openssl/crypto/evp/evp_enc.c
Dr. Stephen Henson 57ae2e2428 Fourth phase EVP revision.
Declare ciphers in terms of macros. This reduces
the amount of code and places each block cipher EVP
definition in a single file instead of being spread
over 4 files.
2000-05-30 02:10:57 +00:00

312 lines
8.1 KiB
C

/* crypto/evp/evp_enc.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.]
*/
#include <stdio.h>
#include "cryptlib.h"
#include <openssl/evp.h>
#include <openssl/err.h>
#include "evp_locl.h"
const char *EVP_version="EVP" OPENSSL_VERSION_PTEXT;
void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
{
memset(ctx,0,sizeof(EVP_CIPHER_CTX));
/* ctx->cipher=NULL; */
}
int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
unsigned char *key, unsigned char *iv, int enc)
{
if(enc) enc = 1;
if (cipher) {
ctx->cipher=cipher;
ctx->key_len = cipher->key_len;
} else if(!ctx->cipher) {
EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_NO_CIPHER_SET);
return 0;
}
if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
switch(EVP_CIPHER_CTX_mode(ctx)) {
case EVP_CIPH_STREAM_CIPHER:
case EVP_CIPH_ECB_MODE:
break;
case EVP_CIPH_CFB_MODE:
case EVP_CIPH_OFB_MODE:
ctx->num = 0;
case EVP_CIPH_CBC_MODE:
if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
break;
default:
return 0;
break;
}
}
if(key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
if(!ctx->cipher->init(ctx,key,iv,enc)) return 0;
}
ctx->encrypt=enc;
ctx->buf_len=0;
return 1;
}
int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
unsigned char *in, int inl)
{
if (ctx->encrypt)
return EVP_EncryptUpdate(ctx,out,outl,in,inl);
else return EVP_DecryptUpdate(ctx,out,outl,in,inl);
}
int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
if (ctx->encrypt)
return EVP_EncryptFinal(ctx,out,outl);
else return(EVP_DecryptFinal(ctx,out,outl));
}
int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
unsigned char *key, unsigned char *iv)
{
return EVP_CipherInit(ctx, cipher, key, iv, 1);
}
int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
unsigned char *key, unsigned char *iv)
{
return EVP_CipherInit(ctx, cipher, key, iv, 0);
}
int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
unsigned char *in, int inl)
{
int i,j,bl;
i=ctx->buf_len;
bl=ctx->cipher->block_size;
*outl=0;
if ((inl == 0) && (i != bl)) return 1;
if (i != 0)
{
if (i+inl < bl)
{
memcpy(&(ctx->buf[i]),in,inl);
ctx->buf_len+=inl;
return 1;
}
else
{
j=bl-i;
if (j != 0) memcpy(&(ctx->buf[i]),in,j);
if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
inl-=j;
in+=j;
out+=bl;
*outl+=bl;
}
}
i=inl%bl; /* how much is left */
inl-=i;
if (inl > 0)
{
if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0;
*outl+=inl;
}
if (i != 0)
memcpy(ctx->buf,&(in[inl]),i);
ctx->buf_len=i;
return 1;
}
int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
int i,n,b,bl;
b=ctx->cipher->block_size;
if (b == 1)
{
*outl=0;
return 1;
}
bl=ctx->buf_len;
n=b-bl;
for (i=bl; i<b; i++)
ctx->buf[i]=n;
if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,b)) return 0;
*outl=b;
return 1;
}
int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
unsigned char *in, int inl)
{
int b,bl,n;
int keep_last=0;
*outl=0;
if (inl == 0) return 1;
b=ctx->cipher->block_size;
if (b > 1)
{
/* Is the input a multiple of the block size? */
bl=ctx->buf_len;
n=inl+bl;
if (n%b == 0)
{
if (inl < b) /* must be 'just one' buff */
{
memcpy(&(ctx->buf[bl]),in,inl);
ctx->buf_len=b;
*outl=0;
return 1;
}
keep_last=1;
inl-=b; /* don't do the last block */
}
}
if(!EVP_EncryptUpdate(ctx,out,outl,in,inl)) return 0;
/* if we have 'decrypted' a multiple of block size, make sure
* we have a copy of this last block */
if (keep_last)
{
memcpy(&(ctx->buf[0]),&(in[inl]),b);
#ifdef DEBUG
if (ctx->buf_len != 0)
{
abort();
}
#endif
ctx->buf_len=b;
}
return 1;
}
int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
int i,b;
int n;
*outl=0;
b=ctx->cipher->block_size;
if (b > 1)
{
if (ctx->buf_len != b)
{
EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
return(0);
}
if(!EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0)) return 0;
if (n != b)
return(0);
n=ctx->buf[b-1];
if (n > b)
{
EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
return(0);
}
for (i=0; i<n; i++)
{
if (ctx->buf[--b] != n)
{
EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
return(0);
}
}
n=ctx->cipher->block_size-n;
for (i=0; i<n; i++)
out[i]=ctx->buf[i];
*outl=n;
}
else
*outl=0;
return(1);
}
int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
{
if ((c->cipher != NULL) && (c->cipher->cleanup != NULL))
{
if(!c->cipher->cleanup(c)) return 0;
}
memset(c,0,sizeof(EVP_CIPHER_CTX));
return 1;
}
int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
{
if(c->key_len == keylen) return 1;
if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
{
c->key_len = keylen;
return 1;
}
EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
return 0;
}