static int dtls1_buffer_record(SSL *s, record_pqueue *q,
unsigned char *priority);
static int dtls1_process_record(SSL *s);
-static void dtls1_clear_timeouts(SSL *s);
/* copy buffered record into SSL structure */
static int
/* Limit the size of the queue to prevent DOS attacks */
if (pqueue_size(queue->q) >= 100)
return 0;
-
+
rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
item = pitem_new(priority, rdata);
if (rdata == NULL || item == NULL)
}
#endif
- /* insert should not fail, since duplicates are dropped */
- if (pqueue_insert(queue->q, item) == NULL)
- {
- OPENSSL_free(rdata);
- pitem_free(item);
- return(0);
- }
-
s->packet = NULL;
s->packet_length = 0;
memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
if (!ssl3_setup_buffers(s))
{
SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
+ if (rdata->rbuf.buf != NULL)
+ OPENSSL_free(rdata->rbuf.buf);
OPENSSL_free(rdata);
pitem_free(item);
- return(0);
+ return(-1);
}
-
+
+ /* insert should not fail, since duplicates are dropped */
+ if (pqueue_insert(queue->q, item) == NULL)
+ {
+ SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
+ if (rdata->rbuf.buf != NULL)
+ OPENSSL_free(rdata->rbuf.buf);
+ OPENSSL_free(rdata);
+ pitem_free(item);
+ return(-1);
+ }
+
return(1);
}
dtls1_get_unprocessed_record(s);
if ( ! dtls1_process_record(s))
return(0);
- dtls1_buffer_record(s, &(s->d1->processed_rcds),
- s->s3->rrec.seq_num);
+ if(dtls1_buffer_record(s, &(s->d1->processed_rcds),
+ s->s3->rrec.seq_num)<0)
+ return -1;
}
}
dtls1_process_record(SSL *s)
{
int i,al;
- int clear=0;
int enc_err;
SSL_SESSION *sess;
SSL3_RECORD *rr;
- unsigned int mac_size;
+ unsigned int mac_size, orig_len;
unsigned char md[EVP_MAX_MD_SIZE];
- int decryption_failed_or_bad_record_mac = 0;
-
rr= &(s->s3->rrec);
sess = s->session;
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)
{
- /* 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
#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) &&
+ (EVP_MD_CTX_md(s->read_hash) != NULL))
{
- /* !clear => s->read_hash != NULL => mac_size != -1 */
- int t;
- t=EVP_MD_CTX_size(s->read_hash);
- OPENSSL_assert(t >= 0);
- mac_size=t;
-
- if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
- {
-#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);
- 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)
+ /* 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 <= EVP_MAX_MD_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 */
al=SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
goto f_err;
-#else
- decryption_failed_or_bad_record_mac = 1;
-#endif
}
- rr->length-=mac_size;
- i=s->method->ssl3_enc->mac(s,md,0);
- if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
+
+ if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
{
- decryption_failed_or_bad_record_mac = 1;
+ /* 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;
}
+ else
+ {
+ /* 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+mac_size)
+ enc_err = -1;
}
- if (decryption_failed_or_bad_record_mac)
+ if (enc_err < 0)
{
/* decryption failed, silently discard message */
rr->length = 0;
/* we have pulled in a full packet so zero things */
s->packet_length=0;
- dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
return(1);
f_err:
/* The epoch may have changed. If so, process all the
* pending records. This is a non-blocking operation. */
- dtls1_process_buffered_records(s);
+ if(dtls1_process_buffered_records(s)<0)
+ return -1;
/* if we're renegotiating, then there may be buffered records */
if (dtls1_get_processed_record(s))
p=s->packet;
+ if (s->msg_callback)
+ s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
+
/* Pull apart the header into the DTLS1_RECORD */
rr->type= *(p++);
ssl_major= *(p++);
/* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
i=rr->length;
n=ssl3_read_n(s,i,i,1);
- if (n <= 0) return(n); /* error or non-blocking io */
-
/* this packet contained a partial record, dump it */
if ( n != i)
{
* would be dropped unnecessarily.
*/
if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
- *p == SSL3_MT_CLIENT_HELLO) &&
+ s->packet_length > DTLS1_RT_HEADER_LENGTH &&
+ s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
!dtls1_record_replay_check(s, bitmap))
{
rr->length = 0;
{
if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
{
- dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
+ if(dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num)<0)
+ return -1;
+ dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
}
rr->length = 0;
s->packet_length = 0;
s->packet_length = 0; /* dump this record */
goto again; /* get another record */
}
+ dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
- dtls1_clear_timeouts(s); /* done waiting */
return(1);
}
}
}
+ if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE)
+ {
+ rr->length = 0;
+ goto start;
+ }
+
/* we now have a packet which can be read and processed */
if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
* buffer the application data for later processing rather
* than dropping the connection.
*/
- dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
+ if(dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num)<0)
+ {
+ SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
+ return -1;
+ }
rr->length = 0;
goto start;
}
!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
!s->s3->renegotiate)
{
+ s->d1->handshake_read_seq++;
s->new_session = 1;
ssl3_renegotiate(s);
if (ssl3_renegotiate_check(s))
*/
if (msg_hdr.type == SSL3_MT_FINISHED)
{
+ if (dtls1_check_timeout_num(s) < 0)
+ return -1;
+
dtls1_retransmit_buffered_messages(s);
rr->length = 0;
goto start;
unsigned char *p,*pseq;
int i,mac_size,clear=0;
int prefix_len = 0;
+ int eivlen;
SSL3_RECORD *wr;
SSL3_BUFFER *wb;
SSL_SESSION *sess;
- int bs;
/* first check if there is a SSL3_BUFFER still being written
* out. This will happen with non blocking IO */
*(p++)=type&0xff;
wr->type=type;
-
- *(p++)=(s->version>>8);
- *(p++)=s->version&0xff;
+ /* Special case: for hello verify request, client version 1.0 and
+ * we haven't decided which version to use yet send back using
+ * version 1.0 header: otherwise some clients will ignore it.
+ */
+ if (s->method->version == DTLS_ANY_VERSION)
+ {
+ *(p++)=DTLS1_VERSION>>8;
+ *(p++)=DTLS1_VERSION&0xff;
+ }
+ else
+ {
+ *(p++)=s->version>>8;
+ *(p++)=s->version&0xff;
+ }
/* field where we are to write out packet epoch, seq num and len */
pseq=p;
p+=10;
- /* lets setup the record stuff. */
-
- /* Make space for the explicit IV in case of CBC.
- * (this is a bit of a boundary violation, but what the heck).
- */
- if ( s->enc_write_ctx &&
- (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
- bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
- else
- bs = 0;
+ /* Explicit IV length, block ciphers appropriate version flag */
+ if (s->enc_write_ctx)
+ {
+ 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;
- wr->data=p + bs; /* make room for IV in case of CBC */
+ /* lets setup the record stuff. */
+ wr->data=p + eivlen; /* make room for IV in case of CBC */
wr->length=(int)len;
wr->input=(unsigned char *)buf;
if (mac_size != 0)
{
- if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),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;
+ if (eivlen)
+ wr->length += eivlen;
- /* ssl3_enc can only have an error on read */
- if (bs) /* bs != 0 in case of CBC */
- {
- RAND_pseudo_bytes(p,bs);
- /* master IV and last CBC residue stand for
- * the rest of randomness */
- wr->length += bs;
- }
-
- s->method->ssl3_enc->enc(s,1);
+ if(s->method->ssl3_enc->enc(s,1) < 1) goto err;
/* record length after mac and block padding */
/* if (type == SSL3_RT_APPLICATION_DATA ||
pseq+=6;
s2n(wr->length,pseq);
+ if (s->msg_callback)
+ s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
+
/* we should now have
* wr->data pointing to the encrypted data, which is
* wr->length long */
memset(seq, 0x00, seq_bytes);
}
-
-
-static void
-dtls1_clear_timeouts(SSL *s)
- {
- memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
- }
projects / openssl.git / blobdiff