/* ssl/s3_pkt.c */ /* 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 <stdio.h> #include <errno.h> #define USE_SOCKETS #include "ssl_locl.h" #include <openssl/evp.h> #include <openssl/buffer.h> static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment); static int ssl3_get_record(SSL *s); int ssl3_read_n(SSL *s, int n, int max, int extend) { /* 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].) */ int i,off,newb; if (!extend) { /* start with empty packet ... */ if (s->s3->rbuf.left == 0) s->s3->rbuf.offset = 0; s->packet = s->s3->rbuf.buf + s->s3->rbuf.offset; s->packet_length = 0; /* ... now we can act as if 'extend' was set */ } /* extend reads should not span multiple packets for DTLS */ if ( SSL_version(s) == DTLS1_VERSION && extend) { if ( s->s3->rbuf.left > 0 && n > s->s3->rbuf.left) n = s->s3->rbuf.left; } /* if there is enough in the buffer from a previous read, take some */ if (s->s3->rbuf.left >= (int)n) { s->packet_length+=n; s->s3->rbuf.left-=n; s->s3->rbuf.offset+=n; return(n); } /* else we need to read more data */ if (!s->read_ahead) max=n; { /* avoid buffer overflow */ int max_max = s->s3->rbuf.len - s->packet_length; if (max > max_max) max = max_max; } if (n > max) /* does not happen */ { SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR); return -1; } off = s->packet_length; newb = s->s3->rbuf.left; /* Move any available bytes to front of buffer: * 'off' bytes already pointed to by 'packet', * 'newb' extra ones at the end */ if (s->packet != s->s3->rbuf.buf) { /* off > 0 */ memmove(s->s3->rbuf.buf, s->packet, off+newb); s->packet = s->s3->rbuf.buf; } while (newb < n) { /* Now we have off+newb bytes at the front of s->s3->rbuf.buf and need * to read in more until we have off+n (up to off+max if possible) */ clear_sys_error(); if (s->rbio != NULL) { s->rwstate=SSL_READING; i=BIO_read(s->rbio, &(s->s3->rbuf.buf[off+newb]), max-newb); } else { SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET); i = -1; } if (i <= 0) { s->s3->rbuf.left = newb; return(i); } newb+=i; } /* done reading, now the book-keeping */ s->s3->rbuf.offset = off + n; s->s3->rbuf.left = newb - n; s->packet_length += n; s->rwstate=SSL_NOTHING; return(n); } /* 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 enc_err,n,i,ret= -1; SSL3_RECORD *rr; SSL_SESSION *sess; unsigned char *p; unsigned char md[EVP_MAX_MD_SIZE]; short version; unsigned int mac_size; int clear=0; size_t extra; int decryption_failed_or_bad_record_mac = 0; unsigned char *mac = NULL; rr= &(s->s3->rrec); sess=s->session; if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER) extra=SSL3_RT_MAX_EXTRA; else extra=0; if (extra != s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE) { /* actually likely an application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER * set after ssl3_setup_buffers() was done */ SSLerr(SSL_F_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; /* 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); /* Lets check version */ if (!s->first_packet) { if (version != s->version) { SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER); /* Send back error using their * version number :-) */ s->version=version; al=SSL_AD_PROTOCOL_VERSION; goto f_err; } } if ((version>>8) != SSL3_VERSION_MAJOR) { SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER); goto err; } if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra) { al=SSL_AD_RECORD_OVERFLOW; SSLerr(SSL_F_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) return(n); /* error or non-blocking io */ /* now n == rr->length, * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */ } 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 either * the decryption or by the decompression * 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; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG); goto f_err; } /* decrypt in place in 'rr->input' */ rr->data=rr->input; enc_err = s->method->ssl3_enc->enc(s,0); if (enc_err <= 0) { if (enc_err == 0) /* SSLerr() and ssl3_send_alert() have been called */ goto err; /* Otherwise enc_err == -1, which indicates bad padding * (rec->length has not been changed in this case). * To minimize information leaked via timing, we will perform * the MAC computation anyway. */ decryption_failed_or_bad_record_mac = 1; } #ifdef TLS_DEBUG printf("dec %d\n",rr->length); { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } printf("\n"); #endif /* r->length is now the compressed data plus mac */ if ( (sess == NULL) || (s->enc_read_ctx == NULL) || (s->read_hash == NULL)) clear=1; if (!clear) { mac_size=EVP_MD_size(s->read_hash); if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size) { #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */ al=SSL_AD_RECORD_OVERFLOW; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG); goto f_err; #else decryption_failed_or_bad_record_mac = 1; #endif } /* check the MAC for rr->input (it's in mac_size bytes at the tail) */ if (rr->length >= mac_size) { rr->length -= mac_size; mac = &rr->data[rr->length]; } else { /* record (minus padding) is too short to contain a MAC */ #if 0 /* OK only for stream ciphers */ al=SSL_AD_DECODE_ERROR; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT); goto f_err; #else decryption_failed_or_bad_record_mac = 1; rr->length = 0; #endif } i=s->method->ssl3_enc->mac(s,md,0); if (mac == NULL || memcmp(md, mac, mac_size) != 0) { decryption_failed_or_bad_record_mac = 1; } } if (decryption_failed_or_bad_record_mac) { /* A separate 'decryption_failed' alert was introduced with TLS 1.0, * SSL 3.0 only has 'bad_record_mac'. But unless a decryption * failure is directly visible from the ciphertext anyway, * we should not reveal which kind of error occured -- this * might become visible to an attacker (e.g. via a logfile) */ al=SSL_AD_BAD_RECORD_MAC; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); goto f_err; } /* r->length is now just compressed */ if (s->expand != NULL) { if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra) { al=SSL_AD_RECORD_OVERFLOW; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); goto f_err; } if (!ssl3_do_uncompress(s)) { al=SSL_AD_DECOMPRESSION_FAILURE; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION); goto f_err; } } if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra) { al=SSL_AD_RECORD_OVERFLOW; SSLerr(SSL_F_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 == number of bytes in record * ssl->s3->rrec.off == offset to first valid byte * ssl->s3->rrec.data == 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) goto again; return(1); f_err: ssl3_send_alert(s,SSL3_AL_FATAL,al); err: return(ret); } int ssl3_do_uncompress(SSL *ssl) { #ifndef OPENSSL_NO_COMP int i; SSL3_RECORD *rr; rr= &(ssl->s3->rrec); i=COMP_expand_block(ssl->expand,rr->comp, SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length); if (i < 0) return(0); else rr->length=i; rr->data=rr->comp; #endif return(1); } int ssl3_do_compress(SSL *ssl) { #ifndef OPENSSL_NO_COMP int i; SSL3_RECORD *wr; wr= &(ssl->s3->wrec); i=COMP_compress_block(ssl->compress,wr->data, SSL3_RT_MAX_COMPRESSED_LENGTH, wr->input,(int)wr->length); if (i < 0) return(0); else wr->length=i; wr->input=wr->data; #endif return(1); } /* 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; 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) { SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); return -1; } } n=(len-tot); for (;;) { if (n > SSL3_RT_MAX_PLAIN_LENGTH) nw=SSL3_RT_MAX_PLAIN_LENGTH; else nw=n; i=do_ssl3_write(s, type, &(buf[tot]), nw, 0); 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, int create_empty_fragment) { unsigned char *p,*plen; int i,mac_size,clear=0; int prefix_len = 0; SSL3_RECORD *wr; SSL3_BUFFER *wb; SSL_SESSION *sess; /* first check if there is a SSL3_BUFFER still being written * out. This will happen with non blocking IO */ if (s->s3->wbuf.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 (len == 0 && !create_empty_fragment) return 0; wr= &(s->s3->wrec); wb= &(s->s3->wbuf); sess=s->session; if ( (sess == NULL) || (s->enc_write_ctx == NULL) || (s->write_hash == NULL)) clear=1; if (clear) mac_size=0; else mac_size=EVP_MD_size(s->write_hash); /* 'create_empty_fragment' is true only when this function calls itself */ if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done) { /* countermeasure against known-IV weakness in CBC ciphersuites * (see http://www.openssl.org/~bodo/tls-cbc.txt) */ if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) { /* recursive function call with 'create_empty_fragment' set; * this prepares and buffers the data for an empty fragment * (these 'prefix_len' bytes are sent out later * together with the actual payload) */ prefix_len = do_ssl3_write(s, type, buf, 0, 1); if (prefix_len <= 0) goto err; if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) { /* insufficient space */ SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR); goto err; } } s->s3->empty_fragment_done = 1; } p = wb->buf + prefix_len; /* write the header */ *(p++)=type&0xff; wr->type=type; *(p++)=(s->version>>8); *(p++)=s->version&0xff; /* field where we are to write out packet length */ plen=p; p+=2; /* lets setup the record stuff. */ wr->data=p; wr->length=(int)len; wr->input=(unsigned char *)buf; /* we now 'read' from wr->input, wr->length bytes into * wr->data */ /* first we compress */ if (s->compress != NULL) { if (!ssl3_do_compress(s)) { SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE); goto err; } } else { 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 */ if (mac_size != 0) { s->method->ssl3_enc->mac(s,&(p[wr->length]),1); wr->length+=mac_size; wr->input=p; wr->data=p; } /* ssl3_enc can only have an error on read */ s->method->ssl3_enc->enc(s,1); /* record length after mac and block padding */ s2n(wr->length,plen); /* 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 (create_empty_fragment) { /* we are in a recursive call; * just return the length, don't write out anything here */ return wr->length; } /* now let's set up wb */ wb->left = prefix_len + wr->length; wb->offset = 0; /* 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 unsigned char *buf, unsigned int len) { int i; /* 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)) { SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY); return(-1); } for (;;) { clear_sys_error(); if (s->wbio != NULL) { s->rwstate=SSL_WRITING; i=BIO_write(s->wbio, (char *)&(s->s3->wbuf.buf[s->s3->wbuf.offset]), (unsigned int)s->s3->wbuf.left); } else { SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET); i= -1; } if (i == s->s3->wbuf.left) { s->s3->wbuf.left=0; s->rwstate=SSL_NOTHING; return(s->s3->wpend_ret); } else if (i <= 0) { if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER) { /* For DTLS, just drop it. That's kind of the whole point in using a datagram service */ s->s3->wbuf.left = 0; } return(i); } s->s3->wbuf.offset+=i; s->s3->wbuf.left-=i; } } /* 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 al,i,j,ret; unsigned int n; SSL3_RECORD *rr; void (*cb)(const SSL *ssl,int type2,int val)=NULL; if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ if (!ssl3_setup_buffers(s)) return(-1); if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) || (peek && (type != SSL3_RT_APPLICATION_DATA))) { SSLerr(SSL_F_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 */ { unsigned char *src = s->s3->handshake_fragment; unsigned char *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) { SSLerr(SSL_F_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; SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 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->enc_read_ctx == NULL)) { al=SSL_AD_UNEXPECTED_MESSAGE; SSLerr(SSL_F_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; } } 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. */ { unsigned int dest_maxlen = 0; unsigned char *dest = NULL; unsigned int *dest_len = NULL; if (rr->type == SSL3_RT_HANDSHAKE) { dest_maxlen = sizeof s->s3->handshake_fragment; dest = s->s3->handshake_fragment; dest_len = &s->s3->handshake_fragment_len; } else if (rr->type == SSL3_RT_ALERT) { dest_maxlen = sizeof s->s3->alert_fragment; dest = s->s3->alert_fragment; dest_len = &s->s3->alert_fragment_len; } if (dest_maxlen > 0) { n = dest_maxlen - *dest_len; /* available space in 'dest' */ if (rr->length < n) n = rr->length; /* available bytes */ /* now move 'n' bytes: */ while (n-- > 0) { dest[(*dest_len)++] = rr->data[rr->off++]; rr->length--; } if (*dest_len < dest_maxlen) goto start; /* fragment was too small */ } } /* s->s3->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE; * s->s3->alert_fragment_len == 2 iff rr->type == SSL3_RT_ALERT. * (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; SSLerr(SSL_F_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->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && !s->s3->renegotiate) { ssl3_renegotiate(s); if (ssl3_renegotiate_check(s)) { i=s->handshake_func(s); if (i < 0) return(i); if (i == 0) { SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); return(-1); } if (!(s->mode & SSL_MODE_AUTO_RETRY)) { if (s->s3->rbuf.left == 0) /* no read-ahead left? */ { BIO *bio; /* In the case where we try to read application data, * but we trigger an SSL handshake, we return -1 with * the retry option set. Otherwise renegotiation may * cause nasty problems in the blocking world */ s->rwstate=SSL_READING; bio=SSL_get_rbio(s); BIO_clear_retry_flags(bio); BIO_set_retry_read(bio); 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 (s->s3->alert_fragment_len >= 2) { int alert_level = s->s3->alert_fragment[0]; int alert_descr = s->s3->alert_fragment[1]; s->s3->alert_fragment_len = 0; if (s->msg_callback) s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 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); } } else if (alert_level == 2) /* fatal */ { char tmp[16]; s->rwstate=SSL_NOTHING; s->s3->fatal_alert = alert_descr; SSLerr(SSL_F_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; SSLerr(SSL_F_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; SSLerr(SSL_F_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; SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY); goto f_err; } 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->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { #if 0 /* worked only because C operator preferences are not as expected (and * because this is not really needed for clients except for detecting * protocol violations): */ s->state=SSL_ST_BEFORE|(s->server) ?SSL_ST_ACCEPT :SSL_ST_CONNECT; #else s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; #endif s->new_session=1; } i=s->handshake_func(s); if (i < 0) return(i); if (i == 0) { SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); return(-1); } if (!(s->mode & SSL_MODE_AUTO_RETRY)) { if (s->s3->rbuf.left == 0) /* no read-ahead left? */ { BIO *bio; /* In the case where we try to read application data, * but we trigger an SSL handshake, we return -1 with * the retry option set. Otherwise renegotiation may * cause nasty problems in the blocking world */ s->rwstate=SSL_READING; bio=SSL_get_rbio(s); BIO_clear_retry_flags(bio); BIO_set_retry_read(bio); return(-1); } } goto start; } switch (rr->type) { default: #ifndef OPENSSL_NO_TLS /* TLS just ignores unknown message types */ if (s->version == TLS1_VERSION) { rr->length = 0; goto start; } #endif al=SSL_AD_UNEXPECTED_MESSAGE; SSLerr(SSL_F_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; SSLerr(SSL_F_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; SSLerr(SSL_F_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; const char *sender; int slen; 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) { /* might happen if dtls1_read_bytes() calls this */ SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY); return (0); } s->session->cipher=s->s3->tmp.new_cipher; if (!s->method->ssl3_enc->setup_key_block(s)) return(0); } if (!s->method->ssl3_enc->change_cipher_state(s,i)) return(0); /* we have to record the message digest at * this point so we can get it before we read * the finished message */ if (s->state & SSL_ST_CONNECT) { sender=s->method->ssl3_enc->server_finished_label; slen=s->method->ssl3_enc->server_finished_label_len; } else { sender=s->method->ssl3_enc->client_finished_label; slen=s->method->ssl3_enc->client_finished_label_len; } s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s, &(s->s3->finish_dgst1), &(s->s3->finish_dgst2), sender,slen,s->s3->tmp.peer_finish_md); return(1); } void ssl3_send_alert(SSL *s, int level, int desc) { /* Map tls/ssl alert value to correct one */ desc=s->method->ssl3_enc->alert_value(desc); if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION) desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */ if (desc < 0) return; /* 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 still being written out? */ s->method->ssl_dispatch_alert(s); /* else data is still being written out, we will get written * some time in the future */ } 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); 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) (void)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); }