| /* 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 <assert.h> |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include <openssl/buf.h> |
| #include <openssl/mem.h> |
| #include <openssl/evp.h> |
| #include <openssl/err.h> |
| #include <openssl/rand.h> |
| |
| #include "internal.h" |
| |
| |
| /* mod 128 saturating subtract of two 64-bit values in big-endian order */ |
| static int satsub64be(const uint8_t *v1, const uint8_t *v2) { |
| int ret, sat, brw, i; |
| |
| if (sizeof(long) == 8) { |
| do { |
| const union { |
| long one; |
| char little; |
| } is_endian = {1}; |
| long l; |
| |
| if (is_endian.little) { |
| 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); |
| static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); |
| static int dtls1_process_record(SSL *s); |
| static int do_dtls1_write(SSL *s, int type, const uint8_t *buf, |
| unsigned int len); |
| |
| static int dtls1_process_record(SSL *s) { |
| int al; |
| SSL3_RECORD *rr; |
| |
| rr = &(s->s3->rrec); |
| |
| /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, and |
| * we have that many bytes in s->packet. */ |
| rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]); |
| |
| /* ok, we can now read from 's->packet' data into 'rr' rr->input points at |
| * rr->length bytes, which need to be copied into rr->data by either the |
| * decryption or by the decompression When the data is 'copied' into the |
| * rr->data buffer, rr->input will be pointed at the new buffer */ |
| |
| /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length bytes |
| * of encrypted compressed stuff. */ |
| |
| /* check is not needed I believe */ |
| if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { |
| al = SSL_AD_RECORD_OVERFLOW; |
| OPENSSL_PUT_ERROR(SSL, dtls1_process_record, |
| SSL_R_ENCRYPTED_LENGTH_TOO_LONG); |
| goto f_err; |
| } |
| |
| /* decrypt in place in 'rr->input' */ |
| rr->data = rr->input; |
| |
| if (!s->enc_method->enc(s, 0)) { |
| /* Bad packets are silently dropped in DTLS. Clear the error queue of any |
| * errors decryption may have added. */ |
| ERR_clear_error(); |
| rr->length = 0; |
| s->packet_length = 0; |
| goto err; |
| } |
| |
| if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { |
| al = SSL_AD_RECORD_OVERFLOW; |
| OPENSSL_PUT_ERROR(SSL, dtls1_process_record, SSL_R_DATA_LENGTH_TOO_LONG); |
| goto f_err; |
| } |
| |
| rr->off = 0; |
| /* So at this point the following is true |
| * ssl->s3->rrec.type is the type of record |
| * ssl->s3->rrec.length == number of bytes in record |
| * ssl->s3->rrec.off == offset to first valid byte |
| * ssl->s3->rrec.data == where to take bytes from, increment |
| * after use :-). */ |
| |
| /* we have pulled in a full packet so zero things */ |
| s->packet_length = 0; |
| return 1; |
| |
| f_err: |
| ssl3_send_alert(s, SSL3_AL_FATAL, al); |
| |
| 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->rrec.type - is the type of record |
| * ssl->s3->rrec.data, - data |
| * ssl->s3->rrec.length, - number of bytes |
| * |
| * used only by dtls1_read_bytes */ |
| int dtls1_get_record(SSL *s) { |
| int ssl_major, ssl_minor; |
| int i, n; |
| SSL3_RECORD *rr; |
| unsigned char *p = NULL; |
| unsigned short version; |
| |
| rr = &(s->s3->rrec); |
| |
| /* get something from the wire */ |
| again: |
| /* check if we have the header */ |
| if ((s->rstate != SSL_ST_READ_BODY) || |
| (s->packet_length < DTLS1_RT_HEADER_LENGTH)) { |
| n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, 0); |
| /* read timeout is handled by dtls1_read_bytes */ |
| if (n <= 0) { |
| return n; /* error or non-blocking */ |
| } |
| |
| /* 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; |
| |
| 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++); |
| ssl_minor = *(p++); |
| version = (ssl_major << 8) | ssl_minor; |
| |
| /* sequence number is 64 bits, with top 2 bytes = epoch */ |
| n2s(p, rr->epoch); |
| |
| memcpy(&(s->s3->read_sequence[2]), p, 6); |
| p += 6; |
| |
| n2s(p, rr->length); |
| |
| /* Lets check version */ |
| if (s->s3->have_version) { |
| if (version != s->version) { |
| /* The record's version doesn't match, so silently drop it. |
| * |
| * TODO(davidben): This doesn't work. The DTLS record layer is not |
| * packet-based, so the remainder of the packet isn't dropped and we |
| * get a framing error. It's also unclear what it means to silently |
| * drop a record in a packet containing two records. */ |
| rr->length = 0; |
| s->packet_length = 0; |
| goto again; |
| } |
| } |
| |
| if ((version & 0xff00) != (s->version & 0xff00)) { |
| /* wrong version, silently discard record */ |
| rr->length = 0; |
| s->packet_length = 0; |
| goto again; |
| } |
| |
| if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { |
| /* record too long, silently discard it */ |
| rr->length = 0; |
| s->packet_length = 0; |
| goto again; |
| } |
| |
| /* now s->rstate == SSL_ST_READ_BODY */ |
| } |
| |
| /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ |
| |
| if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) { |
| /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ |
| i = rr->length; |
| n = ssl3_read_n(s, i, 1); |
| if (n <= 0) { |
| return n; /* error or non-blocking io */ |
| } |
| |
| /* this packet contained a partial record, dump it */ |
| if (n != i) { |
| rr->length = 0; |
| s->packet_length = 0; |
| goto again; |
| } |
| |
| /* now n == rr->length, |
| * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ |
| } |
| s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ |
| |
| if (rr->epoch != s->d1->r_epoch) { |
| /* This record is from the wrong epoch. If it is the next epoch, it could be |
| * buffered. For simplicity, drop it and expect retransmit to handle it |
| * later; DTLS is supposed to handle packet loss. */ |
| rr->length = 0; |
| s->packet_length = 0; |
| goto again; |
| } |
| |
| /* Check whether this is a repeat, or aged record. */ |
| if (!dtls1_record_replay_check(s, &s->d1->bitmap)) { |
| rr->length = 0; |
| s->packet_length = 0; /* dump this record */ |
| goto again; /* get another record */ |
| } |
| |
| /* just read a 0 length packet */ |
| if (rr->length == 0) { |
| goto again; |
| } |
| |
| if (!dtls1_process_record(s)) { |
| rr->length = 0; |
| s->packet_length = 0; /* dump this record */ |
| goto again; /* get another record */ |
| } |
| dtls1_record_bitmap_update(s, &s->d1->bitmap); /* Mark receipt of record. */ |
| |
| 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; |
| unsigned int n; |
| SSL3_RECORD *rr; |
| void (*cb)(const SSL *ssl, int type2, int val) = NULL; |
| |
| /* XXX: check what the second '&& type' is about */ |
| if ((type && (type != SSL3_RT_APPLICATION_DATA) && |
| (type != SSL3_RT_HANDSHAKE) && type) || |
| (peek && (type != SSL3_RT_APPLICATION_DATA))) { |
| OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, ERR_R_INTERNAL_ERROR); |
| return -1; |
| } |
| |
| if (!s->in_handshake && SSL_in_init(s)) { |
| /* type == SSL3_RT_APPLICATION_DATA */ |
| i = s->handshake_func(s); |
| if (i < 0) { |
| return i; |
| } |
| if (i == 0) { |
| OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); |
| return -1; |
| } |
| } |
| |
| start: |
| s->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; |
| |
| /* Check for timeout */ |
| if (DTLSv1_handle_timeout(s) > 0) { |
| goto start; |
| } |
| |
| /* get new packet if necessary */ |
| if (rr->length == 0 || s->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; |
| } |
| } |
| } |
| |
| /* we now have a packet which can be read and processed */ |
| |
| /* |change_cipher_spec is set when we receive a ChangeCipherSpec and reset by |
| * ssl3_get_finished. */ |
| if (s->s3->change_cipher_spec && rr->type != SSL3_RT_HANDSHAKE && |
| rr->type != SSL3_RT_ALERT) { |
| /* We now have an unexpected record between CCS and Finished. Most likely |
| * the packets were reordered on their way. DTLS is unreliable, so drop the |
| * packet and expect the peer to retransmit. */ |
| rr->length = 0; |
| goto start; |
| } |
| |
| /* If the other end has shut down, throw anything we read away (even in |
| * 'peek' mode) */ |
| if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { |
| rr->length = 0; |
| s->rwstate = SSL_NOTHING; |
| return 0; |
| } |
| |
| |
| if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ |
| /* 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) && |
| (s->aead_read_ctx == NULL)) { |
| /* TODO(davidben): Is this check redundant with the handshake_func |
| * check? */ |
| al = SSL_AD_UNEXPECTED_MESSAGE; |
| OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_APP_DATA_IN_HANDSHAKE); |
| goto f_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->rstate = SSL_ST_READ_HEADER; |
| rr->off = 0; |
| } |
| } |
| |
| return n; |
| } |
| |
| /* If we get here, then type != rr->type. */ |
| |
| /* If an alert record, process one alert out of the record. Note that we allow |
| * a single record to contain multiple alerts. */ |
| if (rr->type == SSL3_RT_ALERT) { |
| /* Alerts may not be fragmented. */ |
| if (rr->length < 2) { |
| al = SSL_AD_DECODE_ERROR; |
| OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_ALERT); |
| goto f_err; |
| } |
| |
| if (s->msg_callback) { |
| s->msg_callback(0, s->version, SSL3_RT_ALERT, &rr->data[rr->off], 2, s, |
| s->msg_callback_arg); |
| } |
| const uint8_t alert_level = rr->data[rr->off++]; |
| const uint8_t alert_descr = rr->data[rr->off++]; |
| rr->length -= 2; |
| |
| if (s->info_callback != NULL) { |
| cb = s->info_callback; |
| } else if (s->ctx->info_callback != NULL) { |
| cb = s->ctx->info_callback; |
| } |
| |
| if (cb != NULL) { |
| uint16_t alert = (alert_level << 8) | alert_descr; |
| cb(s, SSL_CB_READ_ALERT, alert); |
| } |
| |
| if (alert_level == SSL3_AL_WARNING) { |
| s->s3->warn_alert = alert_descr; |
| if (alert_descr == SSL_AD_CLOSE_NOTIFY) { |
| s->shutdown |= SSL_RECEIVED_SHUTDOWN; |
| return 0; |
| } |
| } else if (alert_level == SSL3_AL_FATAL) { |
| char tmp[16]; |
| |
| s->rwstate = SSL_NOTHING; |
| s->s3->fatal_alert = alert_descr; |
| OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, |
| SSL_AD_REASON_OFFSET + alert_descr); |
| BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr); |
| ERR_add_error_data(2, "SSL alert number ", tmp); |
| s->shutdown |= SSL_RECEIVED_SHUTDOWN; |
| SSL_CTX_remove_session(s->ctx, s->session); |
| return 0; |
| } else { |
| al = SSL_AD_ILLEGAL_PARAMETER; |
| OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNKNOWN_ALERT_TYPE); |
| goto f_err; |
| } |
| |
| goto start; |
| } |
| |
| if (s->shutdown & SSL_SENT_SHUTDOWN) { |
| /* but we have not received a shutdown */ |
| s->rwstate = SSL_NOTHING; |
| rr->length = 0; |
| return 0; |
| } |
| |
| if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { |
| /* 'Change Cipher Spec' is just a single byte, so we know exactly what the |
| * record payload has to look like */ |
| if (rr->length != 1 || rr->off != 0 || rr->data[0] != SSL3_MT_CCS) { |
| al = SSL_AD_ILLEGAL_PARAMETER; |
| OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_CHANGE_CIPHER_SPEC); |
| goto f_err; |
| } |
| |
| rr->length = 0; |
| |
| if (s->msg_callback) { |
| 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; |
| } |
| |
| /* do this whenever CCS is processed */ |
| dtls1_reset_seq_numbers(s, SSL3_CC_READ); |
| |
| goto start; |
| } |
| |
| /* Unexpected handshake message. It may be a retransmitted Finished (the only |
| * post-CCS message). Otherwise, it's a pre-CCS handshake message from an |
| * unsupported renegotiation attempt. */ |
| if (rr->type == SSL3_RT_HANDSHAKE && !s->in_handshake) { |
| if (rr->length < DTLS1_HM_HEADER_LENGTH) { |
| al = SSL_AD_DECODE_ERROR; |
| OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_HANDSHAKE_RECORD); |
| goto f_err; |
| } |
| struct hm_header_st msg_hdr; |
| dtls1_get_message_header(&rr->data[rr->off], &msg_hdr); |
| |
| /* Ignore a stray Finished from the previous handshake. */ |
| if (msg_hdr.type == SSL3_MT_FINISHED) { |
| if (msg_hdr.frag_off == 0) { |
| /* Retransmit our last flight of messages. If the peer sends the second |
| * Finished, they may not have received ours. Only do this for the |
| * first fragment, in case the Finished was fragmented. */ |
| if (dtls1_check_timeout_num(s) < 0) { |
| return -1; |
| } |
| |
| dtls1_retransmit_buffered_messages(s); |
| } |
| |
| rr->length = 0; |
| goto start; |
| } |
| } |
| |
| /* We already handled these. */ |
| assert(rr->type != SSL3_RT_CHANGE_CIPHER_SPEC && rr->type != SSL3_RT_ALERT); |
| |
| al = SSL_AD_UNEXPECTED_MESSAGE; |
| OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNEXPECTED_RECORD); |
| |
| f_err: |
| ssl3_send_alert(s, SSL3_AL_FATAL, al); |
| err: |
| 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->in_handshake) { |
| i = s->handshake_func(s); |
| if (i < 0) { |
| return i; |
| } |
| if (i == 0) { |
| OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data_bytes, |
| SSL_R_SSL_HANDSHAKE_FAILURE); |
| return -1; |
| } |
| } |
| |
| if (len > SSL3_RT_MAX_PLAIN_LENGTH) { |
| OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data_bytes, |
| 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; |
| |
| assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); |
| s->rwstate = SSL_NOTHING; |
| i = do_dtls1_write(s, type, buf, len); |
| return i; |
| } |
| |
| static int do_dtls1_write(SSL *s, int type, const uint8_t *buf, |
| unsigned int len) { |
| uint8_t *p, *pseq; |
| int i; |
| int prefix_len = 0; |
| int eivlen = 0; |
| SSL3_RECORD *wr; |
| SSL3_BUFFER *wb; |
| |
| /* ssl3_write_pending drops the write if |BIO_write| fails in DTLS, so there |
| * is never pending data. */ |
| assert(s->s3->wbuf.left == 0); |
| |
| /* If we have an alert to send, lets send it */ |
| if (s->s3->alert_dispatch) { |
| i = s->method->ssl_dispatch_alert(s); |
| if (i <= 0) { |
| return i; |
| } |
| /* if it went, fall through and send more stuff */ |
| } |
| |
| if (len == 0) { |
| return 0; |
| } |
| |
| wr = &(s->s3->wrec); |
| wb = &(s->s3->wbuf); |
| |
| if (wb->buf == NULL && !ssl3_setup_write_buffer(s)) { |
| return -1; |
| } |
| p = wb->buf + prefix_len; |
| |
| /* write the header */ |
| |
| *(p++) = type & 0xff; |
| wr->type = type; |
| /* 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->s3->have_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; |
| |
| /* Leave room for the variable nonce for AEADs which specify it explicitly. */ |
| if (s->aead_write_ctx != NULL && |
| s->aead_write_ctx->variable_nonce_included_in_record) { |
| eivlen = s->aead_write_ctx->variable_nonce_len; |
| } |
| |
| /* Assemble the input for |s->enc_method->enc|. The input is the plaintext |
| * with |eivlen| bytes of space prepended for the explicit nonce. */ |
| wr->input = p; |
| wr->length = eivlen + len; |
| memcpy(p + eivlen, buf, len); |
| |
| /* Encrypt in-place, so the output also goes into |p|. */ |
| wr->data = p; |
| |
| if (!s->enc_method->enc(s, 1)) { |
| goto err; |
| } |
| |
| /* there's only one epoch between handshake and app data */ |
| s2n(s->d1->w_epoch, pseq); |
| |
| memcpy(pseq, &(s->s3->write_sequence[2]), 6); |
| 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 */ |
| wr->type = type; /* not needed but helps for debugging */ |
| wr->length += DTLS1_RT_HEADER_LENGTH; |
| |
| if (!ssl3_record_sequence_update(&s->s3->write_sequence[2], 6)) { |
| goto err; |
| } |
| |
| /* now let's set up wb */ |
| wb->left = prefix_len + wr->length; |
| wb->offset = 0; |
| |
| /* 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: |
| return -1; |
| } |
| |
| static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) { |
| int cmp; |
| unsigned int shift; |
| const uint8_t *seq = s->s3->read_sequence; |
| |
| cmp = satsub64be(seq, bitmap->max_seq_num); |
| if (cmp > 0) { |
| memcpy(s->s3->rrec.seq_num, seq, 8); |
| return 1; /* this record in new */ |
| } |
| shift = -cmp; |
| if (shift >= sizeof(bitmap->map) * 8) { |
| return 0; /* stale, outside the window */ |
| } else if (bitmap->map & (((uint64_t)1) << shift)) { |
| return 0; /* record previously received */ |
| } |
| |
| memcpy(s->s3->rrec.seq_num, seq, 8); |
| return 1; |
| } |
| |
| static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) { |
| int cmp; |
| unsigned int shift; |
| const uint8_t *seq = s->s3->read_sequence; |
| |
| 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 |= ((uint64_t)1) << shift; |
| } |
| } |
| } |
| |
| int dtls1_dispatch_alert(SSL *s) { |
| int i, j; |
| void (*cb)(const SSL *ssl, int type, int val) = NULL; |
| uint8_t buf[DTLS1_AL_HEADER_LENGTH]; |
| uint8_t *ptr = &buf[0]; |
| |
| s->s3->alert_dispatch = 0; |
| |
| memset(buf, 0x00, sizeof(buf)); |
| *ptr++ = s->s3->send_alert[0]; |
| *ptr++ = s->s3->send_alert[1]; |
| |
| i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf)); |
| if (i <= 0) { |
| s->s3->alert_dispatch = 1; |
| } else { |
| if (s->s3->send_alert[0] == SSL3_AL_FATAL) { |
| (void)BIO_flush(s->wbio); |
| } |
| |
| if (s->msg_callback) { |
| s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, |
| s->msg_callback_arg); |
| } |
| |
| if (s->info_callback != NULL) { |
| cb = s->info_callback; |
| } else if (s->ctx->info_callback != NULL) { |
| cb = s->ctx->info_callback; |
| } |
| |
| if (cb != NULL) { |
| j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]; |
| cb(s, SSL_CB_WRITE_ALERT, j); |
| } |
| } |
| |
| return i; |
| } |
| |
| void dtls1_reset_seq_numbers(SSL *s, int rw) { |
| uint8_t *seq; |
| unsigned int seq_bytes = sizeof(s->s3->read_sequence); |
| |
| if (rw & SSL3_CC_READ) { |
| seq = s->s3->read_sequence; |
| s->d1->r_epoch++; |
| memset(&s->d1->bitmap, 0, sizeof(DTLS1_BITMAP)); |
| } else { |
| seq = s->s3->write_sequence; |
| memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); |
| s->d1->w_epoch++; |
| } |
| |
| memset(seq, 0x00, seq_bytes); |
| } |