|
- /*
- * 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; } }
-
- #if 0
- #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
- long ii; \
- printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
- printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
- printf("\n"); }
- #endif
-
- 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};
-
- /* XDTLS: figure out the right values */
- static const unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
-
- static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
- 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 void dtls1_set_message_header_int(SSL *s, unsigned char mt,
- unsigned long len, unsigned short seq_num, unsigned long frag_off,
- unsigned long frag_len);
- 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;
- }
-
- static void
- dtls1_hm_fragment_free(hm_fragment *frag)
- {
-
- if (frag->msg_header.is_ccs)
- {
- EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
- EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
- }
- 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, enum should_add_to_finished_hash should_add_to_finished_hash)
- {
- int ret;
- int curr_mtu;
- unsigned int len, frag_off, mac_size, blocksize;
-
- /* 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))
- {
- s->d1->mtu =
- BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
-
- /* I've seen the kernel return bogus numbers when it doesn't know
- * (initial write), so just make sure we have a reasonable number */
- if (s->d1->mtu < dtls1_min_mtu())
- {
- s->d1->mtu = 0;
- s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
- BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
- s->d1->mtu, NULL);
- }
- }
- #if 0
- mtu = s->d1->mtu;
-
- fprintf(stderr, "using MTU = %d\n", mtu);
-
- mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
-
- curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
-
- if ( curr_mtu > 0)
- mtu = curr_mtu;
- else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
- return ret;
-
- if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
- {
- ret = BIO_flush(SSL_get_wbio(s));
- if ( ret <= 0)
- return ret;
- mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
- }
- #endif
-
- assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */
-
- 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);
-
- if (s->write_hash)
- {
- if (s->enc_write_ctx && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE)
- mac_size = 0;
- else
- mac_size = EVP_MD_CTX_size(s->write_hash);
- }
- else
- mac_size = 0;
-
- if (s->enc_write_ctx &&
- (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
- blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
- else
- blocksize = 0;
-
- frag_off = 0;
- while( s->init_num)
- {
- curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
- DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
-
- if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
- {
- /* grr.. we could get an error if MTU picked was wrong */
- ret = BIO_flush(SSL_get_wbio(s));
- if ( ret <= 0)
- return ret;
- curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
- mac_size - blocksize;
- }
-
- if ( s->init_num > curr_mtu)
- len = curr_mtu;
- else
- len = s->init_num;
-
-
- /* XDTLS: this function is too long. split out the CCS part */
- if ( type == SSL3_RT_HANDSHAKE)
- {
- 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 ( s->init_num > curr_mtu)
- len = curr_mtu;
- else
- len = s->init_num;
- }
-
- dtls1_fix_message_header(s, frag_off,
- len - DTLS1_HM_HEADER_LENGTH);
-
- dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
-
- assert(len >= DTLS1_HM_HEADER_LENGTH);
- }
-
- ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
- len);
- if (ret < 0)
- {
- /* might need to update MTU here, but we don't know
- * which previous packet caused the failure -- so can't
- * really retransmit anything. continue as if everything
- * is fine and wait for an alert to handle the
- * retransmit
- */
- if ( BIO_ctrl(SSL_get_wbio(s),
- BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
- s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
- BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
- else
- return(-1);
- }
- else
- {
-
- /* bad if this assert fails, only part of the handshake
- * message got sent. but why would this happen? */
- assert(len == (unsigned int)ret);
-
- if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting &&
- should_add_to_finished_hash == add_to_finished_hash)
- {
- /* should not be done for 'Hello Request's, but in that case
- * we'll ignore the result anyway */
- unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
- const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
- int xlen;
-
- if (frag_off == 0)
- {
- /* reconstruct message header is if it
- * is being sent in single fragment */
- *p++ = msg_hdr->type;
- l2n3(msg_hdr->msg_len,p);
- s2n (msg_hdr->seq,p);
- l2n3(0,p);
- l2n3(msg_hdr->msg_len,p);
- p -= DTLS1_HM_HEADER_LENGTH;
- xlen = ret;
- }
- else
- {
- p += DTLS1_HM_HEADER_LENGTH;
- xlen = ret - DTLS1_HM_HEADER_LENGTH;
- }
-
- ssl3_finish_mac(s, p, xlen);
- }
-
- 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;
- unsigned char *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 = (unsigned char *)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;
-
- *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)
- {
- unsigned long 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 */
- {
- unsigned char *p = (unsigned char *)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;
- }
- else
- return 0;
- }
-
- /* 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;
- unsigned char 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] = (unsigned char) (msg_hdr->seq>>8);
- seq64be[7] = (unsigned char) 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)
- {
- unsigned char 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;
- unsigned char 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] = (unsigned char) (msg_hdr->seq>>8);
- seq64be[7] = (unsigned char) 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))
- {
- unsigned char 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)
- {
- unsigned char 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)
- {
- unsigned char *p=(unsigned char *)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)
- {
- unsigned char *p;
-
- if (s->state == a)
- {
- p=(unsigned char *)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_int(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, dont_add_to_finished_hash));
- }
-
- 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;
- unsigned char 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.enc_write_ctx = s->enc_write_ctx;
- frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
- 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] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
- frag->msg_header.is_ccs)>>8);
- seq64be[7] = (unsigned char)(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;
- }
-
- #if 0
- fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
- fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
- fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
- #endif
-
- 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;
- unsigned char seq64be[8];
- struct dtls1_retransmit_state saved_state;
- unsigned char 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] = (unsigned char)(seq>>8);
- seq64be[7] = (unsigned char)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_int(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.enc_write_ctx = s->enc_write_ctx;
- saved_state.write_hash = s->write_hash;
- saved_state.session = s->session;
- saved_state.epoch = s->d1->w_epoch;
-
- s->d1->retransmitting = 1;
-
- /* restore state in which the message was originally sent */
- s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
- s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
- 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, add_to_finished_hash);
-
- /* restore current state */
- s->enc_write_ctx = saved_state.enc_write_ctx;
- s->write_hash = saved_state.write_hash;
- 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));
- }
-
- s->d1->retransmitting = 0;
-
- (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);
- }
- }
-
-
- unsigned char *
- dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
- unsigned long len, unsigned long frag_off, unsigned long frag_len)
- {
- if (frag_off == 0)
- {
- s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
- s->d1->next_handshake_write_seq++;
- }
-
- dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
- frag_off, frag_len);
-
- return p += DTLS1_HM_HEADER_LENGTH;
- }
-
-
- /* don't actually do the writing, wait till the MTU has been retrieved */
- static void
- dtls1_set_message_header_int(SSL *s, unsigned char 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 unsigned char *
- dtls1_write_message_header(SSL *s, unsigned char *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 (g_probable_mtu[(sizeof(g_probable_mtu) /
- sizeof(g_probable_mtu[0])) - 1]);
- }
-
- static unsigned int
- dtls1_guess_mtu(unsigned int curr_mtu)
- {
- unsigned int i;
-
- if ( curr_mtu == 0 )
- return g_probable_mtu[0] ;
-
- for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
- if ( curr_mtu > g_probable_mtu[i])
- return g_probable_mtu[i];
-
- return curr_mtu;
- }
-
- void
- dtls1_get_message_header(unsigned char *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(unsigned char *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;
- }
|