/* 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 #include #include #include "ssl_locl.h" static int do_ssl3_write(SSL *s, int type, const unsigned char *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 == 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,len,left; long align=0; unsigned char *pkt; SSL3_BUFFER *rb; if (n <= 0) return n; rb = &(s->s3->rbuf); if (rb->buf == NULL) if (!ssl3_setup_read_buffer(s)) return -1; left = rb->left; #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0 align = (long)rb->buf + SSL3_RT_HEADER_LENGTH; align = (-align)&(SSL3_ALIGN_PAYLOAD-1); #endif 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 */ { OPENSSL_PUT_ERROR(SSL, ssl3_read_n, ERR_R_INTERNAL_ERROR); return -1; } 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)) 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); } /* 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 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 mac_size, orig_len; size_t extra; unsigned empty_record_count = 0; 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->init_extra) { /* An application error: SLS_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 0 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length); #endif /* Lets check version */ if (!s->first_packet) { if (version != s->version) { OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_WRONG_VERSION_NUMBER); if ((s->version & 0xFF00) == (version & 0xFF00) && !s->enc_write_ctx && !s->write_hash) /* 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) 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; 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; enc_err = s->method->ssl3_enc->enc(s,0); /* enc_err is: * 0: (in non-constant time) if the record is publically invalid. * 1: if the padding is valid * -1: if the padding is invalid */ if (enc_err == 0) { al=SSL_AD_DECRYPTION_FAILED; OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); goto f_err; } #ifdef TLS_DEBUG printf("dec %d\n",rr->length); { unsigned int z; for (z=0; zlength; 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) && (EVP_MD_CTX_md(s->read_hash) != NULL)) { /* s->read_hash != NULL => mac_size != -1 */ unsigned char *mac = NULL; unsigned char mac_tmp[EVP_MAX_MD_SIZE]; mac_size=EVP_MD_CTX_size(s->read_hash); assert(mac_size <= EVP_MAX_MD_SIZE); /* kludge: *_cbc_remove_padding passes padding length in rr->type */ orig_len = rr->length+((unsigned int)rr->type>>8); /* orig_len is the length of the record before any padding was * removed. This is public information, as is the MAC in use, * therefore we can safely process the record in a different * amount of time if it's too short to possibly contain a MAC. */ if (orig_len < mac_size || /* CBC records must have a padding length byte too. */ (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && orig_len < mac_size+1)) { al=SSL_AD_DECODE_ERROR; OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_LENGTH_TOO_SHORT); goto f_err; } if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { /* We update the length so that the TLS header bytes * can be constructed correctly but we need to extract * the MAC in constant time from within the record, * without leaking the contents of the padding bytes. * */ mac = mac_tmp; ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); rr->length -= mac_size; } else { /* In this case there's no padding, so |orig_len| * equals |rec->length| and we checked that there's * enough bytes for |mac_size| above. */ rr->length -= mac_size; mac = &rr->data[rr->length]; } i=s->method->ssl3_enc->mac(s,md,0 /* not send */); if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) enc_err = -1; if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size) enc_err = -1; } if (enc_err < 0) { /* 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; OPENSSL_PUT_ERROR(SSL, 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; OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_COMPRESSED_LENGTH_TOO_LONG); goto f_err; } if (!ssl3_do_uncompress(s)) { al=SSL_AD_DECOMPRESSION_FAILURE; OPENSSL_PUT_ERROR(SSL, ssl3_get_record, SSL_R_BAD_DECOMPRESSION); 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 == 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) { 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; } #if 0 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length); #endif return(1); f_err: ssl3_send_alert(s,SSL3_AL_FATAL,al); err: return(ret); } int ssl3_do_uncompress(SSL *ssl) { return(1); } int ssl3_do_compress(SSL *ssl) { 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) { 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 < 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; /* The first byte will be in its own record, so we * can write an extra byte. */ max++; /* 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; 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 unsigned char *buf, unsigned int len, char fragment, char is_fragment) { unsigned char *p,*plen; int i,mac_size; int prefix_len=0; int eivlen; long align=0; SSL3_RECORD *wr; SSL3_BUFFER *wb=&(s->s3->wbuf); SSL_SESSION *sess; if (wb->buf == NULL) if (!ssl3_setup_write_buffer(s)) return -1; /* 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 */ } /* Dispatching the alert may have released the write buffer. */ if (wb->buf == NULL) if (!ssl3_setup_write_buffer(s)) return -1; if (len == 0) return 0; wr= &(s->s3->wrec); sess=s->session; if ( (sess == NULL) || (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL)) { mac_size=0; } else { mac_size=EVP_MD_CTX_size(s->write_hash); if (mac_size < 0) goto err; } 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) { #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0 /* 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); #endif p = wb->buf + align; wb->offset = align; } else if (prefix_len) { p = wb->buf + wb->offset + prefix_len; } else { #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH; align = (-align)&(SSL3_ALIGN_PAYLOAD-1); #endif p = wb->buf + align; wb->offset = align; } /* write the header */ *(p++)=type&0xff; wr->type=type; *(p++)=(s->version>>8); /* Some servers hang if iniatial client hello is larger than 256 * bytes and record version number > TLS 1.0 */ if (s->state == SSL3_ST_CW_CLNT_HELLO_B && !s->renegotiate && TLS1_get_version(s) > TLS1_VERSION) *(p++) = 0x1; else *(p++)=s->version&0xff; /* field where we are to write out packet length */ plen=p; p+=2; /* Explicit IV length, block ciphers appropriate version flag */ if (s->enc_write_ctx && SSL_USE_EXPLICIT_IV(s)) { int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx); if (mode == EVP_CIPH_CBC_MODE) { eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx); if (eivlen <= 1) eivlen = 0; } /* Need explicit part of IV for GCM mode */ else if (mode == EVP_CIPH_GCM_MODE) eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN; else eivlen = 0; } else if (s->aead_write_ctx != NULL && s->aead_write_ctx->variable_nonce_included_in_record) { eivlen = s->aead_write_ctx->variable_nonce_len; } else eivlen = 0; /* lets setup the record stuff. */ wr->data=p + eivlen; wr->length=(int)(len - (fragment != 0)); wr->input=(unsigned char *)buf + (fragment != 0); /* we now 'read' from wr->input, wr->length bytes into * wr->data */ /* first we compress */ if (s->compress != NULL) { if (!ssl3_do_compress(s)) { OPENSSL_PUT_ERROR(SSL, 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) { if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0) goto err; wr->length+=mac_size; } wr->input=p; wr->data=p; if (eivlen) { /* if (RAND_pseudo_bytes(p, eivlen) <= 0) goto err; */ wr->length += eivlen; } /* 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); 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 unsigned char *buf, unsigned int len) { int i; SSL3_BUFFER *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)) { 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 (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 */ wb->left = 0; } return(i); } wb->offset+=i; wb->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_read_buffer(s)) return(-1); if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) || (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 */ { 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) { 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 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; 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. */ { 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; } #ifndef OPENSSL_NO_HEARTBEATS else if (rr->type == TLS1_RT_HEARTBEAT) { tls1_process_heartbeat(s); /* Exit and notify application to read again */ rr->length = 0; s->rwstate=SSL_READING; BIO_clear_retry_flags(SSL_get_rbio(s)); BIO_set_retry_read(SSL_get_rbio(s)); return(-1); } #endif 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; 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->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) { OPENSSL_PUT_ERROR(SSL, 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 we are a server and get a client hello when renegotiation isn't * allowed send back a no renegotiation alert and carry on. * WARNING: experimental code, needs reviewing (steve) */ if (s->server && SSL_is_init_finished(s) && !s->s3->send_connection_binding && (s->version > SSL3_VERSION) && (s->s3->handshake_fragment_len >= 4) && (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) && (s->session != NULL) && (s->session->cipher != NULL) && !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) { /*s->s3->handshake_fragment_len = 0;*/ rr->length = 0; ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION); 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); } /* 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; } #ifdef SSL_AD_MISSING_SRP_USERNAME else if (alert_descr == SSL_AD_MISSING_SRP_USERNAME) return(0); #endif } 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; } 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->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); } 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 up to v1.1 just ignores unknown message types: * TLS v1.2 give an unexpected message alert. */ if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION) { rr->length = 0; goto start; } #endif 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; 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 */ 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->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; } i = s->method->ssl3_enc->final_finish_mac(s, sender,slen,s->s3->tmp.peer_finish_md); if (i == 0) { OPENSSL_PUT_ERROR(SSL, ssl3_do_change_cipher_spec, ERR_R_INTERNAL_ERROR); return 0; } s->s3->tmp.peer_finish_md_len = i; return(1); } int 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 -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 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) (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); }