/* $OpenBSD: d1_pkt.c,v 1.121 2022/03/18 18:00:54 jsing Exp $ */ /* * DTLS implementation written by Nagendra Modadugu * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. */ /* ==================================================================== * Copyright (c) 1998-2005 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). * */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * 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 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 acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS 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 AUTHOR OR 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. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ #include #include #include #include #include #include "bytestring.h" #include "dtls_locl.h" #include "pqueue.h" #include "ssl_locl.h" /* mod 128 saturating subtract of two 64-bit values in big-endian order */ static int satsub64be(const unsigned char *v1, const unsigned char *v2) { int ret, sat, brw, i; if (sizeof(long) == 8) do { long l; if (BYTE_ORDER == LITTLE_ENDIAN) break; /* not reached on little-endians */ /* following test is redundant, because input is * always aligned, but I take no chances... */ if (((size_t)v1 | (size_t)v2) & 0x7) break; l = *((long *)v1); l -= *((long *)v2); if (l > 128) return 128; else if (l<-128) return -128; else return (int)l; } while (0); ret = (int)v1[7] - (int)v2[7]; sat = 0; brw = ret >> 8; /* brw is either 0 or -1 */ if (ret & 0x80) { for (i = 6; i >= 0; i--) { brw += (int)v1[i]-(int)v2[i]; sat |= ~brw; brw >>= 8; } } else { for (i = 6; i >= 0; i--) { brw += (int)v1[i]-(int)v2[i]; sat |= brw; brw >>= 8; } } brw <<= 8; /* brw is either 0 or -256 */ if (sat & 0xff) return brw | 0x80; else return brw + (ret & 0xFF); } static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, const unsigned char *seq); static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, const unsigned char *seq); static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch); static int dtls1_buffer_record(SSL *s, record_pqueue *q, unsigned char *priority); static int dtls1_process_record(SSL *s); /* copy buffered record into SSL structure */ static int dtls1_copy_record(SSL *s, DTLS1_RECORD_DATA_INTERNAL *rdata) { ssl3_release_buffer(&s->s3->rbuf); s->internal->packet = rdata->packet; s->internal->packet_length = rdata->packet_length; memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD_INTERNAL)); return (1); } static int dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) { DTLS1_RECORD_DATA_INTERNAL *rdata; pitem *item; /* Limit the size of the queue to prevent DOS attacks */ if (pqueue_size(queue->q) >= 100) return 0; rdata = malloc(sizeof(DTLS1_RECORD_DATA_INTERNAL)); item = pitem_new(priority, rdata); if (rdata == NULL || item == NULL) goto init_err; rdata->packet = s->internal->packet; rdata->packet_length = s->internal->packet_length; memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER_INTERNAL)); memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD_INTERNAL)); item->data = rdata; s->internal->packet = NULL; s->internal->packet_length = 0; memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL)); memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD_INTERNAL)); if (!ssl3_setup_buffers(s)) goto err; /* insert should not fail, since duplicates are dropped */ if (pqueue_insert(queue->q, item) == NULL) goto err; return (1); err: ssl3_release_buffer(&rdata->rbuf); init_err: SSLerror(s, ERR_R_INTERNAL_ERROR); free(rdata); pitem_free(item); return (-1); } static int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) { pitem *item; item = pqueue_pop(queue->q); if (item) { dtls1_copy_record(s, item->data); free(item->data); pitem_free(item); return (1); } return (0); } static int dtls1_process_buffered_record(SSL *s) { /* Check if epoch is current. */ if (s->d1->unprocessed_rcds.epoch != tls12_record_layer_read_epoch(s->internal->rl)) return (0); /* Update epoch once all unprocessed records have been processed. */ if (pqueue_peek(s->d1->unprocessed_rcds.q) == NULL) { s->d1->unprocessed_rcds.epoch = tls12_record_layer_read_epoch(s->internal->rl) + 1; return (0); } /* Process one of the records. */ if (!dtls1_retrieve_buffered_record(s, &s->d1->unprocessed_rcds)) return (-1); if (!dtls1_process_record(s)) return (-1); return (1); } static int dtls1_process_record(SSL *s) { SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec); uint8_t alert_desc; uint8_t *out; size_t out_len; tls12_record_layer_set_version(s->internal->rl, s->version); if (!tls12_record_layer_open_record(s->internal->rl, s->internal->packet, s->internal->packet_length, &out, &out_len)) { tls12_record_layer_alert(s->internal->rl, &alert_desc); if (alert_desc == 0) goto err; /* * DTLS should silently discard invalid records, including those * with a bad MAC, as per RFC 6347 section 4.1.2.1. */ if (alert_desc == SSL_AD_BAD_RECORD_MAC) { out_len = 0; goto done; } if (alert_desc == SSL_AD_RECORD_OVERFLOW) SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); goto fatal_err; } done: rr->data = out; rr->length = out_len; rr->off = 0; s->internal->packet_length = 0; return (1); fatal_err: ssl3_send_alert(s, SSL3_AL_FATAL, alert_desc); err: return (0); } /* 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. * When it finishes, one packet has been decoded and can be found in * ssl->s3->internal->rrec.type - is the type of record * ssl->s3->internal->rrec.data, - data * ssl->s3->internal->rrec.length, - number of bytes */ /* used only by dtls1_read_bytes */ int dtls1_get_record(SSL *s) { SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec); unsigned char *p = NULL; DTLS1_BITMAP *bitmap; unsigned int is_next_epoch; int ret, n; /* See if there are pending records that can now be processed. */ if ((ret = dtls1_process_buffered_record(s)) != 0) return (ret); /* get something from the wire */ if (0) { again: /* dump this record on all retries */ rr->length = 0; s->internal->packet_length = 0; } /* check if we have the header */ if ((s->internal->rstate != SSL_ST_READ_BODY) || (s->internal->packet_length < DTLS1_RT_HEADER_LENGTH)) { CBS header, seq_no; uint16_t epoch, len, ssl_version; uint8_t type; n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH); if (n <= 0) return (n); /* If this packet contained a partial record, dump it. */ if (n != DTLS1_RT_HEADER_LENGTH) goto again; s->internal->rstate = SSL_ST_READ_BODY; CBS_init(&header, s->internal->packet, s->internal->packet_length); /* Pull apart the header into the DTLS1_RECORD */ if (!CBS_get_u8(&header, &type)) goto again; if (!CBS_get_u16(&header, &ssl_version)) goto again; /* Sequence number is 64 bits, with top 2 bytes = epoch. */ if (!CBS_get_bytes(&header, &seq_no, SSL3_SEQUENCE_SIZE)) goto again; if (!CBS_get_u16(&seq_no, &epoch)) goto again; if (!CBS_write_bytes(&seq_no, &rr->seq_num[2], sizeof(rr->seq_num) - 2, NULL)) goto again; if (!CBS_get_u16(&header, &len)) goto again; rr->type = type; rr->epoch = epoch; rr->length = len; /* unexpected version, silently discard */ if (!s->internal->first_packet && ssl_version != s->version) goto again; /* wrong version, silently discard record */ if ((ssl_version & 0xff00) != (s->version & 0xff00)) goto again; /* record too long, silently discard it */ if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) goto again; /* now s->internal->rstate == SSL_ST_READ_BODY */ p = (unsigned char *)CBS_data(&header); } /* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */ n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length); if (n <= 0) return (n); /* If this packet contained a partial record, dump it. */ if (n != DTLS1_RT_HEADER_LENGTH + rr->length) goto again; s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ /* match epochs. NULL means the packet is dropped on the floor */ bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); if (bitmap == NULL) goto again; /* * 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 != NULL && *p == SSL3_MT_CLIENT_HELLO) && !dtls1_record_replay_check(s, bitmap, rr->seq_num)) goto again; /* just read a 0 length packet */ if (rr->length == 0) goto again; /* If this record is from the next epoch (either HM or ALERT), * and a handshake is currently in progress, buffer it since it * cannot be processed at this time. However, do not buffer * anything while listening. */ if (is_next_epoch) { if ((SSL_in_init(s) || s->internal->in_handshake) && !s->d1->listen) { if (dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0) return (-1); /* Mark receipt of record. */ dtls1_record_bitmap_update(s, bitmap, rr->seq_num); } goto again; } if (!dtls1_process_record(s)) goto again; /* Mark receipt of record. */ dtls1_record_bitmap_update(s, bitmap, rr->seq_num); return (1); } static int dtls1_read_handshake_unexpected(SSL *s) { SSL3_RECORD_INTERNAL *rr = &s->s3->rrec; struct hm_header_st hs_msg_hdr; CBS cbs; int ret; if (s->internal->in_handshake) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } if (rr->off != 0) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } /* Parse handshake message header. */ CBS_init(&cbs, rr->data, rr->length); if (!dtls1_get_message_header(&cbs, &hs_msg_hdr)) return -1; /* XXX - probably should drop/continue. */ /* This may just be a stale retransmit. */ if (rr->epoch != tls12_record_layer_read_epoch(s->internal->rl)) { rr->length = 0; return 1; } if (hs_msg_hdr.type == SSL3_MT_HELLO_REQUEST) { /* * Incoming HelloRequest messages should only be received by a * client. A server may send these at any time - a client should * ignore the message if received in the middle of a handshake. * See RFC 5246 sections 7.4 and 7.4.1.1. */ if (s->server) { SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } /* XXX - should also check frag offset/length. */ if (hs_msg_hdr.msg_len != 0) { SSLerror(s, SSL_R_BAD_HELLO_REQUEST); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return -1; } ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE, rr->data, DTLS1_HM_HEADER_LENGTH); rr->length = 0; /* * It should be impossible to hit this, but keep the safety * harness for now... */ if (s->session == NULL || s->session->cipher == NULL) return 1; /* * Ignore this message if we're currently handshaking, * renegotiation is already pending or renegotiation is disabled * via flags. */ if (!SSL_is_init_finished(s) || s->s3->renegotiate || (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) return 1; s->d1->handshake_read_seq++; /* XXX - why is this set here but not in ssl3? */ s->internal->new_session = 1; if (!ssl3_renegotiate(s)) return 1; if (!ssl3_renegotiate_check(s)) return 1; } else if (hs_msg_hdr.type == SSL3_MT_CLIENT_HELLO) { /* * Incoming ClientHello messages should only be received by a * server. A client may send these in response to server * initiated renegotiation (HelloRequest) or in order to * initiate renegotiation by the client. See RFC 5246 section * 7.4.1.2. */ if (!s->server) { SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } /* * A client should not be sending a ClientHello unless we're not * currently handshaking. */ if (!SSL_is_init_finished(s)) { SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } if ((s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION) != 0) { ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_NO_RENEGOTIATION); return -1; } if (s->session == NULL || s->session->cipher == NULL) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } /* Client requested renegotiation but it is not permitted. */ if (!s->s3->send_connection_binding || (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) { ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION); return 1; } s->s3->hs.state = SSL_ST_ACCEPT; s->internal->renegotiate = 1; s->internal->new_session = 1; } else if (hs_msg_hdr.type == SSL3_MT_FINISHED && s->server) { /* * If we are server, we may have a repeated FINISHED of the * client here, then retransmit our CCS and FINISHED. */ if (dtls1_check_timeout_num(s) < 0) return -1; /* XXX - should this be calling ssl_msg_callback()? */ dtls1_retransmit_buffered_messages(s); rr->length = 0; return 1; } else { SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } if ((ret = s->internal->handshake_func(s)) < 0) return ret; if (ret == 0) { SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); return -1; } if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { if (s->s3->rbuf.left == 0) { ssl_force_want_read(s); return -1; } } /* * We either finished a handshake or ignored the request, now try again * to obtain the (application) data we were asked for. */ return 1; } /* Return up to 'len' payload bytes received in 'type' records. * 'type' is one of the following: * * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) * - 0 (during a shutdown, no data has to be returned) * * If we don't have stored data to work from, read a SSL/TLS record first * (possibly multiple records if we still don't have anything to return). * * This function must handle any surprises the peer may have for us, such as * Alert records (e.g. close_notify), ChangeCipherSpec records (not really * a surprise, but handled as if it were), or renegotiation requests. * Also if record payloads contain fragments too small to process, we store * them until there is enough for the respective protocol (the record protocol * may use arbitrary fragmentation and even interleaving): * Change cipher spec protocol * just 1 byte needed, no need for keeping anything stored * Alert protocol * 2 bytes needed (AlertLevel, AlertDescription) * Handshake protocol * 4 bytes needed (HandshakeType, uint24 length) -- we just have * to detect unexpected Client Hello and Hello Request messages * here, anything else is handled by higher layers * Application data protocol * none of our business */ int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) { int al, i, ret; int rrcount = 0; unsigned int n; SSL3_RECORD_INTERNAL *rr; if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ if (!ssl3_setup_buffers(s)) return (-1); if ((type && type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) || (peek && (type != SSL3_RT_APPLICATION_DATA))) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } if (!s->internal->in_handshake && SSL_in_init(s)) { i = s->internal->handshake_func(s); if (i < 0) return (i); if (i == 0) { SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); return (-1); } } start: /* * Do not process more than three consecutive records, otherwise the * peer can cause us to loop indefinitely. Instead, return with an * SSL_ERROR_WANT_READ so the caller can choose when to handle further * processing. In the future, the total number of non-handshake and * non-application data records per connection should probably also be * limited... */ if (rrcount++ >= 3) { ssl_force_want_read(s); return -1; } s->internal->rwstate = SSL_NOTHING; /* s->s3->rrec.type - is the type of record * s->s3->rrec.data, - data * s->s3->rrec.off, - offset into 'data' for next read * s->s3->rrec.length, - number of bytes. */ rr = &(s->s3->rrec); /* We are not handshaking and have no data yet, * so process data buffered during the last handshake * in advance, if any. */ if (s->s3->hs.state == SSL_ST_OK && rr->length == 0) dtls1_retrieve_buffered_record(s, &(s->d1->buffered_app_data)); /* Check for timeout */ if (dtls1_handle_timeout(s) > 0) goto start; /* get new packet if necessary */ if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) { ret = dtls1_get_record(s); if (ret <= 0) { ret = dtls1_read_failed(s, ret); /* anything other than a timeout is an error */ if (ret <= 0) return (ret); else goto start; } } 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, * reset by ssl3_get_finished */ && (rr->type != SSL3_RT_HANDSHAKE)) { /* We now have application data between CCS and Finished. * Most likely the packets were reordered on their way, so * buffer the application data for later processing rather * than dropping the connection. */ if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) < 0) { SSLerror(s, ERR_R_INTERNAL_ERROR); return (-1); } rr->length = 0; goto start; } /* If the other end has shut down, throw anything we read away * (even in 'peek' mode) */ if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { rr->length = 0; s->internal->rwstate = SSL_NOTHING; return (0); } /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ if (type == rr->type) { /* make sure that we are not getting application data when we * are doing a handshake for the first time */ if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && !tls12_record_layer_read_protected(s->internal->rl)) { al = SSL_AD_UNEXPECTED_MESSAGE; SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); goto fatal_err; } if (len <= 0) return (len); if ((unsigned int)len > rr->length) n = rr->length; else n = (unsigned int)len; memcpy(buf, &(rr->data[rr->off]), n); if (!peek) { rr->length -= n; rr->off += n; if (rr->length == 0) { s->internal->rstate = SSL_ST_READ_HEADER; rr->off = 0; } } return (n); } /* * If we get here, then type != rr->type; if we have a handshake * message, then it was unexpected (Hello Request or Client Hello). */ { unsigned int record_min_len = 0; if (rr->type == SSL3_RT_HANDSHAKE) { record_min_len = DTLS1_HM_HEADER_LENGTH; } else if (rr->type == SSL3_RT_ALERT) { record_min_len = DTLS1_AL_HEADER_LENGTH; } else if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { record_min_len = DTLS1_CCS_HEADER_LENGTH; } else if (rr->type == SSL3_RT_APPLICATION_DATA) { /* * Application data while renegotiating is allowed. * Try reading again. */ s->s3->in_read_app_data = 2; ssl_force_want_read(s); return -1; } else { /* Not certain if this is the right error handling */ al = SSL_AD_UNEXPECTED_MESSAGE; SSLerror(s, SSL_R_UNEXPECTED_RECORD); goto fatal_err; } if (record_min_len > 0 && rr->length < record_min_len) { s->internal->rstate = SSL_ST_READ_HEADER; rr->length = 0; goto start; } } if (rr->type == SSL3_RT_ALERT) { if ((ret = ssl3_read_alert(s)) <= 0) return ret; goto start; } if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { s->internal->rwstate = SSL_NOTHING; rr->length = 0; return (0); } if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { if ((ret = ssl3_read_change_cipher_spec(s)) <= 0) return ret; goto start; } if (rr->type == SSL3_RT_HANDSHAKE) { if ((ret = dtls1_read_handshake_unexpected(s)) <= 0) return ret; goto start; } switch (rr->type) { default: al = SSL_AD_UNEXPECTED_MESSAGE; SSLerror(s, SSL_R_UNEXPECTED_RECORD); goto fatal_err; case SSL3_RT_CHANGE_CIPHER_SPEC: case SSL3_RT_ALERT: case SSL3_RT_HANDSHAKE: /* we already handled all of these, with the possible exception * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that * should not happen when type != rr->type */ al = SSL_AD_UNEXPECTED_MESSAGE; SSLerror(s, ERR_R_INTERNAL_ERROR); goto fatal_err; case SSL3_RT_APPLICATION_DATA: /* At this point, we were expecting handshake data, * but have application data. If the library was * running inside ssl3_read() (i.e. in_read_app_data * is set) and it makes sense to read application data * at this point (session renegotiation not yet started), * we will indulge it. */ if (s->s3->in_read_app_data && (s->s3->total_renegotiations != 0) && (((s->s3->hs.state & SSL_ST_CONNECT) && (s->s3->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && (s->s3->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( (s->s3->hs.state & SSL_ST_ACCEPT) && (s->s3->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && (s->s3->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { s->s3->in_read_app_data = 2; return (-1); } else { al = SSL_AD_UNEXPECTED_MESSAGE; SSLerror(s, SSL_R_UNEXPECTED_RECORD); goto fatal_err; } } /* not reached */ fatal_err: ssl3_send_alert(s, SSL3_AL_FATAL, al); return (-1); } int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len) { int i; if (SSL_in_init(s) && !s->internal->in_handshake) { i = s->internal->handshake_func(s); if (i < 0) return (i); if (i == 0) { SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); return -1; } } if (len > SSL3_RT_MAX_PLAIN_LENGTH) { SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG); return -1; } i = dtls1_write_bytes(s, type, buf_, len); return i; } /* 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 i; OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); s->internal->rwstate = SSL_NOTHING; i = do_dtls1_write(s, type, buf, len); return i; } int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len) { SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf); size_t out_len; CBB cbb; int ret; memset(&cbb, 0, sizeof(cbb)); /* * First check if there is a SSL3_BUFFER_INTERNAL still being written * out. This will happen with non blocking IO. */ if (wb->left != 0) { OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */ return (ssl3_write_pending(s, type, buf, len)); } /* If we have an alert to send, let's send it */ if (s->s3->alert_dispatch) { if ((ret = ssl3_dispatch_alert(s)) <= 0) return (ret); /* If it went, fall through and send more stuff. */ } if (len == 0) return 0; wb->offset = 0; if (!CBB_init_fixed(&cbb, wb->buf, wb->len)) goto err; tls12_record_layer_set_version(s->internal->rl, s->version); if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) goto err; if (!CBB_finish(&cbb, NULL, &out_len)) goto err; wb->left = out_len; /* * 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); err: CBB_cleanup(&cbb); return -1; } static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap, const unsigned char *seq) { unsigned int shift; int cmp; cmp = satsub64be(seq, bitmap->max_seq_num); if (cmp > 0) return 1; /* this record in new */ shift = -cmp; if (shift >= sizeof(bitmap->map)*8) return 0; /* stale, outside the window */ else if (bitmap->map & (1UL << shift)) return 0; /* record previously received */ return 1; } static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap, const unsigned char *seq) { unsigned int shift; int cmp; cmp = satsub64be(seq, bitmap->max_seq_num); if (cmp > 0) { shift = cmp; if (shift < sizeof(bitmap->map)*8) bitmap->map <<= shift, bitmap->map |= 1UL; else bitmap->map = 1UL; memcpy(bitmap->max_seq_num, seq, 8); } else { shift = -cmp; if (shift < sizeof(bitmap->map) * 8) bitmap->map |= 1UL << shift; } } static DTLS1_BITMAP * dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch) { uint16_t read_epoch, read_epoch_next; *is_next_epoch = 0; read_epoch = tls12_record_layer_read_epoch(s->internal->rl); read_epoch_next = read_epoch + 1; /* In current epoch, accept HM, CCS, DATA, & ALERT */ if (rr->epoch == read_epoch) return &s->d1->bitmap; /* Only HM and ALERT messages can be from the next epoch */ if (rr->epoch == read_epoch_next && (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) { *is_next_epoch = 1; return &s->d1->next_bitmap; } return NULL; } void dtls1_reset_read_seq_numbers(SSL *s) { memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP)); memset(&(s->d1->next_bitmap), 0, sizeof(DTLS1_BITMAP)); }