endif #if defined(POLARSSL_CAMELLIA_C) if ( ssl->session->cipher == SSL_RSA_CAMELLIA_128_SHA || ssl->session->cipher == SSL_RSA_CAMELLIA_256_SHA || ssl->session->cipher == SSL_EDH_RSA_CAMELLIA_256_SHA) { camellia_crypt_cbc( (camellia_context *) ssl->ctx_dec, CAMELLIA_DECRYPT, ssl->in_msglen, ssl->iv_dec, ssl->in_msg, ssl->in_msg ); break; } #endif default: return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); } padlen = 1 + ssl->in_msg[ssl->in_msglen - 1]; if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { if( padlen > ssl->ivlen ) { SSL_DEBUG_MSG( 1, ( "bad padding length: is %d, " "should be no more than %d", padlen, ssl->ivlen ) ); padlen = 0; } } else { /* * TLSv1: always check the padding */ for( i = 1; i <= padlen; i++ ) { if( ssl->in_msg[ssl->in_msglen - i] != padlen - 1 ) { SSL_DEBUG_MSG( 1, ( "bad padding byte: should be " "%02x, but is %02x", padlen - 1, ssl->in_msg[ssl->in_msglen - i] ) ); padlen = 0; } } } } SSL_DEBUG_BUF( 4, "raw buffer after decryption", ssl->in_msg, ssl->in_msglen ); /* * Always compute the MAC (RFC4346, CBCTIME). */ ssl->in_msglen -= ( ssl->maclen + padlen ); ssl->in_hdr[3] = (unsigned char)( ssl->in_msglen >> 8 ); ssl->in_hdr[4] = (unsigned char)( ssl->in_msglen ); memcpy( tmp, ssl->in_msg + ssl->in_msglen, 20 ); if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { if( ssl->maclen == 16 ) ssl_mac_md5( ssl->mac_dec, ssl->in_msg, ssl->in_msglen, ssl->in_ctr, ssl->in_msgtype ); else ssl_mac_sha1( ssl->mac_dec, ssl->in_msg, ssl->in_msglen, ssl->in_ctr, ssl->in_msgtype ); } else { if( ssl->maclen == 16 ) md5_hmac( ssl->mac_dec, 16, ssl->in_ctr, ssl->in_msglen + 13, ssl->in_msg + ssl->in_msglen ); else sha1_hmac( ssl->mac_dec, 20, ssl->in_ctr, ssl->in_msglen + 13, ssl->in_msg + ssl->in_msglen ); } SSL_DEBUG_BUF( 4, "message mac", tmp, ssl->maclen ); SSL_DEBUG_BUF( 4, "computed mac", ssl->in_msg + ssl->in_msglen, ssl->maclen ); if( memcmp( tmp, ssl->in_msg + ssl->in_msglen, ssl->maclen ) != 0 ) { SSL_DEBUG_MSG( 1, ( "message mac does not match" ) ); return( POLARSSL_ERR_SSL_INVALID_MAC ); } /* * Finally check the padding length; bad padding * will produce the same error as an invalid MAC. */ if( ssl->ivlen != 0 && padlen == 0 ) return( POLARSSL_ERR_SSL_INVALID_MAC ); if( ssl->in_msglen == 0 ) { ssl->nb_zero++; /* * Three or more empty messages may be a DoS attack * (excessive CPU consumption). */ if( ssl->nb_zero > 3 ) { SSL_DEBUG_MSG( 1, ( "received four consecutive empty " "messages, possible DoS attack" ) ); return( POLARSSL_ERR_SSL_INVALID_MAC ); } } else ssl->nb_zero = 0; for( i = 7; i >= 0; i-- ) if( ++ssl->in_ctr[i] != 0 ) break; SSL_DEBUG_MSG( 2, ( "<= decrypt buf" ) ); return( 0 ); } /* * Fill the input message buffer */ int ssl_fetch_input( ssl_context *ssl, int nb_want ) { int ret, len; SSL_DEBUG_MSG( 2, ( "=> fetch input" ) ); while( ssl->in_left < nb_want ) { len = nb_want - ssl->in_left; ret = ssl->f_recv( ssl->p_recv, ssl->in_hdr + ssl->in_left, len ); SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d", ssl->in_left, nb_want ) ); SSL_DEBUG_RET( 2, "ssl->f_recv", ret ); if( ret < 0 ) return( ret ); ssl->in_left += ret; } SSL_DEBUG_MSG( 2, ( "<= fetch input" ) ); return( 0 ); } /* * Flush any data not yet written */ int ssl_flush_output( ssl_context *ssl ) { int ret; unsigned char *buf; SSL_DEBUG_MSG( 2, ( "=> flush output" ) ); while( ssl->out_left > 0 ) { SSL_DEBUG_MSG( 2, ( "message length: %d, out_left: %d", 5 + ssl->out_msglen, ssl->out_left ) ); buf = ssl->out_hdr + 5 + ssl->out_msglen - ssl->out_left; ret = ssl->f_send( ssl->p_send, buf, ssl->out_left ); SSL_DEBUG_RET( 2, "ssl->f_send", ret ); if( ret <= 0 ) return( ret ); ssl->out_left -= ret; } SSL_DEBUG_MSG( 2, ( "<= flush output" ) ); return( 0 ); } /* * Record layer functions */ int ssl_write_record( ssl_context *ssl ) { int ret, len = ssl->out_msglen; SSL_DEBUG_MSG( 2, ( "=> write record" ) ); ssl->out_hdr[0] = (unsigned char) ssl->out_msgtype; ssl->out_hdr[1] = (unsigned char) ssl->major_ver; ssl->out_hdr[2] = (unsigned char) ssl->minor_ver; ssl->out_hdr[3] = (unsigned char)( len >> 8 ); ssl->out_hdr[4] = (unsigned char)( len ); if( ssl->out_msgtype == SSL_MSG_HANDSHAKE ) { ssl->out_msg[1] = (unsigned char)( ( len - 4 ) >> 16 ); ssl->out_msg[2] = (unsigned char)( ( len - 4 ) >> 8 ); ssl->out_msg[3] = (unsigned char)( ( len - 4 ) ); md5_update( &ssl->fin_md5 , ssl->out_msg, len ); sha1_update( &ssl->fin_sha1, ssl->out_msg, len ); } if( ssl->do_crypt != 0 ) { if( ( ret = ssl_encrypt_buf( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret ); return( ret ); } len = ssl->out_msglen; ssl->out_hdr[3] = (unsigned char)( len >> 8 ); ssl->out_hdr[4] = (unsigned char)( len ); } ssl->out_left = 5 + ssl->out_msglen; SSL_DEBUG_MSG( 3, ( "output record: msgtype = %d, " "version = [%d:%d], msglen = %d", ssl->out_hdr[0], ssl->out_hdr[1], ssl->out_hdr[2], ( ssl->out_hdr[3] << 8 ) | ssl->out_hdr[4] ) ); SSL_DEBUG_BUF( 4, "output record sent to network", ssl->out_hdr, 5 + ssl->out_msglen ); if( ( ret = ssl_flush_output( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_flush_output", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= write record" ) ); return( 0 ); } int ssl_read_record( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> read record" ) ); if( ssl->in_hslen != 0 && ssl->in_hslen < ssl->in_msglen ) { /* * Get next Handshake message in the current record */ ssl->in_msglen -= ssl->in_hslen; memcpy( ssl->in_msg, ssl->in_msg + ssl->in_hslen, ssl->in_msglen ); ssl->in_hslen = 4; ssl->in_hslen += ( ssl->in_msg[2] << 8 ) | ssl->in_msg[3]; SSL_DEBUG_MSG( 3, ( "handshake message: msglen =" " %d, type = %d, hslen = %d", ssl->in_msglen, ssl->in_msg[0], ssl->in_hslen ) ); if( ssl->in_msglen < 4 || ssl->in_msg[1] != 0 ) { SSL_DEBUG_MSG( 1, ( "bad handshake length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } if( ssl->in_msglen < ssl->in_hslen ) { SSL_DEBUG_MSG( 1, ( "bad handshake length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } md5_update( &ssl->fin_md5 , ssl->in_msg, ssl->in_hslen ); sha1_update( &ssl->fin_sha1, ssl->in_msg, ssl->in_hslen ); return( 0 ); } ssl->in_hslen = 0; /* * Read the record header and validate it */ if( ( ret = ssl_fetch_input( ssl, 5 ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); return( ret ); } ssl->in_msgtype = ssl->in_hdr[0]; ssl->in_msglen = ( ssl->in_hdr[3] << 8 ) | ssl->in_hdr[4]; SSL_DEBUG_MSG( 3, ( "input record: msgtype = %d, " "version = [%d:%d], msglen = %d", ssl->in_hdr[0], ssl->in_hdr[1], ssl->in_hdr[2], ( ssl->in_hdr[3] << 8 ) | ssl->in_hdr[4] ) ); if( ssl->in_hdr[1] != ssl->major_ver ) { SSL_DEBUG_MSG( 1, ( "major version mismatch" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } if( ssl->in_hdr[2] != SSL_MINOR_VERSION_0 && ssl->in_hdr[2] != SSL_MINOR_VERSION_1 ) { SSL_DEBUG_MSG( 1, ( "minor version mismatch" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } /* * Make sure the message length is acceptable */ if( ssl->do_crypt == 0 ) { if( ssl->in_msglen < 1 || ssl->in_msglen > SSL_MAX_CONTENT_LEN ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } } else { if( ssl->in_msglen < ssl->minlen ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } if( ssl->minor_ver == SSL_MINOR_VERSION_0 && ssl->in_msglen > ssl->minlen + SSL_MAX_CONTENT_LEN ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } /* * TLS encrypted messages can have up to 256 bytes of padding */ if( ssl->minor_ver == SSL_MINOR_VERSION_1 && ssl->in_msglen > ssl->minlen + SSL_MAX_CONTENT_LEN + 256 ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } } /* * Read and optionally decrypt the message contents */ if( ( ret = ssl_fetch_input( ssl, 5 + ssl->in_msglen ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); return( ret ); } SSL_DEBUG_BUF( 4, "input record from network", ssl->in_hdr, 5 + ssl->in_msglen ); if( ssl->do_crypt != 0 ) { if( ( ret = ssl_decrypt_buf( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_decrypt_buf", ret ); return( ret ); } SSL_DEBUG_BUF( 4, "input payload after decrypt", ssl->in_msg, ssl->in_msglen ); if( ssl->in_msglen > SSL_MAX_CONTENT_LEN ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } } if( ssl->in_msgtype == SSL_MSG_HANDSHAKE ) { ssl->in_hslen = 4; ssl->in_hslen += ( ssl->in_msg[2] << 8 ) | ssl->in_msg[3]; SSL_DEBUG_MSG( 3, ( "handshake message: msglen =" " %d, type = %d, hslen = %d", ssl->in_msglen, ssl->in_msg[0], ssl->in_hslen ) ); /* * Additional checks to validate the handshake header */ if( ssl->in_msglen < 4 || ssl->in_msg[1] != 0 ) { SSL_DEBUG_MSG( 1, ( "bad handshake length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } if( ssl->in_msglen < ssl->in_hslen ) { SSL_DEBUG_MSG( 1, ( "bad handshake length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } md5_update( &ssl->fin_md5 , ssl->in_msg, ssl->in_hslen ); sha1_update( &ssl->fin_sha1, ssl->in_msg, ssl->in_hslen ); } if( ssl->in_msgtype == SSL_MSG_ALERT ) { SSL_DEBUG_MSG( 2, ( "got an alert message, type: [%d:%d]", ssl->in_msg[0], ssl->in_msg[1] ) ); /* * Ignore non-fatal alerts, except close_notify */ if( ssl->in_msg[0] == SSL_ALERT_FATAL ) { SSL_DEBUG_MSG( 1, ( "is a fatal alert message" ) ); return( POLARSSL_ERR_SSL_FATAL_ALERT_MESSAGE | ssl->in_msg[1] ); } if( ssl->in_msg[0] == SSL_ALERT_WARNING && ssl->in_msg[1] == SSL_ALERT_CLOSE_NOTIFY ) { SSL_DEBUG_MSG( 2, ( "is a close notify message" ) ); return( POLARSSL_ERR_SSL_PEER_CLOSE_NOTIFY ); } } ssl->in_left = 0; SSL_DEBUG_MSG( 2, ( "<= read record" ) ); return( 0 ); } /* * Handshake functions */ int ssl_write_certificate( ssl_context *ssl ) { int ret, i, n; x509_cert *crt; SSL_DEBUG_MSG( 2, ( "=> write certificate" ) ); if( ssl->endpoint == SSL_IS_CLIENT ) { if( ssl->client_auth == 0 ) { SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) ); ssl->state++; return( 0 ); } /* * If using SSLv3 and got no cert, send an Alert message * (otherwise an empty Certificate message will be sent). */ if( ssl->own_cert == NULL && ssl->minor_ver == SSL_MINOR_VERSION_0 ) { ssl->out_msglen = 2; ssl->out_msgtype = SSL_MSG_ALERT; ssl->out_msg[0] = SSL_ALERT_WARNING; ssl->out_msg[1] = SSL_ALERT_NO_CERTIFICATE; SSL_DEBUG_MSG( 2, ( "got no certificate to send" ) ); goto write_msg; } } else /* SSL_IS_SERVER */ { if( ssl->own_cert == NULL ) { SSL_DEBUG_MSG( 1, ( "got no certificate to send" ) ); return( POLARSSL_ERR_SSL_CERTIFICATE_REQUIRED ); } } SSL_DEBUG_CRT( 3, "own certificate", ssl->own_cert ); /* * 0 . 0 handshake type * 1 . 3 handshake length * 4 . 6 length of all certs * 7 . 9 length of cert. 1 * 10 . n-1 peer certificate * n . n+2 length of cert. 2 * n+3 . ... upper level cert, etc. */ i = 7; crt = ssl->own_cert; while( crt != NULL && crt->next != NULL ) { n = crt->raw.len; if( i + 3 + n > SSL_MAX_CONTENT_LEN ) { SSL_DEBUG_MSG( 1, ( "certificate too large, %d > %d", i + 3 + n, SSL_MAX_CONTENT_LEN ) ); return( POLARSSL_ERR_SSL_CERTIFICATE_TOO_LARGE ); } ssl->out_msg[i ] = (unsigned char)( n >> 16 ); ssl->out_msg[i + 1] = (unsigned char)( n >> 8 ); ssl->out_msg[i + 2] = (unsigned char)( n ); i += 3; memcpy( ssl->out_msg + i, crt->raw.p, n ); i += n; crt = crt->next; } ssl->out_msg[4] = (unsigned char)( ( i - 7 ) >> 16 ); ssl->out_msg[5] = (unsigned char)( ( i - 7 ) >> 8 ); ssl->out_msg[6] = (unsigned char)( ( i - 7 ) ); ssl->out_msglen = i; ssl->out_msgtype = SSL_MSG_HANDSHAKE; ssl->out_msg[0] = SSL_HS_CERTIFICATE; write_msg: ssl->state++; if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= write certificate" ) ); return( 0 ); } int ssl_parse_certificate( ssl_context *ssl ) { int ret, i, n; SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) ); if( ssl->endpoint == SSL_IS_SERVER && ssl->authmode == SSL_VERIFY_NONE ) { SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) ); ssl->state++; return( 0 ); } if( ( ret = ssl_read_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_read_record", ret ); return( ret ); } ssl->state++; /* * Check if the client sent an empty certificate */ if( ssl->endpoint == SSL_IS_SERVER && ssl->minor_ver == SSL_MINOR_VERSION_0 ) { if( ssl->in_msglen == 2 && ssl->in_msgtype == SSL_MSG_ALERT && ssl->in_msg[0] == SSL_ALERT_WARNING && ssl->in_msg[1] == SSL_ALERT_NO_CERTIFICATE ) { SSL_DEBUG_MSG( 1, ( "SSLv3 client has no certificate" ) ); if( ssl->authmode == SSL_VERIFY_OPTIONAL ) return( 0 ); else return( POLARSSL_ERR_SSL_NO_CLIENT_CERTIFICATE ); } } if( ssl->endpoint == SSL_IS_SERVER && ssl->minor_ver != SSL_MINOR_VERSION_0 ) { if( ssl->in_hslen == 7 && ssl->in_msgtype == SSL_MSG_HANDSHAKE && ssl->in_msg[0] == SSL_HS_CERTIFICATE && memcmp( ssl->in_msg + 4, "\0\0\0", 3 ) == 0 ) { SSL_DEBUG_MSG( 1, ( "TLSv1 client has no certificate" ) ); if( ssl->authmode == SSL_VERIFY_REQUIRED ) return( POLARSSL_ERR_SSL_NO_CLIENT_CERTIFICATE ); else return( 0 ); } } if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } if( ssl->in_msg[0] != SSL_HS_CERTIFICATE || ssl->in_hslen < 10 ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } /* * Same message structure as in ssl_write_certificate() */ n = ( ssl->in_msg[5] << 8 ) | ssl->in_msg[6]; if( ssl->in_msg[4] != 0 || ssl->in_hslen != 7 + n ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } if( ( ssl->peer_cert = (x509_cert *) malloc( sizeof( x509_cert ) ) ) == NULL ) { SSL_DEBUG_MSG( 1, ( "malloc(%d bytes) failed", sizeof( x509_cert ) ) ); return( 1 ); } memset( ssl->peer_cert, 0, sizeof( x509_cert ) ); i = 7; while( i < ssl->in_hslen ) { if( ssl->in_msg[i] != 0 ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } n = ( (unsigned int) ssl->in_msg[i + 1] << 8 ) | (unsigned int) ssl->in_msg[i + 2]; i += 3; if( n < 128 || i + n > ssl->in_hslen ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } ret = x509parse_crt( ssl->peer_cert, ssl->in_msg + i, n ); if( ret != 0 ) { SSL_DEBUG_RET( 1, " x509parse_crt", ret ); return( ret ); } i += n; } SSL_DEBUG_CRT( 3, "peer certificate", ssl->peer_cert ); if( ssl->authmode != SSL_VERIFY_NONE ) { if( ssl->ca_chain == NULL ) { SSL_DEBUG_MSG( 1, ( "got no CA chain" ) ); return( POLARSSL_ERR_SSL_CA_CHAIN_REQUIRED ); } ret = x509parse_verify( ssl->peer_cert, ssl->ca_chain, ssl->peer_cn, &ssl->verify_result ); if( ret != 0 ) SSL_DEBUG_RET( 1, "x509_verify_cert", ret ); if( ssl->authmode != SSL_VERIFY_REQUIRED ) ret = 0; } SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) ); return( ret ); } int ssl_write_change_cipher_spec( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> write change cipher spec" ) ); ssl->out_msgtype = SSL_MSG_CHANGE_CIPHER_SPEC; ssl->out_msglen = 1; ssl->out_msg[0] = 1; ssl->do_crypt = 0; ssl->state++; if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= write change cipher spec" ) ); return( 0 ); } int ssl_parse_change_cipher_spec( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> parse change cipher spec" ) ); ssl->do_crypt = 0; if( ( ret = ssl_read_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_read_record", ret ); return( ret ); } if( ssl->in_msgtype != SSL_MSG_CHANGE_CIPHER_SPEC ) { SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) ); return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } if( ssl->in_msglen != 1 || ssl->in_msg[0] != 1 ) { SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CHANGE_CIPHER_SPEC ); } ssl->state++; SSL_DEBUG_MSG( 2, ( "<= parse change cipher spec" ) ); return( 0 ); } static void ssl_calc_finished( ssl_context *ssl, unsigned char *buf, int from, md5_context *md5, sha1_context *sha1 ) { int len = 12; char *sender; unsigned char padbuf[48]; unsigned char md5sum[16]; unsigned char sha1sum[20]; SSL_DEBUG_MSG( 2, ( "=> calc finished" ) ); /* * SSLv3: * hash = * MD5( master + pad2 + * MD5( handshake + sender + master + pad1 ) ) * + SHA1( master + pad2 + * SHA1( handshake + sender + master + pad1 ) ) * * TLSv1: * hash = PRF( master, finished_label, * MD5( handshake ) + SHA1( handshake ) )[0..11] */ SSL_DEBUG_BUF( 4, "finished md5 state", (unsigned char *) md5->state, sizeof( md5->state ) ); SSL_DEBUG_BUF( 4, "finished sha1 state", (unsigned char *) sha1->state, sizeof( sha1->state ) ); if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { sender = ( from == SSL_IS_CLIENT ) ? (char *) "CLNT" : (char *) "SRVR"; memset( padbuf, 0x36, 48 ); md5_update( md5, (unsigned char *) sender, 4 ); md5_update( md5, ssl->session->master, 48 ); md5_update( md5, padbuf, 48 ); md5_finish( md5, md5sum ); sha1_update( sha1, (unsigned char *) sender, 4 ); sha1_update( sha1, ssl->session->master, 48 ); sha1_update( sha1, padbuf, 40 ); sha1_finish( sha1, sha1sum ); memset( padbuf, 0x5C, 48 ); md5_starts( md5 ); md5_update( md5, ssl->session->master, 48 ); md5_update( md5, padbuf, 48 ); md5_update( md5, md5sum, 16 ); md5_finish( md5, buf ); sha1_starts( sha1 ); sha1_update( sha1, ssl->session->master, 48 ); sha1_update( sha1, padbuf , 40 ); sha1_update( sha1, sha1sum, 20 ); sha1_finish( sha1, buf + 16 ); len += 24; } else { sender = ( from == SSL_IS_CLIENT ) ? (char *) "client finished" : (char *) "server finished"; md5_finish( md5, padbuf ); sha1_finish( sha1, padbuf + 16 ); tls1_prf( ssl->session->master, 48, sender, padbuf, 36, buf, len ); } SSL_DEBUG_BUF( 3, "calc finished result", buf, len ); memset( md5, 0, sizeof( md5_context ) ); memset( sha1, 0, sizeof( sha1_context ) ); memset( padbuf, 0, sizeof( padbuf ) ); memset( md5sum, 0, sizeof( md5sum ) ); memset( sha1sum, 0, sizeof( sha1sum ) ); SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } int ssl_write_finished( ssl_context *ssl ) { int ret, hash_len; md5_context md5; sha1_context sha1; SSL_DEBUG_MSG( 2, ( "=> write finished" ) ); memcpy( &md5 , &ssl->fin_md5 , sizeof( md5_context ) ); memcpy( &sha1, &ssl->fin_sha1, sizeof( sha1_context ) ); ssl_calc_finished( ssl, ssl->out_msg + 4, ssl->endpoint, &md5, &sha1 ); hash_len = ( ssl->minor_ver == SSL_MINOR_VERSION_0 ) ? 36 : 12; ssl->out_msglen = 4 + hash_len; ssl->out_msgtype = SSL_MSG_HANDSHAKE; ssl->out_msg[0] = SSL_HS_FINISHED; /* * In case of session resuming, invert the client and server * ChangeCipherSpec messages order. */ if( ssl->resume != 0 ) { if( ssl->endpoint == SSL_IS_CLIENT ) ssl->state = SSL_HANDSHAKE_OVER; else ssl->state = SSL_CLIENT_CHANGE_CIPHER_SPEC; } else ssl->state++; ssl->do_crypt = 1; if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= write finished" ) ); return( 0 ); } int ssl_parse_finished( ssl_context *ssl ) { int ret, hash_len; md5_context md5; sha1_context sha1; unsigned char buf[36]; SSL_DEBUG_MSG( 2, ( "=> parse finished" ) ); memcpy( &md5 , &ssl->fin_md5 , sizeof( md5_context ) ); memcpy( &sha1, &ssl->fin_sha1, sizeof( sha1_context ) ); ssl->do_crypt = 1; 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 finished message" ) ); return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } hash_len = ( ssl->minor_ver == SSL_MINOR_VERSION_0 ) ? 36 : 12; if( ssl->in_msg[0] != SSL_HS_FINISHED || ssl->in_hslen != 4 + hash_len ) { SSL_DEBUG_MSG( 1, ( "bad finished message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_FINISHED ); } ssl_calc_finished( ssl, buf, ssl->endpoint ^ 1, &md5, &sha1 ); if( memcmp( ssl->in_msg + 4, buf, hash_len ) != 0 ) { SSL_DEBUG_MSG( 1, ( "bad finished message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_FINISHED ); } if( ssl->resume != 0 ) { if( ssl->endpoint == SSL_IS_CLIENT ) ssl->state = SSL_CLIENT_CHANGE_CIPHER_SPEC; if( ssl->endpoint == SSL_IS_SERVER ) ssl->state = SSL_HANDSHAKE_OVER; } else ssl->state++; SSL_DEBUG_MSG( 2, ( "<= parse finished" ) ); return( 0 ); } /* * Initialize an SSL context */ int ssl_init( ssl_context *ssl ) { int len = SSL_BUFFER_LEN; memset( ssl, 0, sizeof( ssl_context ) ); ssl->in_ctr = (unsigned char *) malloc( len ); ssl->in_hdr = ssl->in_ctr + 8; ssl->in_msg = ssl->in_ctr + 13; if( ssl->in_ctr == NULL ) { SSL_DEBUG_MSG( 1, ( "malloc(%d bytes) failed", len ) ); return( 1 ); } ssl->out_ctr = (unsigned char *) malloc( len ); ssl->out_hdr = ssl->out_ctr + 8; ssl->out_msg = ssl->out_ctr + 13; if( ssl->out_ctr == NULL ) { SSL_DEBUG_MSG( 1, ( "malloc(%d bytes) failed", len ) ); free( ssl-> in_ctr ); return( 1 ); } memset( ssl-> in_ctr, 0, SSL_BUFFER_LEN ); memset( ssl->out_ctr, 0, SSL_BUFFER_LEN ); ssl->hostname = NULL; ssl->hostname_len = 0; md5_starts( &ssl->fin_md5 ); sha1_starts( &ssl->fin_sha1 ); return( 0 ); } /* * SSL set accessors */ void ssl_set_endpoint( ssl_context *ssl, int endpoint ) { ssl->endpoint = endpoint; } void ssl_set_authmode( ssl_context *ssl, int authmode ) { ssl->authmode = authmode; } void ssl_set_rng( ssl_context *ssl, int (*f_rng)(void *), void *p_rng ) { ssl->f_rng = f_rng; ssl->p_rng = p_rng; } void ssl_set_dbg( ssl_context *ssl, void (*f_dbg)(void *, int, char *), void *p_dbg ) { ssl->f_dbg = f_dbg; ssl->p_dbg = p_dbg; } void ssl_set_bio( ssl_context *ssl, int (*f_recv)(void *, unsigned char *, int), void *p_recv, int (*f_send)(void *, unsigned char *, int), void *p_send ) { ssl->f_recv = f_recv; ssl->f_send = f_send; ssl->p_recv = p_recv; ssl->p_send = p_send; } void ssl_set_scb( ssl_context *ssl, int (*s_get)(ssl_context *), int (*s_set)(ssl_context *) ) { ssl->s_get = s_get; ssl->s_set = s_set; } void ssl_set_session( ssl_context *ssl, int resume, int timeout, ssl_session *session ) { ssl->resume = resume; ssl->timeout = timeout; ssl->session = session; } void ssl_set_ciphers( ssl_context *ssl, int *ciphers ) { ssl->ciphers = ciphers; } void ssl_set_ca_chain( ssl_context *ssl, x509_cert *ca_chain, char *peer_cn ) { ssl->ca_chain = ca_chain; ssl->peer_cn = peer_cn; } void ssl_set_own_cert( ssl_context *ssl, x509_cert *own_cert, rsa_context *rsa_key ) { ssl->own_cert = own_cert; ssl->rsa_key = rsa_key; } int ssl_set_dh_param( ssl_context *ssl, char *dhm_P, char *dhm_G ) { int ret; if( ( ret = mpi_read_string( &ssl->dhm_ctx.P, 16, dhm_P ) ) != 0 ) { SSL_DEBUG_RET( 1, "mpi_read_string", ret ); return( ret ); } if( ( ret = mpi_read_string( &ssl->dhm_ctx.G, 16, dhm_G ) ) != 0 ) { SSL_DEBUG_RET( 1, "mpi_read_string", ret ); return( ret ); } return( 0 ); } int ssl_set_hostname( ssl_context *ssl, char *hostname ) { if( hostname == NULL ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); ssl->hostname_len = strlen( hostname ); ssl->hostname = (unsigned char *) malloc( ssl->hostname_len ); memcpy( ssl->hostname, (unsigned char *) hostname, ssl->hostname_len ); return( 0 ); } /* * SSL get accessors */ int ssl_get_bytes_avail( ssl_context *ssl ) { return( ssl->in_offt == NULL ? 0 : ssl->in_msglen ); } int ssl_get_verify_result( ssl_context *ssl ) { return( ssl->verify_result ); } char *ssl_get_cipher( ssl_context *ssl ) { switch( ssl->session->cipher ) { #if defined(POLARSSL_ARC4_C) case SSL_RSA_RC4_128_MD5: return( "SSL_RSA_RC4_128_MD5" ); case SSL_RSA_RC4_128_SHA: return( "SSL_RSA_RC4_128_SHA" ); #endif #if defined(POLARSSL_DES_C) case SSL_RSA_DES_168_SHA: return( "SSL_RSA_DES_168_SHA" ); case SSL_EDH_RSA_DES_168_SHA: return( "SSL_EDH_RSA_DES_168_SHA" ); #endif #if defined(POLARSSL_AES_C) case SSL_RSA_AES_128_SHA: return( "SSL_RSA_AES_128_SHA" ); case SSL_RSA_AES_256_SHA: return( "SSL_RSA_AES_256_SHA" ); case SSL_EDH_RSA_AES_256_SHA: return( "SSL_EDH_RSA_AES_256_SHA" ); #endif #if defined(POLARSSL_CAMELLIA_C) case SSL_RSA_CAMELLIA_128_SHA: return( "SSL_RSA_CAMELLIA_128_SHA" ); case SSL_RSA_CAMELLIA_256_SHA: return( "SSL_RSA_CAMELLIA_256_SHA" ); case SSL_EDH_RSA_CAMELLIA_256_SHA: return( "SSL_EDH_RSA_CAMELLIA_256_SHA" ); #endif default: break; } return( "unknown" ); } int ssl_default_ciphers[] = { #if defined(POLARSSL_DHM_C) #if defined(POLARSSL_AES_C) SSL_EDH_RSA_AES_256_SHA, #endif #if defined(POLARSSL_CAMELLIA_C) SSL_EDH_RSA_CAMELLIA_256_SHA, #endif #if defined(POLARSSL_DES_C) SSL_EDH_RSA_DES_168_SHA, #endif #endif #if defined(POLARSSL_AES_C) SSL_RSA_AES_256_SHA, #endif #if defined(POLARSSL_CAMELLIA_C) SSL_RSA_CAMELLIA_256_SHA, #endif #if defined(POLARSSL_AES_C) SSL_RSA_AES_128_SHA, #endif #if defined(POLARSSL_CAMELLIA_C) SSL_RSA_CAMELLIA_128_SHA, #endif #if defined(POLARSSL_DES_C) SSL_RSA_DES_168_SHA, #endif #if defined(POLARSSL_ARC4_C) SSL_RSA_RC4_128_SHA, SSL_RSA_RC4_128_MD5, #endif 0 }; /* * Perform the SSL handshake */ int ssl_handshake( ssl_context *ssl ) { int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; SSL_DEBUG_MSG( 2, ( "=> handshake" ) ); #if defined(POLARSSL_SSL_CLI_C) if( ssl->endpoint == SSL_IS_CLIENT ) ret = ssl_handshake_client( ssl ); #endif #if defined(POLARSSL_SSL_SRV_C) if( ssl->endpoint == SSL_IS_SERVER ) ret = ssl_handshake_server( ssl ); #endif SSL_DEBUG_MSG( 2, ( "<= handshake" ) ); return( ret ); } /* * Receive application data decrypted from the SSL layer */ int ssl_read( ssl_context *ssl, unsigned char *buf, int len ) { int ret, n; SSL_DEBUG_MSG( 2, ( "=> read" ) ); if( ssl->state != SSL_HANDSHAKE_OVER ) { if( ( ret = ssl_handshake( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_handshake", ret ); return( ret ); } } if( ssl->in_offt == NULL ) { if( ( ret = ssl_read_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_read_record", ret ); return( ret ); } if( ssl->in_msglen == 0 && ssl->in_msgtype == SSL_MSG_APPLICATION_DATA ) { /* * OpenSSL sends empty messages to randomize the IV */ if( ( ret = ssl_read_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_read_record", ret ); return( ret ); } } if( ssl->in_msgtype != SSL_MSG_APPLICATION_DATA ) { SSL_DEBUG_MSG( 1, ( "bad application data message" ) ); return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } ssl->in_offt = ssl->in_msg; } n = ( len < ssl->in_msglen ) ? len : ssl->in_msglen; memcpy( buf, ssl->in_offt, n ); ssl->in_msglen -= n; if( ssl->in_msglen == 0 ) /* all bytes consumed */ ssl->in_offt = NULL; else /* more data available */ ssl->in_offt += n; SSL_DEBUG_MSG( 2, ( "<= read" ) ); return( n ); } /* * Send application data to be encrypted by the SSL layer */ int ssl_write( ssl_context *ssl, unsigned char *buf, int len ) { int ret, n; SSL_DEBUG_MSG( 2, ( "=> write" ) ); if( ssl->state != SSL_HANDSHAKE_OVER ) { if( ( ret = ssl_handshake( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_handshake", ret ); return( ret ); } } n = ( len < SSL_MAX_CONTENT_LEN ) ? len : SSL_MAX_CONTENT_LEN; if( ssl->out_left != 0 ) { if( ( ret = ssl_flush_output( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_flush_output", ret ); return( ret ); } } else { ssl->out_msglen = n; ssl->out_msgtype = SSL_MSG_APPLICATION_DATA; memcpy( ssl->out_msg, buf, n ); if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } } SSL_DEBUG_MSG( 2, ( "<= write" ) ); return( n ); } /* * Notify the peer that the connection is being closed */ int ssl_close_notify( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> write close notify" ) ); if( ( ret = ssl_flush_output( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_flush_output", ret ); return( ret ); } if( ssl->state == SSL_HANDSHAKE_OVER ) { ssl->out_msgtype = SSL_MSG_ALERT; ssl->out_msglen = 2; ssl->out_msg[0] = SSL_ALERT_WARNING; ssl->out_msg[1] = SSL_ALERT_CLOSE_NOTIFY; if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } } SSL_DEBUG_MSG( 2, ( "<= write close notify" ) ); return( ret ); } /* * Free an SSL context */ void ssl_free( ssl_context *ssl ) { SSL_DEBUG_MSG( 2, ( "=> free" ) ); if( ssl->peer_cert != NULL ) { x509_free( ssl->peer_cert ); memset( ssl->peer_cert, 0, sizeof( x509_cert ) ); free( ssl->peer_cert ); } if( ssl->out_ctr != NULL ) { memset( ssl->out_ctr, 0, SSL_BUFFER_LEN ); free( ssl->out_ctr ); } if( ssl->in_ctr != NULL ) { memset( ssl->in_ctr, 0, SSL_BUFFER_LEN ); free( ssl->in_ctr ); } #if defined(POLARSSL_DHM_C) dhm_free( &ssl->dhm_ctx ); #endif if ( ssl->hostname != NULL) { memset( ssl->hostname, 0, ssl->hostname_len ); free( ssl->hostname ); ssl->hostname_len = 0; } SSL_DEBUG_MSG( 2, ( "<= free" ) ); /* Actually free after last debug message */ memset( ssl, 0, sizeof( ssl_context ) ); } #endif