diff options
author | Parménides GV <parmegv@sdf.org> | 2014-06-13 12:13:04 +0200 |
---|---|---|
committer | Parménides GV <parmegv@sdf.org> | 2014-06-13 12:13:04 +0200 |
commit | 3a71bc9e4aa4296f460e2e3c55de74c9852477ad (patch) | |
tree | f816597a7c4322137f0657e7aa2bf392404d1870 /app/openssl/ssl/s3_pkt.c | |
parent | cfe67bfd8260253ce9288225b9e26f666d27133f (diff) | |
parent | 36247e71df88fa13c6c5a887de3b11d9a883615f (diff) |
Merge branch 'feature/establish-an-upstream-relationship-with-ics-openvpn-codebase-#5381' into develop
Diffstat (limited to 'app/openssl/ssl/s3_pkt.c')
-rw-r--r-- | app/openssl/ssl/s3_pkt.c | 345 |
1 files changed, 198 insertions, 147 deletions
diff --git a/app/openssl/ssl/s3_pkt.c b/app/openssl/ssl/s3_pkt.c index 0d3874ae..75997ac2 100644 --- a/app/openssl/ssl/s3_pkt.c +++ b/app/openssl/ssl/s3_pkt.c @@ -115,9 +115,10 @@ #include "ssl_locl.h" #include <openssl/evp.h> #include <openssl/buffer.h> +#include <openssl/rand.h> static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, - unsigned int len, int create_empty_fragment); + unsigned int len, char fragment, char is_fragment); static int ssl3_get_record(SSL *s); int ssl3_read_n(SSL *s, int n, int max, int extend) @@ -289,16 +290,8 @@ 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, orig_len; size_t extra; - int decryption_failed_or_bad_record_mac = 0; - unsigned char *mac = NULL; -#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0 - long align=SSL3_ALIGN_PAYLOAD; -#else - long align=0; -#endif rr= &(s->s3->rrec); sess=s->session; @@ -307,8 +300,7 @@ static int ssl3_get_record(SSL *s) extra=SSL3_RT_MAX_EXTRA; else extra=0; - if (!(SSL_get_mode(s) & SSL_MODE_SMALL_BUFFERS) && - extra && !s->s3->init_extra) + if (extra && !s->s3->init_extra) { /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER * set after ssl3_setup_buffers() was done */ @@ -343,7 +335,7 @@ 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; @@ -357,21 +349,6 @@ fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length); goto err; } - /* If we receive a valid record larger than the current buffer size, - * allocate some memory for it. - */ - if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH - align) - { - if ((p=OPENSSL_realloc(s->s3->rbuf.buf, rr->length + SSL3_RT_HEADER_LENGTH + align))==NULL) - { - SSLerr(SSL_F_SSL3_GET_RECORD,ERR_R_MALLOC_FAILURE); - goto err; - } - s->s3->rbuf.buf=p; - s->s3->rbuf.len=rr->length + SSL3_RT_HEADER_LENGTH + align; - s->packet= &(s->s3->rbuf.buf[0]); - } - if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH) { al=SSL_AD_RECORD_OVERFLOW; @@ -423,17 +400,15 @@ fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length); rr->data=rr->input; 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 @@ -443,53 +418,62 @@ 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)) { - /* !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) + /* kludge: *_cbc_remove_padding passes padding length in rr->type */ + orig_len = rr->length+((unsigned int)rr->type>>8); + + /* 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 (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 && + 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, orig_len); 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 |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 @@ -598,7 +582,6 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) const unsigned char *buf=buf_; unsigned int tot,n,nw; int i; - unsigned int max_plain_length; s->rwstate=SSL_NOTHING; tot=s->s3->wnum; @@ -618,17 +601,34 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) n=(len-tot); for (;;) { - if (type == SSL3_RT_APPLICATION_DATA && (SSL_get_mode(s) & SSL_MODE_SMALL_BUFFERS)) - max_plain_length = SSL3_RT_DEFAULT_PLAIN_LENGTH; - else - max_plain_length = s->max_send_fragment; + /* max contains the maximum number of bytes that we can put + * into a record. */ + unsigned max = s->max_send_fragment; + /* fragment is true if do_ssl3_write should send the first byte + * in its own record in order to randomise a CBC IV. */ + int fragment = 0; + + if (n > 1 && + s->s3->need_record_splitting && + type == SSL3_RT_APPLICATION_DATA && + !s->s3->record_split_done) + { + fragment = 1; + /* The first byte will be in its own record, so we + * can write an extra byte. */ + max++; + /* record_split_done records that the splitting has + * been done in case we hit an SSL_WANT_WRITE condition. + * In that case, we don't need to do the split again. */ + s->s3->record_split_done = 1; + } - if (n > max_plain_length) - nw = max_plain_length; + if (n > max) + nw=max; else nw=n; - i=do_ssl3_write(s, type, &(buf[tot]), nw, 0); + i=do_ssl3_write(s, type, &(buf[tot]), nw, fragment, 0); if (i <= 0) { s->s3->wnum=tot; @@ -639,10 +639,10 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) (type == SSL3_RT_APPLICATION_DATA && (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { - /* next chunk of data should get another prepended empty fragment - * in ciphersuites with known-IV weakness: */ - s->s3->empty_fragment_done = 0; - + /* next chunk of data should get another prepended, + * one-byte fragment in ciphersuites with known-IV + * weakness. */ + s->s3->record_split_done = 0; return tot+i; } @@ -651,12 +651,18 @@ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) } } +/* do_ssl3_write writes an SSL record of the given type. If |fragment| is 1 + * then it splits the record into a one byte record and a record with the rest + * of the data in order to randomise a CBC IV. If |is_fragment| is true then + * this call resulted from do_ssl3_write calling itself in order to create that + * one byte fragment. */ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, - unsigned int len, int create_empty_fragment) + unsigned int len, char fragment, char is_fragment) { unsigned char *p,*plen; - int i,mac_size,clear=0; + int i,mac_size; int prefix_len=0; + int eivlen; long align=0; SSL3_RECORD *wr; SSL3_BUFFER *wb=&(s->s3->wbuf); @@ -680,7 +686,7 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, /* if it went, fall through and send more stuff */ } - if (len == 0 && !create_empty_fragment) + if (len == 0) return 0; wr= &(s->s3->wrec); @@ -689,10 +695,9 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, if ( (sess == NULL) || (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL)) - clear=1; - - if (clear) + { mac_size=0; + } else { mac_size=EVP_MD_CTX_size(s->write_hash); @@ -700,54 +705,33 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, goto err; } - /* 'create_empty_fragment' is true only when this function calls itself */ - if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done) + if (fragment) { /* countermeasure against known-IV weakness in CBC ciphersuites * (see http://www.openssl.org/~bodo/tls-cbc.txt) */ + prefix_len = do_ssl3_write(s, type, buf, 1 /* length */, + 0 /* fragment */, + 1 /* is_fragment */); + if (prefix_len <= 0) + goto err; - if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) - { - /* recursive function call with 'create_empty_fragment' set; - * this prepares and buffers the data for an empty fragment - * (these 'prefix_len' bytes are sent out later - * together with the actual payload) */ - prefix_len = do_ssl3_write(s, type, buf, 0, 1); - if (prefix_len <= 0) - goto err; - - if (prefix_len > - (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD)) - { - /* insufficient space */ - SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR); - goto err; - } - } - - s->s3->empty_fragment_done = 1; - } - - /* resize if necessary to hold the data. */ - if (len + SSL3_RT_DEFAULT_WRITE_OVERHEAD > wb->len) - { - if ((p=OPENSSL_realloc(wb->buf, len + SSL3_RT_DEFAULT_WRITE_OVERHEAD))==NULL) + if (prefix_len > (SSL3_RT_HEADER_LENGTH + + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD)) { - SSLerr(SSL_F_DO_SSL3_WRITE,ERR_R_MALLOC_FAILURE); + /* insufficient space */ + SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR); goto err; } - wb->buf = p; - wb->len = len + SSL3_RT_DEFAULT_WRITE_OVERHEAD; } - if (create_empty_fragment) + if (is_fragment) { #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0 - /* extra fragment would be couple of cipher blocks, - * which would be multiple of SSL3_ALIGN_PAYLOAD, so - * if we want to align the real payload, then we can - * just pretent we simply have two headers. */ - align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH; + /* The extra fragment would be couple of cipher blocks, and + * that will be a multiple of SSL3_ALIGN_PAYLOAD. So, if we + * want to align the real payload, we can just pretend that we + * have two headers and a byte. */ + align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH + 1; align = (-align)&(SSL3_ALIGN_PAYLOAD-1); #endif p = wb->buf + align; @@ -773,16 +757,42 @@ 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; + 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) + { + int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx); + if (mode == EVP_CIPH_CBC_MODE) + { + eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx); + if (eivlen <= 1) + eivlen = 0; + } + /* Need explicit part of IV for GCM mode */ + else if (mode == EVP_CIPH_GCM_MODE) + eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN; + else + eivlen = 0; + } + else + eivlen = 0; /* lets setup the record stuff. */ - wr->data=p; - wr->length=(int)len; - wr->input=(unsigned char *)buf; + wr->data=p + eivlen; + wr->length=(int)(len - (fragment != 0)); + wr->input=(unsigned char *)buf + (fragment != 0); /* we now 'read' from wr->input, wr->length bytes into * wr->data */ @@ -808,11 +818,19 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, if (mac_size != 0) { - if (s->method->ssl3_enc->mac(s,&(p[wr->length]),1) < 0) + if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0) goto err; wr->length+=mac_size; - wr->input=p; - wr->data=p; + } + + wr->input=p; + wr->data=p; + + if (eivlen) + { + /* if (RAND_pseudo_bytes(p, eivlen) <= 0) + goto err; */ + wr->length += eivlen; } /* ssl3_enc can only have an error on read */ @@ -827,11 +845,10 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, wr->type=type; /* not needed but helps for debugging */ wr->length+=SSL3_RT_HEADER_LENGTH; - if (create_empty_fragment) + if (is_fragment) { - /* we are in a recursive call; - * just return the length, don't write out anything here - */ + /* we are in a recursive call; just return the length, don't + * write out anything. */ return wr->length; } @@ -1081,6 +1098,19 @@ start: dest = s->s3->alert_fragment; dest_len = &s->s3->alert_fragment_len; } +#ifndef OPENSSL_NO_HEARTBEATS + else if (rr->type == TLS1_RT_HEARTBEAT) + { + tls1_process_heartbeat(s); + + /* Exit and notify application to read again */ + rr->length = 0; + s->rwstate=SSL_READING; + BIO_clear_retry_flags(SSL_get_rbio(s)); + BIO_set_retry_read(SSL_get_rbio(s)); + return(-1); + } +#endif if (dest_maxlen > 0) { @@ -1224,6 +1254,10 @@ start: SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION); goto f_err; } +#ifdef SSL_AD_MISSING_SRP_USERNAME + else if (alert_descr == SSL_AD_MISSING_SRP_USERNAME) + return(0); +#endif } else if (alert_level == 2) /* fatal */ { @@ -1275,6 +1309,13 @@ start: goto f_err; } + if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) + { + al=SSL_AD_UNEXPECTED_MESSAGE; + SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_CCS); + goto f_err; + } + rr->length=0; if (s->msg_callback) @@ -1302,6 +1343,7 @@ start: #else s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; #endif + s->renegotiate=1; s->new_session=1; } i=s->handshake_func(s); @@ -1335,8 +1377,10 @@ start: { default: #ifndef OPENSSL_NO_TLS - /* TLS just ignores unknown message types */ - if (s->version == TLS1_VERSION) + /* TLS up to v1.1 just ignores unknown message types: + * TLS v1.2 give an unexpected message alert. + */ + if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION) { rr->length = 0; goto start; @@ -1396,10 +1440,8 @@ err: int ssl3_do_change_cipher_spec(SSL *s) { int i; -#ifdef OPENSSL_NO_NEXTPROTONEG const char *sender; int slen; -#endif if (s->state & SSL_ST_ACCEPT) i=SSL3_CHANGE_CIPHER_SERVER_READ; @@ -1408,7 +1450,12 @@ int ssl3_do_change_cipher_spec(SSL *s) if (s->s3->tmp.key_block == NULL) { - if (s->session == NULL) + if (s->session->master_key_length == 0) + { + SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_UNEXPECTED_CCS); + return (0); + } + if (s->session == NULL) { /* might happen if dtls1_read_bytes() calls this */ SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY); @@ -1422,7 +1469,6 @@ int ssl3_do_change_cipher_spec(SSL *s) if (!s->method->ssl3_enc->change_cipher_state(s,i)) return(0); -#ifdef OPENSSL_NO_NEXTPROTONEG /* we have to record the message digest at * this point so we can get it before we read * the finished message */ @@ -1437,9 +1483,14 @@ 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); -#endif + 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); } @@ -1471,7 +1522,7 @@ int ssl3_dispatch_alert(SSL *s) void (*cb)(const SSL *ssl,int type,int val)=NULL; s->s3->alert_dispatch=0; - i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0); + i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0, 0); if (i <= 0) { s->s3->alert_dispatch=1; |