155714Skris/* crypto/des/enc_read.c */ 255714Skris/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 355714Skris * All rights reserved. 455714Skris * 555714Skris * This package is an SSL implementation written 655714Skris * by Eric Young (eay@cryptsoft.com). 755714Skris * The implementation was written so as to conform with Netscapes SSL. 855714Skris * 955714Skris * This library is free for commercial and non-commercial use as long as 1055714Skris * the following conditions are aheared to. The following conditions 1155714Skris * apply to all code found in this distribution, be it the RC4, RSA, 1255714Skris * lhash, DES, etc., code; not just the SSL code. The SSL documentation 1355714Skris * included with this distribution is covered by the same copyright terms 1455714Skris * except that the holder is Tim Hudson (tjh@cryptsoft.com). 1555714Skris * 1655714Skris * Copyright remains Eric Young's, and as such any Copyright notices in 1755714Skris * the code are not to be removed. 1855714Skris * If this package is used in a product, Eric Young should be given attribution 1955714Skris * as the author of the parts of the library used. 2055714Skris * This can be in the form of a textual message at program startup or 2155714Skris * in documentation (online or textual) provided with the package. 2255714Skris * 2355714Skris * Redistribution and use in source and binary forms, with or without 2455714Skris * modification, are permitted provided that the following conditions 2555714Skris * are met: 2655714Skris * 1. Redistributions of source code must retain the copyright 2755714Skris * notice, this list of conditions and the following disclaimer. 2855714Skris * 2. Redistributions in binary form must reproduce the above copyright 2955714Skris * notice, this list of conditions and the following disclaimer in the 3055714Skris * documentation and/or other materials provided with the distribution. 3155714Skris * 3. All advertising materials mentioning features or use of this software 3255714Skris * must display the following acknowledgement: 3355714Skris * "This product includes cryptographic software written by 3455714Skris * Eric Young (eay@cryptsoft.com)" 3555714Skris * The word 'cryptographic' can be left out if the rouines from the library 3655714Skris * being used are not cryptographic related :-). 3755714Skris * 4. If you include any Windows specific code (or a derivative thereof) from 3855714Skris * the apps directory (application code) you must include an acknowledgement: 3955714Skris * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 4055714Skris * 4155714Skris * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 4255714Skris * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 4355714Skris * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 4455714Skris * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 4555714Skris * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 4655714Skris * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 4755714Skris * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 4855714Skris * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 4955714Skris * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 5055714Skris * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 5155714Skris * SUCH DAMAGE. 5255714Skris * 5355714Skris * The licence and distribution terms for any publically available version or 5455714Skris * derivative of this code cannot be changed. i.e. this code cannot simply be 5555714Skris * copied and put under another distribution licence 5655714Skris * [including the GNU Public Licence.] 5755714Skris */ 5855714Skris 5955714Skris#include <stdio.h> 6055714Skris#include <errno.h> 6155714Skris#include "cryptlib.h" 6255714Skris#include "des_locl.h" 6355714Skris 6455714Skris/* This has some uglies in it but it works - even over sockets. */ 6555714Skris/*extern int errno;*/ 66238405SjkimOPENSSL_IMPLEMENT_GLOBAL(int,DES_rw_mode,DES_PCBC_MODE) 6755714Skris 6855714Skris 6955714Skris/* 7055714Skris * WARNINGS: 7155714Skris * 72109998Smarkm * - The data format used by DES_enc_write() and DES_enc_read() 7355714Skris * has a cryptographic weakness: When asked to write more 74109998Smarkm * than MAXWRITE bytes, DES_enc_write will split the data 7555714Skris * into several chunks that are all encrypted 7655714Skris * using the same IV. So don't use these functions unless you 7755714Skris * are sure you know what you do (in which case you might 7855714Skris * not want to use them anyway). 7955714Skris * 8055714Skris * - This code cannot handle non-blocking sockets. 8155714Skris * 8255714Skris * - This function uses an internal state and thus cannot be 8355714Skris * used on multiple files. 8455714Skris */ 8555714Skris 8655714Skris 87109998Smarkmint DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched, 88109998Smarkm DES_cblock *iv) 8955714Skris { 90238405Sjkim#if defined(OPENSSL_NO_POSIX_IO) 91238405Sjkim return(0); 92238405Sjkim#else 9355714Skris /* data to be unencrypted */ 9455714Skris int net_num=0; 9555714Skris static unsigned char *net=NULL; 9655714Skris /* extra unencrypted data 9755714Skris * for when a block of 100 comes in but is des_read one byte at 9855714Skris * a time. */ 9955714Skris static unsigned char *unnet=NULL; 10055714Skris static int unnet_start=0; 10155714Skris static int unnet_left=0; 10255714Skris static unsigned char *tmpbuf=NULL; 10355714Skris int i; 10455714Skris long num=0,rnum; 10555714Skris unsigned char *p; 10655714Skris 10755714Skris if (tmpbuf == NULL) 10855714Skris { 10968651Skris tmpbuf=OPENSSL_malloc(BSIZE); 11055714Skris if (tmpbuf == NULL) return(-1); 11155714Skris } 11255714Skris if (net == NULL) 11355714Skris { 11468651Skris net=OPENSSL_malloc(BSIZE); 11555714Skris if (net == NULL) return(-1); 11655714Skris } 11755714Skris if (unnet == NULL) 11855714Skris { 11968651Skris unnet=OPENSSL_malloc(BSIZE); 12055714Skris if (unnet == NULL) return(-1); 12155714Skris } 12255714Skris /* left over data from last decrypt */ 12355714Skris if (unnet_left != 0) 12455714Skris { 12555714Skris if (unnet_left < len) 12655714Skris { 12755714Skris /* we still still need more data but will return 12855714Skris * with the number of bytes we have - should always 12955714Skris * check the return value */ 13055714Skris memcpy(buf,&(unnet[unnet_start]), 13155714Skris unnet_left); 13255714Skris /* eay 26/08/92 I had the next 2 lines 13355714Skris * reversed :-( */ 13455714Skris i=unnet_left; 13555714Skris unnet_start=unnet_left=0; 13655714Skris } 13755714Skris else 13855714Skris { 13955714Skris memcpy(buf,&(unnet[unnet_start]),len); 14055714Skris unnet_start+=len; 14155714Skris unnet_left-=len; 14255714Skris i=len; 14355714Skris } 14455714Skris return(i); 14555714Skris } 14655714Skris 14755714Skris /* We need to get more data. */ 14855714Skris if (len > MAXWRITE) len=MAXWRITE; 14955714Skris 15055714Skris /* first - get the length */ 15155714Skris while (net_num < HDRSIZE) 15255714Skris { 153238405Sjkim#ifndef OPENSSL_SYS_WIN32 15459191Skris i=read(fd,(void *)&(net[net_num]),HDRSIZE-net_num); 155194206Ssimon#else 156194206Ssimon i=_read(fd,(void *)&(net[net_num]),HDRSIZE-net_num); 157194206Ssimon#endif 15855714Skris#ifdef EINTR 15955714Skris if ((i == -1) && (errno == EINTR)) continue; 16055714Skris#endif 16155714Skris if (i <= 0) return(0); 16255714Skris net_num+=i; 16355714Skris } 16455714Skris 16555714Skris /* we now have at net_num bytes in net */ 16655714Skris p=net; 16755714Skris /* num=0; */ 16855714Skris n2l(p,num); 16955714Skris /* num should be rounded up to the next group of eight 17055714Skris * we make sure that we have read a multiple of 8 bytes from the net. 17155714Skris */ 17255714Skris if ((num > MAXWRITE) || (num < 0)) /* error */ 17355714Skris return(-1); 17455714Skris rnum=(num < 8)?8:((num+7)/8*8); 17555714Skris 17655714Skris net_num=0; 17755714Skris while (net_num < rnum) 17855714Skris { 179238405Sjkim#ifndef OPENSSL_SYS_WIN32 18059191Skris i=read(fd,(void *)&(net[net_num]),rnum-net_num); 181238405Sjkim#else 182238405Sjkim i=_read(fd,(void *)&(net[net_num]),rnum-net_num); 183238405Sjkim#endif 18455714Skris#ifdef EINTR 18555714Skris if ((i == -1) && (errno == EINTR)) continue; 18655714Skris#endif 18755714Skris if (i <= 0) return(0); 18855714Skris net_num+=i; 18955714Skris } 19055714Skris 19155714Skris /* Check if there will be data left over. */ 19255714Skris if (len < num) 19355714Skris { 194109998Smarkm if (DES_rw_mode & DES_PCBC_MODE) 195109998Smarkm DES_pcbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT); 19655714Skris else 197109998Smarkm DES_cbc_encrypt(net,unnet,num,sched,iv,DES_DECRYPT); 19855714Skris memcpy(buf,unnet,len); 19955714Skris unnet_start=len; 20055714Skris unnet_left=num-len; 20155714Skris 20255714Skris /* The following line is done because we return num 20355714Skris * as the number of bytes read. */ 20455714Skris num=len; 20555714Skris } 20655714Skris else 20755714Skris { 20855714Skris /* >output is a multiple of 8 byes, if len < rnum 20955714Skris * >we must be careful. The user must be aware that this 21055714Skris * >routine will write more bytes than he asked for. 21155714Skris * >The length of the buffer must be correct. 21255714Skris * FIXED - Should be ok now 18-9-90 - eay */ 21355714Skris if (len < rnum) 21455714Skris { 21555714Skris 216109998Smarkm if (DES_rw_mode & DES_PCBC_MODE) 217109998Smarkm DES_pcbc_encrypt(net,tmpbuf,num,sched,iv, 21855714Skris DES_DECRYPT); 21955714Skris else 220109998Smarkm DES_cbc_encrypt(net,tmpbuf,num,sched,iv, 22155714Skris DES_DECRYPT); 22255714Skris 22355714Skris /* eay 26/08/92 fix a bug that returned more 22455714Skris * bytes than you asked for (returned len bytes :-( */ 22555714Skris memcpy(buf,tmpbuf,num); 22655714Skris } 22755714Skris else 22855714Skris { 229109998Smarkm if (DES_rw_mode & DES_PCBC_MODE) 230109998Smarkm DES_pcbc_encrypt(net,buf,num,sched,iv, 23155714Skris DES_DECRYPT); 23255714Skris else 233109998Smarkm DES_cbc_encrypt(net,buf,num,sched,iv, 23455714Skris DES_DECRYPT); 23555714Skris } 23655714Skris } 23755714Skris return num; 238238405Sjkim#endif /* OPENSSL_NO_POSIX_IO */ 23955714Skris } 24055714Skris 241