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home:Alexander_Naumov:SLE-12:Update
compat-openssl098.503
CVE-2013-0169.patch
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File CVE-2013-0169.patch of Package compat-openssl098.503
Index: openssl-0.9.8j/crypto/cryptlib.c =================================================================== --- openssl-0.9.8j.orig/crypto/cryptlib.c +++ openssl-0.9.8j/crypto/cryptlib.c @@ -568,3 +568,19 @@ void OpenSSLDie(const char *file,int lin } void *OPENSSL_stderr(void) { return stderr; } + +#ifndef OPENSSL_FIPS + +int CRYPTO_memcmp(const void *in_a, const void *in_b, size_t len) +{ + size_t i; + const unsigned char *a = in_a; + const unsigned char *b = in_b; + unsigned char x = 0; + + for (i = 0; i < len; i++) + x |= a[i] ^ b[i]; + + return x; +} +#endif Index: openssl-0.9.8j/crypto/crypto.h =================================================================== --- openssl-0.9.8j.orig/crypto/crypto.h +++ openssl-0.9.8j/crypto/crypto.h @@ -588,6 +588,13 @@ int OPENSSL_isservice(void); #endif /* def OPENSSL_FIPS */ +/* CRYPTO_memcmp returns zero iff the |len| bytes at |a| and |b| are equal. It + * takes an amount of time dependent on |len|, but independent of the contents + * of |a| and |b|. Unlike memcmp, it cannot be used to put elements into a + * defined order as the return value when a != b is undefined, other than to be + * non-zero. */ +int CRYPTO_memcmp(const void *a, const void *b, size_t len); + /* BEGIN ERROR CODES */ /* The following lines are auto generated by the script mkerr.pl. Any changes * made after this point may be overwritten when the script is next run. Index: openssl-0.9.8j/crypto/rsa/rsa_oaep.c =================================================================== --- openssl-0.9.8j.orig/crypto/rsa/rsa_oaep.c +++ openssl-0.9.8j/crypto/rsa/rsa_oaep.c @@ -143,7 +143,7 @@ int RSA_padding_check_PKCS1_OAEP(unsigne EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1(), NULL); - if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad) + if (CRYPTO_memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad) goto decoding_err; else { Index: openssl-0.9.8j/ssl/d1_pkt.c =================================================================== --- openssl-0.9.8j.orig/ssl/d1_pkt.c +++ openssl-0.9.8j/ssl/d1_pkt.c @@ -328,9 +328,8 @@ dtls1_get_buffered_record(SSL *s) static int dtls1_process_record(SSL *s) { - int i,al; - int clear=0; - int enc_err; + int i,al; + int enc_err; SSL_SESSION *sess; SSL3_RECORD *rr; unsigned int mac_size; @@ -367,14 +366,19 @@ dtls1_process_record(SSL *s) /* decrypt in place in 'rr->input' */ rr->data=rr->input; + rr->orig_len=rr->length; enc_err = s->method->ssl3_enc->enc(s,0); - if (enc_err <= 0) + /* enc_err is: + * 0: (in non-constant time) if the record is publically invalid. + * 1: if the padding is valid + * -1: if the padding is invalid */ + if (enc_err == 0) { - /* To minimize information leaked via timing, we will always - * perform all computations before discarding the message. - */ - decryption_failed_or_bad_record_mac = 1; + /* For DTLS we simply ignore bad packets. */ + rr->length = 0; + s->packet_length = 0; + goto err; } #ifdef TLS_DEBUG @@ -384,41 +388,59 @@ printf("\n"); #endif /* r->length is now the compressed data plus mac */ -if ( (sess == NULL) || - (s->enc_read_ctx == NULL) || - (s->read_hash == NULL)) - clear=1; - - if (!clear) + if ((sess != NULL) && + (s->enc_read_ctx != NULL) && + (s->read_hash != NULL)) { + /* s->read_hash != NULL => mac_size != -1 */ + unsigned char *mac = NULL; + unsigned char mac_tmp[EVP_MAX_MD_SIZE]; mac_size=EVP_MD_size(s->read_hash); + OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); - if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) + /* orig_len is the length of the record before any padding was + * removed. This is public information, as is the MAC in use, + * therefore we can safely process the record in a different + * amount of time if it's too short to possibly contain a MAC. + */ + if (rr->orig_len < mac_size || + /* CBC records must have a padding length byte too. */ + (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && + rr->orig_len < mac_size+1)) { -#if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */ - al=SSL_AD_RECORD_OVERFLOW; - SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG); + al=SSL_AD_DECODE_ERROR; + SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT); goto f_err; -#else - decryption_failed_or_bad_record_mac = 1; -#endif } - /* check the MAC for rr->input (it's in mac_size bytes at the tail) */ - if (rr->length >= mac_size) + + if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { + /* We update the length so that the TLS header bytes + * can be constructed correctly but we need to extract + * the MAC in constant time from within the record, + * without leaking the contents of the padding bytes. + */ + mac = mac_tmp; + ssl3_cbc_copy_mac(mac_tmp, rr, mac_size); rr->length -= mac_size; - mac = &rr->data[rr->length]; } else - rr->length = 0; - i=s->method->ssl3_enc->mac(s,md,0); - if (mac == NULL || memcmp(md, mac, mac_size) != 0) { - decryption_failed_or_bad_record_mac = 1; + /* In this case there's no padding, so |rec->orig_len| + * equals |rec->length| and we checked that there's + * enough bytes for |mac_size| above. */ + rr->length -= mac_size; + mac = &rr->data[rr->length]; } + + i=s->method->ssl3_enc->mac(s,md,0 /* not send */); + if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) + enc_err = -1; + if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size) + enc_err = -1; } - if (decryption_failed_or_bad_record_mac) + if (enc_err < 0) { /* decryption failed, silently discard message */ rr->length = 0; Index: openssl-0.9.8j/ssl/s2_clnt.c =================================================================== --- openssl-0.9.8j.orig/ssl/s2_clnt.c +++ openssl-0.9.8j/ssl/s2_clnt.c @@ -935,7 +935,7 @@ static int get_server_verify(SSL *s) s->msg_callback(0, s->version, 0, p, len, s, s->msg_callback_arg); /* SERVER-VERIFY */ p += 1; - if (memcmp(p,s->s2->challenge,s->s2->challenge_length) != 0) + if (CRYPTO_memcmp(p,s->s2->challenge,s->s2->challenge_length) != 0) { ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR); SSLerr(SSL_F_GET_SERVER_VERIFY,SSL_R_CHALLENGE_IS_DIFFERENT); Index: openssl-0.9.8j/ssl/s2_pkt.c =================================================================== --- openssl-0.9.8j.orig/ssl/s2_pkt.c +++ openssl-0.9.8j/ssl/s2_pkt.c @@ -267,8 +267,7 @@ static int ssl2_read_internal(SSL *s, vo s->s2->ract_data_length-=mac_size; ssl2_mac(s,mac,0); s->s2->ract_data_length-=s->s2->padding; - if ( (memcmp(mac,s->s2->mac_data, - (unsigned int)mac_size) != 0) || + if ( (CRYPTO_memcmp(mac,s->s2->mac_data,mac_size) != 0) || (s->s2->rlength%EVP_CIPHER_CTX_block_size(s->enc_read_ctx) != 0)) { SSLerr(SSL_F_SSL2_READ_INTERNAL,SSL_R_BAD_MAC_DECODE); Index: openssl-0.9.8j/ssl/s3_both.c =================================================================== --- openssl-0.9.8j.orig/ssl/s3_both.c +++ openssl-0.9.8j/ssl/s3_both.c @@ -243,7 +243,7 @@ int ssl3_get_finished(SSL *s, int a, int goto f_err; } - if (memcmp(p, s->s3->tmp.peer_finish_md, i) != 0) + if (CRYPTO_memcmp(p, s->s3->tmp.peer_finish_md, i) != 0) { al=SSL_AD_DECRYPT_ERROR; SSLerr(SSL_F_SSL3_GET_FINISHED,SSL_R_DIGEST_CHECK_FAILED); Index: openssl-0.9.8j/ssl/s3_pkt.c =================================================================== --- openssl-0.9.8j.orig/ssl/s3_pkt.c +++ openssl-0.9.8j/ssl/s3_pkt.c @@ -237,11 +237,8 @@ static int ssl3_get_record(SSL *s) unsigned char *p; unsigned char md[EVP_MAX_MD_SIZE]; short version; - unsigned int mac_size; - int clear=0; + unsigned mac_size; size_t extra; - int decryption_failed_or_bad_record_mac = 0; - unsigned char *mac = NULL; rr= &(s->s3->rrec); sess=s->session; @@ -345,20 +342,19 @@ again: /* decrypt in place in 'rr->input' */ rr->data=rr->input; + rr->orig_len=rr->length; enc_err = s->method->ssl3_enc->enc(s,0); - if (enc_err <= 0) - { - if (enc_err == 0) - /* SSLerr() and ssl3_send_alert() have been called */ - goto err; - - /* Otherwise enc_err == -1, which indicates bad padding - * (rec->length has not been changed in this case). - * To minimize information leaked via timing, we will perform - * the MAC computation anyway. */ - decryption_failed_or_bad_record_mac = 1; - } + /* enc_err is: + * 0: (in non-constant time) if the record is publically invalid. + * 1: if the padding is valid + * -1: if the padding is invalid */ + if (enc_err == 0) + { + al=SSL_AD_DECRYPTION_FAILED; + SSLerr(SSL_F_TLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); + goto f_err; + } #ifdef TLS_DEBUG printf("dec %d\n",rr->length); @@ -367,51 +363,59 @@ printf("\n"); #endif /* r->length is now the compressed data plus mac */ - if ( (sess == NULL) || - (s->enc_read_ctx == NULL) || - (s->read_hash == NULL)) - clear=1; - - if (!clear) - { - mac_size=EVP_MD_size(s->read_hash); - - if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size) + if ((sess != NULL) && + (s->enc_read_ctx != NULL) && + (s->read_hash != NULL)) + { + /* s->read_hash != NULL => mac_size != -1 */ + unsigned char *mac = NULL; + unsigned char mac_tmp[EVP_MAX_MD_SIZE]; + mac_size=EVP_MD_size(s->read_hash); + OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); + + /* orig_len is the length of the record before any padding was + * removed. This is public information, as is the MAC in use, + * therefore we can safely process the record in a different + * amount of time if it's too short to possibly contain a MAC. + */ + if (rr->orig_len < mac_size || + /* CBC records must have a padding length byte too. */ + (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && + rr->orig_len < mac_size+1)) { -#if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */ - al=SSL_AD_RECORD_OVERFLOW; - SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG); - goto f_err; -#else - decryption_failed_or_bad_record_mac = 1; -#endif + al=SSL_AD_DECODE_ERROR; + SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT); + goto f_err; } - /* check the MAC for rr->input (it's in mac_size bytes at the tail) */ - if (rr->length >= mac_size) + + if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { - rr->length -= mac_size; - mac = &rr->data[rr->length]; + /* We update the length so that the TLS header bytes + * can be constructed correctly but we need to extract + * the MAC in constant time from within the record, + * without leaking the contents of the padding bytes. + */ + mac = mac_tmp; + ssl3_cbc_copy_mac(mac_tmp, rr, mac_size); + rr->length -= mac_size; } else { - /* record (minus padding) is too short to contain a MAC */ -#if 0 /* OK only for stream ciphers */ - al=SSL_AD_DECODE_ERROR; - SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT); - goto f_err; -#else - decryption_failed_or_bad_record_mac = 1; - rr->length = 0; -#endif - } - i=s->method->ssl3_enc->mac(s,md,0); - if (mac == NULL || memcmp(md, mac, mac_size) != 0) - { - decryption_failed_or_bad_record_mac = 1; + /* In this case there's no padding, so |rec->orig_len| + * equals |rec->length| and we checked that there's + * enough bytes for |mac_size| above. */ + rr->length -= mac_size; + mac = &rr->data[rr->length]; } + + i=s->method->ssl3_enc->mac(s,md,0 /* not send */); + if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) + enc_err = -1; + if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size) + enc_err = -1; } - if (decryption_failed_or_bad_record_mac) + if (enc_err < 0) { /* A separate 'decryption_failed' alert was introduced with TLS 1.0, * SSL 3.0 only has 'bad_record_mac'. But unless a decryption Index: openssl-0.9.8j/ssl/t1_lib.c =================================================================== --- openssl-0.9.8j.orig/ssl/t1_lib.c +++ openssl-0.9.8j/ssl/t1_lib.c @@ -956,7 +956,7 @@ static int tls_decrypt_ticket(SSL *s, co HMAC_Update(&hctx, etick, eticklen); HMAC_Final(&hctx, tick_hmac, NULL); HMAC_CTX_cleanup(&hctx); - if (memcmp(tick_hmac, etick + eticklen, mlen)) + if (CRYPTO_memcmp(tick_hmac, etick + eticklen, mlen)) goto tickerr; /* Attempt to decrypt session data */ /* Move p after IV to start of encrypted ticket, update length */ Index: openssl-0.9.8j/ssl/Makefile =================================================================== --- openssl-0.9.8j.orig/ssl/Makefile +++ openssl-0.9.8j/ssl/Makefile @@ -22,7 +22,7 @@ LIB=$(TOP)/libssl.a SHARED_LIB= libssl$(SHLIB_EXT) LIBSRC= \ s2_meth.c s2_srvr.c s2_clnt.c s2_lib.c s2_enc.c s2_pkt.c \ - s3_meth.c s3_srvr.c s3_clnt.c s3_lib.c s3_enc.c s3_pkt.c s3_both.c \ + s3_meth.c s3_srvr.c s3_clnt.c s3_lib.c s3_enc.c s3_pkt.c s3_both.c s3_cbc.c \ s23_meth.c s23_srvr.c s23_clnt.c s23_lib.c s23_pkt.c \ t1_meth.c t1_srvr.c t1_clnt.c t1_lib.c t1_enc.c \ d1_meth.c d1_srvr.c d1_clnt.c d1_lib.c d1_pkt.c \ @@ -33,7 +33,7 @@ LIBSRC= \ bio_ssl.c ssl_err.c kssl.c t1_reneg.c LIBOBJ= \ s2_meth.o s2_srvr.o s2_clnt.o s2_lib.o s2_enc.o s2_pkt.o \ - s3_meth.o s3_srvr.o s3_clnt.o s3_lib.o s3_enc.o s3_pkt.o s3_both.o \ + s3_meth.o s3_srvr.o s3_clnt.o s3_lib.o s3_enc.o s3_pkt.o s3_both.o s3_cbc.o \ s23_meth.o s23_srvr.o s23_clnt.o s23_lib.o s23_pkt.o \ t1_meth.o t1_srvr.o t1_clnt.o t1_lib.o t1_enc.o \ d1_meth.o d1_srvr.o d1_clnt.o d1_lib.o d1_pkt.o \ Index: openssl-0.9.8j/ssl/d1_enc.c =================================================================== --- openssl-0.9.8j.orig/ssl/d1_enc.c +++ openssl-0.9.8j/ssl/d1_enc.c @@ -126,16 +126,30 @@ #include <openssl/des.h> #endif +/* dtls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively. + * + * Returns: + * 0: (in non-constant time) if the record is publically invalid (i.e. too + * short etc). + * 1: if the record's padding is valid / the encryption was successful. + * -1: if the record's padding/AEAD-authenticator is invalid or, if sending, + * an internal error occured. */ int dtls1_enc(SSL *s, int send) { SSL3_RECORD *rec; EVP_CIPHER_CTX *ds; unsigned long l; - int bs,i,ii,j,k,n=0; + int bs,i,ii,j,k,mac_size=0, n=0; const EVP_CIPHER *enc; if (send) { + if (s->write_hash) + { + mac_size=EVP_MD_size(s->write_hash); + if (mac_size < 0) + return -1; + } if (s->write_hash != NULL) n=EVP_MD_size(s->write_hash); ds=s->enc_write_ctx; @@ -158,8 +172,11 @@ int dtls1_enc(SSL *s, int send) } else { - if (s->read_hash != NULL) - n=EVP_MD_size(s->read_hash); + if (s->read_hash) + { + mac_size=EVP_MD_size(s->read_hash); + OPENSSL_assert(mac_size >= 0); + } ds=s->enc_read_ctx; rec= &(s->s3->rrec); if (s->enc_read_ctx == NULL) @@ -224,11 +241,7 @@ int dtls1_enc(SSL *s, int send) if (!send) { if (l == 0 || l%bs != 0) - { - SSLerr(SSL_F_DTLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); - ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED); return 0; - } } EVP_Cipher(ds,rec->data,rec->input,l); @@ -243,44 +256,7 @@ int dtls1_enc(SSL *s, int send) #endif /* KSSL_DEBUG */ if ((bs != 1) && !send) - { - ii=i=rec->data[l-1]; /* padding_length */ - i++; - if (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG) - { - /* First packet is even in size, so check */ - if ((memcmp(s->s3->read_sequence, - "\0\0\0\0\0\0\0\0",8) == 0) && !(ii & 1)) - s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG; - if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) - i--; - } - /* TLS 1.0 does not bound the number of padding bytes by the block size. - * All of them must have value 'padding_length'. */ - if (i > (int)rec->length) - if (i + bs > (int)rec->length) - { - /* Incorrect padding. SSLerr() and ssl3_alert are done - * by caller: we don't want to reveal whether this is - * a decryption error or a MAC verification failure - * (see http://www.openssl.org/~bodo/tls-cbc.txt) - */ - return -1; - } - for (j=(int)(l-i); j<(int)l; j++) - { - if (rec->data[j] != ii) - { - /* Incorrect padding */ - return -1; - } - } - rec->length-=i; - - rec->data += bs; /* skip the implicit IV */ - rec->input += bs; - rec->length -= bs; - } + return tls1_cbc_remove_padding(s, rec, bs, mac_size); } return(1); } Index: openssl-0.9.8j/ssl/s3_enc.c =================================================================== --- openssl-0.9.8j.orig/ssl/s3_enc.c +++ openssl-0.9.8j/ssl/s3_enc.c @@ -434,12 +434,21 @@ void ssl3_cleanup_key_block(SSL *s) s->s3->tmp.key_block_length=0; } +/* ssl3_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively. + * + * Returns: + * 0: (in non-constant time) if the record is publically invalid (i.e. too + * short etc). + * 1: if the record's padding is valid / the encryption was successful. + * -1: if the record's padding is invalid or, if sending, an internal error + * occured. + */ int ssl3_enc(SSL *s, int send) { SSL3_RECORD *rec; EVP_CIPHER_CTX *ds; unsigned long l; - int bs,i; + int bs,i,mac_size=0; const EVP_CIPHER *enc; if (send) @@ -490,32 +499,18 @@ int ssl3_enc(SSL *s, int send) if (!send) { if (l == 0 || l%bs != 0) - { - SSLerr(SSL_F_SSL3_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); - ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED); return 0; - } /* otherwise, rec->length >= bs */ } EVP_Cipher(ds,rec->data,rec->input,l); + rec->orig_len = rec->length; + + if (s->read_hash != NULL) + mac_size = EVP_MD_size(s->read_hash); if ((bs != 1) && !send) - { - i=rec->data[l-1]+1; - /* SSL 3.0 bounds the number of padding bytes by the block size; - * padding bytes (except the last one) are arbitrary */ - if (i > bs) - { - /* Incorrect padding. SSLerr() and ssl3_alert are done - * by caller: we don't want to reveal whether this is - * a decryption error or a MAC verification failure - * (see http://www.openssl.org/~bodo/tls-cbc.txt) */ - return -1; - } - /* now i <= bs <= rec->length */ - rec->length-=i; - } + return ssl3_cbc_remove_padding(s, rec, bs, mac_size); } return(1); } @@ -592,7 +587,7 @@ int ssl3_mac(SSL *ssl, unsigned char *md EVP_MD_CTX md_ctx; const EVP_MD *hash; unsigned char *p,rec_char; - unsigned int md_size; + size_t md_size; int npad; if (send) @@ -613,29 +608,68 @@ int ssl3_mac(SSL *ssl, unsigned char *md md_size=EVP_MD_size(hash); npad=(48/md_size)*md_size; - /* Chop the digest off the end :-) */ - EVP_MD_CTX_init(&md_ctx); - - EVP_DigestInit_ex( &md_ctx,hash, NULL); - EVP_DigestUpdate(&md_ctx,mac_sec,md_size); - EVP_DigestUpdate(&md_ctx,ssl3_pad_1,npad); - EVP_DigestUpdate(&md_ctx,seq,8); - rec_char=rec->type; - EVP_DigestUpdate(&md_ctx,&rec_char,1); - p=md; - s2n(rec->length,p); - EVP_DigestUpdate(&md_ctx,md,2); - EVP_DigestUpdate(&md_ctx,rec->input,rec->length); - EVP_DigestFinal_ex( &md_ctx,md,NULL); - - EVP_DigestInit_ex( &md_ctx,hash, NULL); - EVP_DigestUpdate(&md_ctx,mac_sec,md_size); - EVP_DigestUpdate(&md_ctx,ssl3_pad_2,npad); - EVP_DigestUpdate(&md_ctx,md,md_size); - EVP_DigestFinal_ex( &md_ctx,md,&md_size); - - EVP_MD_CTX_cleanup(&md_ctx); + if (!send && + EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE && + ssl3_cbc_record_digest_supported(hash)) + { + /* This is a CBC-encrypted record. We must avoid leaking any + * timing-side channel information about how many blocks of + * data we are hashing because that gives an attacker a + * timing-oracle. */ + + /* npad is, at most, 48 bytes and that's with MD5: + * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75. + * + * With SHA-1 (the largest hash speced for SSLv3) the hash size + * goes up 4, but npad goes down by 8, resulting in a smaller + * total size. */ + unsigned char header[75]; + unsigned j = 0; + memcpy(header+j, mac_sec, md_size); + j += md_size; + memcpy(header+j, ssl3_pad_1, npad); + j += npad; + memcpy(header+j, seq, 8); + j += 8; + header[j++] = rec->type; + header[j++] = rec->length >> 8; + header[j++] = rec->length & 0xff; + + ssl3_cbc_digest_record( + hash, + md, &md_size, + header, rec->input, + rec->length + md_size, rec->orig_len, + mac_sec, md_size, + 1 /* is SSLv3 */); + } + else + { + unsigned int md_size_u; + /* Chop the digest off the end :-) */ + EVP_MD_CTX_init(&md_ctx); + + EVP_DigestInit_ex( &md_ctx,hash, NULL); + EVP_DigestUpdate(&md_ctx,mac_sec,md_size); + EVP_DigestUpdate(&md_ctx,ssl3_pad_1,npad); + EVP_DigestUpdate(&md_ctx,seq,8); + rec_char=rec->type; + EVP_DigestUpdate(&md_ctx,&rec_char,1); + p=md; + s2n(rec->length,p); + EVP_DigestUpdate(&md_ctx,md,2); + EVP_DigestUpdate(&md_ctx,rec->input,rec->length); + EVP_DigestFinal_ex( &md_ctx,md,NULL); + + EVP_DigestInit_ex( &md_ctx,hash, NULL); + EVP_DigestUpdate(&md_ctx,mac_sec,md_size); + EVP_DigestUpdate(&md_ctx,ssl3_pad_2,npad); + EVP_DigestUpdate(&md_ctx,md,md_size); + EVP_DigestFinal_ex( &md_ctx,md,&md_size_u); + md_size = md_size_u; + EVP_MD_CTX_cleanup(&md_ctx); + } ssl3_record_sequence_update(seq); return(md_size); } Index: openssl-0.9.8j/ssl/ssl3.h =================================================================== --- openssl-0.9.8j.orig/ssl/ssl3.h +++ openssl-0.9.8j/ssl/ssl3.h @@ -305,6 +305,10 @@ typedef struct ssl3_record_st /*r */ unsigned char *comp; /* only used with decompression - malloc()ed */ /*r */ unsigned long epoch; /* epoch number, needed by DTLS1 */ /*r */ PQ_64BIT seq_num; /* sequence number, needed by DTLS1 */ +/*rw*/ unsigned int orig_len; /* How many bytes were available before padding + was removed? This is used to implement the + MAC check in constant time for CBC records. + */ } SSL3_RECORD; typedef struct ssl3_buffer_st Index: openssl-0.9.8j/ssl/ssl_locl.h =================================================================== --- openssl-0.9.8j.orig/ssl/ssl_locl.h +++ openssl-0.9.8j/ssl/ssl_locl.h @@ -189,6 +189,15 @@ *((c)++)=(unsigned char)(((l)>> 8)&0xff), \ *((c)++)=(unsigned char)(((l) )&0xff)) +#define l2n8(l,c) (*((c)++)=(unsigned char)(((l)>>56)&0xff), \ + *((c)++)=(unsigned char)(((l)>>48)&0xff), \ + *((c)++)=(unsigned char)(((l)>>40)&0xff), \ + *((c)++)=(unsigned char)(((l)>>32)&0xff), \ + *((c)++)=(unsigned char)(((l)>>24)&0xff), \ + *((c)++)=(unsigned char)(((l)>>16)&0xff), \ + *((c)++)=(unsigned char)(((l)>> 8)&0xff), \ + *((c)++)=(unsigned char)(((l) )&0xff)) + #define n2l6(c,l) (l =((BN_ULLONG)(*((c)++)))<<40, \ l|=((BN_ULLONG)(*((c)++)))<<32, \ l|=((BN_ULLONG)(*((c)++)))<<24, \ @@ -992,5 +1001,33 @@ int ssl_add_clienthello_renegotiate_ext( int ssl_parse_clienthello_renegotiate_ext(SSL *s, unsigned char *d, int len, int *al); #endif +/* s3_cbc.c */ +void ssl3_cbc_copy_mac(unsigned char* out, + const SSL3_RECORD *rec, + unsigned md_size); +int ssl3_cbc_remove_padding(const SSL* s, + SSL3_RECORD *rec, + unsigned block_size, + unsigned mac_size); +int tls1_cbc_remove_padding(const SSL* s, + SSL3_RECORD *rec, + unsigned block_size, + unsigned mac_size); +char ssl3_cbc_record_digest_supported(const EVP_MD *hash); +void ssl3_cbc_digest_record( + const EVP_MD *hash, + unsigned char* md_out, + size_t* md_out_size, + const unsigned char header[13], + const unsigned char *data, + size_t data_plus_mac_size, + size_t data_plus_mac_plus_padding_size, + const unsigned char *mac_secret, + unsigned mac_secret_length, + char is_sslv3); + +void tls_fips_digest_extra( + const EVP_CIPHER_CTX *cipher_ctx, const EVP_MD *hash, HMAC_CTX *hctx, + const unsigned char *data, size_t data_len, size_t orig_len); #endif Index: openssl-0.9.8j/ssl/t1_enc.c =================================================================== --- openssl-0.9.8j.orig/ssl/t1_enc.c +++ openssl-0.9.8j/ssl/t1_enc.c @@ -530,12 +530,21 @@ err: return(0); } +/* tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively. + * + * Returns: + * 0: (in non-constant time) if the record is publically invalid (i.e. too + * short etc). + * 1: if the record's padding is valid / the encryption was successful. + * -1: if the record's padding/AEAD-authenticator is invalid or, if sending, + * an internal error occured. + */ int tls1_enc(SSL *s, int send) { SSL3_RECORD *rec; EVP_CIPHER_CTX *ds; unsigned long l; - int bs,i,ii,j,k,n=0; + int bs,i,ii,j,k,n=0, pad=0, ret, mac_size=0; const EVP_CIPHER *enc; if (send) @@ -565,11 +574,11 @@ int tls1_enc(SSL *s, int send) printf("tls1_enc(%d)\n", send); #endif /* KSSL_DEBUG */ - if ((s->session == NULL) || (ds == NULL) || - (enc == NULL)) + if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) { memmove(rec->data,rec->input,rec->length); rec->input=rec->data; + ret = 1; } else { @@ -597,14 +606,13 @@ int tls1_enc(SSL *s, int send) #ifdef KSSL_DEBUG { - unsigned long ui; + unsigned long ui; printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n", - (void *)ds,rec->data,rec->input,l); - printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%ld %ld], %d iv_len\n", - ds->buf_len, ds->cipher->key_len, - (unsigned long)DES_KEY_SZ, - (unsigned long)DES_SCHEDULE_SZ, - ds->cipher->iv_len); + ds,rec->data,rec->input,l); + printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n", + ds->buf_len, ds->cipher->key_len, + DES_KEY_SZ, DES_SCHEDULE_SZ, + ds->cipher->iv_len); printf("\t\tIV: "); for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]); printf("\n"); @@ -617,11 +625,7 @@ int tls1_enc(SSL *s, int send) if (!send) { if (l == 0 || l%bs != 0) - { - SSLerr(SSL_F_TLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); - ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED); return 0; - } } EVP_Cipher(ds,rec->data,rec->input,l); @@ -635,49 +639,15 @@ int tls1_enc(SSL *s, int send) } #endif /* KSSL_DEBUG */ + ret = 1; + if (s->read_hash != NULL) + mac_size = EVP_MD_size(s->read_hash); if ((bs != 1) && !send) - { - ii=i=rec->data[l-1]; /* padding_length */ - i++; - /* NB: if compression is in operation the first packet - * may not be of even length so the padding bug check - * cannot be performed. This bug workaround has been - * around since SSLeay so hopefully it is either fixed - * now or no buggy implementation supports compression - * [steve] - */ - if ( (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG) - && !s->expand) - { - /* First packet is even in size, so check */ - if ((memcmp(s->s3->read_sequence, - "\0\0\0\0\0\0\0\0",8) == 0) && !(ii & 1)) - s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG; - if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) - i--; - } - /* TLS 1.0 does not bound the number of padding bytes by the block size. - * All of them must have value 'padding_length'. */ - if (i > (int)rec->length) - { - /* Incorrect padding. SSLerr() and ssl3_alert are done - * by caller: we don't want to reveal whether this is - * a decryption error or a MAC verification failure - * (see http://www.openssl.org/~bodo/tls-cbc.txt) */ - return -1; - } - for (j=(int)(l-i); j<(int)l; j++) - { - if (rec->data[j] != ii) - { - /* Incorrect padding */ - return -1; - } - } - rec->length-=i; - } + ret = tls1_cbc_remove_padding(s, rec, bs, mac_size); + if (pad && !send) + rec->length -= pad; } - return(1); + return ret; } int tls1_cert_verify_mac(SSL *s, EVP_MD_CTX *in_ctx, unsigned char *out) @@ -725,10 +695,10 @@ int tls1_mac(SSL *ssl, unsigned char *md SSL3_RECORD *rec; unsigned char *mac_sec,*seq; const EVP_MD *hash; - unsigned int md_size; + size_t md_size; int i; HMAC_CTX hmac; - unsigned char buf[5]; + unsigned char header[13]; if (send) { @@ -747,20 +717,6 @@ int tls1_mac(SSL *ssl, unsigned char *md md_size=EVP_MD_size(hash); - buf[0]=rec->type; - if (ssl->version == DTLS1_VERSION && ssl->client_version == DTLS1_BAD_VER) - { - buf[1]=TLS1_VERSION_MAJOR; - buf[2]=TLS1_VERSION_MINOR; - } - else { - buf[1]=(unsigned char)(ssl->version>>8); - buf[2]=(unsigned char)(ssl->version); - } - - buf[3]=rec->length>>8; - buf[4]=rec->length&0xff; - /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */ HMAC_CTX_init(&hmac); HMAC_Init_ex(&hmac,mac_sec,EVP_MD_size(hash),hash,NULL); @@ -772,16 +728,53 @@ int tls1_mac(SSL *ssl, unsigned char *md s2n(send?ssl->d1->w_epoch:ssl->d1->r_epoch, p); memcpy (p,&seq[2],6); - HMAC_Update(&hmac,dtlsseq,8); + memcpy(header, dtlsseq, 8); } else - HMAC_Update(&hmac,seq,8); + memcpy(header, seq, 8); - HMAC_Update(&hmac,buf,5); - HMAC_Update(&hmac,rec->input,rec->length); - HMAC_Final(&hmac,md,&md_size); - HMAC_CTX_cleanup(&hmac); + header[8]=rec->type; + header[9]=(unsigned char)(ssl->version>>8); + header[10]=(unsigned char)(ssl->version); + header[11]=(rec->length)>>8; + header[12]=(rec->length)&0xff; + + if (!send && + EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE && + ssl3_cbc_record_digest_supported(hash)) + { + /* This is a CBC-encrypted record. We must avoid leaking any + * timing-side channel information about how many blocks of + * data we are hashing because that gives an attacker a + * timing-oracle. */ + ssl3_cbc_digest_record( + hash, + md, &md_size, + header, rec->input, + rec->length + md_size, rec->orig_len, + ssl->s3->read_mac_secret, + EVP_MD_size(ssl->read_hash), + 0 /* not SSLv3 */); + } + else + { + unsigned mds; + HMAC_Update(&hmac,header,sizeof(header)); + HMAC_Update(&hmac,rec->input,rec->length); + HMAC_Final(&hmac,md,&mds); + md_size = mds; +#ifdef OPENSSL_FIPS + if (!send && FIPS_mode()) + tls_fips_digest_extra( + ssl->enc_read_ctx, + hash, + &hmac, rec->input, + rec->length, rec->orig_len); +#endif + } + + HMAC_CTX_cleanup(&hmac); #ifdef TLS_DEBUG printf("sec="); {unsigned int z; for (z=0; z<md_size; z++) printf("%02X ",mac_sec[z]); printf("\n"); } Index: openssl-0.9.8j/ssl/s3_cbc.c =================================================================== --- /dev/null +++ openssl-0.9.8j/ssl/s3_cbc.c @@ -0,0 +1,760 @@ +/* ssl/s3_cbc.c */ +/* ==================================================================== + * Copyright (c) 2012 The OpenSSL Project. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. All advertising materials mentioning features or use of this + * software must display the following acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * openssl-core@openssl.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.openssl.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + * + * This product includes cryptographic software written by Eric Young + * (eay@cryptsoft.com). This product includes software written by Tim + * Hudson (tjh@cryptsoft.com). + * + */ + +#include "ssl_locl.h" + +#include <openssl/md5.h> +#include <openssl/sha.h> + +/* MAX_HASH_BIT_COUNT_BYTES is the maximum number of bytes in the hash's length + * field. (SHA-384/512 have 128-bit length.) */ +#define MAX_HASH_BIT_COUNT_BYTES 16 + +/* MAX_HASH_BLOCK_SIZE is the maximum hash block size that we'll support. + * Currently SHA-384/512 has a 128-byte block size and that's the largest + * supported by TLS.) */ +#define MAX_HASH_BLOCK_SIZE 128 + +/* Some utility functions are needed: + * + * These macros return the given value with the MSB copied to all the other + * bits. They use the fact that arithmetic shift shifts-in the sign bit. + * However, this is not ensured by the C standard so you may need to replace + * them with something else on odd CPUs. */ +#define DUPLICATE_MSB_TO_ALL(x) ( (unsigned)( (int)(x) >> (sizeof(int)*8-1) ) ) +#define DUPLICATE_MSB_TO_ALL_8(x) ((unsigned char)(DUPLICATE_MSB_TO_ALL(x))) + +/* constant_time_ge returns 0xff if a>=b and 0x00 otherwise. */ +static unsigned constant_time_ge(unsigned a, unsigned b) + { + a -= b; + return DUPLICATE_MSB_TO_ALL(~a); + } + +/* constant_time_eq_8 returns 0xff if a==b and 0x00 otherwise. */ +static unsigned char constant_time_eq_8(unsigned char a, unsigned char b) + { + unsigned c = a ^ b; + c--; + return DUPLICATE_MSB_TO_ALL_8(c); + } + +/* ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC + * record in |rec| by updating |rec->length| in constant time. + * + * block_size: the block size of the cipher used to encrypt the record. + * returns: + * 0: (in non-constant time) if the record is publicly invalid. + * 1: if the padding was valid + * -1: otherwise. */ +int ssl3_cbc_remove_padding(const SSL* s, + SSL3_RECORD *rec, + unsigned block_size, + unsigned mac_size) + { + unsigned padding_length, good; + const unsigned overhead = 1 /* padding length byte */ + mac_size; + + /* These lengths are all public so we can test them in non-constant + * time. */ + if (overhead > rec->length) + return 0; + + padding_length = rec->data[rec->length-1]; + good = constant_time_ge(rec->length, padding_length+overhead); + /* SSLv3 requires that the padding is minimal. */ + good &= constant_time_ge(block_size, padding_length+1); + rec->length -= good & (padding_length+1); + return (int)((good & 1) | (~good & -1)); +} + +/* tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC + * record in |rec| in constant time and returns 1 if the padding is valid and + * -1 otherwise. It also removes any explicit IV from the start of the record + * without leaking any timing about whether there was enough space after the + * padding was removed. + * + * block_size: the block size of the cipher used to encrypt the record. + * returns: + * 0: (in non-constant time) if the record is publicly invalid. + * 1: if the padding was valid + * -1: otherwise. */ +int tls1_cbc_remove_padding(const SSL* s, + SSL3_RECORD *rec, + unsigned block_size, + unsigned mac_size) + { + unsigned padding_length, good, to_check, i; + const char has_explicit_iv = s->version == DTLS1_VERSION; + const unsigned overhead = 1 /* padding length byte */ + + mac_size + + (has_explicit_iv ? block_size : 0); + + /* These lengths are all public so we can test them in non-constant + * time. */ + if (overhead > rec->length) + return 0; + + padding_length = rec->data[rec->length-1]; + + /* NB: if compression is in operation the first packet may not be of + * even length so the padding bug check cannot be performed. This bug + * workaround has been around since SSLeay so hopefully it is either + * fixed now or no buggy implementation supports compression [steve] + */ + if ( (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG) && !s->expand) + { + /* First packet is even in size, so check */ + if ((memcmp(s->s3->read_sequence, "\0\0\0\0\0\0\0\0",8) == 0) && + !(padding_length & 1)) + { + s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG; + } + if ((s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) && + padding_length > 0) + { + padding_length--; + } + } + + good = constant_time_ge(rec->length, overhead+padding_length); + /* The padding consists of a length byte at the end of the record and + * then that many bytes of padding, all with the same value as the + * length byte. Thus, with the length byte included, there are i+1 + * bytes of padding. + * + * We can't check just |padding_length+1| bytes because that leaks + * decrypted information. Therefore we always have to check the maximum + * amount of padding possible. (Again, the length of the record is + * public information so we can use it.) */ + to_check = 255; /* maximum amount of padding. */ + if (to_check > rec->length-1) + to_check = rec->length-1; + + for (i = 0; i < to_check; i++) + { + unsigned char mask = constant_time_ge(padding_length, i); + unsigned char b = rec->data[rec->length-1-i]; + /* The final |padding_length+1| bytes should all have the value + * |padding_length|. Therefore the XOR should be zero. */ + good &= ~(mask&(padding_length ^ b)); + } + + /* If any of the final |padding_length+1| bytes had the wrong value, + * one or more of the lower eight bits of |good| will be cleared. We + * AND the bottom 8 bits together and duplicate the result to all the + * bits. */ + good &= good >> 4; + good &= good >> 2; + good &= good >> 1; + good <<= sizeof(good)*8-1; + good = DUPLICATE_MSB_TO_ALL(good); + + rec->length -= good & (padding_length+1); + + /* We can always safely skip the explicit IV. We check at the beginning + * of this function that the record has at least enough space for the + * IV, MAC and padding length byte. (These can be checked in + * non-constant time because it's all public information.) So, if the + * padding was invalid, then we didn't change |rec->length| and this is + * safe. If the padding was valid then we know that we have at least + * overhead+padding_length bytes of space and so this is still safe + * because overhead accounts for the explicit IV. */ + if (has_explicit_iv) + { + rec->data += block_size; + rec->input += block_size; + rec->length -= block_size; + rec->orig_len -= block_size; + } + + return (int)((good & 1) | (~good & -1)); + } + +#if defined(_M_AMD64) || defined(__x86_64__) +#define CBC_MAC_ROTATE_IN_PLACE +#endif + +/* ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in + * constant time (independent of the concrete value of rec->length, which may + * vary within a 256-byte window). + * + * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to + * this function. + * + * On entry: + * rec->orig_len >= md_size + * md_size <= EVP_MAX_MD_SIZE + * + * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with + * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into + * a single cache-line, then the variable memory accesses don't actually affect + * the timing. This has been tested to be true on Intel amd64 chips. + */ +void ssl3_cbc_copy_mac(unsigned char* out, + const SSL3_RECORD *rec, + unsigned md_size) + { +#if defined(CBC_MAC_ROTATE_IN_PLACE) + unsigned char rotated_mac_buf[EVP_MAX_MD_SIZE*2]; + unsigned char *rotated_mac; +#else + unsigned char rotated_mac[EVP_MAX_MD_SIZE]; +#endif + + /* mac_end is the index of |rec->data| just after the end of the MAC. */ + unsigned mac_end = rec->length; + unsigned mac_start = mac_end - md_size; + /* scan_start contains the number of bytes that we can ignore because + * the MAC's position can only vary by 255 bytes. */ + unsigned scan_start = 0; + unsigned i, j; + unsigned div_spoiler; + unsigned rotate_offset; + + OPENSSL_assert(rec->orig_len >= md_size); + OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE); + +#if defined(CBC_MAC_ROTATE_IN_PLACE) + rotated_mac = (unsigned char*) (((intptr_t)(rotated_mac_buf + 64)) & ~63); +#endif + + /* This information is public so it's safe to branch based on it. */ + if (rec->orig_len > md_size + 255 + 1) + scan_start = rec->orig_len - (md_size + 255 + 1); + /* div_spoiler contains a multiple of md_size that is used to cause the + * modulo operation to be constant time. Without this, the time varies + * based on the amount of padding when running on Intel chips at least. + * + * The aim of right-shifting md_size is so that the compiler doesn't + * figure out that it can remove div_spoiler as that would require it + * to prove that md_size is always even, which I hope is beyond it. */ + div_spoiler = md_size >> 1; + div_spoiler <<= (sizeof(div_spoiler)-1)*8; + rotate_offset = (div_spoiler + mac_start - scan_start) % md_size; + + memset(rotated_mac, 0, md_size); + for (i = scan_start; i < rec->orig_len;) + { + for (j = 0; j < md_size && i < rec->orig_len; i++, j++) + { + unsigned char mac_started = constant_time_ge(i, mac_start); + unsigned char mac_ended = constant_time_ge(i, mac_end); + unsigned char b = 0; + b = rec->data[i]; + rotated_mac[j] |= b & mac_started & ~mac_ended; + } + } + + /* Now rotate the MAC */ +#if defined(CBC_MAC_ROTATE_IN_PLACE) + j = 0; + for (i = 0; i < md_size; i++) + { + unsigned char offset = (div_spoiler + rotate_offset + i) % md_size; + out[j++] = rotated_mac[offset]; + } +#else + memset(out, 0, md_size); + for (i = 0; i < md_size; i++) + { + unsigned char offset = (div_spoiler + md_size - rotate_offset + i) % md_size; + for (j = 0; j < md_size; j++) + out[j] |= rotated_mac[i] & constant_time_eq_8(j, offset); + } +#endif + } + +/* These functions serialize the state of a hash and thus perform the standard + * "final" operation without adding the padding and length that such a function + * typically does. */ +static void tls1_md5_final_raw(void* ctx, unsigned char *md_out) + { + MD5_CTX *md5 = ctx; + l2n(md5->A, md_out); + l2n(md5->B, md_out); + l2n(md5->C, md_out); + l2n(md5->D, md_out); + } + +static void tls1_sha1_final_raw(void* ctx, unsigned char *md_out) + { + SHA_CTX *sha1 = ctx; + l2n(sha1->h0, md_out); + l2n(sha1->h1, md_out); + l2n(sha1->h2, md_out); + l2n(sha1->h3, md_out); + l2n(sha1->h4, md_out); + } + +#define LARGEST_DIGEST_CTX SHA_CTX + +#ifndef OPENSSL_NO_SHA256 +static void tls1_sha256_final_raw(void* ctx, unsigned char *md_out) + { + SHA256_CTX *sha256 = ctx; + unsigned i; + + for (i = 0; i < 8; i++) + { + l2n(sha256->h[i], md_out); + } + } +#undef LARGEST_DIGEST_CTX +#define LARGEST_DIGEST_CTX SHA256_CTX +#endif + +#ifndef OPENSSL_NO_SHA512 +static void tls1_sha512_final_raw(void* ctx, unsigned char *md_out) + { + SHA512_CTX *sha512 = ctx; + unsigned i; + + for (i = 0; i < 8; i++) + { + l2n8(sha512->h[i], md_out); + } + } +#undef LARGEST_DIGEST_CTX +#define LARGEST_DIGEST_CTX SHA512_CTX +#endif + +/* ssl3_cbc_record_digest_supported returns 1 iff |ctx| uses a hash function + * which ssl3_cbc_digest_record supports. */ +char ssl3_cbc_record_digest_supported(const EVP_MD *digest) +{ +#ifdef OPENSSL_FIPS + if (FIPS_mode()) + return 0; +#endif + switch (EVP_MD_type(digest)) + { + case NID_md5: + case NID_sha1: +#ifndef OPENSSL_NO_SHA256 + case NID_sha224: + case NID_sha256: +#endif +#ifndef OPENSSL_NO_SHA512 + case NID_sha384: + case NID_sha512: +#endif + return 1; + default: + return 0; + } + } + +/* ssl3_cbc_digest_record computes the MAC of a decrypted, padded SSLv3/TLS + * record. + * + * ctx: the EVP_MD_CTX from which we take the hash function. + * ssl3_cbc_record_digest_supported must return true for this EVP_MD_CTX. + * md_out: the digest output. At most EVP_MAX_MD_SIZE bytes will be written. + * md_out_size: if non-NULL, the number of output bytes is written here. + * header: the 13-byte, TLS record header. + * data: the record data itself, less any preceeding explicit IV. + * data_plus_mac_size: the secret, reported length of the data and MAC + * once the padding has been removed. + * data_plus_mac_plus_padding_size: the public length of the whole + * record, including padding. + * is_sslv3: non-zero if we are to use SSLv3. Otherwise, TLS. + * + * On entry: by virtue of having been through one of the remove_padding + * functions, above, we know that data_plus_mac_size is large enough to contain + * a padding byte and MAC. (If the padding was invalid, it might contain the + * padding too. ) */ +void ssl3_cbc_digest_record( + const EVP_MD *digest, + unsigned char* md_out, + size_t* md_out_size, + const unsigned char header[13], + const unsigned char *data, + size_t data_plus_mac_size, + size_t data_plus_mac_plus_padding_size, + const unsigned char *mac_secret, + unsigned mac_secret_length, + char is_sslv3) + { + union { double align; + unsigned char c[sizeof(LARGEST_DIGEST_CTX)]; } md_state; + void (*md_final_raw)(void *ctx, unsigned char *md_out); + void (*md_transform)(void *ctx, const unsigned char *block); + unsigned md_size, md_block_size = 64; + unsigned sslv3_pad_length = 40, header_length, variance_blocks, + len, max_mac_bytes, num_blocks, + num_starting_blocks, k, mac_end_offset, c, index_a, index_b; + unsigned int bits; /* at most 18 bits */ + unsigned char length_bytes[MAX_HASH_BIT_COUNT_BYTES]; + /* hmac_pad is the masked HMAC key. */ + unsigned char hmac_pad[MAX_HASH_BLOCK_SIZE]; + unsigned char first_block[MAX_HASH_BLOCK_SIZE]; + unsigned char mac_out[EVP_MAX_MD_SIZE]; + unsigned i, j, md_out_size_u; + EVP_MD_CTX md_ctx; + /* mdLengthSize is the number of bytes in the length field that terminates + * the hash. */ + unsigned md_length_size = 8; + + /* This is a, hopefully redundant, check that allows us to forget about + * many possible overflows later in this function. */ + OPENSSL_assert(data_plus_mac_plus_padding_size < 1024*1024); + + switch (EVP_MD_type(digest)) + { + case NID_md5: + MD5_Init((MD5_CTX*)md_state.c); + md_final_raw = tls1_md5_final_raw; + md_transform = (void(*)(void *ctx, const unsigned char *block)) MD5_Transform; + md_size = 16; + sslv3_pad_length = 48; + break; + case NID_sha1: + SHA1_Init((SHA_CTX*)md_state.c); + md_final_raw = tls1_sha1_final_raw; + md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA1_Transform; + md_size = 20; + break; +#ifndef OPENSSL_NO_SHA256 + case NID_sha224: + SHA224_Init((SHA256_CTX*)md_state.c); + md_final_raw = tls1_sha256_final_raw; + md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA256_Transform; + md_size = 224/8; + break; + case NID_sha256: + SHA256_Init((SHA256_CTX*)md_state.c); + md_final_raw = tls1_sha256_final_raw; + md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA256_Transform; + md_size = 32; + break; +#endif +#ifndef OPENSSL_NO_SHA512 + case NID_sha384: + SHA384_Init((SHA512_CTX*)md_state.c); + md_final_raw = tls1_sha512_final_raw; + md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA512_Transform; + md_size = 384/8; + md_block_size = 128; + md_length_size = 16; + break; + case NID_sha512: + SHA512_Init((SHA512_CTX*)md_state.c); + md_final_raw = tls1_sha512_final_raw; + md_transform = (void(*)(void *ctx, const unsigned char *block)) SHA512_Transform; + md_size = 64; + md_block_size = 128; + md_length_size = 16; + break; +#endif + default: + /* ssl3_cbc_record_digest_supported should have been + * called first to check that the hash function is + * supported. */ + OPENSSL_assert(0); + if (md_out_size) + *md_out_size = -1; + return; + } + + OPENSSL_assert(md_length_size <= MAX_HASH_BIT_COUNT_BYTES); + OPENSSL_assert(md_block_size <= MAX_HASH_BLOCK_SIZE); + OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE); + + header_length = 13; + if (is_sslv3) + { + header_length = + mac_secret_length + + sslv3_pad_length + + 8 /* sequence number */ + + 1 /* record type */ + + 2 /* record length */; + } + + /* variance_blocks is the number of blocks of the hash that we have to + * calculate in constant time because they could be altered by the + * padding value. + * + * In SSLv3, the padding must be minimal so the end of the plaintext + * varies by, at most, 15+20 = 35 bytes. (We conservatively assume that + * the MAC size varies from 0..20 bytes.) In case the 9 bytes of hash + * termination (0x80 + 64-bit length) don't fit in the final block, we + * say that the final two blocks can vary based on the padding. + * + * TLSv1 has MACs up to 48 bytes long (SHA-384) and the padding is not + * required to be minimal. Therefore we say that the final six blocks + * can vary based on the padding. + * + * Later in the function, if the message is short and there obviously + * cannot be this many blocks then variance_blocks can be reduced. */ + variance_blocks = is_sslv3 ? 2 : 6; + /* From now on we're dealing with the MAC, which conceptually has 13 + * bytes of `header' before the start of the data (TLS) or 71/75 bytes + * (SSLv3) */ + len = data_plus_mac_plus_padding_size + header_length; + /* max_mac_bytes contains the maximum bytes of bytes in the MAC, including + * |header|, assuming that there's no padding. */ + max_mac_bytes = len - md_size - 1; + /* num_blocks is the maximum number of hash blocks. */ + num_blocks = (max_mac_bytes + 1 + md_length_size + md_block_size - 1) / md_block_size; + /* In order to calculate the MAC in constant time we have to handle + * the final blocks specially because the padding value could cause the + * end to appear somewhere in the final |variance_blocks| blocks and we + * can't leak where. However, |num_starting_blocks| worth of data can + * be hashed right away because no padding value can affect whether + * they are plaintext. */ + num_starting_blocks = 0; + /* k is the starting byte offset into the conceptual header||data where + * we start processing. */ + k = 0; + /* mac_end_offset is the index just past the end of the data to be + * MACed. */ + mac_end_offset = data_plus_mac_size + header_length - md_size; + /* c is the index of the 0x80 byte in the final hash block that + * contains application data. */ + c = mac_end_offset % md_block_size; + /* index_a is the hash block number that contains the 0x80 terminating + * value. */ + index_a = mac_end_offset / md_block_size; + /* index_b is the hash block number that contains the 64-bit hash + * length, in bits. */ + index_b = (mac_end_offset + md_length_size) / md_block_size; + /* bits is the hash-length in bits. It includes the additional hash + * block for the masked HMAC key, or whole of |header| in the case of + * SSLv3. */ + + /* For SSLv3, if we're going to have any starting blocks then we need + * at least two because the header is larger than a single block. */ + if (num_blocks > variance_blocks + (is_sslv3 ? 1 : 0)) + { + num_starting_blocks = num_blocks - variance_blocks; + k = md_block_size*num_starting_blocks; + } + + bits = 8*mac_end_offset; + if (!is_sslv3) + { + /* Compute the initial HMAC block. For SSLv3, the padding and + * secret bytes are included in |header| because they take more + * than a single block. */ + bits += 8*md_block_size; + memset(hmac_pad, 0, md_block_size); + OPENSSL_assert(mac_secret_length <= sizeof(hmac_pad)); + memcpy(hmac_pad, mac_secret, mac_secret_length); + for (i = 0; i < md_block_size; i++) + hmac_pad[i] ^= 0x36; + + md_transform(md_state.c, hmac_pad); + } + + memset(length_bytes,0,md_length_size-4); + length_bytes[md_length_size-4] = (unsigned char)(bits>>24); + length_bytes[md_length_size-3] = (unsigned char)(bits>>16); + length_bytes[md_length_size-2] = (unsigned char)(bits>>8); + length_bytes[md_length_size-1] = (unsigned char)bits; + + if (k > 0) + { + if (is_sslv3) + { + /* The SSLv3 header is larger than a single block. + * overhang is the number of bytes beyond a single + * block that the header consumes: either 7 bytes + * (SHA1) or 11 bytes (MD5). */ + unsigned overhang = header_length-md_block_size; + md_transform(md_state.c, header); + memcpy(first_block, header + md_block_size, overhang); + memcpy(first_block + overhang, data, md_block_size-overhang); + md_transform(md_state.c, first_block); + for (i = 1; i < k/md_block_size - 1; i++) + md_transform(md_state.c, data + md_block_size*i - overhang); + } + else + { + /* k is a multiple of md_block_size. */ + memcpy(first_block, header, 13); + memcpy(first_block+13, data, md_block_size-13); + md_transform(md_state.c, first_block); + for (i = 1; i < k/md_block_size; i++) + md_transform(md_state.c, data + md_block_size*i - 13); + } + } + + memset(mac_out, 0, sizeof(mac_out)); + + /* We now process the final hash blocks. For each block, we construct + * it in constant time. If the |i==index_a| then we'll include the 0x80 + * bytes and zero pad etc. For each block we selectively copy it, in + * constant time, to |mac_out|. */ + for (i = num_starting_blocks; i <= num_starting_blocks+variance_blocks; i++) + { + unsigned char block[MAX_HASH_BLOCK_SIZE]; + unsigned char is_block_a = constant_time_eq_8(i, index_a); + unsigned char is_block_b = constant_time_eq_8(i, index_b); + for (j = 0; j < md_block_size; j++) + { + unsigned char b = 0, is_past_c, is_past_cp1; + if (k < header_length) + b = header[k]; + else if (k < data_plus_mac_plus_padding_size + header_length) + b = data[k-header_length]; + k++; + + is_past_c = is_block_a & constant_time_ge(j, c); + is_past_cp1 = is_block_a & constant_time_ge(j, c+1); + /* If this is the block containing the end of the + * application data, and we are at the offset for the + * 0x80 value, then overwrite b with 0x80. */ + b = (b&~is_past_c) | (0x80&is_past_c); + /* If this the the block containing the end of the + * application data and we're past the 0x80 value then + * just write zero. */ + b = b&~is_past_cp1; + /* If this is index_b (the final block), but not + * index_a (the end of the data), then the 64-bit + * length didn't fit into index_a and we're having to + * add an extra block of zeros. */ + b &= ~is_block_b | is_block_a; + + /* The final bytes of one of the blocks contains the + * length. */ + if (j >= md_block_size - md_length_size) + { + /* If this is index_b, write a length byte. */ + b = (b&~is_block_b) | (is_block_b&length_bytes[j-(md_block_size-md_length_size)]); + } + block[j] = b; + } + + md_transform(md_state.c, block); + md_final_raw(md_state.c, block); + /* If this is index_b, copy the hash value to |mac_out|. */ + for (j = 0; j < md_size; j++) + mac_out[j] |= block[j]&is_block_b; + } + + EVP_MD_CTX_init(&md_ctx); + EVP_DigestInit_ex(&md_ctx, digest, NULL /* engine */); + if (is_sslv3) + { + /* We repurpose |hmac_pad| to contain the SSLv3 pad2 block. */ + memset(hmac_pad, 0x5c, sslv3_pad_length); + + EVP_DigestUpdate(&md_ctx, mac_secret, mac_secret_length); + EVP_DigestUpdate(&md_ctx, hmac_pad, sslv3_pad_length); + EVP_DigestUpdate(&md_ctx, mac_out, md_size); + } + else + { + /* Complete the HMAC in the standard manner. */ + for (i = 0; i < md_block_size; i++) + hmac_pad[i] ^= 0x6a; + + EVP_DigestUpdate(&md_ctx, hmac_pad, md_block_size); + EVP_DigestUpdate(&md_ctx, mac_out, md_size); + } + EVP_DigestFinal(&md_ctx, md_out, &md_out_size_u); + if (md_out_size) + *md_out_size = md_out_size_u; + EVP_MD_CTX_cleanup(&md_ctx); + } + +#ifdef OPENSSL_FIPS + +/* Due to the need to use EVP in FIPS mode we can't reimplement digests but + * we can ensure the number of blocks processed is equal for all cases + * by digesting additional data. + */ + +void tls_fips_digest_extra( + const EVP_CIPHER_CTX *cipher_ctx, const EVP_MD *hash, HMAC_CTX *hctx, + const unsigned char *data, size_t data_len, size_t orig_len) +{ + size_t block_size, digest_pad, blocks_data, blocks_orig; + if (EVP_CIPHER_CTX_mode(cipher_ctx) != EVP_CIPH_CBC_MODE) + return; + block_size = EVP_MD_block_size(hash); + /* We are in FIPS mode if we get this far so we know we have only SHA* + * digests and TLS to deal with. + * Minimum digest padding length is 17 for SHA384/SHA512 and 9 + * otherwise. + * Additional header is 13 bytes. To get the number of digest blocks + * processed round up the amount of data plus padding to the nearest + * block length. Block length is 128 for SHA384/SHA512 and 64 otherwise. + * So we have: + * blocks = (payload_len + digest_pad + 13 + block_size - 1)/block_size + * equivalently: + * blocks = (payload_len + digest_pad + 12)/block_size + 1 + * HMAC adds a constant overhead. + * We're ultimately only interested in differences so this becomes + * blocks = (payload_len + 29)/128 + * for SHA384/SHA512 and + * blocks = (payload_len + 21)/64 + * otherwise. + */ + digest_pad = block_size == 64 ? 21 : 29; + blocks_orig = (orig_len + digest_pad)/block_size; + blocks_data = (data_len + digest_pad)/block_size; + /* MAC enough blocks to make up the difference between the original + * and actual lengths plus one extra block to ensure this is never a + * no op. The "data" pointer should always have enough space to + * perform this operation as it is large enough for a maximum + * length TLS buffer. + */ + HMAC_Update(hctx, data, + (blocks_orig - blocks_data + 1) * block_size); +} +#endif Index: openssl-0.9.8j/crypto/o_init.c =================================================================== --- openssl-0.9.8j.orig/crypto/o_init.c +++ openssl-0.9.8j/crypto/o_init.c @@ -153,4 +153,18 @@ void OPENSSL_init(void) #endif } +#ifdef OPENSSL_FIPS +int CRYPTO_memcmp(const void *in_a, const void *in_b, size_t len) + { + size_t i; + const unsigned char *a = in_a; + const unsigned char *b = in_b; + unsigned char x = 0; + + for (i = 0; i < len; i++) + x |= a[i] ^ b[i]; + + return x; + } +#endif
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