- /*
- * 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 <limits.h>
- #include <stdio.h>
- #include <string.h>
-
- #include <openssl/buf.h>
- #include <openssl/err.h>
- #include <openssl/evp.h>
- #include <openssl/mem.h>
- #include <openssl/obj.h>
- #include <openssl/rand.h>
- #include <openssl/x509.h>
-
- #include "ssl_locl.h"
-
- #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
-
- #define RSMBLY_BITMASK_MARK(bitmask, start, end) \
- { \
- if ((end) - (start) <= 8) { \
- long ii; \
- for (ii = (start); ii < (end); ii++) \
- bitmask[((ii) >> 3)] |= (1 << ((ii)&7)); \
- } else { \
- long ii; \
- bitmask[((start) >> 3)] |= bitmask_start_values[((start)&7)]; \
- for (ii = (((start) >> 3) + 1); ii < ((((end)-1)) >> 3); ii++) \
- bitmask[ii] = 0xff; \
- bitmask[(((end)-1) >> 3)] |= bitmask_end_values[((end)&7)]; \
- } \
- }
-
- #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) \
- { \
- long ii; \
- assert((msg_len) > 0); \
- is_complete = 1; \
- if (bitmask[(((msg_len)-1) >> 3)] != bitmask_end_values[((msg_len)&7)]) \
- is_complete = 0; \
- if (is_complete) \
- for (ii = (((msg_len)-1) >> 3) - 1; ii >= 0; ii--) \
- if (bitmask[ii] != 0xff) { \
- is_complete = 0; \
- break; \
- } \
- }
-
- static const uint8_t bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8,
- 0xf0, 0xe0, 0xc0, 0x80};
- static const uint8_t bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07,
- 0x0f, 0x1f, 0x3f, 0x7f};
-
- /* TODO(davidben): 28 comes from the size of IP + UDP header. Is this reasonable
- * for these values? Notably, why is kMinMTU a function of the transport
- * protocol's overhead rather than, say, what's needed to hold a minimally-sized
- * handshake fragment plus protocol overhead. */
-
- /* kMinMTU is the minimum acceptable MTU value. */
- static const unsigned int kMinMTU = 256 - 28;
-
- /* kDefaultMTU is the default MTU value to use if neither the user nor
- * the underlying BIO supplies one. */
- static const unsigned int kDefaultMTU = 1500 - 28;
-
- static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
- unsigned long frag_len);
- static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p);
- static long dtls1_get_message_fragment(SSL *s, int stn, long max, int *ok);
-
- static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len,
- int reassembly) {
- hm_fragment *frag = NULL;
- unsigned char *buf = NULL;
- unsigned char *bitmask = NULL;
-
- frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
- if (frag == NULL) {
- return NULL;
- }
-
- if (frag_len) {
- buf = (unsigned char *)OPENSSL_malloc(frag_len);
- if (buf == NULL) {
- OPENSSL_free(frag);
- return NULL;
- }
- }
-
- /* zero length fragment gets zero frag->fragment */
- frag->fragment = buf;
-
- /* Initialize reassembly bitmask if necessary */
- if (reassembly) {
- bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
- if (bitmask == NULL) {
- if (buf != NULL) {
- OPENSSL_free(buf);
- }
- OPENSSL_free(frag);
- return NULL;
- }
- memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
- }
-
- frag->reassembly = bitmask;
-
- return frag;
- }
-
- void dtls1_hm_fragment_free(hm_fragment *frag) {
- if (frag->msg_header.is_ccs) {
- /* TODO(davidben): Simplify aead_write_ctx ownership, probably by just
- * forbidding DTLS renego. */
- SSL_AEAD_CTX *aead_write_ctx =
- frag->msg_header.saved_retransmit_state.aead_write_ctx;
- if (aead_write_ctx) {
- EVP_AEAD_CTX_cleanup(&aead_write_ctx->ctx);
- OPENSSL_free(aead_write_ctx);
- }
- }
- if (frag->fragment) {
- OPENSSL_free(frag->fragment);
- }
- if (frag->reassembly) {
- OPENSSL_free(frag->reassembly);
- }
- OPENSSL_free(frag);
- }
-
- /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
- * SSL3_RT_CHANGE_CIPHER_SPEC) */
- int dtls1_do_write(SSL *s, int type) {
- int ret;
- int curr_mtu;
- unsigned int len, frag_off;
- size_t max_overhead = 0;
-
- /* AHA! Figure out the MTU, and stick to the right size */
- if (s->d1->mtu < dtls1_min_mtu() &&
- !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
- long mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
- if (mtu >= 0 && mtu <= (1 << 30) && (unsigned)mtu >= dtls1_min_mtu()) {
- s->d1->mtu = (unsigned)mtu;
- } else {
- s->d1->mtu = kDefaultMTU;
- BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, s->d1->mtu, NULL);
- }
- }
-
- /* should have something reasonable now */
- assert(s->d1->mtu >= dtls1_min_mtu());
-
- if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) {
- assert(s->init_num ==
- (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
- }
-
- /* Determine the maximum overhead of the current cipher. */
- if (s->aead_write_ctx != NULL) {
- max_overhead = EVP_AEAD_max_overhead(s->aead_write_ctx->ctx.aead);
- if (s->aead_write_ctx->variable_nonce_included_in_record) {
- max_overhead += s->aead_write_ctx->variable_nonce_len;
- }
- }
-
- frag_off = 0;
- while (s->init_num) {
- /* Account for data in the buffering BIO; multiple records may be packed
- * into a single packet during the handshake.
- *
- * TODO(davidben): This is buggy; if the MTU is larger than the buffer size,
- * the large record will be split across two packets. Moreover, in that
- * case, the |dtls1_write_bytes| call may not return synchronously. This
- * will break on retry as the |s->init_off| and |s->init_num| adjustment
- * will run a second time. */
- curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
- DTLS1_RT_HEADER_LENGTH - max_overhead;
-
- if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
- /* Flush the buffer and continue with a fresh packet.
- *
- * TODO(davidben): If |BIO_flush| is not synchronous and requires multiple
- * calls to |dtls1_do_write|, |frag_off| will be wrong. */
- ret = BIO_flush(SSL_get_wbio(s));
- if (ret <= 0) {
- return ret;
- }
- assert(BIO_wpending(SSL_get_wbio(s)) == 0);
- curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - max_overhead;
- }
-
- /* XDTLS: this function is too long. split out the CCS part */
- if (type == SSL3_RT_HANDSHAKE) {
- /* If this isn't the first fragment, reserve space to prepend a new
- * fragment header. This will override the body of a previous fragment. */
- if (s->init_off != 0) {
- assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
- s->init_off -= DTLS1_HM_HEADER_LENGTH;
- s->init_num += DTLS1_HM_HEADER_LENGTH;
- }
-
- if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
- /* To make forward progress, the MTU must, at minimum, fit the handshake
- * header and one byte of handshake body. */
- OPENSSL_PUT_ERROR(SSL, dtls1_do_write, SSL_R_MTU_TOO_SMALL);
- return -1;
- }
-
- if (s->init_num > curr_mtu) {
- len = curr_mtu;
- } else {
- len = s->init_num;
- }
- assert(len >= DTLS1_HM_HEADER_LENGTH);
-
- dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH);
- dtls1_write_message_header(
- s, (uint8_t *)&s->init_buf->data[s->init_off]);
- } else {
- assert(type == SSL3_RT_CHANGE_CIPHER_SPEC);
- /* ChangeCipherSpec cannot be fragmented. */
- if (s->init_num > curr_mtu) {
- OPENSSL_PUT_ERROR(SSL, dtls1_do_write, SSL_R_MTU_TOO_SMALL);
- return -1;
- }
- len = s->init_num;
- }
-
- ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len);
- if (ret < 0) {
- return -1;
- }
-
- /* bad if this assert fails, only part of the handshake message got sent.
- * But why would this happen? */
- assert(len == (unsigned int)ret);
-
- if (ret == s->init_num) {
- if (s->msg_callback) {
- s->msg_callback(1, s->version, type, s->init_buf->data,
- (size_t)(s->init_off + s->init_num), s,
- s->msg_callback_arg);
- }
-
- s->init_off = 0; /* done writing this message */
- s->init_num = 0;
-
- return 1;
- }
- s->init_off += ret;
- s->init_num -= ret;
- frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
- }
-
- return 0;
- }
-
-
- /* Obtain handshake message of message type 'mt' (any if mt == -1), maximum
- * acceptable body length 'max'. Read an entire handshake message. Handshake
- * messages arrive in fragments. */
- long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max,
- int hash_message, int *ok) {
- int i, al;
- struct hm_header_st *msg_hdr;
- uint8_t *p;
- unsigned long msg_len;
-
- /* s3->tmp is used to store messages that are unexpected, caused
- * by the absence of an optional handshake message */
- if (s->s3->tmp.reuse_message) {
- /* A SSL_GET_MESSAGE_DONT_HASH_MESSAGE call cannot be combined
- * with reuse_message; the SSL_GET_MESSAGE_DONT_HASH_MESSAGE
- * would have to have been applied to the previous call. */
- assert(hash_message != SSL_GET_MESSAGE_DONT_HASH_MESSAGE);
- s->s3->tmp.reuse_message = 0;
- if (mt >= 0 && s->s3->tmp.message_type != mt) {
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, dtls1_get_message, SSL_R_UNEXPECTED_MESSAGE);
- goto f_err;
- }
- *ok = 1;
- s->init_msg = (uint8_t *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
- s->init_num = (int)s->s3->tmp.message_size;
- return s->init_num;
- }
-
- msg_hdr = &s->d1->r_msg_hdr;
- memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
-
- again:
- i = dtls1_get_message_fragment(s, stn, max, ok);
- if (i == DTLS1_HM_BAD_FRAGMENT ||
- i == DTLS1_HM_FRAGMENT_RETRY) {
- /* bad fragment received */
- goto again;
- } else if (i <= 0 && !*ok) {
- return i;
- }
-
- p = (uint8_t *)s->init_buf->data;
- msg_len = msg_hdr->msg_len;
-
- /* reconstruct message header */
- *(p++) = msg_hdr->type;
- l2n3(msg_len, p);
- s2n(msg_hdr->seq, p);
- l2n3(0, p);
- l2n3(msg_len, p);
- p -= DTLS1_HM_HEADER_LENGTH;
- msg_len += DTLS1_HM_HEADER_LENGTH;
-
- s->init_msg = (uint8_t *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
-
- if (hash_message != SSL_GET_MESSAGE_DONT_HASH_MESSAGE) {
- ssl3_hash_current_message(s);
- }
- if (s->msg_callback) {
- s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, p, msg_len, s,
- s->msg_callback_arg);
- }
-
- memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
-
- s->d1->handshake_read_seq++;
-
- return s->init_num;
-
- f_err:
- ssl3_send_alert(s, SSL3_AL_FATAL, al);
- *ok = 0;
- return -1;
- }
-
- static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr,
- int max) {
- size_t frag_off, frag_len, msg_len;
-
- msg_len = msg_hdr->msg_len;
- frag_off = msg_hdr->frag_off;
- frag_len = msg_hdr->frag_len;
-
- /* sanity checking */
- if ((frag_off + frag_len) > msg_len) {
- OPENSSL_PUT_ERROR(SSL, dtls1_preprocess_fragment,
- SSL_R_EXCESSIVE_MESSAGE_SIZE);
- return SSL_AD_ILLEGAL_PARAMETER;
- }
-
- if ((frag_off + frag_len) > (unsigned long)max) {
- OPENSSL_PUT_ERROR(SSL, dtls1_preprocess_fragment,
- SSL_R_EXCESSIVE_MESSAGE_SIZE);
- return SSL_AD_ILLEGAL_PARAMETER;
- }
-
- if (s->d1->r_msg_hdr.frag_off == 0) {
- /* first fragment */
- /* msg_len is limited to 2^24, but is effectively checked
- * against max above */
- if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
- OPENSSL_PUT_ERROR(SSL, dtls1_preprocess_fragment, ERR_R_BUF_LIB);
- return SSL_AD_INTERNAL_ERROR;
- }
-
- s->s3->tmp.message_size = msg_len;
- s->d1->r_msg_hdr.msg_len = msg_len;
- s->s3->tmp.message_type = msg_hdr->type;
- s->d1->r_msg_hdr.type = msg_hdr->type;
- s->d1->r_msg_hdr.seq = msg_hdr->seq;
- } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
- /* They must be playing with us! BTW, failure to enforce
- * upper limit would open possibility for buffer overrun. */
- OPENSSL_PUT_ERROR(SSL, dtls1_preprocess_fragment,
- SSL_R_EXCESSIVE_MESSAGE_SIZE);
- return SSL_AD_ILLEGAL_PARAMETER;
- }
-
- return 0; /* no error */
- }
-
-
- static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok) {
- /* (0) check whether the desired fragment is available
- * if so:
- * (1) copy over the fragment to s->init_buf->data[]
- * (2) update s->init_num */
- pitem *item;
- hm_fragment *frag;
- int al;
- unsigned long frag_len;
-
- *ok = 0;
- item = pqueue_peek(s->d1->buffered_messages);
- if (item == NULL) {
- return 0;
- }
-
- frag = (hm_fragment *)item->data;
-
- /* Don't return if reassembly still in progress */
- if (frag->reassembly != NULL) {
- return 0;
- }
-
- if (s->d1->handshake_read_seq != frag->msg_header.seq) {
- return 0;
- }
-
- frag_len = frag->msg_header.frag_len;
- pqueue_pop(s->d1->buffered_messages);
-
- al = dtls1_preprocess_fragment(s, &frag->msg_header, max);
-
- if (al == 0) {
- /* no alert */
- uint8_t *p = (uint8_t *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
- memcpy(&p[frag->msg_header.frag_off], frag->fragment,
- frag->msg_header.frag_len);
- }
-
- dtls1_hm_fragment_free(frag);
- pitem_free(item);
-
- if (al == 0) {
- *ok = 1;
- return frag_len;
- }
-
- ssl3_send_alert(s, SSL3_AL_FATAL, al);
- s->init_num = 0;
- *ok = 0;
- return -1;
- }
-
- /* dtls1_max_handshake_message_len returns the maximum number of bytes
- * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
- * be greater if the maximum certificate list size requires it. */
- static unsigned long dtls1_max_handshake_message_len(const SSL *s) {
- unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
- if (max_len < (unsigned long)s->max_cert_list) {
- return s->max_cert_list;
- }
- return max_len;
- }
-
- static int dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr,
- int *ok) {
- hm_fragment *frag = NULL;
- pitem *item = NULL;
- int i = -1, is_complete;
- uint8_t seq64be[8];
- unsigned long frag_len = msg_hdr->frag_len;
-
- if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
- msg_hdr->msg_len > dtls1_max_handshake_message_len(s)) {
- goto err;
- }
-
- if (frag_len == 0) {
- return DTLS1_HM_FRAGMENT_RETRY;
- }
-
- /* Try to find item in queue */
- memset(seq64be, 0, sizeof(seq64be));
- seq64be[6] = (uint8_t)(msg_hdr->seq >> 8);
- seq64be[7] = (uint8_t)msg_hdr->seq;
- item = pqueue_find(s->d1->buffered_messages, seq64be);
-
- if (item == NULL) {
- frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
- if (frag == NULL) {
- goto err;
- }
- memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
- frag->msg_header.frag_len = frag->msg_header.msg_len;
- frag->msg_header.frag_off = 0;
- } else {
- frag = (hm_fragment *)item->data;
- if (frag->msg_header.msg_len != msg_hdr->msg_len) {
- item = NULL;
- frag = NULL;
- goto err;
- }
- }
-
- /* If message is already reassembled, this must be a
- * retransmit and can be dropped. In this case item != NULL and so frag
- * does not need to be freed. */
- if (frag->reassembly == NULL) {
- uint8_t devnull[256];
-
- assert(item != NULL);
- while (frag_len) {
- i = s->method->ssl_read_bytes(
- s, SSL3_RT_HANDSHAKE, devnull,
- frag_len > sizeof(devnull) ? sizeof(devnull) : frag_len, 0);
- if (i <= 0) {
- goto err;
- }
- frag_len -= i;
- }
- return DTLS1_HM_FRAGMENT_RETRY;
- }
-
- /* read the body of the fragment (header has already been read */
- i = s->method->ssl_read_bytes(
- s, SSL3_RT_HANDSHAKE, frag->fragment + msg_hdr->frag_off, frag_len, 0);
- if ((unsigned long)i != frag_len) {
- i = -1;
- }
- if (i <= 0) {
- goto err;
- }
-
- RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
- (long)(msg_hdr->frag_off + frag_len));
-
- RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
- is_complete);
-
- if (is_complete) {
- OPENSSL_free(frag->reassembly);
- frag->reassembly = NULL;
- }
-
- if (item == NULL) {
- item = pitem_new(seq64be, frag);
- if (item == NULL) {
- i = -1;
- goto err;
- }
-
- item = pqueue_insert(s->d1->buffered_messages, item);
- /* pqueue_insert fails iff a duplicate item is inserted.
- * However, |item| cannot be a duplicate. If it were,
- * |pqueue_find|, above, would have returned it and control
- * would never have reached this branch. */
- assert(item != NULL);
- }
-
- return DTLS1_HM_FRAGMENT_RETRY;
-
- err:
- if (frag != NULL && item == NULL) {
- dtls1_hm_fragment_free(frag);
- }
- *ok = 0;
- return i;
- }
-
- static int dtls1_process_out_of_seq_message(SSL *s,
- const struct hm_header_st *msg_hdr,
- int *ok) {
- int i = -1;
- hm_fragment *frag = NULL;
- pitem *item = NULL;
- uint8_t seq64be[8];
- unsigned long frag_len = msg_hdr->frag_len;
-
- if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len) {
- goto err;
- }
-
- /* Try to find item in queue, to prevent duplicate entries */
- memset(seq64be, 0, sizeof(seq64be));
- seq64be[6] = (uint8_t)(msg_hdr->seq >> 8);
- seq64be[7] = (uint8_t)msg_hdr->seq;
- item = pqueue_find(s->d1->buffered_messages, seq64be);
-
- /* If we already have an entry and this one is a fragment,
- * don't discard it and rather try to reassemble it. */
- if (item != NULL && frag_len != msg_hdr->msg_len) {
- item = NULL;
- }
-
- /* Discard the message if sequence number was already there, is
- * too far in the future, already in the queue or if we received
- * a FINISHED before the SERVER_HELLO, which then must be a stale
- * retransmit. */
- if (msg_hdr->seq <= s->d1->handshake_read_seq ||
- msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
- (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) {
- uint8_t devnull[256];
-
- while (frag_len) {
- i = s->method->ssl_read_bytes(
- s, SSL3_RT_HANDSHAKE, devnull,
- frag_len > sizeof(devnull) ? sizeof(devnull) : frag_len, 0);
- if (i <= 0) {
- goto err;
- }
- frag_len -= i;
- }
- } else {
- if (frag_len != msg_hdr->msg_len) {
- return dtls1_reassemble_fragment(s, msg_hdr, ok);
- }
-
- if (frag_len > dtls1_max_handshake_message_len(s)) {
- goto err;
- }
-
- frag = dtls1_hm_fragment_new(frag_len, 0);
- if (frag == NULL) {
- goto err;
- }
-
- memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
-
- if (frag_len) {
- /* read the body of the fragment (header has already been read */
- i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, frag->fragment,
- frag_len, 0);
- if ((unsigned long)i != frag_len) {
- i = -1;
- }
- if (i <= 0) {
- goto err;
- }
- }
-
- item = pitem_new(seq64be, frag);
- if (item == NULL) {
- goto err;
- }
-
- item = pqueue_insert(s->d1->buffered_messages, item);
- /* pqueue_insert fails iff a duplicate item is inserted.
- * However, |item| cannot be a duplicate. If it were,
- * |pqueue_find|, above, would have returned it. Then, either
- * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
- * to NULL and it will have been processed with
- * |dtls1_reassemble_fragment|, above, or the record will have
- * been discarded. */
- assert(item != NULL);
- }
-
- return DTLS1_HM_FRAGMENT_RETRY;
-
- err:
- if (frag != NULL && item == NULL) {
- dtls1_hm_fragment_free(frag);
- }
- *ok = 0;
- return i;
- }
-
-
- static long dtls1_get_message_fragment(SSL *s, int stn, long max, int *ok) {
- uint8_t wire[DTLS1_HM_HEADER_LENGTH];
- unsigned long len, frag_off, frag_len;
- int i, al;
- struct hm_header_st msg_hdr;
-
- redo:
- /* see if we have the required fragment already */
- if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) {
- if (*ok) {
- s->init_num = frag_len;
- }
- return frag_len;
- }
-
- /* read handshake message header */
- i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire,
- DTLS1_HM_HEADER_LENGTH, 0);
- if (i <= 0) {
- /* nbio, or an error */
- s->rwstate = SSL_READING;
- *ok = 0;
- return i;
- }
-
- /* Handshake fails if message header is incomplete */
- if (i != DTLS1_HM_HEADER_LENGTH) {
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, dtls1_get_message_fragment,
- SSL_R_UNEXPECTED_MESSAGE);
- goto f_err;
- }
-
- /* parse the message fragment header */
- dtls1_get_message_header(wire, &msg_hdr);
-
- /* if this is a future (or stale) message it gets buffered
- * (or dropped)--no further processing at this time. */
- if (msg_hdr.seq != s->d1->handshake_read_seq) {
- return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
- }
-
- len = msg_hdr.msg_len;
- frag_off = msg_hdr.frag_off;
- frag_len = msg_hdr.frag_len;
-
- if (frag_len && frag_len < len) {
- return dtls1_reassemble_fragment(s, &msg_hdr, ok);
- }
-
- if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
- wire[0] == SSL3_MT_HELLO_REQUEST) {
- /* The server may always send 'Hello Request' messages --
- * we are doing a handshake anyway now, so ignore them
- * if their format is correct. Does not count for
- * 'Finished' MAC. */
- if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
- if (s->msg_callback) {
- s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, wire,
- DTLS1_HM_HEADER_LENGTH, s, s->msg_callback_arg);
- }
-
- s->init_num = 0;
- goto redo;
- } else {
- /* Incorrectly formated Hello request */
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, dtls1_get_message_fragment,
- SSL_R_UNEXPECTED_MESSAGE);
- goto f_err;
- }
- }
-
- if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max))) {
- goto f_err;
- }
-
- /* XDTLS: ressurect this when restart is in place */
- s->state = stn;
-
- if (frag_len > 0) {
- uint8_t *p = (uint8_t *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
-
- i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &p[frag_off], frag_len,
- 0);
- /* XDTLS: fix this--message fragments cannot span multiple packets */
- if (i <= 0) {
- s->rwstate = SSL_READING;
- *ok = 0;
- return i;
- }
- } else {
- i = 0;
- }
-
- /* XDTLS: an incorrectly formatted fragment should cause the
- * handshake to fail */
- if (i != (int)frag_len) {
- al = SSL3_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, dtls1_get_message_fragment,
- SSL3_AD_ILLEGAL_PARAMETER);
- goto f_err;
- }
-
- *ok = 1;
-
- /* Note that s->init_num is *not* used as current offset in
- * s->init_buf->data, but as a counter summing up fragments'
- * lengths: as soon as they sum up to handshake packet
- * length, we assume we have got all the fragments. */
- s->init_num = frag_len;
- return frag_len;
-
- f_err:
- ssl3_send_alert(s, SSL3_AL_FATAL, al);
- s->init_num = 0;
-
- *ok = 0;
- return -1;
- }
-
- /* for these 2 messages, we need to
- * ssl->enc_read_ctx re-init
- * ssl->s3->read_sequence zero
- * ssl->s3->read_mac_secret re-init
- * ssl->session->read_sym_enc assign
- * ssl->session->read_compression assign
- * ssl->session->read_hash assign */
- int dtls1_send_change_cipher_spec(SSL *s, int a, int b) {
- uint8_t *p;
-
- if (s->state == a) {
- p = (uint8_t *)s->init_buf->data;
- *p++ = SSL3_MT_CCS;
- s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
- s->init_num = DTLS1_CCS_HEADER_LENGTH;
-
- s->init_off = 0;
-
- dtls1_set_message_header(s, SSL3_MT_CCS, 0, s->d1->handshake_write_seq, 0,
- 0);
-
- /* buffer the message to handle re-xmits */
- dtls1_buffer_message(s, 1);
-
- s->state = b;
- }
-
- /* SSL3_ST_CW_CHANGE_B */
- return dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
- }
-
- int dtls1_read_failed(SSL *s, int code) {
- if (code > 0) {
- fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
- return 1;
- }
-
- if (!dtls1_is_timer_expired(s)) {
- /* not a timeout, none of our business, let higher layers handle this. In
- * fact, it's probably an error */
- return code;
- }
-
- if (!SSL_in_init(s)) {
- /* done, no need to send a retransmit */
- BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
- return code;
- }
-
- return dtls1_handle_timeout(s);
- }
-
- int dtls1_get_queue_priority(unsigned short seq, int is_ccs) {
- /* The index of the retransmission queue actually is the message sequence
- * number, since the queue only contains messages of a single handshake.
- * However, the ChangeCipherSpec has no message sequence number and so using
- * only the sequence will result in the CCS and Finished having the same
- * index. To prevent this, the sequence number is multiplied by 2. In case of
- * a CCS 1 is subtracted. This does not only differ CSS and Finished, it also
- * maintains the order of the index (important for priority queues) and fits
- * in the unsigned short variable. */
- return seq * 2 - is_ccs;
- }
-
- int dtls1_retransmit_buffered_messages(SSL *s) {
- pqueue sent = s->d1->sent_messages;
- piterator iter;
- pitem *item;
- hm_fragment *frag;
- int found = 0;
-
- iter = pqueue_iterator(sent);
-
- for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
- frag = (hm_fragment *)item->data;
- if (dtls1_retransmit_message(
- s, (unsigned short)dtls1_get_queue_priority(
- frag->msg_header.seq, frag->msg_header.is_ccs),
- 0, &found) <= 0 &&
- found) {
- fprintf(stderr, "dtls1_retransmit_message() failed\n");
- return -1;
- }
- }
-
- return 1;
- }
-
- int dtls1_buffer_message(SSL *s, int is_ccs) {
- pitem *item;
- hm_fragment *frag;
- uint8_t seq64be[8];
-
- /* this function is called immediately after a message has
- * been serialized */
- assert(s->init_off == 0);
-
- frag = dtls1_hm_fragment_new(s->init_num, 0);
- if (!frag) {
- return 0;
- }
-
- memcpy(frag->fragment, s->init_buf->data, s->init_num);
-
- if (is_ccs) {
- assert(s->d1->w_msg_hdr.msg_len + DTLS1_CCS_HEADER_LENGTH ==
- (unsigned int)s->init_num);
- } else {
- assert(s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH ==
- (unsigned int)s->init_num);
- }
-
- frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
- frag->msg_header.seq = s->d1->w_msg_hdr.seq;
- frag->msg_header.type = s->d1->w_msg_hdr.type;
- frag->msg_header.frag_off = 0;
- frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
- frag->msg_header.is_ccs = is_ccs;
-
- /* save current state*/
- frag->msg_header.saved_retransmit_state.aead_write_ctx = s->aead_write_ctx;
- frag->msg_header.saved_retransmit_state.session = s->session;
- frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
-
- memset(seq64be, 0, sizeof(seq64be));
- seq64be[6] = (uint8_t)(
- dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs) >>
- 8);
- seq64be[7] = (uint8_t)(
- dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs));
-
- item = pitem_new(seq64be, frag);
- if (item == NULL) {
- dtls1_hm_fragment_free(frag);
- return 0;
- }
-
- pqueue_insert(s->d1->sent_messages, item);
- return 1;
- }
-
- int dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
- int *found) {
- int ret;
- /* XDTLS: for now assuming that read/writes are blocking */
- pitem *item;
- hm_fragment *frag;
- unsigned long header_length;
- uint8_t seq64be[8];
- struct dtls1_retransmit_state saved_state;
- uint8_t save_write_sequence[8];
-
- /* assert(s->init_num == 0);
- assert(s->init_off == 0); */
-
- /* XDTLS: the requested message ought to be found, otherwise error */
- memset(seq64be, 0, sizeof(seq64be));
- seq64be[6] = (uint8_t)(seq >> 8);
- seq64be[7] = (uint8_t)seq;
-
- item = pqueue_find(s->d1->sent_messages, seq64be);
- if (item == NULL) {
- fprintf(stderr, "retransmit: message %d non-existant\n", seq);
- *found = 0;
- return 0;
- }
-
- *found = 1;
- frag = (hm_fragment *)item->data;
-
- if (frag->msg_header.is_ccs) {
- header_length = DTLS1_CCS_HEADER_LENGTH;
- } else {
- header_length = DTLS1_HM_HEADER_LENGTH;
- }
-
- memcpy(s->init_buf->data, frag->fragment,
- frag->msg_header.msg_len + header_length);
- s->init_num = frag->msg_header.msg_len + header_length;
-
- dtls1_set_message_header(s, frag->msg_header.type,
- frag->msg_header.msg_len, frag->msg_header.seq,
- 0, frag->msg_header.frag_len);
-
- /* save current state */
- saved_state.aead_write_ctx = s->aead_write_ctx;
- saved_state.session = s->session;
- saved_state.epoch = s->d1->w_epoch;
-
- /* restore state in which the message was originally sent */
- s->aead_write_ctx = frag->msg_header.saved_retransmit_state.aead_write_ctx;
- s->session = frag->msg_header.saved_retransmit_state.session;
- s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
-
- if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) {
- memcpy(save_write_sequence, s->s3->write_sequence,
- sizeof(s->s3->write_sequence));
- memcpy(s->s3->write_sequence, s->d1->last_write_sequence,
- sizeof(s->s3->write_sequence));
- }
-
- ret = dtls1_do_write(s, frag->msg_header.is_ccs ? SSL3_RT_CHANGE_CIPHER_SPEC
- : SSL3_RT_HANDSHAKE);
-
- /* restore current state */
- s->aead_write_ctx = saved_state.aead_write_ctx;
- s->session = saved_state.session;
- s->d1->w_epoch = saved_state.epoch;
-
- if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) {
- memcpy(s->d1->last_write_sequence, s->s3->write_sequence,
- sizeof(s->s3->write_sequence));
- memcpy(s->s3->write_sequence, save_write_sequence,
- sizeof(s->s3->write_sequence));
- }
-
- (void)BIO_flush(SSL_get_wbio(s));
- return ret;
- }
-
- /* call this function when the buffered messages are no longer needed */
- void dtls1_clear_record_buffer(SSL *s) {
- pitem *item;
-
- for (item = pqueue_pop(s->d1->sent_messages); item != NULL;
- item = pqueue_pop(s->d1->sent_messages)) {
- dtls1_hm_fragment_free((hm_fragment *)item->data);
- pitem_free(item);
- }
- }
-
- /* don't actually do the writing, wait till the MTU has been retrieved */
- void dtls1_set_message_header(SSL *s, uint8_t mt, unsigned long len,
- unsigned short seq_num, unsigned long frag_off,
- unsigned long frag_len) {
- struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
-
- msg_hdr->type = mt;
- msg_hdr->msg_len = len;
- msg_hdr->seq = seq_num;
- msg_hdr->frag_off = frag_off;
- msg_hdr->frag_len = frag_len;
- }
-
- static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
- unsigned long frag_len) {
- struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
-
- msg_hdr->frag_off = frag_off;
- msg_hdr->frag_len = frag_len;
- }
-
- static uint8_t *dtls1_write_message_header(SSL *s, uint8_t *p) {
- struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
-
- *p++ = msg_hdr->type;
- l2n3(msg_hdr->msg_len, p);
-
- s2n(msg_hdr->seq, p);
- l2n3(msg_hdr->frag_off, p);
- l2n3(msg_hdr->frag_len, p);
-
- return p;
- }
-
- unsigned int dtls1_min_mtu(void) {
- return kMinMTU;
- }
-
- void dtls1_get_message_header(uint8_t *data,
- struct hm_header_st *msg_hdr) {
- memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
- msg_hdr->type = *(data++);
- n2l3(data, msg_hdr->msg_len);
-
- n2s(data, msg_hdr->seq);
- n2l3(data, msg_hdr->frag_off);
- n2l3(data, msg_hdr->frag_len);
- }
-
- void dtls1_get_ccs_header(uint8_t *data, struct ccs_header_st *ccs_hdr) {
- memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
-
- ccs_hdr->type = *(data++);
- }
-
- int dtls1_shutdown(SSL *s) {
- int ret;
- ret = ssl3_shutdown(s);
- return ret;
- }
|