| /* |
| * 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 "internal.h" |
| |
| |
| /* 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; |
| |
| /* kMaxHandshakeBuffer is the maximum number of handshake messages ahead of the |
| * current one to buffer. */ |
| static const unsigned int kHandshakeBufferSize = 10; |
| |
| 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 hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len, |
| int reassembly) { |
| hm_fragment *frag = NULL; |
| uint8_t *buf = NULL; |
| uint8_t *bitmask = NULL; |
| |
| frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment)); |
| if (frag == NULL) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); |
| return NULL; |
| } |
| |
| if (frag_len) { |
| buf = (uint8_t *)OPENSSL_malloc(frag_len); |
| if (buf == NULL) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); |
| OPENSSL_free(frag); |
| return NULL; |
| } |
| } |
| |
| /* zero length fragment gets zero frag->fragment */ |
| frag->fragment = buf; |
| |
| /* Initialize reassembly bitmask if necessary */ |
| if (reassembly && frag_len > 0) { |
| if (frag_len + 7 < frag_len) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW); |
| return NULL; |
| } |
| size_t bitmask_len = (frag_len + 7) / 8; |
| bitmask = (uint8_t *)OPENSSL_malloc(bitmask_len); |
| if (bitmask == NULL) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); |
| if (buf != NULL) { |
| OPENSSL_free(buf); |
| } |
| OPENSSL_free(frag); |
| return NULL; |
| } |
| memset(bitmask, 0, bitmask_len); |
| } |
| |
| frag->reassembly = bitmask; |
| |
| return frag; |
| } |
| |
| void dtls1_hm_fragment_free(hm_fragment *frag) { |
| if (frag == NULL) { |
| return; |
| } |
| OPENSSL_free(frag->fragment); |
| OPENSSL_free(frag->reassembly); |
| OPENSSL_free(frag); |
| } |
| |
| #if !defined(inline) |
| #define inline __inline |
| #endif |
| |
| /* bit_range returns a |uint8_t| with bits |start|, inclusive, to |end|, |
| * exclusive, set. */ |
| static inline uint8_t bit_range(size_t start, size_t end) { |
| return (uint8_t)(~((1u << start) - 1) & ((1u << end) - 1)); |
| } |
| |
| /* dtls1_hm_fragment_mark marks bytes |start|, inclusive, to |end|, exclusive, |
| * as received in |frag|. If |frag| becomes complete, it clears |
| * |frag->reassembly|. The range must be within the bounds of |frag|'s message |
| * and |frag->reassembly| must not be NULL. */ |
| static void dtls1_hm_fragment_mark(hm_fragment *frag, size_t start, |
| size_t end) { |
| size_t i; |
| size_t msg_len = frag->msg_header.msg_len; |
| |
| if (frag->reassembly == NULL || start > end || end > msg_len) { |
| assert(0); |
| return; |
| } |
| /* A zero-length message will never have a pending reassembly. */ |
| assert(msg_len > 0); |
| |
| if ((start >> 3) == (end >> 3)) { |
| frag->reassembly[start >> 3] |= bit_range(start & 7, end & 7); |
| } else { |
| frag->reassembly[start >> 3] |= bit_range(start & 7, 8); |
| for (i = (start >> 3) + 1; i < (end >> 3); i++) { |
| frag->reassembly[i] = 0xff; |
| } |
| if ((end & 7) != 0) { |
| frag->reassembly[end >> 3] |= bit_range(0, end & 7); |
| } |
| } |
| |
| /* Check if the fragment is complete. */ |
| for (i = 0; i < (msg_len >> 3); i++) { |
| if (frag->reassembly[i] != 0xff) { |
| return; |
| } |
| } |
| if ((msg_len & 7) != 0 && |
| frag->reassembly[msg_len >> 3] != bit_range(0, msg_len & 7)) { |
| return; |
| } |
| |
| OPENSSL_free(frag->reassembly); |
| frag->reassembly = NULL; |
| } |
| |
| /* 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 dtls1_use_epoch_t use_epoch) { |
| int ret; |
| int curr_mtu; |
| unsigned int len, frag_off; |
| |
| /* 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. */ |
| size_t max_overhead = SSL_AEAD_CTX_max_overhead(s->aead_write_ctx); |
| |
| 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, 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, 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, |
| use_epoch); |
| 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; |
| } |
| |
| /* dtls1_is_next_message_complete returns one if the next handshake message is |
| * complete and zero otherwise. */ |
| static int dtls1_is_next_message_complete(SSL *s) { |
| pitem *item = pqueue_peek(s->d1->buffered_messages); |
| if (item == NULL) { |
| return 0; |
| } |
| |
| hm_fragment *frag = (hm_fragment *)item->data; |
| assert(s->d1->handshake_read_seq <= frag->msg_header.seq); |
| |
| return s->d1->handshake_read_seq == frag->msg_header.seq && |
| frag->reassembly == NULL; |
| } |
| |
| /* dtls1_discard_fragment_body discards a handshake fragment body of length |
| * |frag_len|. It returns one on success and zero on error. |
| * |
| * TODO(davidben): This function will go away when ssl_read_bytes is gone from |
| * the DTLS side. */ |
| static int dtls1_discard_fragment_body(SSL *s, size_t frag_len) { |
| uint8_t discard[256]; |
| while (frag_len > 0) { |
| size_t chunk = frag_len < sizeof(discard) ? frag_len : sizeof(discard); |
| int ret = dtls1_read_bytes(s, SSL3_RT_HANDSHAKE, discard, chunk, 0); |
| if (ret != chunk) { |
| return 0; |
| } |
| frag_len -= chunk; |
| } |
| return 1; |
| } |
| |
| /* dtls1_get_buffered_message returns the buffered message corresponding to |
| * |msg_hdr|. If none exists, it creates a new one and inserts it in the |
| * queue. Otherwise, it checks |msg_hdr| is consistent with the existing one. It |
| * returns NULL on failure. The caller does not take ownership of the result. */ |
| static hm_fragment *dtls1_get_buffered_message( |
| SSL *s, const struct hm_header_st *msg_hdr) { |
| uint8_t seq64be[8]; |
| memset(seq64be, 0, sizeof(seq64be)); |
| seq64be[6] = (uint8_t)(msg_hdr->seq >> 8); |
| seq64be[7] = (uint8_t)msg_hdr->seq; |
| pitem *item = pqueue_find(s->d1->buffered_messages, seq64be); |
| |
| hm_fragment *frag; |
| if (item == NULL) { |
| /* This is the first fragment from this message. */ |
| frag = dtls1_hm_fragment_new(msg_hdr->msg_len, |
| 1 /* reassembly buffer needed */); |
| if (frag == NULL) { |
| return NULL; |
| } |
| memcpy(&frag->msg_header, msg_hdr, sizeof(*msg_hdr)); |
| item = pitem_new(seq64be, frag); |
| if (item == NULL) { |
| dtls1_hm_fragment_free(frag); |
| return NULL; |
| } |
| item = pqueue_insert(s->d1->buffered_messages, item); |
| /* |pqueue_insert| fails iff a duplicate item is inserted, but |item| cannot |
| * be a duplicate. */ |
| assert(item != NULL); |
| } else { |
| frag = item->data; |
| assert(frag->msg_header.seq == msg_hdr->seq); |
| if (frag->msg_header.type != msg_hdr->type || |
| frag->msg_header.msg_len != msg_hdr->msg_len) { |
| /* The new fragment must be compatible with the previous fragments from |
| * this message. */ |
| OPENSSL_PUT_ERROR(SSL, SSL_R_FRAGMENT_MISMATCH); |
| ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return NULL; |
| } |
| } |
| return frag; |
| } |
| |
| /* 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 size_t dtls1_max_handshake_message_len(const SSL *s) { |
| size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; |
| if (max_len < s->max_cert_list) { |
| return s->max_cert_list; |
| } |
| return max_len; |
| } |
| |
| /* dtls1_process_fragment reads a handshake fragment and processes it. It |
| * returns one if a fragment was successfully processed and 0 or -1 on error. */ |
| static int dtls1_process_fragment(SSL *s) { |
| /* Read handshake message header. */ |
| uint8_t header[DTLS1_HM_HEADER_LENGTH]; |
| int ret = dtls1_read_bytes(s, SSL3_RT_HANDSHAKE, header, |
| DTLS1_HM_HEADER_LENGTH, 0); |
| if (ret <= 0) { |
| return ret; |
| } |
| if (ret != DTLS1_HM_HEADER_LENGTH) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE); |
| ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); |
| return -1; |
| } |
| |
| /* Parse the message fragment header. */ |
| struct hm_header_st msg_hdr; |
| dtls1_get_message_header(header, &msg_hdr); |
| |
| /* TODO(davidben): dtls1_read_bytes is the wrong abstraction for DTLS. There |
| * should be no need to reach into |s->s3->rrec.length|. */ |
| const size_t frag_off = msg_hdr.frag_off; |
| const size_t frag_len = msg_hdr.frag_len; |
| const size_t msg_len = msg_hdr.msg_len; |
| if (frag_off > msg_len || frag_off + frag_len < frag_off || |
| frag_off + frag_len > msg_len || |
| msg_len > dtls1_max_handshake_message_len(s) || |
| frag_len > s->s3->rrec.length) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESSIVE_MESSAGE_SIZE); |
| ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return -1; |
| } |
| |
| if (msg_hdr.seq < s->d1->handshake_read_seq || |
| msg_hdr.seq > (unsigned)s->d1->handshake_read_seq + |
| kHandshakeBufferSize) { |
| /* Ignore fragments from the past, or ones too far in the future. */ |
| if (!dtls1_discard_fragment_body(s, frag_len)) { |
| return -1; |
| } |
| return 1; |
| } |
| |
| hm_fragment *frag = dtls1_get_buffered_message(s, &msg_hdr); |
| if (frag == NULL) { |
| return -1; |
| } |
| assert(frag->msg_header.msg_len == msg_len); |
| |
| if (frag->reassembly == NULL) { |
| /* The message is already assembled. */ |
| if (!dtls1_discard_fragment_body(s, frag_len)) { |
| return -1; |
| } |
| return 1; |
| } |
| assert(msg_len > 0); |
| |
| /* Read the body of the fragment. */ |
| ret = dtls1_read_bytes(s, SSL3_RT_HANDSHAKE, frag->fragment + frag_off, |
| frag_len, 0); |
| if (ret != frag_len) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); |
| return -1; |
| } |
| dtls1_hm_fragment_mark(frag, frag_off, frag_off + frag_len); |
| |
| return 1; |
| } |
| |
| /* dtls1_get_message reads a handshake message of message type |msg_type| (any |
| * if |msg_type| == -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 msg_type, long max, |
| enum ssl_hash_message_t hash_message, int *ok) { |
| pitem *item = NULL; |
| hm_fragment *frag = NULL; |
| int al; |
| |
| /* 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_dont_hash_message call cannot be combined with reuse_message; the |
| * ssl_dont_hash_message would have to have been applied to the previous |
| * call. */ |
| assert(hash_message == ssl_hash_message); |
| s->s3->tmp.reuse_message = 0; |
| if (msg_type >= 0 && s->s3->tmp.message_type != msg_type) { |
| al = SSL_AD_UNEXPECTED_MESSAGE; |
| OPENSSL_PUT_ERROR(SSL, 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; |
| } |
| |
| /* Process fragments until one is found. */ |
| while (!dtls1_is_next_message_complete(s)) { |
| int ret = dtls1_process_fragment(s); |
| if (ret <= 0) { |
| *ok = 0; |
| return ret; |
| } |
| } |
| |
| /* Read out the next complete handshake message. */ |
| item = pqueue_pop(s->d1->buffered_messages); |
| assert(item != NULL); |
| frag = (hm_fragment *)item->data; |
| assert(s->d1->handshake_read_seq == frag->msg_header.seq); |
| assert(frag->reassembly == NULL); |
| |
| if (frag->msg_header.msg_len > (size_t)max) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESSIVE_MESSAGE_SIZE); |
| goto err; |
| } |
| |
| /* Reconstruct the assembled message. */ |
| size_t len; |
| CBB cbb; |
| CBB_zero(&cbb); |
| if (!BUF_MEM_grow(s->init_buf, |
| (size_t)frag->msg_header.msg_len + |
| DTLS1_HM_HEADER_LENGTH) || |
| !CBB_init_fixed(&cbb, (uint8_t *)s->init_buf->data, s->init_buf->max) || |
| !CBB_add_u8(&cbb, frag->msg_header.type) || |
| !CBB_add_u24(&cbb, frag->msg_header.msg_len) || |
| !CBB_add_u16(&cbb, frag->msg_header.seq) || |
| !CBB_add_u24(&cbb, 0 /* frag_off */) || |
| !CBB_add_u24(&cbb, frag->msg_header.msg_len) || |
| !CBB_add_bytes(&cbb, frag->fragment, frag->msg_header.msg_len) || |
| !CBB_finish(&cbb, NULL, &len)) { |
| CBB_cleanup(&cbb); |
| OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| assert(len == (size_t)frag->msg_header.msg_len + DTLS1_HM_HEADER_LENGTH); |
| |
| s->d1->handshake_read_seq++; |
| |
| /* TODO(davidben): This function has a lot of implicit outputs. Simplify the |
| * |ssl_get_message| API. */ |
| s->s3->tmp.message_type = frag->msg_header.type; |
| s->s3->tmp.message_size = frag->msg_header.msg_len; |
| s->init_msg = (uint8_t *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH; |
| s->init_num = frag->msg_header.msg_len; |
| |
| if (msg_type >= 0 && s->s3->tmp.message_type != msg_type) { |
| al = SSL_AD_UNEXPECTED_MESSAGE; |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE); |
| goto f_err; |
| } |
| if (hash_message == ssl_hash_message && !ssl3_hash_current_message(s)) { |
| goto err; |
| } |
| if (s->msg_callback) { |
| s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data, |
| s->init_num + DTLS1_HM_HEADER_LENGTH, s, |
| s->msg_callback_arg); |
| } |
| |
| pitem_free(item); |
| dtls1_hm_fragment_free(frag); |
| |
| s->state = stn; |
| *ok = 1; |
| return s->init_num; |
| |
| f_err: |
| ssl3_send_alert(s, SSL3_AL_FATAL, al); |
| err: |
| pitem_free(item); |
| dtls1_hm_fragment_free(frag); |
| *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, dtls1_use_current_epoch); |
| } |
| |
| int dtls1_read_failed(SSL *s, int code) { |
| if (code > 0) { |
| assert(0); |
| 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 DTLSv1_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; |
| } |
| |
| static int dtls1_retransmit_message(SSL *s, hm_fragment *frag) { |
| int ret; |
| /* XDTLS: for now assuming that read/writes are blocking */ |
| unsigned long header_length; |
| |
| /* assert(s->init_num == 0); |
| assert(s->init_off == 0); */ |
| |
| 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); |
| |
| /* DTLS renegotiation is unsupported, so only epochs 0 (NULL cipher) and 1 |
| * (negotiated cipher) exist. */ |
| assert(s->d1->w_epoch == 0 || s->d1->w_epoch == 1); |
| assert(frag->msg_header.epoch <= s->d1->w_epoch); |
| enum dtls1_use_epoch_t use_epoch = dtls1_use_current_epoch; |
| if (s->d1->w_epoch == 1 && frag->msg_header.epoch == 0) { |
| use_epoch = dtls1_use_previous_epoch; |
| } |
| |
| ret = dtls1_do_write(s, frag->msg_header.is_ccs ? SSL3_RT_CHANGE_CIPHER_SPEC |
| : SSL3_RT_HANDSHAKE, |
| use_epoch); |
| |
| (void)BIO_flush(SSL_get_wbio(s)); |
| return ret; |
| } |
| |
| |
| int dtls1_retransmit_buffered_messages(SSL *s) { |
| pqueue sent = s->d1->sent_messages; |
| piterator iter = pqueue_iterator(sent); |
| pitem *item; |
| |
| for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) { |
| hm_fragment *frag = (hm_fragment *)item->data; |
| if (dtls1_retransmit_message(s, frag) <= 0) { |
| 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; |
| frag->msg_header.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; |
| } |
| |
| /* 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); |
| } |