/* $OpenBSD: ssl_pkt.c,v 1.64 2022/11/11 17:15:26 jsing Exp $ */ /* 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.] */ /* ==================================================================== * Copyright (c) 1998-2002 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). * */ #include #include #include #include #include #include "bytestring.h" #include "dtls_locl.h" #include "ssl_locl.h" #include "tls_content.h" static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len); static int ssl3_get_record(SSL *s); /* * Force a WANT_READ return for certain error conditions where * we don't want to spin internally. */ void ssl_force_want_read(SSL *s) { BIO *bio; bio = SSL_get_rbio(s); BIO_clear_retry_flags(bio); BIO_set_retry_read(bio); s->rwstate = SSL_READING; } /* * If extend == 0, obtain new n-byte packet; if extend == 1, increase * packet by another n bytes. * The packet will be in the sub-array of s->s3->rbuf.buf specified * by s->packet and s->packet_length. * (If s->read_ahead is set, 'max' bytes may be stored in rbuf * [plus s->packet_length bytes if extend == 1].) */ static int ssl3_read_n(SSL *s, int n, int max, int extend) { SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf); int i, len, left; size_t align; unsigned char *pkt; if (n <= 0) return n; if (rb->buf == NULL) { if (!ssl3_setup_read_buffer(s)) return -1; } if (rb->buf == NULL) return -1; left = rb->left; align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH; align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); if (!extend) { /* start with empty packet ... */ if (left == 0) rb->offset = align; else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) { /* check if next packet length is large * enough to justify payload alignment... */ pkt = rb->buf + rb->offset; if (pkt[0] == SSL3_RT_APPLICATION_DATA && (pkt[3]<<8|pkt[4]) >= 128) { /* Note that even if packet is corrupted * and its length field is insane, we can * only be led to wrong decision about * whether memmove will occur or not. * Header values has no effect on memmove * arguments and therefore no buffer * overrun can be triggered. */ memmove(rb->buf + align, pkt, left); rb->offset = align; } } s->packet = rb->buf + rb->offset; s->packet_length = 0; /* ... now we can act as if 'extend' was set */ } /* For DTLS/UDP reads should not span multiple packets * because the read operation returns the whole packet * at once (as long as it fits into the buffer). */ if (SSL_is_dtls(s)) { if (left > 0 && n > left) n = left; } /* if there is enough in the buffer from a previous read, take some */ if (left >= n) { s->packet_length += n; rb->left = left - n; rb->offset += n; return (n); } /* else we need to read more data */ len = s->packet_length; pkt = rb->buf + align; /* Move any available bytes to front of buffer: * 'len' bytes already pointed to by 'packet', * 'left' extra ones at the end */ if (s->packet != pkt) { /* len > 0 */ memmove(pkt, s->packet, len + left); s->packet = pkt; rb->offset = len + align; } if (n > (int)(rb->len - rb->offset)) { /* does not happen */ SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } if (s->read_ahead || SSL_is_dtls(s)) { if (max < n) max = n; if (max > (int)(rb->len - rb->offset)) max = rb->len - rb->offset; } else { /* ignore max parameter */ max = n; } while (left < n) { /* Now we have len+left bytes at the front of s->s3->rbuf.buf * and need to read in more until we have len+n (up to * len+max if possible) */ errno = 0; if (s->rbio != NULL) { s->rwstate = SSL_READING; i = BIO_read(s->rbio, pkt + len + left, max - left); } else { SSLerror(s, SSL_R_READ_BIO_NOT_SET); i = -1; } if (i <= 0) { rb->left = left; if (s->mode & SSL_MODE_RELEASE_BUFFERS && !SSL_is_dtls(s)) { if (len + left == 0) ssl3_release_read_buffer(s); } return (i); } left += i; /* * reads should *never* span multiple packets for DTLS because * the underlying transport protocol is message oriented as * opposed to byte oriented as in the TLS case. */ if (SSL_is_dtls(s)) { if (n > left) n = left; /* makes the while condition false */ } } /* done reading, now the book-keeping */ rb->offset += n; rb->left = left - n; s->packet_length += n; s->rwstate = SSL_NOTHING; return (n); } int ssl3_packet_read(SSL *s, int plen) { int n; n = ssl3_read_n(s, plen, s->s3->rbuf.len, 0); if (n <= 0) return n; if (s->packet_length < plen) return s->packet_length; return plen; } int ssl3_packet_extend(SSL *s, int plen) { int rlen, n; if (s->packet_length >= plen) return plen; rlen = plen - s->packet_length; n = ssl3_read_n(s, rlen, rlen, 1); if (n <= 0) return n; if (s->packet_length < plen) return s->packet_length; return plen; } /* Call this to get a new input record. * It will return <= 0 if more data is needed, normally due to an error * or non-blocking IO. * When it finishes, one packet has been decoded and can be found in * ssl->s3->rrec.type - is the type of record * ssl->s3->rrec.data, - data * ssl->s3->rrec.length, - number of bytes */ /* used only by ssl3_read_bytes */ static int ssl3_get_record(SSL *s) { SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf); SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec); uint8_t alert_desc; int al, n; int ret = -1; again: /* check if we have the header */ if ((s->rstate != SSL_ST_READ_BODY) || (s->packet_length < SSL3_RT_HEADER_LENGTH)) { CBS header; uint16_t len, ssl_version; uint8_t type; n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH); if (n <= 0) return (n); s->mac_packet = 1; s->rstate = SSL_ST_READ_BODY; if (s->server && s->first_packet) { if ((ret = ssl_server_legacy_first_packet(s)) != 1) return (ret); ret = -1; } CBS_init(&header, s->packet, SSL3_RT_HEADER_LENGTH); /* Pull apart the header into the SSL3_RECORD_INTERNAL */ if (!CBS_get_u8(&header, &type) || !CBS_get_u16(&header, &ssl_version) || !CBS_get_u16(&header, &len)) { SSLerror(s, SSL_R_BAD_PACKET_LENGTH); goto err; } rr->type = type; rr->length = len; /* Lets check version */ if (!s->first_packet && ssl_version != s->version) { if ((s->version & 0xFF00) == (ssl_version & 0xFF00) && !tls12_record_layer_write_protected(s->rl)) { /* Send back error using their minor version number :-) */ s->version = ssl_version; } SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); al = SSL_AD_PROTOCOL_VERSION; goto fatal_err; } if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) { SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); goto err; } if (rr->length > rb->len - SSL3_RT_HEADER_LENGTH) { al = SSL_AD_RECORD_OVERFLOW; SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG); goto fatal_err; } } n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length); if (n <= 0) return (n); if (n != SSL3_RT_HEADER_LENGTH + rr->length) return (n); s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ /* * A full record has now been read from the wire, which now needs * to be processed. */ tls12_record_layer_set_version(s->rl, s->version); if (!tls12_record_layer_open_record(s->rl, s->packet, s->packet_length, s->s3->rcontent)) { tls12_record_layer_alert(s->rl, &alert_desc); if (alert_desc == 0) goto err; if (alert_desc == SSL_AD_RECORD_OVERFLOW) SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); else if (alert_desc == SSL_AD_BAD_RECORD_MAC) SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); al = alert_desc; goto fatal_err; } /* we have pulled in a full packet so zero things */ s->packet_length = 0; if (tls_content_remaining(s->s3->rcontent) == 0) { /* * Zero-length fragments are only permitted for application * data, as per RFC 5246 section 6.2.1. */ if (rr->type != SSL3_RT_APPLICATION_DATA) { SSLerror(s, SSL_R_BAD_LENGTH); al = SSL_AD_UNEXPECTED_MESSAGE; goto fatal_err; } tls_content_clear(s->s3->rcontent); /* * CBC countermeasures for known IV weaknesses can legitimately * insert a single empty record, so we allow ourselves to read * once past a single empty record without forcing want_read. */ if (s->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) { SSLerror(s, SSL_R_PEER_BEHAVING_BADLY); return -1; } if (s->empty_record_count > 1) { ssl_force_want_read(s); return -1; } goto again; } s->empty_record_count = 0; return (1); fatal_err: ssl3_send_alert(s, SSL3_AL_FATAL, al); err: return (ret); } /* Call this to write data in records of type 'type' * It will return <= 0 if not all data has been sent or non-blocking IO. */ int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) { const unsigned char *buf = buf_; unsigned int tot, n, nw; int i; if (len < 0) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } s->rwstate = SSL_NOTHING; tot = s->s3->wnum; s->s3->wnum = 0; if (SSL_in_init(s) && !s->in_handshake) { i = s->handshake_func(s); if (i < 0) return (i); if (i == 0) { SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); return -1; } } if (len < tot) len = tot; n = (len - tot); for (;;) { if (n > s->max_send_fragment) nw = s->max_send_fragment; else nw = n; i = do_ssl3_write(s, type, &(buf[tot]), nw); if (i <= 0) { s->s3->wnum = tot; return i; } if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA && (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { /* * Next chunk of data should get another prepended * empty fragment in ciphersuites with known-IV * weakness. */ s->s3->empty_fragment_done = 0; return tot + i; } n -= i; tot += i; } } static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len) { SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf); SSL_SESSION *sess = s->session; int need_empty_fragment = 0; size_t align, out_len; uint16_t version; CBB cbb; int ret; memset(&cbb, 0, sizeof(cbb)); if (wb->buf == NULL) if (!ssl3_setup_write_buffer(s)) return -1; /* * First check if there is a SSL3_BUFFER_INTERNAL still being written * out. This will happen with non blocking IO. */ if (wb->left != 0) return (ssl3_write_pending(s, type, buf, len)); /* If we have an alert to send, let's send it. */ if (s->s3->alert_dispatch) { if ((ret = ssl3_dispatch_alert(s)) <= 0) return (ret); /* If it went, fall through and send more stuff. */ /* We may have released our buffer, if so get it again. */ if (wb->buf == NULL) if (!ssl3_setup_write_buffer(s)) return -1; } if (len == 0) return 0; /* * Some servers hang if initial client hello is larger than 256 * bytes and record version number > TLS 1.0. */ version = s->version; if (s->s3->hs.state == SSL3_ST_CW_CLNT_HELLO_B && !s->renegotiate && s->s3->hs.our_max_tls_version > TLS1_VERSION) version = TLS1_VERSION; /* * Countermeasure against known-IV weakness in CBC ciphersuites * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this * is unnecessary for AEAD. */ if (sess != NULL && tls12_record_layer_write_protected(s->rl)) { if (s->s3->need_empty_fragments && !s->s3->empty_fragment_done && type == SSL3_RT_APPLICATION_DATA) need_empty_fragment = 1; } /* * An extra fragment would be a couple of cipher blocks, which would * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real * payload, then we can just simply pretend we have two headers. */ align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH; if (need_empty_fragment) align += SSL3_RT_HEADER_LENGTH; align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); wb->offset = align; if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align)) goto err; tls12_record_layer_set_version(s->rl, version); if (need_empty_fragment) { if (!tls12_record_layer_seal_record(s->rl, type, buf, 0, &cbb)) goto err; s->s3->empty_fragment_done = 1; } if (!tls12_record_layer_seal_record(s->rl, type, buf, len, &cbb)) goto err; if (!CBB_finish(&cbb, NULL, &out_len)) goto err; wb->left = out_len; /* * Memorize arguments so that ssl3_write_pending can detect * bad write retries later. */ s->s3->wpend_tot = len; s->s3->wpend_buf = buf; s->s3->wpend_type = type; s->s3->wpend_ret = len; /* We now just need to write the buffer. */ return ssl3_write_pending(s, type, buf, len); err: CBB_cleanup(&cbb); return -1; } /* if s->s3->wbuf.left != 0, we need to call this */ int ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len) { int i; SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf); /* XXXX */ if ((s->s3->wpend_tot > (int)len) || ((s->s3->wpend_buf != buf) && !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) || (s->s3->wpend_type != type)) { SSLerror(s, SSL_R_BAD_WRITE_RETRY); return (-1); } for (;;) { errno = 0; if (s->wbio != NULL) { s->rwstate = SSL_WRITING; i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]), (unsigned int)wb->left); } else { SSLerror(s, SSL_R_BIO_NOT_SET); i = -1; } if (i == wb->left) { wb->left = 0; wb->offset += i; if (s->mode & SSL_MODE_RELEASE_BUFFERS && !SSL_is_dtls(s)) ssl3_release_write_buffer(s); s->rwstate = SSL_NOTHING; return (s->s3->wpend_ret); } else if (i <= 0) { /* * For DTLS, just drop it. That's kind of the * whole point in using a datagram service. */ if (SSL_is_dtls(s)) wb->left = 0; return (i); } wb->offset += i; wb->left -= i; } } static ssize_t ssl3_read_cb(void *buf, size_t n, void *cb_arg) { SSL *s = cb_arg; return tls_content_read(s->s3->rcontent, buf, n); } #define SSL3_ALERT_LENGTH 2 int ssl3_read_alert(SSL *s) { uint8_t alert_level, alert_descr; ssize_t ret; CBS cbs; /* * TLSv1.2 permits an alert to be fragmented across multiple records or * for multiple alerts to be be coalesced into a single alert record. * In the case of DTLS, there is no way to reassemble an alert * fragmented across multiple records, hence a full alert must be * available in the record. */ if (s->s3->alert_fragment == NULL) { if ((s->s3->alert_fragment = tls_buffer_new(0)) == NULL) return -1; tls_buffer_set_capacity_limit(s->s3->alert_fragment, SSL3_ALERT_LENGTH); } ret = tls_buffer_extend(s->s3->alert_fragment, SSL3_ALERT_LENGTH, ssl3_read_cb, s); if (ret <= 0 && ret != TLS_IO_WANT_POLLIN) return -1; if (ret != SSL3_ALERT_LENGTH) { if (SSL_is_dtls(s)) { SSLerror(s, SSL_R_BAD_LENGTH); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return -1; } return 1; } if (!tls_buffer_data(s->s3->alert_fragment, &cbs)) return -1; ssl_msg_callback_cbs(s, 0, SSL3_RT_ALERT, &cbs); if (!CBS_get_u8(&cbs, &alert_level)) return -1; if (!CBS_get_u8(&cbs, &alert_descr)) return -1; tls_buffer_free(s->s3->alert_fragment); s->s3->alert_fragment = NULL; ssl_info_callback(s, SSL_CB_READ_ALERT, (alert_level << 8) | alert_descr); if (alert_level == SSL3_AL_WARNING) { s->s3->warn_alert = alert_descr; if (alert_descr == SSL_AD_CLOSE_NOTIFY) { s->shutdown |= SSL_RECEIVED_SHUTDOWN; return 0; } /* We requested renegotiation and the peer rejected it. */ if (alert_descr == SSL_AD_NO_RENEGOTIATION) { SSLerror(s, SSL_R_NO_RENEGOTIATION); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return -1; } } else if (alert_level == SSL3_AL_FATAL) { s->rwstate = SSL_NOTHING; s->s3->fatal_alert = alert_descr; SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); ERR_asprintf_error_data("SSL alert number %d", alert_descr); s->shutdown |= SSL_RECEIVED_SHUTDOWN; SSL_CTX_remove_session(s->ctx, s->session); return 0; } else { SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); return -1; } return 1; } int ssl3_read_change_cipher_spec(SSL *s) { const uint8_t ccs[1] = { SSL3_MT_CCS }; /* * 'Change Cipher Spec' is just a single byte, so we know exactly what * the record payload has to look like. */ if (tls_content_remaining(s->s3->rcontent) != sizeof(ccs)) { SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return -1; } if (!tls_content_equal(s->s3->rcontent, ccs, sizeof(ccs))) { SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); return -1; } /* XDTLS: check that epoch is consistent */ ssl_msg_callback_cbs(s, 0, SSL3_RT_CHANGE_CIPHER_SPEC, tls_content_cbs(s->s3->rcontent)); /* Check that we have a cipher to change to. */ if (s->s3->hs.cipher == NULL) { SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } /* Check that we should be receiving a Change Cipher Spec. */ if (SSL_is_dtls(s)) { if (!s->d1->change_cipher_spec_ok) { /* * We can't process a CCS now, because previous * handshake messages are still missing, so just * drop it. */ tls_content_clear(s->s3->rcontent); return 1; } s->d1->change_cipher_spec_ok = 0; } else { if ((s->s3->flags & SSL3_FLAGS_CCS_OK) == 0) { SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } s->s3->flags &= ~SSL3_FLAGS_CCS_OK; } tls_content_clear(s->s3->rcontent); s->s3->change_cipher_spec = 1; if (!ssl3_do_change_cipher_spec(s)) return -1; return 1; } static int ssl3_read_handshake_unexpected(SSL *s) { uint32_t hs_msg_length; uint8_t hs_msg_type; ssize_t ssret; CBS cbs; int ret; /* * We need four bytes of handshake data so we have a handshake message * header - this may be in the same record or fragmented across multiple * records. */ if (s->s3->handshake_fragment == NULL) { if ((s->s3->handshake_fragment = tls_buffer_new(0)) == NULL) return -1; tls_buffer_set_capacity_limit(s->s3->handshake_fragment, SSL3_HM_HEADER_LENGTH); } ssret = tls_buffer_extend(s->s3->handshake_fragment, SSL3_HM_HEADER_LENGTH, ssl3_read_cb, s); if (ssret <= 0 && ssret != TLS_IO_WANT_POLLIN) return -1; if (ssret != SSL3_HM_HEADER_LENGTH) return 1; if (s->in_handshake) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } /* * This code currently deals with HelloRequest and ClientHello messages - * anything else is pushed to the handshake_func. Almost all of this * belongs in the client/server handshake code. */ /* Parse handshake message header. */ if (!tls_buffer_data(s->s3->handshake_fragment, &cbs)) return -1; if (!CBS_get_u8(&cbs, &hs_msg_type)) return -1; if (!CBS_get_u24(&cbs, &hs_msg_length)) return -1; if (hs_msg_type == SSL3_MT_HELLO_REQUEST) { /* * Incoming HelloRequest messages should only be received by a * client. A server may send these at any time - a client should * ignore the message if received in the middle of a handshake. * See RFC 5246 sections 7.4 and 7.4.1.1. */ if (s->server) { SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } if (hs_msg_length != 0) { SSLerror(s, SSL_R_BAD_HELLO_REQUEST); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return -1; } if (!tls_buffer_data(s->s3->handshake_fragment, &cbs)) return -1; ssl_msg_callback_cbs(s, 0, SSL3_RT_HANDSHAKE, &cbs); tls_buffer_free(s->s3->handshake_fragment); s->s3->handshake_fragment = NULL; /* * It should be impossible to hit this, but keep the safety * harness for now... */ if (s->session == NULL || s->session->cipher == NULL) return 1; /* * Ignore this message if we're currently handshaking, * renegotiation is already pending or renegotiation is disabled * via flags. */ if (!SSL_is_init_finished(s) || s->s3->renegotiate || (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) return 1; if (!ssl3_renegotiate(s)) return 1; if (!ssl3_renegotiate_check(s)) return 1; } else if (hs_msg_type == SSL3_MT_CLIENT_HELLO) { /* * Incoming ClientHello messages should only be received by a * server. A client may send these in response to server * initiated renegotiation (HelloRequest) or in order to * initiate renegotiation by the client. See RFC 5246 section * 7.4.1.2. */ if (!s->server) { SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } /* * A client should not be sending a ClientHello unless we're not * currently handshaking. */ if (!SSL_is_init_finished(s)) { SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } if ((s->options & SSL_OP_NO_CLIENT_RENEGOTIATION) != 0) { ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_NO_RENEGOTIATION); return -1; } if (s->session == NULL || s->session->cipher == NULL) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } /* Client requested renegotiation but it is not permitted. */ if (!s->s3->send_connection_binding || (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) { ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION); return 1; } s->s3->hs.state = SSL_ST_ACCEPT; s->renegotiate = 1; s->new_session = 1; } else { SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } if ((ret = s->handshake_func(s)) < 0) return ret; if (ret == 0) { SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); return -1; } if (!(s->mode & SSL_MODE_AUTO_RETRY)) { if (s->s3->rbuf.left == 0) { ssl_force_want_read(s); return -1; } } /* * We either finished a handshake or ignored the request, now try again * to obtain the (application) data we were asked for. */ return 1; } /* Return up to 'len' payload bytes received in 'type' records. * 'type' is one of the following: * * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) * - 0 (during a shutdown, no data has to be returned) * * If we don't have stored data to work from, read a SSL/TLS record first * (possibly multiple records if we still don't have anything to return). * * This function must handle any surprises the peer may have for us, such as * Alert records (e.g. close_notify), ChangeCipherSpec records (not really * a surprise, but handled as if it were), or renegotiation requests. * Also if record payloads contain fragments too small to process, we store * them until there is enough for the respective protocol (the record protocol * may use arbitrary fragmentation and even interleaving): * Change cipher spec protocol * just 1 byte needed, no need for keeping anything stored * Alert protocol * 2 bytes needed (AlertLevel, AlertDescription) * Handshake protocol * 4 bytes needed (HandshakeType, uint24 length) -- we just have * to detect unexpected Client Hello and Hello Request messages * here, anything else is handled by higher layers * Application data protocol * none of our business */ int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) { int rrcount = 0; ssize_t ssret; int ret; if (s->s3->rbuf.buf == NULL) { if (!ssl3_setup_read_buffer(s)) return -1; } if (s->s3->rcontent == NULL) { if ((s->s3->rcontent = tls_content_new()) == NULL) return -1; } if (len < 0) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } if (type != 0 && type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } if (peek && type != SSL3_RT_APPLICATION_DATA) { SSLerror(s, ERR_R_INTERNAL_ERROR); return -1; } if (type == SSL3_RT_HANDSHAKE && s->s3->handshake_fragment != NULL && tls_buffer_remaining(s->s3->handshake_fragment) > 0) { ssize_t ssn; if ((ssn = tls_buffer_read(s->s3->handshake_fragment, buf, len)) <= 0) return -1; if (tls_buffer_remaining(s->s3->handshake_fragment) == 0) { tls_buffer_free(s->s3->handshake_fragment); s->s3->handshake_fragment = NULL; } return (int)ssn; } if (SSL_in_init(s) && !s->in_handshake) { if ((ret = s->handshake_func(s)) < 0) return ret; if (ret == 0) { SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); return -1; } } start: /* * Do not process more than three consecutive records, otherwise the * peer can cause us to loop indefinitely. Instead, return with an * SSL_ERROR_WANT_READ so the caller can choose when to handle further * processing. In the future, the total number of non-handshake and * non-application data records per connection should probably also be * limited... */ if (rrcount++ >= 3) { ssl_force_want_read(s); return -1; } s->rwstate = SSL_NOTHING; if (tls_content_remaining(s->s3->rcontent) == 0) { if ((ret = ssl3_get_record(s)) <= 0) return ret; } /* We now have a packet which can be read and processed. */ if (s->s3->change_cipher_spec && tls_content_type(s->s3->rcontent) != SSL3_RT_HANDSHAKE) { SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } /* * If the other end has shut down, throw anything we read away (even in * 'peek' mode). */ if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { s->rwstate = SSL_NOTHING; tls_content_clear(s->s3->rcontent); s->s3->rrec.length = 0; return 0; } /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ if (tls_content_type(s->s3->rcontent) == type) { /* * Make sure that we are not getting application data when we * are doing a handshake for the first time. */ if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && !tls12_record_layer_read_protected(s->rl)) { SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } if (len <= 0) return len; if (peek) { ssret = tls_content_peek(s->s3->rcontent, buf, len); } else { ssret = tls_content_read(s->s3->rcontent, buf, len); } if (ssret < INT_MIN || ssret > INT_MAX) return -1; if (ssret < 0) return (int)ssret; if (tls_content_remaining(s->s3->rcontent) == 0) { s->rstate = SSL_ST_READ_HEADER; if (s->mode & SSL_MODE_RELEASE_BUFFERS && s->s3->rbuf.left == 0) ssl3_release_read_buffer(s); } return ssret; } if (tls_content_type(s->s3->rcontent) == SSL3_RT_ALERT) { if ((ret = ssl3_read_alert(s)) <= 0) return ret; goto start; } if (s->shutdown & SSL_SENT_SHUTDOWN) { s->rwstate = SSL_NOTHING; tls_content_clear(s->s3->rcontent); s->s3->rrec.length = 0; return 0; } if (tls_content_type(s->s3->rcontent) == SSL3_RT_APPLICATION_DATA) { /* * At this point, we were expecting handshake data, but have * application data. If the library was running inside * ssl3_read() (i.e. in_read_app_data is set) and it makes * sense to read application data at this point (session * renegotiation not yet started), we will indulge it. */ if (s->s3->in_read_app_data != 0 && s->s3->total_renegotiations != 0 && (((s->s3->hs.state & SSL_ST_CONNECT) && (s->s3->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && (s->s3->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( (s->s3->hs.state & SSL_ST_ACCEPT) && (s->s3->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && (s->s3->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { s->s3->in_read_app_data = 2; return -1; } else { SSLerror(s, SSL_R_UNEXPECTED_RECORD); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } } if (tls_content_type(s->s3->rcontent) == SSL3_RT_CHANGE_CIPHER_SPEC) { if ((ret = ssl3_read_change_cipher_spec(s)) <= 0) return ret; goto start; } if (tls_content_type(s->s3->rcontent) == SSL3_RT_HANDSHAKE) { if ((ret = ssl3_read_handshake_unexpected(s)) <= 0) return ret; goto start; } /* * Unknown record type - TLSv1.2 sends an unexpected message alert while * earlier versions silently ignore the record. */ if (ssl_effective_tls_version(s) <= TLS1_1_VERSION) { tls_content_clear(s->s3->rcontent); goto start; } SSLerror(s, SSL_R_UNEXPECTED_RECORD); ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } int ssl3_do_change_cipher_spec(SSL *s) { if (s->s3->hs.tls12.key_block == NULL) { if (s->session == NULL || s->session->master_key_length == 0) { /* might happen if dtls1_read_bytes() calls this */ SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); return (0); } s->session->cipher = s->s3->hs.cipher; if (!tls1_setup_key_block(s)) return (0); } if (!tls1_change_read_cipher_state(s)) return (0); /* * We have to record the message digest at this point so we can get it * before we read the finished message. */ if (!tls12_derive_peer_finished(s)) return (0); return (1); } static int ssl3_write_alert(SSL *s) { if (SSL_is_dtls(s)) return do_dtls1_write(s, SSL3_RT_ALERT, s->s3->send_alert, sizeof(s->s3->send_alert)); return do_ssl3_write(s, SSL3_RT_ALERT, s->s3->send_alert, sizeof(s->s3->send_alert)); } int ssl3_send_alert(SSL *s, int level, int desc) { /* If alert is fatal, remove session from cache. */ if (level == SSL3_AL_FATAL) SSL_CTX_remove_session(s->ctx, s->session); s->s3->alert_dispatch = 1; s->s3->send_alert[0] = level; s->s3->send_alert[1] = desc; /* * If data is still being written out, the alert will be dispatched at * some point in the future. */ if (s->s3->wbuf.left != 0) return -1; return ssl3_dispatch_alert(s); } int ssl3_dispatch_alert(SSL *s) { int ret; s->s3->alert_dispatch = 0; if ((ret = ssl3_write_alert(s)) <= 0) { s->s3->alert_dispatch = 1; return ret; } /* * Alert sent to BIO. If it is important, flush it now. * If the message does not get sent due to non-blocking IO, * we will not worry too much. */ if (s->s3->send_alert[0] == SSL3_AL_FATAL) (void)BIO_flush(s->wbio); ssl_msg_callback(s, 1, SSL3_RT_ALERT, s->s3->send_alert, 2); ssl_info_callback(s, SSL_CB_WRITE_ALERT, (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]); return ret; }