X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fs3_pkt.c;h=4c7dec06810464ea75653bfde76972e285566096;hp=ca5412dc2a4c15dfc7e0baf8f0986b8fd6c2a00c;hb=a51f767645c117667d337f77fe1dd9c0a66d8410;hpb=fc90e42c8623af13308d8ef7e7ada84af0a36509 diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c index ca5412dc2a..4c7dec0681 100644 --- a/ssl/s3_pkt.c +++ b/ssl/s3_pkt.c @@ -117,6 +117,20 @@ #include #include +#ifndef EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK +# define EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK 0 +#endif + +#if defined(OPENSSL_SMALL_FOOTPRINT) || \ + !( defined(AES_ASM) && ( \ + defined(__x86_64) || defined(__x86_64__) || \ + defined(_M_AMD64) || defined(_M_X64) || \ + defined(__INTEL__) ) \ + ) +# undef EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK +# define EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK 0 +#endif + static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment); static int ssl3_get_record(SSL *s); @@ -180,7 +194,7 @@ int ssl3_read_n(SSL *s, int n, int max, int extend) /* For DTLS/UDP reads should not span multiple packets * because the read operation returns the whole packet * at once (as long as it fits into the buffer). */ - if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER) + if (SSL_IS_DTLS(s)) { if (left > 0 && n > left) n = left; @@ -248,7 +262,7 @@ int ssl3_read_n(SSL *s, int n, int max, int extend) { rb->left = left; if (s->mode & SSL_MODE_RELEASE_BUFFERS && - SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) + !SSL_IS_DTLS(s)) if (len+left == 0) ssl3_release_read_buffer(s); return(i); @@ -257,7 +271,7 @@ int ssl3_read_n(SSL *s, int n, int max, int extend) /* reads should *never* span multiple packets for DTLS because * the underlying transport protocol is message oriented as opposed * to byte oriented as in the TLS case. */ - if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER) + if (SSL_IS_DTLS(s)) { if (n > left) n = left; /* makes the while condition false */ @@ -272,6 +286,12 @@ int ssl3_read_n(SSL *s, int n, int max, int extend) return(n); } +/* MAX_EMPTY_RECORDS defines the number of consecutive, empty records that will + * be processed per call to ssl3_get_record. Without this limit an attacker + * could send empty records at a faster rate than we can process and cause + * ssl3_get_record to loop forever. */ +#define MAX_EMPTY_RECORDS 32 + /* Call this to get a new input record. * It will return <= 0 if more data is needed, normally due to an error * or non-blocking IO. @@ -290,11 +310,9 @@ static int ssl3_get_record(SSL *s) unsigned char *p; unsigned char md[EVP_MAX_MD_SIZE]; short version; - int mac_size; - int clear=0; + unsigned mac_size; size_t extra; - int decryption_failed_or_bad_record_mac = 0; - unsigned char *mac = NULL; + unsigned empty_record_count = 0; rr= &(s->s3->rrec); sess=s->session; @@ -321,6 +339,8 @@ again: s->rstate=SSL_ST_READ_BODY; p=s->packet; + if (s->msg_callback) + s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s, s->msg_callback_arg); /* Pull apart the header into the SSL3_RECORD */ rr->type= *(p++); @@ -338,7 +358,7 @@ fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length); if (version != s->version) { SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER); - if ((s->version & 0xFF00) == (version & 0xFF00)) + if ((s->version & 0xFF00) == (version & 0xFF00) && !s->enc_write_ctx && !s->write_hash) /* Send back error using their minor version number :-) */ s->version = (unsigned short)version; al=SSL_AD_PROTOCOL_VERSION; @@ -401,19 +421,42 @@ fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length); /* decrypt in place in 'rr->input' */ rr->data=rr->input; + rr->orig_len=rr->length; + /* If in encrypt-then-mac mode calculate mac from encrypted record. + * All the details below are public so no timing details can leak. + */ + if (SSL_USE_ETM(s) && s->read_hash) + { + unsigned char *mac; + mac_size=EVP_MD_CTX_size(s->read_hash); + OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); + if (rr->length < mac_size) + { + al=SSL_AD_DECODE_ERROR; + SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT); + goto f_err; + } + rr->length -= mac_size; + mac = rr->data + rr->length; + i=s->method->ssl3_enc->mac(s,md,0 /* not send */); + if (i < 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) + { + al=SSL_AD_BAD_RECORD_MAC; + SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); + goto f_err; + } + } 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) { - 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; + al=SSL_AD_DECRYPTION_FAILED; + SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); + goto f_err; } #ifdef TLS_DEBUG @@ -423,58 +466,64 @@ printf("\n"); #endif /* r->length is now the compressed data plus mac */ - if ( (sess == NULL) || - (s->enc_read_ctx == NULL) || - (EVP_MD_CTX_md(s->read_hash) == NULL)) - clear=1; - - if (!clear) + if ((sess != NULL) && + (s->enc_read_ctx != NULL) && + (EVP_MD_CTX_md(s->read_hash) != NULL) && !SSL_USE_ETM(s)) { - /* !clear => s->read_hash != NULL => mac_size != -1 */ + /* s->read_hash != NULL => mac_size != -1 */ + unsigned char *mac = NULL; + unsigned char mac_tmp[EVP_MAX_MD_SIZE]; mac_size=EVP_MD_CTX_size(s->read_hash); - OPENSSL_assert(mac_size >= 0); + OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); - if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+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_SSL3_GET_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 >= (unsigned int)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 { - /* 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 (i < 0 || mac == NULL || memcmp(md, mac, (size_t)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 * failure is directly visible from the ciphertext anyway, - * we should not reveal which kind of error occured -- this + * we should not reveal which kind of error occurred -- this * might become visible to an attacker (e.g. via a logfile) */ al=SSL_AD_BAD_RECORD_MAC; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); @@ -518,7 +567,17 @@ printf("\n"); s->packet_length=0; /* just read a 0 length packet */ - if (rr->length == 0) goto again; + if (rr->length == 0) + { + empty_record_count++; + if (empty_record_count > MAX_EMPTY_RECORDS) + { + al=SSL_AD_UNEXPECTED_MESSAGE; + SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_TOO_MANY_EMPTY_FRAGMENTS); + goto f_err; + } + goto again; + } #if 0 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length); @@ -576,7 +635,8 @@ int ssl3_do_compress(SSL *ssl) int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) { const unsigned char *buf=buf_; - unsigned int tot,n,nw; + unsigned int tot,n,nw,max_send_fragment; + SSL3_BUFFER *wb=&(s->s3->wbuf); int i; s->rwstate=SSL_NOTHING; @@ -594,6 +654,163 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) } } + /* first check if there is a SSL3_BUFFER still being written + * out. This will happen with non blocking IO */ + if (wb->left != 0) + { + i = ssl3_write_pending(s,type,&buf[tot],s->s3->wpend_tot); + if (i<=0) + { + /* XXX should we ssl3_release_write_buffer if i<0? */ + s->s3->wnum=tot; + return i; + } + tot += i; /* this might be last fragment */ + } + +#if !defined(OPENSSL_NO_MULTIBLOCK) && EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK + /* + * Depending on platform multi-block can deliver several *times* + * better performance. Downside is that it has to allocate + * jumbo buffer to accomodate up to 8 records, but the + * compromise is considered worthy. + */ + if (type==SSL3_RT_APPLICATION_DATA && + len >= 4*(max_send_fragment=s->max_send_fragment) && + s->compress==NULL && s->msg_callback==NULL && + !SSL_USE_ETM(s) && SSL_USE_EXPLICIT_IV(s) && + EVP_CIPHER_flags(s->enc_write_ctx->cipher)&EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK) + { + unsigned char aad[13]; + EVP_CTRL_TLS1_1_MULTIBLOCK_PARAM mb_param; + int packlen; + + /* minimize address aliasing conflicts */ + if ((max_send_fragment&0xffff) == 0) + max_send_fragment -= 512; + + if (tot==0 || wb->buf==NULL) /* allocate jumbo buffer */ + { + ssl3_release_write_buffer(s); + + packlen = EVP_CIPHER_CTX_ctrl(s->enc_write_ctx, + EVP_CTRL_TLS1_1_MULTIBLOCK_MAX_BUFSIZE, + max_send_fragment,NULL); + + if (len>=8*max_send_fragment) packlen *= 8; + else packlen *= 4; + + wb->buf=OPENSSL_malloc(packlen); + wb->len=packlen; + } + else if (tot==len) /* done? */ + { + OPENSSL_free(wb->buf); /* free jumbo buffer */ + wb->buf = NULL; + return tot; + } + + n=(len-tot); + for (;;) + { + if (n < 4*max_send_fragment) + { + OPENSSL_free(wb->buf); /* free jumbo buffer */ + wb->buf = NULL; + break; + } + + if (s->s3->alert_dispatch) + { + i=s->method->ssl_dispatch_alert(s); + if (i <= 0) + { + s->s3->wnum=tot; + return i; + } + } + + if (n >= 8*max_send_fragment) + nw = max_send_fragment*(mb_param.interleave=8); + else + nw = max_send_fragment*(mb_param.interleave=4); + + memcpy(aad,s->s3->write_sequence,8); + aad[8]=type; + aad[9]=(unsigned char)(s->version>>8); + aad[10]=(unsigned char)(s->version); + aad[11]=0; + aad[12]=0; + mb_param.out = NULL; + mb_param.inp = aad; + mb_param.len = nw; + + packlen = EVP_CIPHER_CTX_ctrl(s->enc_write_ctx, + EVP_CTRL_TLS1_1_MULTIBLOCK_AAD, + sizeof(mb_param),&mb_param); + + if (packlen<=0 || packlen>wb->len) /* never happens */ + { + OPENSSL_free(wb->buf); /* free jumbo buffer */ + wb->buf = NULL; + break; + } + + mb_param.out = wb->buf; + mb_param.inp = &buf[tot]; + mb_param.len = nw; + + EVP_CIPHER_CTX_ctrl(s->enc_write_ctx, + EVP_CTRL_TLS1_1_MULTIBLOCK_ENCRYPT, + sizeof(mb_param),&mb_param); + + s->s3->write_sequence[7] += mb_param.interleave; + if (s->s3->write_sequence[7] < mb_param.interleave) + { + int j=6; + while (j>=0 && (++s->s3->write_sequence[j--])==0) ; + } + + wb->offset = 0; + wb->left = packlen; + + s->s3->wpend_tot = nw; + s->s3->wpend_buf = &buf[tot]; + s->s3->wpend_type= type; + s->s3->wpend_ret = nw; + + i = ssl3_write_pending(s,type,&buf[tot],nw); + if (i<=0) + { + if (i<0) + { + OPENSSL_free(wb->buf); + wb->buf = NULL; + } + s->s3->wnum=tot; + return i; + } + if (i==(int)n) + { + OPENSSL_free(wb->buf); /* free jumbo buffer */ + wb->buf = NULL; + return tot+i; + } + n-=i; + tot+=i; + } + } + else +#endif + if (tot==len) /* done? */ + { + if (s->mode & SSL_MODE_RELEASE_BUFFERS && + !SSL_IS_DTLS(s)) + ssl3_release_write_buffer(s); + + return tot; + } + n=(len-tot); for (;;) { @@ -605,6 +822,7 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) i=do_ssl3_write(s, type, &(buf[tot]), nw, 0); if (i <= 0) { + /* XXX should we ssl3_release_write_buffer if i<0? */ s->s3->wnum=tot; return i; } @@ -616,7 +834,11 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) /* next chunk of data should get another prepended empty fragment * in ciphersuites with known-IV weakness: */ s->s3->empty_fragment_done = 0; - + + if ((i==(int)n) && s->mode & SSL_MODE_RELEASE_BUFFERS && + !SSL_IS_DTLS(s)) + ssl3_release_write_buffer(s); + return tot+i; } @@ -679,6 +901,55 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, goto err; } +#if 0 && !defined(OPENSSL_NO_MULTIBLOCK) && EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK + if (type==SSL3_RT_APPLICATION_DATA && s->compress==NULL && + !SSL_USE_ETM(s) && SSL_USE_EXPLICIT_IV(s) && /*!SSL_IS_DTLS(s) &&*/ + EVP_CIPHER_flags(s->enc_write_ctx->cipher)&EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK) + do { + unsigned char aad[13]; + EVP_CTRL_TLS1_1_MULTIBLOCK_PARAM mb_param = {NULL,aad,sizeof(aad),0}; + int packlen; + + memcpy(aad,s->s3->write_sequence,8); + aad[8]=type; + aad[9]=(unsigned char)(s->version>>8); + aad[10]=(unsigned char)(s->version); + aad[11]=(unsigned char)(len>>8); + aad[12]=(unsigned char)len; + packlen = EVP_CIPHER_CTX_ctrl(s->enc_write_ctx, + EVP_CTRL_TLS1_1_MULTIBLOCK_AAD, + sizeof(mb_param),&mb_param); + + if (packlen==0 || packlen > wb->len) break; + + mb_param.out = wb->buf; + mb_param.inp = buf; + mb_param.len = len; + EVP_CIPHER_CTX_ctrl(s->enc_write_ctx, + EVP_CTRL_TLS1_1_MULTIBLOCK_ENCRYPT, + sizeof(mb_param),&mb_param); + + s->s3->write_sequence[7] += mb_param.interleave; + if (s->s3->write_sequence[7] < mb_param.interleave) + { + int j=6; + while (j>=0 && (++s->s3->write_sequence[j--])==0) ; + } + + wb->offset=0; + wb->left = packlen; + + /* memorize arguments so that ssl3_write_pending can detect bad write retries later */ + s->s3->wpend_tot=len; + s->s3->wpend_buf=buf; + s->s3->wpend_type=type; + s->s3->wpend_ret=len; + + /* we now just need to write the buffer */ + return ssl3_write_pending(s,type,buf,len); + } while (0); +#endif + /* 'create_empty_fragment' is true only when this function calls itself */ if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done) { @@ -740,13 +1011,21 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, wr->type=type; *(p++)=(s->version>>8); - *(p++)=s->version&0xff; + /* Some servers hang if iniatial client hello is larger than 256 + * bytes and record version number > TLS 1.0 + */ + if (s->state == SSL3_ST_CW_CLNT_HELLO_B + && !s->renegotiate + && TLS1_get_version(s) > TLS1_VERSION) + *(p++) = 0x1; + else + *(p++)=s->version&0xff; /* field where we are to write out packet length */ plen=p; p+=2; - /* Explicit IV length, block ciphers and TLS version 1.1 or later */ - if (s->enc_write_ctx && s->version >= TLS1_1_VERSION) + /* Explicit IV length, block ciphers appropriate version flag */ + if (s->enc_write_ctx && SSL_USE_EXPLICIT_IV(s)) { int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx); if (mode == EVP_CIPH_CBC_MODE) @@ -791,7 +1070,7 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, * from wr->input. Length should be wr->length. * wr->data still points in the wb->buf */ - if (mac_size != 0) + if (!SSL_USE_ETM(s) && mac_size != 0) { if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0) goto err; @@ -811,9 +1090,19 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, /* ssl3_enc can only have an error on read */ s->method->ssl3_enc->enc(s,1); + if (SSL_USE_ETM(s) && mac_size != 0) + { + if (s->method->ssl3_enc->mac(s,p + wr->length,1) < 0) + goto err; + wr->length+=mac_size; + } + /* record length after mac and block padding */ s2n(wr->length,plen); + if (s->msg_callback) + s->msg_callback(1, 0, SSL3_RT_HEADER, plen - 5, 5, s, s->msg_callback_arg); + /* we should now have * wr->data pointing to the encrypted data, which is * wr->length long */ @@ -879,9 +1168,6 @@ int ssl3_write_pending(SSL *s, int type, const unsigned char *buf, { wb->left=0; wb->offset+=i; - if (s->mode & SSL_MODE_RELEASE_BUFFERS && - SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) - ssl3_release_write_buffer(s); s->rwstate=SSL_NOTHING; return(s->s3->wpend_ret); } @@ -1447,8 +1733,14 @@ int ssl3_do_change_cipher_spec(SSL *s) slen=s->method->ssl3_enc->client_finished_label_len; } - s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s, + i = s->method->ssl3_enc->final_finish_mac(s, sender,slen,s->s3->tmp.peer_finish_md); + if (i == 0) + { + SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR); + return 0; + } + s->s3->tmp.peer_finish_md_len = i; return(1); }