diff options
Diffstat (limited to 'src/ssl/s3_pkt.c')
-rw-r--r-- | src/ssl/s3_pkt.c | 1216 |
1 files changed, 1216 insertions, 0 deletions
diff --git a/src/ssl/s3_pkt.c b/src/ssl/s3_pkt.c new file mode 100644 index 0000000..4263cb0 --- /dev/null +++ b/src/ssl/s3_pkt.c @@ -0,0 +1,1216 @@ +/* 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 <assert.h> +#include <errno.h> +#include <limits.h> +#include <stdio.h> + +#include <openssl/buf.h> +#include <openssl/err.h> +#include <openssl/evp.h> +#include <openssl/mem.h> +#include <openssl/rand.h> + +#include "ssl_locl.h" + + +static int do_ssl3_write(SSL *s, int type, const uint8_t *buf, unsigned int len, + char fragment, char is_fragment); +static int ssl3_get_record(SSL *s); + +int ssl3_read_n(SSL *s, int n, int max, int extend) { + /* If |extend| is 0, obtain new n-byte packet; + * if |extend| is 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| + * is one.) */ + int i, len, left; + long align = 0; + uint8_t *pkt; + SSL3_BUFFER *rb; + + if (n <= 0) { + return n; + } + + rb = &s->s3->rbuf; + if (rb->buf == NULL && !ssl3_setup_read_buffer(s)) { + return -1; + } + + left = rb->left; + + align = (long)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) && 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; + } + + assert(n <= (int)(rb->len - rb->offset)); + + if (!s->read_ahead) { + /* ignore max parameter */ + max = n; + } else { + if (max < n) { + max = n; + } + if (max > (int)(rb->len - rb->offset)) { + max = rb->len - rb->offset; + } + } + + 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). */ + ERR_clear_system_error(); + if (s->rbio != NULL) { + s->rwstate = SSL_READING; + i = BIO_read(s->rbio, pkt + len + left, max - left); + } else { + OPENSSL_PUT_ERROR(SSL, ssl3_read_n, 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) && + 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) && 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; +} + +/* MAX_EMPTY_RECORDS defines the number of consecutive, empty records that will + * be processed per call to ssl3_get_record. Without this limit an attacker + * could send empty records at a faster rate than we can process and cause + * ssl3_get_record to loop forever. */ +#define MAX_EMPTY_RECORDS 32 + +/* 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) { + int ssl_major, ssl_minor, al; + int n, i, ret = -1; + SSL3_RECORD *rr; + uint8_t *p; + short version; + size_t extra; + unsigned empty_record_count = 0; + + rr = &s->s3->rrec; + + if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER) { + extra = SSL3_RT_MAX_EXTRA; + } else { + extra = 0; + } + + if (extra && !s->s3->init_extra) { + /* An application error: SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER set after + * ssl3_setup_buffers() was done */ + OPENSSL_PUT_ERROR(SSL, ssl3_get_record, ERR_R_INTERNAL_ERROR); + return -1; + } + +again: + /* check if we have the header */ + if (s->rstate != SSL_ST_READ_BODY || + s->packet_length < SSL3_RT_HEADER_LENGTH) { + n = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); + if (n <= 0) { + return n; /* error or non-blocking */ + } + s->rstate = SSL_ST_READ_BODY; + + p = s->packet; + if (s->msg_callback) { + s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s, s->msg_callback_arg); + } + + /* Pull apart the header into the SSL3_RECORD */ + rr->type = *(p++); + ssl_major = *(p++); + ssl_minor = *(p++); + version = (ssl_major << 8) | ssl_minor; + n2s(p, rr->length); + + if (s->s3->have_version && version != s->version) { + OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_WRONG_VERSION_NUMBER); + if ((s->version & 0xFF00) == (version & 0xFF00)) { + /* Send back error using their minor version number. */ + s->version = (unsigned short)version; + } + al = SSL_AD_PROTOCOL_VERSION; + goto f_err; + } + + if ((version >> 8) != SSL3_VERSION_MAJOR) { + OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_WRONG_VERSION_NUMBER); + goto err; + } + + if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH) { + al = SSL_AD_RECORD_OVERFLOW; + OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_PACKET_LENGTH_TOO_LONG); + goto f_err; + } + + /* now s->rstate == SSL_ST_READ_BODY */ + } + + /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ + + if (rr->length > s->packet_length - SSL3_RT_HEADER_LENGTH) { + /* now s->packet_length == SSL3_RT_HEADER_LENGTH */ + i = rr->length; + n = ssl3_read_n(s, i, i, 1); + if (n <= 0) { + /* Error or non-blocking IO. Now |n| == |rr->length|, and + * |s->packet_length| == |SSL3_RT_HEADER_LENGTH| + |rr->length|. */ + return n; + } + } + + s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ + + /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, and + * we have that many bytes in s->packet. */ + rr->input = &s->packet[SSL3_RT_HEADER_LENGTH]; + + /* ok, we can now read from |s->packet| data into |rr|. |rr->input| points at + * |rr->length| bytes, which need to be copied into |rr->data| by decryption. + * When the data is 'copied' into the |rr->data| buffer, |rr->input| will be + * pointed at the new buffer. */ + + /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] + * rr->length bytes of encrypted compressed stuff. */ + + /* check is not needed I believe */ + if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH + extra) { + al = SSL_AD_RECORD_OVERFLOW; + OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); + goto f_err; + } + + /* decrypt in place in 'rr->input' */ + rr->data = rr->input; + + if (!s->enc_method->enc(s, 0)) { + al = SSL_AD_BAD_RECORD_MAC; + OPENSSL_PUT_ERROR(SSL, ssl3_get_record, + SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); + goto f_err; + } + + if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH + extra) { + al = SSL_AD_RECORD_OVERFLOW; + OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_DATA_LENGTH_TOO_LONG); + goto f_err; + } + + rr->off = 0; + /* So at this point the following is true: + * ssl->s3->rrec.type is the type of record; + * ssl->s3->rrec.length is the number of bytes in the record; + * ssl->s3->rrec.off is the offset to first valid byte; + * ssl->s3->rrec.data is where to take bytes from (increment after use). */ + + /* we have pulled in a full packet so zero things */ + s->packet_length = 0; + + /* just read a 0 length packet */ + if (rr->length == 0) { + empty_record_count++; + if (empty_record_count > MAX_EMPTY_RECORDS) { + al = SSL_AD_UNEXPECTED_MESSAGE; + OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_TOO_MANY_EMPTY_FRAGMENTS); + goto f_err; + } + goto again; + } + + return 1; + +f_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 uint8_t *buf = buf_; + unsigned int tot, n, nw; + int i; + + s->rwstate = SSL_NOTHING; + assert(s->s3->wnum <= INT_MAX); + 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) { + OPENSSL_PUT_ERROR(SSL, ssl3_write_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); + return -1; + } + } + + /* Ensure that if we end up with a smaller value of data to write out than + * the the original len from a write which didn't complete for non-blocking + * I/O and also somehow ended up avoiding the check for this in + * ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as it must never be possible to + * end up with (len-tot) as a large number that will then promptly send + * beyond the end of the users buffer ... so we trap and report the error in + * a way the user will notice. */ + if (len < 0 || (size_t)len < tot) { + OPENSSL_PUT_ERROR(SSL, ssl3_write_bytes, SSL_R_BAD_LENGTH); + return -1; + } + + n = (len - tot); + for (;;) { + /* max contains the maximum number of bytes that we can put into a + * record. */ + unsigned max = s->max_send_fragment; + /* fragment is true if do_ssl3_write should send the first byte in its own + * record in order to randomise a CBC IV. */ + int fragment = 0; + + if (n > 1 && s->s3->need_record_splitting && + type == SSL3_RT_APPLICATION_DATA && !s->s3->record_split_done) { + fragment = 1; + /* record_split_done records that the splitting has been done in case we + * hit an SSL_WANT_WRITE condition. In that case, we don't need to do the + * split again. */ + s->s3->record_split_done = 1; + } + + if (n > max) { + nw = max; + } else { + nw = n; + } + + i = do_ssl3_write(s, type, &(buf[tot]), nw, fragment, 0); + if (i <= 0) { + s->s3->wnum = tot; + s->s3->record_split_done = 0; + 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, one-byte fragment in + * ciphersuites with known-IV weakness. */ + s->s3->record_split_done = 0; + return tot + i; + } + + n -= i; + tot += i; + } +} + +/* do_ssl3_write writes an SSL record of the given type. If |fragment| is 1 + * then it splits the record into a one byte record and a record with the rest + * of the data in order to randomise a CBC IV. If |is_fragment| is true then + * this call resulted from do_ssl3_write calling itself in order to create that + * one byte fragment. */ +static int do_ssl3_write(SSL *s, int type, const uint8_t *buf, unsigned int len, + char fragment, char is_fragment) { + uint8_t *p, *plen; + int i; + int prefix_len = 0; + int eivlen = 0; + long align = 0; + SSL3_RECORD *wr; + SSL3_BUFFER *wb = &(s->s3->wbuf); + + /* first check if there is a SSL3_BUFFER 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, lets send it */ + if (s->s3->alert_dispatch) { + i = s->method->ssl_dispatch_alert(s); + if (i <= 0) { + return i; + } + /* if it went, fall through and send more stuff */ + } + + if (wb->buf == NULL && !ssl3_setup_write_buffer(s)) { + return -1; + } + + if (len == 0) { + return 0; + } + + wr = &s->s3->wrec; + + if (fragment) { + /* countermeasure against known-IV weakness in CBC ciphersuites (see + * http://www.openssl.org/~bodo/tls-cbc.txt) */ + prefix_len = do_ssl3_write(s, type, buf, 1 /* length */, 0 /* fragment */, + 1 /* is_fragment */); + if (prefix_len <= 0) { + goto err; + } + + if (prefix_len > + (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD)) { + /* insufficient space */ + OPENSSL_PUT_ERROR(SSL, do_ssl3_write, ERR_R_INTERNAL_ERROR); + goto err; + } + } + + if (is_fragment) { + /* The extra fragment would be couple of cipher blocks, and that will be a + * multiple of SSL3_ALIGN_PAYLOAD. So, if we want to align the real + * payload, we can just pretend that we have two headers and a byte. */ + align = (long)wb->buf + 2 * SSL3_RT_HEADER_LENGTH + 1; + align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); + p = wb->buf + align; + wb->offset = align; + } else if (prefix_len) { + p = wb->buf + wb->offset + prefix_len; + } else { + align = (long)wb->buf + SSL3_RT_HEADER_LENGTH; + align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); + p = wb->buf + align; + wb->offset = align; + } + + /* write the header */ + + *(p++) = type & 0xff; + wr->type = type; + + /* Some servers hang if initial ClientHello is larger than 256 bytes and + * record version number > TLS 1.0. */ + if (!s->s3->have_version && s->version > SSL3_VERSION) { + *(p++) = TLS1_VERSION >> 8; + *(p++) = TLS1_VERSION & 0xff; + } else { + *(p++) = s->version >> 8; + *(p++) = s->version & 0xff; + } + + /* field where we are to write out packet length */ + plen = p; + p += 2; + + /* Leave room for the variable nonce for AEADs which specify it explicitly. */ + if (s->aead_write_ctx != NULL && + s->aead_write_ctx->variable_nonce_included_in_record) { + eivlen = s->aead_write_ctx->variable_nonce_len; + } + + /* lets setup the record stuff. */ + wr->data = p + eivlen; + wr->length = (int)(len - (fragment != 0)); + wr->input = (uint8_t *)buf + (fragment != 0); + + /* we now 'read' from wr->input, wr->length bytes into wr->data */ + + memcpy(wr->data, wr->input, wr->length); + wr->input = wr->data; + + /* we should still have the output to wr->data and the input from wr->input. + * Length should be wr->length. wr->data still points in the wb->buf */ + + wr->input = p; + wr->data = p; + wr->length += eivlen; + + if (!s->enc_method->enc(s, 1)) { + goto err; + } + + /* record length after mac and block padding */ + s2n(wr->length, plen); + + if (s->msg_callback) { + s->msg_callback(1, 0, SSL3_RT_HEADER, plen - 5, 5, s, s->msg_callback_arg); + } + + /* we should now have wr->data pointing to the encrypted data, which is + * wr->length long. */ + wr->type = type; /* not needed but helps for debugging */ + wr->length += SSL3_RT_HEADER_LENGTH; + + if (is_fragment) { + /* we are in a recursive call; just return the length, don't write out + * anything. */ + return wr->length; + } + + /* now let's set up wb */ + wb->left = prefix_len + wr->length; + + /* 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: + return -1; +} + +/* if s->s3->wbuf.left != 0, we need to call this */ +int ssl3_write_pending(SSL *s, int type, const uint8_t *buf, unsigned int len) { + int i; + SSL3_BUFFER *wb = &(s->s3->wbuf); + + 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) { + OPENSSL_PUT_ERROR(SSL, ssl3_write_pending, SSL_R_BAD_WRITE_RETRY); + return -1; + } + + for (;;) { + ERR_clear_system_error(); + if (s->wbio != NULL) { + s->rwstate = SSL_WRITING; + i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]), + (unsigned int)wb->left); + } else { + OPENSSL_PUT_ERROR(SSL, ssl3_write_pending, 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) { + if (SSL_IS_DTLS(s)) { + /* For DTLS, just drop it. That's kind of the whole + point in using a datagram service */ + wb->left = 0; + } + return i; + } + wb->offset += i; + wb->left -= i; + } +} + +/* ssl3_expect_change_cipher_spec informs the record layer that a + * ChangeCipherSpec record is required at this point. If a Handshake record is + * received before ChangeCipherSpec, the connection will fail. Moreover, if + * there are unprocessed handshake bytes, the handshake will also fail and the + * function returns zero. Otherwise, the function returns one. */ +int ssl3_expect_change_cipher_spec(SSL *s) { + if (s->s3->handshake_fragment_len > 0 || s->s3->tmp.reuse_message) { + OPENSSL_PUT_ERROR(SSL, ssl3_expect_change_cipher_spec, + SSL_R_UNPROCESSED_HANDSHAKE_DATA); + return 0; + } + + s->s3->flags |= SSL3_FLAGS_EXPECT_CCS; + 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, uint8_t *buf, int len, int peek) { + int al, i, j, ret; + unsigned int n; + SSL3_RECORD *rr; + void (*cb)(const SSL *ssl, int type2, int val) = NULL; + uint8_t alert_buffer[2]; + + if (s->s3->rbuf.buf == NULL && !ssl3_setup_read_buffer(s)) { + return -1; + } + + if ((type && type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) || + (peek && type != SSL3_RT_APPLICATION_DATA)) { + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, ERR_R_INTERNAL_ERROR); + return -1; + } + + if (type == SSL3_RT_HANDSHAKE && s->s3->handshake_fragment_len > 0) { + /* (partially) satisfy request from storage */ + uint8_t *src = s->s3->handshake_fragment; + uint8_t *dst = buf; + unsigned int k; + + /* peek == 0 */ + n = 0; + while (len > 0 && s->s3->handshake_fragment_len > 0) { + *dst++ = *src++; + len--; + s->s3->handshake_fragment_len--; + n++; + } + /* move any remaining fragment bytes: */ + for (k = 0; k < s->s3->handshake_fragment_len; k++) { + s->s3->handshake_fragment[k] = *src++; + } + return n; + } + + /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */ + + if (!s->in_handshake && SSL_in_init(s)) { + /* type == SSL3_RT_APPLICATION_DATA */ + i = s->handshake_func(s); + if (i < 0) { + return i; + } + if (i == 0) { + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); + return -1; + } + } + +start: + s->rwstate = SSL_NOTHING; + + /* s->s3->rrec.type - is the type of record + * s->s3->rrec.data - data + * s->s3->rrec.off - offset into 'data' for next read + * s->s3->rrec.length - number of bytes. */ + rr = &s->s3->rrec; + + /* get new packet if necessary */ + if (rr->length == 0 || s->rstate == SSL_ST_READ_BODY) { + ret = ssl3_get_record(s); + if (ret <= 0) { + return ret; + } + } + + /* we now have a packet which can be read and processed */ + + if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, + * reset by ssl3_get_finished */ + && rr->type != SSL3_RT_HANDSHAKE) { + al = SSL_AD_UNEXPECTED_MESSAGE; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, + SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); + goto f_err; + } + + /* If we are expecting a ChangeCipherSpec, it is illegal to receive a + * Handshake record. */ + if (rr->type == SSL3_RT_HANDSHAKE && (s->s3->flags & SSL3_FLAGS_EXPECT_CCS)) { + al = SSL_AD_UNEXPECTED_MESSAGE; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_HANDSHAKE_RECORD_BEFORE_CCS); + goto f_err; + } + + /* If the other end has shut down, throw anything we read away (even in + * 'peek' mode) */ + if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { + rr->length = 0; + s->rwstate = SSL_NOTHING; + return 0; + } + + if (type == rr->type) { + /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ + /* 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 && + s->aead_read_ctx == NULL) { + /* TODO(davidben): Is this check redundant with the handshake_func + * check? */ + al = SSL_AD_UNEXPECTED_MESSAGE; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_APP_DATA_IN_HANDSHAKE); + goto f_err; + } + + if (len <= 0) { + return len; + } + + if ((unsigned int)len > rr->length) { + n = rr->length; + } else { + n = (unsigned int)len; + } + + memcpy(buf, &(rr->data[rr->off]), n); + if (!peek) { + rr->length -= n; + rr->off += n; + if (rr->length == 0) { + s->rstate = SSL_ST_READ_HEADER; + rr->off = 0; + if (s->mode & SSL_MODE_RELEASE_BUFFERS && s->s3->rbuf.left == 0) { + ssl3_release_read_buffer(s); + } + } + } + + return n; + } + + + /* If we get here, then type != rr->type; if we have a handshake message, + * then it was unexpected (Hello Request or Client Hello). */ + + /* In case of record types for which we have 'fragment' storage, fill that so + * that we can process the data at a fixed place. */ + + if (rr->type == SSL3_RT_HANDSHAKE) { + const size_t size = sizeof(s->s3->handshake_fragment); + const size_t avail = size - s->s3->handshake_fragment_len; + const size_t todo = (rr->length < avail) ? rr->length : avail; + memcpy(s->s3->handshake_fragment + s->s3->handshake_fragment_len, + &rr->data[rr->off], todo); + rr->off += todo; + rr->length -= todo; + s->s3->handshake_fragment_len += todo; + if (s->s3->handshake_fragment_len < size) { + goto start; /* fragment was too small */ + } + } else if (rr->type == SSL3_RT_ALERT) { + /* Note that this will still allow multiple alerts to be processed in the + * same record */ + if (rr->length < sizeof(alert_buffer)) { + al = SSL_AD_DECODE_ERROR; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_BAD_ALERT); + goto f_err; + } + memcpy(alert_buffer, &rr->data[rr->off], sizeof(alert_buffer)); + rr->off += sizeof(alert_buffer); + rr->length -= sizeof(alert_buffer); + } + + /* s->s3->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE; + * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ + + /* If we are a client, check for an incoming 'Hello Request': */ + if (!s->server && s->s3->handshake_fragment_len >= 4 && + s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST && + s->session != NULL && s->session->cipher != NULL) { + s->s3->handshake_fragment_len = 0; + + if (s->s3->handshake_fragment[1] != 0 || + s->s3->handshake_fragment[2] != 0 || + s->s3->handshake_fragment[3] != 0) { + al = SSL_AD_DECODE_ERROR; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_BAD_HELLO_REQUEST); + goto f_err; + } + + if (s->msg_callback) { + s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, + s->s3->handshake_fragment, 4, s, s->msg_callback_arg); + } + + if (SSL_is_init_finished(s) && !s->s3->renegotiate) { + ssl3_renegotiate(s); + if (ssl3_renegotiate_check(s)) { + i = s->handshake_func(s); + if (i < 0) { + return i; + } + if (i == 0) { + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); + return -1; + } + } + } + /* we either finished a handshake or ignored the request, now try again to + * obtain the (application) data we were asked for */ + goto start; + } + + if (rr->type == SSL3_RT_ALERT) { + const uint8_t alert_level = alert_buffer[0]; + const uint8_t alert_descr = alert_buffer[1]; + + if (s->msg_callback) { + s->msg_callback(0, s->version, SSL3_RT_ALERT, alert_buffer, 2, s, + s->msg_callback_arg); + } + + if (s->info_callback != NULL) { + cb = s->info_callback; + } else if (s->ctx->info_callback != NULL) { + cb = s->ctx->info_callback; + } + + if (cb != NULL) { + j = (alert_level << 8) | alert_descr; + cb(s, SSL_CB_READ_ALERT, j); + } + + if (alert_level == 1) { + /* warning */ + s->s3->warn_alert = alert_descr; + if (alert_descr == SSL_AD_CLOSE_NOTIFY) { + s->shutdown |= SSL_RECEIVED_SHUTDOWN; + return 0; + } + + /* This is a warning but we receive it if we requested renegotiation and + * the peer denied it. Terminate with a fatal alert because if + * application tried to renegotiatie it presumably had a good reason and + * expects it to succeed. + * + * In future we might have a renegotiation where we don't care if the + * peer refused it where we carry on. */ + else if (alert_descr == SSL_AD_NO_RENEGOTIATION) { + al = SSL_AD_HANDSHAKE_FAILURE; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_NO_RENEGOTIATION); + goto f_err; + } + } else if (alert_level == 2) { + /* fatal */ + char tmp[16]; + + s->rwstate = SSL_NOTHING; + s->s3->fatal_alert = alert_descr; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, + SSL_AD_REASON_OFFSET + alert_descr); + BIO_snprintf(tmp, sizeof(tmp), "%d", alert_descr); + ERR_add_error_data(2, "SSL alert number ", tmp); + s->shutdown |= SSL_RECEIVED_SHUTDOWN; + SSL_CTX_remove_session(s->ctx, s->session); + return 0; + } else { + al = SSL_AD_ILLEGAL_PARAMETER; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_UNKNOWN_ALERT_TYPE); + goto f_err; + } + + goto start; + } + + if (s->shutdown & SSL_SENT_SHUTDOWN) { + /* but we have not received a shutdown */ + s->rwstate = SSL_NOTHING; + rr->length = 0; + return 0; + } + + if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { + /* 'Change Cipher Spec' is just a single byte, so we know exactly what the + * record payload has to look like */ + if (rr->length != 1 || rr->off != 0 || rr->data[0] != SSL3_MT_CCS) { + al = SSL_AD_ILLEGAL_PARAMETER; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_BAD_CHANGE_CIPHER_SPEC); + goto f_err; + } + + /* Check we have a cipher to change to */ + if (s->s3->tmp.new_cipher == NULL) { + al = SSL_AD_UNEXPECTED_MESSAGE; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_CCS_RECEIVED_EARLY); + goto f_err; + } + + if (!(s->s3->flags & SSL3_FLAGS_EXPECT_CCS)) { + al = SSL_AD_UNEXPECTED_MESSAGE; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_CCS_RECEIVED_EARLY); + goto f_err; + } + + s->s3->flags &= ~SSL3_FLAGS_EXPECT_CCS; + + rr->length = 0; + + if (s->msg_callback) { + s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, + s->msg_callback_arg); + } + + s->s3->change_cipher_spec = 1; + if (!ssl3_do_change_cipher_spec(s)) { + goto err; + } else { + goto start; + } + } + + /* Unexpected handshake message (Client Hello, or protocol violation) */ + if (s->s3->handshake_fragment_len >= 4 && !s->in_handshake) { + if ((s->state & SSL_ST_MASK) == SSL_ST_OK) { + s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; + s->renegotiate = 1; + s->new_session = 1; + } + i = s->handshake_func(s); + if (i < 0) { + return i; + } + if (i == 0) { + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); + return -1; + } + + goto start; + } + + switch (rr->type) { + default: + /* TLS up to v1.1 just ignores unknown message types. TLS v1.2 gives an + * unexpected message alert. */ + if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION) { + rr->length = 0; + goto start; + } + al = SSL_AD_UNEXPECTED_MESSAGE; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_UNEXPECTED_RECORD); + goto f_err; + + case SSL3_RT_CHANGE_CIPHER_SPEC: + case SSL3_RT_ALERT: + case SSL3_RT_HANDSHAKE: + /* we already handled all of these, with the possible exception of + * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not + * happen when type != rr->type */ + al = SSL_AD_UNEXPECTED_MESSAGE; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, ERR_R_INTERNAL_ERROR); + goto f_err; + + case 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 && s->s3->total_renegotiations != 0 && + (((s->state & SSL_ST_CONNECT) && + s->state >= SSL3_ST_CW_CLNT_HELLO_A && + s->state <= SSL3_ST_CR_SRVR_HELLO_A) || + ((s->state & SSL_ST_ACCEPT) && + s->state <= SSL3_ST_SW_HELLO_REQ_A && + s->state >= SSL3_ST_SR_CLNT_HELLO_A))) { + s->s3->in_read_app_data = 2; + return -1; + } else { + al = SSL_AD_UNEXPECTED_MESSAGE; + OPENSSL_PUT_ERROR(SSL, ssl3_read_bytes, SSL_R_UNEXPECTED_RECORD); + goto f_err; + } + } + /* not reached */ + +f_err: + ssl3_send_alert(s, SSL3_AL_FATAL, al); +err: + return -1; +} + +int ssl3_do_change_cipher_spec(SSL *s) { + int i; + + if (s->state & SSL_ST_ACCEPT) { + i = SSL3_CHANGE_CIPHER_SERVER_READ; + } else { + i = SSL3_CHANGE_CIPHER_CLIENT_READ; + } + + if (s->s3->tmp.key_block == NULL) { + if (s->session == NULL || s->session->master_key_length == 0) { + /* might happen if dtls1_read_bytes() calls this */ + OPENSSL_PUT_ERROR(SSL, ssl3_do_change_cipher_spec, + SSL_R_CCS_RECEIVED_EARLY); + return 0; + } + + s->session->cipher = s->s3->tmp.new_cipher; + if (!s->enc_method->setup_key_block(s)) { + return 0; + } + } + + if (!s->enc_method->change_cipher_state(s, i)) { + return 0; + } + + return 1; +} + +int ssl3_send_alert(SSL *s, int level, int desc) { + /* Map tls/ssl alert value to correct one */ + desc = s->enc_method->alert_value(desc); + if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION) { + /* SSL 3.0 does not have protocol_version alerts */ + desc = SSL_AD_HANDSHAKE_FAILURE; + } + if (desc < 0) { + return -1; + } + + /* If a fatal one, remove from cache */ + if (level == 2 && s->session != NULL) { + 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 (s->s3->wbuf.left == 0) { + /* data is still being written out. */ + return s->method->ssl_dispatch_alert(s); + } + + /* else data is still being written out, we will get written some time in the + * future */ + return -1; +} + +int ssl3_dispatch_alert(SSL *s) { + int i, j; + void (*cb)(const SSL *ssl, int type, int val) = NULL; + + s->s3->alert_dispatch = 0; + i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0, 0); + if (i <= 0) { + s->s3->alert_dispatch = 1; + } else { + /* 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) { + BIO_flush(s->wbio); + } + + if (s->msg_callback) { + s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, + s->msg_callback_arg); + } + + if (s->info_callback != NULL) { + cb = s->info_callback; + } else if (s->ctx->info_callback != NULL) { + cb = s->ctx->info_callback; + } + + if (cb != NULL) { + j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]; + cb(s, SSL_CB_WRITE_ALERT, j); + } + } + + return i; +} |