X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fd1_pkt.c;h=3ee46c4721fec3fcafd6d9ba0e505f1add0b926c;hp=2e9d5452f7beb23679ea58275b534c52ff779804;hb=44c8b81eea16ab0d46bce0050178de160ee72abb;hpb=e5fa864f62c096536d700d977a5eb924ad293304 diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c index 2e9d5452f7..3ee46c4721 100644 --- a/ssl/d1_pkt.c +++ b/ssl/d1_pkt.c @@ -207,6 +207,10 @@ dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) DTLS1_RECORD_DATA *rdata; pitem *item; + /* 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) @@ -526,7 +530,7 @@ err: /* used only by dtls1_read_bytes */ int dtls1_get_record(SSL *s) { - int ssl_major,ssl_minor,al; + int ssl_major,ssl_minor; int i,n; SSL3_RECORD *rr; SSL_SESSION *sess; @@ -557,7 +561,12 @@ again: /* read timeout is handled by dtls1_read_bytes */ if (n <= 0) return(n); /* error or non-blocking */ - OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH); + /* this packet contained a partial record, dump it */ + if (s->packet_length != DTLS1_RT_HEADER_LENGTH) + { + s->packet_length = 0; + goto again; + } s->rstate=SSL_ST_READ_BODY; @@ -582,26 +591,27 @@ again: { if (version != s->version) { - SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER); - /* Send back error using their - * version number :-) */ - s->version=version; - al=SSL_AD_PROTOCOL_VERSION; - goto f_err; + /* unexpected version, silently discard */ + rr->length = 0; + s->packet_length = 0; + goto again; } } - if ((version & 0xff00) != (DTLS1_VERSION & 0xff00)) + if ((version & 0xff00) != (s->version & 0xff00)) { - SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER); - goto err; + /* wrong version, silently discard record */ + rr->length = 0; + s->packet_length = 0; + goto again; } if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { - al=SSL_AD_RECORD_OVERFLOW; - SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG); - goto f_err; + /* record too long, silently discard it */ + rr->length = 0; + s->packet_length = 0; + goto again; } /* now s->rstate == SSL_ST_READ_BODY */ @@ -619,6 +629,7 @@ again: /* this packet contained a partial record, dump it */ if ( n != i) { + rr->length = 0; s->packet_length = 0; goto again; } @@ -632,12 +643,20 @@ again: bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); if ( bitmap == NULL) { + rr->length = 0; s->packet_length = 0; /* dump this record */ goto again; /* get another record */ } - /* check whether this is a repeat, or aged record */ - if ( ! dtls1_record_replay_check(s, bitmap)) + /* Check whether this is a repeat, or aged record. + * Don't check if we're listening and this message is + * a ClientHello. They can look as if they're replayed, + * since they arrive from different connections and + * would be dropped unnecessarily. + */ + if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && + *p == SSL3_MT_CLIENT_HELLO) && + !dtls1_record_replay_check(s, bitmap)) { rr->length = 0; s->packet_length=0; /* dump this record */ @@ -656,6 +675,7 @@ again: { dtls1_record_bitmap_update(s, bitmap); dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num); + rr->length = 0; s->packet_length = 0; goto again; } @@ -666,10 +686,6 @@ again: dtls1_clear_timeouts(s); /* done waiting */ return(1); -f_err: - ssl3_send_alert(s,SSL3_AL_FATAL,al); -err: - return(0); } /* Return up to 'len' payload bytes received in 'type' records. @@ -762,7 +778,11 @@ start: pitem_free(item); } } - + + /* Check for timeout */ + if (dtls1_handle_timeout(s) > 0) + goto start; + /* get new packet if necessary */ if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) { @@ -1067,13 +1087,17 @@ start: if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { struct ccs_header_st ccs_hdr; + unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH; dtls1_get_ccs_header(rr->data, &ccs_hdr); + if (s->version == DTLS1_BAD_VER) + ccs_hdr_len = 3; + /* 'Change Cipher Spec' is just a single byte, so we know * exactly what the record payload has to look like */ /* XDTLS: check that epoch is consistent */ - if ( (rr->length != DTLS1_CCS_HEADER_LENGTH) || + if ( (rr->length != ccs_hdr_len) || (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) { i=SSL_AD_ILLEGAL_PARAMETER; @@ -1087,6 +1111,16 @@ start: s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg); + /* We can't process a CCS now, because previous handshake + * messages are still missing, so just drop it. + */ + if (!s->d1->change_cipher_spec_ok) + { + goto start; + } + + s->d1->change_cipher_spec_ok = 0; + s->s3->change_cipher_spec=1; if (!ssl3_do_change_cipher_spec(s)) goto err; @@ -1094,6 +1128,9 @@ start: /* do this whenever CCS is processed */ dtls1_reset_seq_numbers(s, SSL3_CC_READ); + if (s->version == DTLS1_BAD_VER) + s->d1->handshake_read_seq++; + goto start; } @@ -1227,7 +1264,6 @@ err: int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) { - unsigned int n,tot; int i; if (SSL_in_init(s) && !s->in_handshake) @@ -1241,31 +1277,14 @@ dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) } } - tot = s->s3->wnum; - n = len - tot; - - while( n) + if (len > SSL3_RT_MAX_PLAIN_LENGTH) { - /* dtls1_write_bytes sends one record at a time, sized according to - * the currently known MTU */ - i = dtls1_write_bytes(s, type, buf_, len); - if (i <= 0) return i; - - if ((i == (int)n) || - (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; - return tot+i; - } - - tot += i; - n-=i; + SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG); + return -1; } - return tot; + i = dtls1_write_bytes(s, type, buf_, len); + return i; } @@ -1306,46 +1325,13 @@ have_handshake_fragment(SSL *s, int type, unsigned char *buf, /* Call this to write data in records of type 'type' * It will return <= 0 if not all data has been sent or non-blocking IO. */ -int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len) +int dtls1_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 mtu; + OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); s->rwstate=SSL_NOTHING; - tot=s->s3->wnum; - - n=(len-tot); - - /* handshake layer figures out MTU for itself, but data records - * are also sent through this interface, so need to figure out MTU */ -#if 0 - mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL); - mtu += DTLS1_HM_HEADER_LENGTH; /* HM already inserted */ -#endif - mtu = s->d1->mtu; - - if (mtu > SSL3_RT_MAX_PLAIN_LENGTH) - mtu = SSL3_RT_MAX_PLAIN_LENGTH; - - if (n > mtu) - nw=mtu; - else - nw=n; - - i=do_dtls1_write(s, type, &(buf[tot]), nw, 0); - if (i <= 0) - { - s->s3->wnum=tot; - return i; - } - - if ( (int)s->s3->wnum + i == len) - s->s3->wnum = 0; - else - s->s3->wnum += i; - + i=do_dtls1_write(s, type, buf, len, 0); return i; } @@ -1401,7 +1387,7 @@ int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, #if 0 /* 'create_empty_fragment' is true only when this function calls itself */ if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done - && SSL_version(s) != DTLS1_VERSION) + && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER) { /* countermeasure against known-IV weakness in CBC ciphersuites * (see http://www.openssl.org/~bodo/tls-cbc.txt) @@ -1428,7 +1414,6 @@ int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, s->s3->empty_fragment_done = 1; } #endif - p = wb->buf + prefix_len; /* write the header */