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IABSD.fr/src/lib/libssl/d1_both.c
phessler
- lib/libssl/d1_both.c
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/* $OpenBSD: d1_both.c,v 1.57 2019/02/10 16:42:35 phessler Exp $ */ /* * 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 <limits.h> #include <stdio.h> #include <string.h> #include "ssl_locl.h" #include <openssl/buffer.h> #include <openssl/evp.h> #include <openssl/objects.h> #include <openssl/x509.h> #include "pqueue.h" #include "bytestring.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 }; /* XDTLS: figure out the right values */ static 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 int dtls1_write_message_header(const struct hm_header_st *msg_hdr, unsigned long frag_off, unsigned long frag_len, unsigned char *p); static long dtls1_get_message_fragment(SSL *s, int st1, 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 = malloc(sizeof(hm_fragment)); if (frag == NULL) return NULL; if (frag_len) { buf = malloc(frag_len); if (buf == NULL) { free(frag); return NULL; } } /* zero length fragment gets zero frag->fragment */ frag->fragment = buf; /* Initialize reassembly bitmask if necessary */ if (reassembly) { bitmask = malloc(RSMBLY_BITMASK_SIZE(frag_len)); if (bitmask == NULL) { free(buf); 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 == NULL) 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); } free(frag->fragment); free(frag->reassembly); free(frag); } /* send s->internal->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */ int dtls1_do_write(SSL *s, int type) { int ret; int curr_mtu; unsigned int len, frag_off, mac_size, blocksize; /* AHA! Figure out the MTU, and stick to the right size */ if (D1I(s)->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { D1I(s)->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 the MTU (ie., the initial write), so just * make sure we have a reasonable number */ if (D1I(s)->mtu < dtls1_min_mtu()) { D1I(s)->mtu = 0; D1I(s)->mtu = dtls1_guess_mtu(D1I(s)->mtu); BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, D1I(s)->mtu, NULL); } } OPENSSL_assert(D1I(s)->mtu >= dtls1_min_mtu()); /* should have something reasonable now */ if (s->internal->init_off == 0 && type == SSL3_RT_HANDSHAKE) OPENSSL_assert(s->internal->init_num == (int)D1I(s)->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH); if (s->internal->write_hash) mac_size = EVP_MD_CTX_size(s->internal->write_hash); else mac_size = 0; if (s->internal->enc_write_ctx && (EVP_CIPHER_mode( s->internal->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE)) blocksize = 2 * EVP_CIPHER_block_size(s->internal->enc_write_ctx->cipher); else blocksize = 0; frag_off = 0; while (s->internal->init_num) { curr_mtu = D1I(s)->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 = D1I(s)->mtu - DTLS1_RT_HEADER_LENGTH - mac_size - blocksize; } if (s->internal->init_num > curr_mtu) len = curr_mtu; else len = s->internal->init_num; /* XDTLS: this function is too long. split out the CCS part */ if (type == SSL3_RT_HANDSHAKE) { if (s->internal->init_off != 0) { OPENSSL_assert(s->internal->init_off > DTLS1_HM_HEADER_LENGTH); s->internal->init_off -= DTLS1_HM_HEADER_LENGTH; s->internal->init_num += DTLS1_HM_HEADER_LENGTH; if (s->internal->init_num > curr_mtu) len = curr_mtu; else len = s->internal->init_num; } dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH); if (!dtls1_write_message_header(&D1I(s)->w_msg_hdr, D1I(s)->w_msg_hdr.frag_off, D1I(s)->w_msg_hdr.frag_len, (unsigned char *)&s->internal->init_buf->data[s->internal->init_off])) return -1; OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH); } ret = dtls1_write_bytes(s, type, &s->internal->init_buf->data[s->internal->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) D1I(s)->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? */ OPENSSL_assert(len == (unsigned int)ret); if (type == SSL3_RT_HANDSHAKE && !D1I(s)->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->internal->init_buf->data[s->internal->init_off]; const struct hm_header_st *msg_hdr = &D1I(s)->w_msg_hdr; int xlen; if (frag_off == 0) { /* * Reconstruct message header is if it * is being sent in single fragment */ if (!dtls1_write_message_header(msg_hdr, 0, msg_hdr->msg_len, p)) return (-1); xlen = ret; } else { p += DTLS1_HM_HEADER_LENGTH; xlen = ret - DTLS1_HM_HEADER_LENGTH; } tls1_transcript_record(s, p, xlen); } if (ret == s->internal->init_num) { if (s->internal->msg_callback) s->internal->msg_callback(1, s->version, type, s->internal->init_buf->data, (size_t)(s->internal->init_off + s->internal->init_num), s, s->internal->msg_callback_arg); s->internal->init_off = 0; /* done writing this message */ s->internal->init_num = 0; return (1); } s->internal->init_off += ret; s->internal->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 *ok) { int i, al; struct hm_header_st *msg_hdr; unsigned char *p; unsigned long msg_len; /* * s3->internal->tmp is used to store messages that are unexpected, caused * by the absence of an optional handshake message */ if (S3I(s)->tmp.reuse_message) { S3I(s)->tmp.reuse_message = 0; if ((mt >= 0) && (S3I(s)->tmp.message_type != mt)) { al = SSL_AD_UNEXPECTED_MESSAGE; SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); goto f_err; } *ok = 1; s->internal->init_msg = s->internal->init_buf->data + DTLS1_HM_HEADER_LENGTH; s->internal->init_num = (int)S3I(s)->tmp.message_size; return s->internal->init_num; } msg_hdr = &D1I(s)->r_msg_hdr; memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); again: i = dtls1_get_message_fragment(s, st1, 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->internal->init_buf->data; msg_len = msg_hdr->msg_len; /* reconstruct message header */ if (!dtls1_write_message_header(msg_hdr, 0, msg_len, p)) return -1; msg_len += DTLS1_HM_HEADER_LENGTH; tls1_transcript_record(s, p, msg_len); if (s->internal->msg_callback) s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, p, msg_len, s, s->internal->msg_callback_arg); memset(msg_hdr, 0x00, sizeof(struct hm_header_st)); /* Don't change sequence numbers while listening */ if (!D1I(s)->listen) D1I(s)->handshake_read_seq++; s->internal->init_msg = s->internal->init_buf->data + DTLS1_HM_HEADER_LENGTH; return s->internal->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) { SSLerror(s, SSL_R_EXCESSIVE_MESSAGE_SIZE); return SSL_AD_ILLEGAL_PARAMETER; } if ((frag_off + frag_len) > (unsigned long)max) { SSLerror(s, SSL_R_EXCESSIVE_MESSAGE_SIZE); return SSL_AD_ILLEGAL_PARAMETER; } if ( D1I(s)->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->internal->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) { SSLerror(s, ERR_R_BUF_LIB); return SSL_AD_INTERNAL_ERROR; } S3I(s)->tmp.message_size = msg_len; D1I(s)->r_msg_hdr.msg_len = msg_len; S3I(s)->tmp.message_type = msg_hdr->type; D1I(s)->r_msg_hdr.type = msg_hdr->type; D1I(s)->r_msg_hdr.seq = msg_hdr->seq; } else if (msg_len != D1I(s)->r_msg_hdr.msg_len) { /* * They must be playing with us! BTW, failure to enforce * upper limit would open possibility for buffer overrun. */ SSLerror(s, 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->internal->init_buf->data[] * (2) update s->internal->init_num */ pitem *item; hm_fragment *frag; int al; *ok = 0; item = pqueue_peek(D1I(s)->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 (D1I(s)->handshake_read_seq == frag->msg_header.seq) { unsigned long frag_len = frag->msg_header.frag_len; pqueue_pop(D1I(s)->buffered_messages); al = dtls1_preprocess_fragment(s, &frag->msg_header, max); if (al == 0) /* no alert */ { unsigned char *p = (unsigned char *)s->internal->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->internal->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; max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH; if (max_len < (unsigned long)s->internal->max_cert_list) return s->internal->max_cert_list; return max_len; } static int dtls1_reassemble_fragment(SSL *s, 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) { i = DTLS1_HM_FRAGMENT_RETRY; goto err; } /* 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(D1I(s)->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. */ if (frag->reassembly == NULL) { unsigned char devnull [256]; while (frag_len) { i = s->method->internal->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; } i = DTLS1_HM_FRAGMENT_RETRY; goto err; } /* read the body of the fragment (header has already been read */ i = s->method->internal->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, frag->fragment + msg_hdr->frag_off, frag_len, 0); if (i <= 0 || (unsigned long)i != frag_len) 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) { free(frag->reassembly); frag->reassembly = NULL; } if (item == NULL) { memset(seq64be, 0, sizeof(seq64be)); seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); seq64be[7] = (unsigned char)(msg_hdr->seq); item = pitem_new(seq64be, frag); if (item == NULL) { i = -1; goto err; } pqueue_insert(D1I(s)->buffered_messages, item); } return DTLS1_HM_FRAGMENT_RETRY; err: if (item == NULL && frag != NULL) dtls1_hm_fragment_free(frag); *ok = 0; return i; } static int dtls1_process_out_of_seq_message(SSL *s, 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(D1I(s)->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 <= D1I(s)->handshake_read_seq || msg_hdr->seq > D1I(s)->handshake_read_seq + 10 || item != NULL || (D1I(s)->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) { unsigned char devnull [256]; while (frag_len) { i = s->method->internal->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->internal->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, frag->fragment, frag_len, 0); if (i <= 0 || (unsigned long)i != frag_len) goto err; } memset(seq64be, 0, sizeof(seq64be)); seq64be[6] = (unsigned char)(msg_hdr->seq >> 8); seq64be[7] = (unsigned char)(msg_hdr->seq); item = pitem_new(seq64be, frag); if (item == NULL) goto err; pqueue_insert(D1I(s)->buffered_messages, item); } return DTLS1_HM_FRAGMENT_RETRY; err: if (item == NULL && frag != NULL) dtls1_hm_fragment_free(frag); *ok = 0; return i; } static long dtls1_get_message_fragment(SSL *s, int st1, 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; again: /* see if we have the required fragment already */ if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) { if (*ok) s->internal->init_num = frag_len; return frag_len; } /* read handshake message header */ i = s->method->internal->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire, DTLS1_HM_HEADER_LENGTH, 0); if (i <= 0) /* nbio, or an error */ { s->internal->rwstate = SSL_READING; *ok = 0; return i; } /* Handshake fails if message header is incomplete */ if (i != DTLS1_HM_HEADER_LENGTH || /* parse the message fragment header */ dtls1_get_message_header(wire, &msg_hdr) == 0) { al = SSL_AD_UNEXPECTED_MESSAGE; SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 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 != D1I(s)->handshake_read_seq && !(D1I(s)->listen && msg_hdr.seq == 1)) 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 && D1I(s)->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->internal->msg_callback) s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, wire, DTLS1_HM_HEADER_LENGTH, s, s->internal->msg_callback_arg); s->internal->init_num = 0; goto again; } else /* Incorrectly formated Hello request */ { al = SSL_AD_UNEXPECTED_MESSAGE; SSLerror(s, 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 */ S3I(s)->hs.state = stn; if (frag_len > 0) { unsigned char *p = (unsigned char *)s->internal->init_buf->data + DTLS1_HM_HEADER_LENGTH; i = s->method->internal->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->internal->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; SSLerror(s, SSL3_AD_ILLEGAL_PARAMETER); goto f_err; } *ok = 1; /* * Note that s->internal->init_num is *not* used as current offset in * s->internal->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->internal->init_num = frag_len; return frag_len; f_err: ssl3_send_alert(s, SSL3_AL_FATAL, al); s->internal->init_num = 0; *ok = 0; return (-1); } int dtls1_read_failed(SSL *s, int code) { if (code > 0) { #ifdef DEBUG fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__); #endif 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) { #ifdef DEBUG fprintf(stderr, "dtls1_retransmit_message() failed\n"); #endif return -1; } } return 1; } int dtls1_buffer_message(SSL *s, int is_ccs) { pitem *item; hm_fragment *frag; unsigned char seq64be[8]; /* Buffer the messsage in order to handle DTLS retransmissions. */ /* * This function is called immediately after a message has * been serialized */ OPENSSL_assert(s->internal->init_off == 0); frag = dtls1_hm_fragment_new(s->internal->init_num, 0); if (frag == NULL) return 0; memcpy(frag->fragment, s->internal->init_buf->data, s->internal->init_num); if (is_ccs) { OPENSSL_assert(D1I(s)->w_msg_hdr.msg_len + ((s->version == DTLS1_VERSION) ? DTLS1_CCS_HEADER_LENGTH : 3) == (unsigned int)s->internal->init_num); } else { OPENSSL_assert(D1I(s)->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH == (unsigned int)s->internal->init_num); } frag->msg_header.msg_len = D1I(s)->w_msg_hdr.msg_len; frag->msg_header.seq = D1I(s)->w_msg_hdr.seq; frag->msg_header.type = D1I(s)->w_msg_hdr.type; frag->msg_header.frag_off = 0; frag->msg_header.frag_len = D1I(s)->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->internal->enc_write_ctx; frag->msg_header.saved_retransmit_state.write_hash = s->internal->write_hash; frag->msg_header.saved_retransmit_state.session = s->session; frag->msg_header.saved_retransmit_state.epoch = D1I(s)->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; } 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]; /* OPENSSL_assert(s->internal->init_num == 0); OPENSSL_assert(s->internal->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) { #ifdef DEBUG fprintf(stderr, "retransmit: message %d non-existent\n", seq); #endif *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->internal->init_buf->data, frag->fragment, frag->msg_header.msg_len + header_length); s->internal->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->internal->enc_write_ctx; saved_state.write_hash = s->internal->write_hash; saved_state.session = s->session; saved_state.epoch = D1I(s)->w_epoch; D1I(s)->retransmitting = 1; /* restore state in which the message was originally sent */ s->internal->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx; s->internal->write_hash = frag->msg_header.saved_retransmit_state.write_hash; s->session = frag->msg_header.saved_retransmit_state.session; D1I(s)->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, S3I(s)->write_sequence, sizeof(S3I(s)->write_sequence)); memcpy(S3I(s)->write_sequence, D1I(s)->last_write_sequence, sizeof(S3I(s)->write_sequence)); } ret = dtls1_do_write(s, frag->msg_header.is_ccs ? SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE); /* restore current state */ s->internal->enc_write_ctx = saved_state.enc_write_ctx; s->internal->write_hash = saved_state.write_hash; s->session = saved_state.session; D1I(s)->w_epoch = saved_state.epoch; if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1) { memcpy(D1I(s)->last_write_sequence, S3I(s)->write_sequence, sizeof(S3I(s)->write_sequence)); memcpy(S3I(s)->write_sequence, save_write_sequence, sizeof(S3I(s)->write_sequence)); } D1I(s)->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); } } void dtls1_set_message_header(SSL *s, unsigned char mt, unsigned long len, unsigned long frag_off, unsigned long frag_len) { /* Don't change sequence numbers while listening */ if (frag_off == 0 && !D1I(s)->listen) { D1I(s)->handshake_write_seq = D1I(s)->next_handshake_write_seq; D1I(s)->next_handshake_write_seq++; } dtls1_set_message_header_int(s, mt, len, D1I(s)->handshake_write_seq, frag_off, frag_len); } /* don't actually do the writing, wait till the MTU has been retrieved */ 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 = &D1I(s)->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 = &D1I(s)->w_msg_hdr; msg_hdr->frag_off = frag_off; msg_hdr->frag_len = frag_len; } static int dtls1_write_message_header(const struct hm_header_st *msg_hdr, unsigned long frag_off, unsigned long frag_len, unsigned char *p) { CBB cbb; /* We assume DTLS1_HM_HEADER_LENGTH bytes are available for now... */ if (!CBB_init_fixed(&cbb, p, DTLS1_HM_HEADER_LENGTH)) return 0; if (!CBB_add_u8(&cbb, msg_hdr->type)) goto err; if (!CBB_add_u24(&cbb, msg_hdr->msg_len)) goto err; if (!CBB_add_u16(&cbb, msg_hdr->seq)) goto err; if (!CBB_add_u24(&cbb, frag_off)) goto err; if (!CBB_add_u24(&cbb, frag_len)) goto err; if (!CBB_finish(&cbb, NULL, NULL)) goto err; return 1; err: CBB_cleanup(&cbb); return 0; } 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; } int dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr) { CBS header; uint32_t msg_len, frag_off, frag_len; uint16_t seq; uint8_t type; CBS_init(&header, data, sizeof(*msg_hdr)); memset(msg_hdr, 0, sizeof(*msg_hdr)); if (!CBS_get_u8(&header, &type)) return 0; if (!CBS_get_u24(&header, &msg_len)) return 0; if (!CBS_get_u16(&header, &seq)) return 0; if (!CBS_get_u24(&header, &frag_off)) return 0; if (!CBS_get_u24(&header, &frag_len)) return 0; msg_hdr->type = type; msg_hdr->msg_len = msg_len; msg_hdr->seq = seq; msg_hdr->frag_off = frag_off; msg_hdr->frag_len = frag_len; return 1; } 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++); }