--- /dev/null
+/*
+ * Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <limits.h>
+#include <string.h>
+#include <stdio.h>
+#include "../ssl_locl.h"
+#include "statem_locl.h"
+#include <openssl/buffer.h>
+#include <openssl/objects.h>
+#include <openssl/evp.h>
+#include <openssl/x509.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; \
+ OPENSSL_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 unsigned char bitmask_start_values[] =
+ { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
+static unsigned char bitmask_end_values[] =
+ { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
+
+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 int dtls_get_reassembled_message(SSL *s, long *len);
+
+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 = OPENSSL_malloc(sizeof(*frag));
+ if (frag == NULL)
+ return NULL;
+
+ if (frag_len) {
+ buf = 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 = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len));
+ if (bitmask == NULL) {
+ OPENSSL_free(buf);
+ OPENSSL_free(frag);
+ return NULL;
+ }
+ }
+
+ frag->reassembly = bitmask;
+
+ return frag;
+}
+
+void dtls1_hm_fragment_free(hm_fragment *frag)
+{
+ if (!frag)
+ return;
+ if (frag->msg_header.is_ccs) {
+ EVP_CIPHER_CTX_free(frag->msg_header.
+ saved_retransmit_state.enc_write_ctx);
+ EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash);
+ }
+ OPENSSL_free(frag->fragment);
+ 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;
+ unsigned int curr_mtu;
+ int retry = 1;
+ unsigned int len, frag_off, mac_size, blocksize, used_len;
+
+ if (!dtls1_query_mtu(s))
+ return -1;
+
+ if (s->d1->mtu < dtls1_min_mtu(s))
+ /* should have something reasonable now */
+ return -1;
+
+ if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
+ OPENSSL_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_flags(EVP_CIPHER_CTX_cipher(s->enc_write_ctx)) &
+ EVP_CIPH_FLAG_AEAD_CIPHER) != 0)
+ 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_CTX_block_size(s->enc_write_ctx);
+ else
+ blocksize = 0;
+
+ frag_off = 0;
+ s->rwstate = SSL_NOTHING;
+
+ /* s->init_num shouldn't ever be < 0...but just in case */
+ while (s->init_num > 0) {
+ if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
+ /* We must be writing a fragment other than the first one */
+
+ if (frag_off > 0) {
+ /* This is the first attempt at writing out this fragment */
+
+ if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
+ /*
+ * Each fragment that was already sent must at least have
+ * contained the message header plus one other byte.
+ * Therefore |init_off| must have progressed by at least
+ * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
+ * wrong.
+ */
+ return -1;
+ }
+
+ /*
+ * Adjust |init_off| and |init_num| to allow room for a new
+ * message header for this fragment.
+ */
+ s->init_off -= DTLS1_HM_HEADER_LENGTH;
+ s->init_num += DTLS1_HM_HEADER_LENGTH;
+ } else {
+ /*
+ * We must have been called again after a retry so use the
+ * fragment offset from our last attempt. We do not need
+ * to adjust |init_off| and |init_num| as above, because
+ * that should already have been done before the retry.
+ */
+ frag_off = s->d1->w_msg_hdr.frag_off;
+ }
+ }
+
+ used_len = BIO_wpending(s->wbio) + DTLS1_RT_HEADER_LENGTH
+ + mac_size + blocksize;
+ if (s->d1->mtu > used_len)
+ curr_mtu = s->d1->mtu - used_len;
+ else
+ curr_mtu = 0;
+
+ if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
+ /*
+ * grr.. we could get an error if MTU picked was wrong
+ */
+ ret = BIO_flush(s->wbio);
+ if (ret <= 0) {
+ s->rwstate = SSL_WRITING;
+ return ret;
+ }
+ used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
+ if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
+ curr_mtu = s->d1->mtu - used_len;
+ } else {
+ /* Shouldn't happen */
+ return -1;
+ }
+ }
+
+ /*
+ * We just checked that s->init_num > 0 so this cast should be safe
+ */
+ if (((unsigned int)s->init_num) > curr_mtu)
+ len = curr_mtu;
+ else
+ len = s->init_num;
+
+ /* Shouldn't ever happen */
+ if (len > INT_MAX)
+ len = INT_MAX;
+
+ /*
+ * XDTLS: this function is too long. split out the CCS part
+ */
+ if (type == SSL3_RT_HANDSHAKE) {
+ if (len < DTLS1_HM_HEADER_LENGTH) {
+ /*
+ * len is so small that we really can't do anything sensible
+ * so fail
+ */
+ return -1;
+ }
+ 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]);
+ }
+
+ 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 (retry && BIO_ctrl(SSL_get_wbio(s),
+ BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
+ if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
+ if (!dtls1_query_mtu(s))
+ return -1;
+ /* Have one more go */
+ retry = 0;
+ } else
+ return -1;
+ } else {
+ return (-1);
+ }
+ } else {
+
+ /*
+ * bad if this assert fails, only part of the handshake message
+ * got sent. but why would this happen?
+ */
+ OPENSSL_assert(len == (unsigned int)ret);
+
+ if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
+ /*
+ * 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 && s->version != DTLS1_BAD_VER) {
+ /*
+ * 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;
+ }
+
+ if (!ssl3_finish_mac(s, p, xlen))
+ return -1;
+ }
+
+ 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;
+ ret -= DTLS1_HM_HEADER_LENGTH;
+ frag_off += ret;
+
+ /*
+ * We save the fragment offset for the next fragment so we have it
+ * available in case of an IO retry. We don't know the length of the
+ * next fragment yet so just set that to 0 for now. It will be
+ * updated again later.
+ */
+ dtls1_fix_message_header(s, frag_off, 0);
+ }
+ }
+ return (0);
+}
+
+int dtls_get_message(SSL *s, int *mt, unsigned long *len)
+{
+ struct hm_header_st *msg_hdr;
+ unsigned char *p;
+ unsigned long msg_len;
+ int ok;
+ long tmplen;
+
+ msg_hdr = &s->d1->r_msg_hdr;
+ memset(msg_hdr, 0, sizeof(*msg_hdr));
+
+ again:
+ ok = dtls_get_reassembled_message(s, &tmplen);
+ if (tmplen == DTLS1_HM_BAD_FRAGMENT || tmplen == DTLS1_HM_FRAGMENT_RETRY) {
+ /* bad fragment received */
+ goto again;
+ } else if (tmplen <= 0 && !ok) {
+ return 0;
+ }
+
+ *mt = s->s3->tmp.message_type;
+
+ p = (unsigned char *)s->init_buf->data;
+
+ if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
+ if (s->msg_callback) {
+ s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
+ p, 1, s, s->msg_callback_arg);
+ }
+ /*
+ * This isn't a real handshake message so skip the processing below.
+ */
+ *len = (unsigned long)tmplen;
+ return 1;
+ }
+
+ 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);
+ if (s->version != DTLS1_BAD_VER) {
+ p -= DTLS1_HM_HEADER_LENGTH;
+ msg_len += DTLS1_HM_HEADER_LENGTH;
+ }
+
+ if (!ssl3_finish_mac(s, p, msg_len))
+ return 0;
+ if (s->msg_callback)
+ s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
+ p, msg_len, s, s->msg_callback_arg);
+
+ memset(msg_hdr, 0, sizeof(*msg_hdr));
+
+ s->d1->handshake_read_seq++;
+
+ s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
+ *len = s->init_num;
+
+ 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_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
+{
+ 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
+ || msg_len > dtls1_max_handshake_message_len(s)) {
+ SSLerr(SSL_F_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
+ * dtls_max_handshake_message_len(s) above
+ */
+ if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
+ SSLerr(SSL_F_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.
+ */
+ SSLerr(SSL_F_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, 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;
+
+ do {
+ item = pqueue_peek(s->d1->buffered_messages);
+ if (item == NULL)
+ return 0;
+
+ frag = (hm_fragment *)item->data;
+
+ if (frag->msg_header.seq < s->d1->handshake_read_seq) {
+ /* This is a stale message that has been buffered so clear it */
+ pqueue_pop(s->d1->buffered_messages);
+ dtls1_hm_fragment_free(frag);
+ pitem_free(item);
+ item = NULL;
+ frag = NULL;
+ }
+ } while (item == NULL);
+
+ /* 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);
+
+ 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;
+}
+
+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];
+
+ while (frag_len) {
+ i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
+ 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, NULL,
+ 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.
+ */
+ OPENSSL_assert(item != NULL);
+ }
+
+ return DTLS1_HM_FRAGMENT_RETRY;
+
+ err:
+ if (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, NULL,
+ 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, NULL,
+ 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.
+ */
+ OPENSSL_assert(item != NULL);
+ }
+
+ return DTLS1_HM_FRAGMENT_RETRY;
+
+ err:
+ if (item == NULL)
+ dtls1_hm_fragment_free(frag);
+ *ok = 0;
+ return i;
+}
+
+static int dtls_get_reassembled_message(SSL *s, long *len)
+{
+ unsigned char wire[DTLS1_HM_HEADER_LENGTH];
+ unsigned long mlen, frag_off, frag_len;
+ int i, al, recvd_type;
+ struct hm_header_st msg_hdr;
+ int ok;
+
+ redo:
+ /* see if we have the required fragment already */
+ if ((frag_len = dtls1_retrieve_buffered_fragment(s, &ok)) || ok) {
+ if (ok)
+ s->init_num = frag_len;
+ *len = frag_len;
+ return ok;
+ }
+
+ /* read handshake message header */
+ i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
+ DTLS1_HM_HEADER_LENGTH, 0);
+ if (i <= 0) { /* nbio, or an error */
+ s->rwstate = SSL_READING;
+ *len = i;
+ return 0;
+ }
+ if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
+ if (wire[0] != SSL3_MT_CCS) {
+ al = SSL_AD_UNEXPECTED_MESSAGE;
+ SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
+ SSL_R_BAD_CHANGE_CIPHER_SPEC);
+ goto f_err;
+ }
+
+ memcpy(s->init_buf->data, wire, i);
+ s->init_num = i - 1;
+ s->init_msg = s->init_buf->data + 1;
+ s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
+ s->s3->tmp.message_size = i - 1;
+ *len = i - 1;
+ return 1;
+ }
+
+ /* Handshake fails if message header is incomplete */
+ if (i != DTLS1_HM_HEADER_LENGTH) {
+ al = SSL_AD_UNEXPECTED_MESSAGE;
+ SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
+ goto f_err;
+ }
+
+ /* parse the message fragment header */
+ dtls1_get_message_header(wire, &msg_hdr);
+
+ mlen = msg_hdr.msg_len;
+ frag_off = msg_hdr.frag_off;
+ frag_len = msg_hdr.frag_len;
+
+ /*
+ * We must have at least frag_len bytes left in the record to be read.
+ * Fragments must not span records.
+ */
+ if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
+ al = SSL3_AD_ILLEGAL_PARAMETER;
+ SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_BAD_LENGTH);
+ goto f_err;
+ }
+
+ /*
+ * if this is a future (or stale) message it gets buffered
+ * (or dropped)--no further processing at this time
+ * While listening, we accept seq 1 (ClientHello with cookie)
+ * although we're still expecting seq 0 (ClientHello)
+ */
+ if (msg_hdr.seq != s->d1->handshake_read_seq) {
+ *len = dtls1_process_out_of_seq_message(s, &msg_hdr, &ok);
+ return ok;
+ }
+
+ if (frag_len && frag_len < mlen) {
+ *len = dtls1_reassemble_fragment(s, &msg_hdr, &ok);
+ return 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 formatted Hello request */
+
+ al = SSL_AD_UNEXPECTED_MESSAGE;
+ SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
+ SSL_R_UNEXPECTED_MESSAGE);
+ goto f_err;
+ }
+ }
+
+ if ((al = dtls1_preprocess_fragment(s, &msg_hdr)))
+ goto f_err;
+
+ 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, NULL,
+ &p[frag_off], frag_len, 0);
+
+ /*
+ * This shouldn't ever fail due to NBIO because we already checked
+ * that we have enough data in the record
+ */
+ if (i <= 0) {
+ s->rwstate = SSL_READING;
+ *len = i;
+ return 0;
+ }
+ } else
+ i = 0;
+
+ /*
+ * XDTLS: an incorrectly formatted fragment should cause the handshake
+ * to fail
+ */
+ if (i != (int)frag_len) {
+ al = SSL3_AD_ILLEGAL_PARAMETER;
+ SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL3_AD_ILLEGAL_PARAMETER);
+ goto f_err;
+ }
+
+ /*
+ * 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.
+ */
+ *len = s->init_num = frag_len;
+ return 1;
+
+ f_err:
+ ssl3_send_alert(s, SSL3_AL_FATAL, al);
+ s->init_num = 0;
+ *len = -1;
+ return 0;
+}
+
+/*-
+ * for these 2 messages, we need to
+ * ssl->enc_read_ctx re-init
+ * ssl->rlayer.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 dtls_construct_change_cipher_spec(SSL *s)
+{
+ unsigned char *p;
+
+ 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;
+
+ if (s->version == DTLS1_BAD_VER) {
+ s->d1->next_handshake_write_seq++;
+ s2n(s->d1->handshake_write_seq, p);
+ s->init_num += 2;
+ }
+
+ 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 */
+ if (!dtls1_buffer_message(s, 1)) {
+ SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+
+ return 1;
+}
+
+#ifndef OPENSSL_NO_SCTP
+WORK_STATE dtls_wait_for_dry(SSL *s)
+{
+ int ret;
+
+ /* read app data until dry event */
+ ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
+ if (ret < 0)
+ return WORK_ERROR;
+
+ if (ret == 0) {
+ s->s3->in_read_app_data = 2;
+ s->rwstate = SSL_READING;
+ BIO_clear_retry_flags(SSL_get_rbio(s));
+ BIO_set_retry_read(SSL_get_rbio(s));
+ return WORK_MORE_A;
+ }
+ return WORK_FINISHED_CONTINUE;
+}
+#endif
+
+int dtls1_read_failed(SSL *s, int code)
+{
+ if (code > 0) {
+ SSLerr(SSL_F_DTLS1_READ_FAILED, ERR_R_INTERNAL_ERROR);
+ 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;
+ }
+#ifndef OPENSSL_NO_HEARTBEATS
+ /* done, no need to send a retransmit */
+ if (!SSL_in_init(s) && !s->tlsext_hb_pending)
+#else
+ /* done, no need to send a retransmit */
+ if (!SSL_in_init(s))
+#endif
+ {
+ 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), &found) <= 0)
+ 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
+ */
+ OPENSSL_assert(s->init_off == 0);
+
+ frag = dtls1_hm_fragment_new(s->init_num, 0);
+ if (frag == NULL)
+ return 0;
+
+ memcpy(frag->fragment, s->init_buf->data, s->init_num);
+
+ if (is_ccs) {
+ /* For DTLS1_BAD_VER the header length is non-standard */
+ OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
+ ((s->version ==
+ DTLS1_BAD_VER) ? 3 : DTLS1_CCS_HEADER_LENGTH)
+ == (unsigned int)s->init_num);
+ } else {
+ OPENSSL_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.compress = s->compress;
+ frag->msg_header.saved_retransmit_state.session = s->session;
+ frag->msg_header.saved_retransmit_state.epoch =
+ DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
+
+ 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;
+ }
+
+ pqueue_insert(s->d1->sent_messages, item);
+ return 1;
+}
+
+int dtls1_retransmit_message(SSL *s, unsigned short seq, 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;
+
+ /*-
+ OPENSSL_assert(s->init_num == 0);
+ OPENSSL_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) {
+ SSLerr(SSL_F_DTLS1_RETRANSMIT_MESSAGE, ERR_R_INTERNAL_ERROR);
+ *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.compress = s->compress;
+ saved_state.session = s->session;
+ saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
+
+ 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->compress = frag->msg_header.saved_retransmit_state.compress;
+ s->session = frag->msg_header.saved_retransmit_state.session;
+ DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
+ frag->msg_header.
+ saved_retransmit_state.epoch);
+
+ ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
+ SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
+
+ /* restore current state */
+ s->enc_write_ctx = saved_state.enc_write_ctx;
+ s->write_hash = saved_state.write_hash;
+ s->compress = saved_state.compress;
+ s->session = saved_state.session;
+ DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
+
+ s->d1->retransmitting = 0;
+
+ (void)BIO_flush(s->wbio);
+ return ret;
+}
+
+void dtls1_set_message_header(SSL *s,
+ 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);
+}
+
+/* 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;
+}
+
+void dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
+{
+ memset(msg_hdr, 0, sizeof(*msg_hdr));
+ 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);
+}
projects / cassiopeia.git / blobdiff