ref: bae3ac29fc39bc36329abf1823004c0d79b2f6f0
dir: /sys/src/ape/lib/openssl/crypto/evp/bio_enc.c/
/* crypto/evp/bio_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 <errno.h>
#include "cryptlib.h"
#include <openssl/buffer.h>
#include <openssl/evp.h>
static int enc_write(BIO *h, const char *buf, int num);
static int enc_read(BIO *h, char *buf, int size);
/*static int enc_puts(BIO *h, const char *str); */
/*static int enc_gets(BIO *h, char *str, int size); */
static long enc_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int enc_new(BIO *h);
static int enc_free(BIO *data);
static long enc_callback_ctrl(BIO *h, int cmd, bio_info_cb *fps);
#define ENC_BLOCK_SIZE (1024*4)
#define BUF_OFFSET (EVP_MAX_BLOCK_LENGTH*2)
typedef struct enc_struct
{
int buf_len;
int buf_off;
int cont; /* <= 0 when finished */
int finished;
int ok; /* bad decrypt */
EVP_CIPHER_CTX cipher;
/* buf is larger than ENC_BLOCK_SIZE because EVP_DecryptUpdate
* can return up to a block more data than is presented to it
*/
char buf[ENC_BLOCK_SIZE+BUF_OFFSET+2];
} BIO_ENC_CTX;
static BIO_METHOD methods_enc=
{
BIO_TYPE_CIPHER,"cipher",
enc_write,
enc_read,
NULL, /* enc_puts, */
NULL, /* enc_gets, */
enc_ctrl,
enc_new,
enc_free,
enc_callback_ctrl,
};
BIO_METHOD *BIO_f_cipher(void)
{
return(&methods_enc);
}
static int enc_new(BIO *bi)
{
BIO_ENC_CTX *ctx;
ctx=(BIO_ENC_CTX *)OPENSSL_malloc(sizeof(BIO_ENC_CTX));
if (ctx == NULL) return(0);
EVP_CIPHER_CTX_init(&ctx->cipher);
ctx->buf_len=0;
ctx->buf_off=0;
ctx->cont=1;
ctx->finished=0;
ctx->ok=1;
bi->init=0;
bi->ptr=(char *)ctx;
bi->flags=0;
return(1);
}
static int enc_free(BIO *a)
{
BIO_ENC_CTX *b;
if (a == NULL) return(0);
b=(BIO_ENC_CTX *)a->ptr;
EVP_CIPHER_CTX_cleanup(&(b->cipher));
OPENSSL_cleanse(a->ptr,sizeof(BIO_ENC_CTX));
OPENSSL_free(a->ptr);
a->ptr=NULL;
a->init=0;
a->flags=0;
return(1);
}
static int enc_read(BIO *b, char *out, int outl)
{
int ret=0,i;
BIO_ENC_CTX *ctx;
if (out == NULL) return(0);
ctx=(BIO_ENC_CTX *)b->ptr;
if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
/* First check if there are bytes decoded/encoded */
if (ctx->buf_len > 0)
{
i=ctx->buf_len-ctx->buf_off;
if (i > outl) i=outl;
memcpy(out,&(ctx->buf[ctx->buf_off]),i);
ret=i;
out+=i;
outl-=i;
ctx->buf_off+=i;
if (ctx->buf_len == ctx->buf_off)
{
ctx->buf_len=0;
ctx->buf_off=0;
}
}
/* At this point, we have room of outl bytes and an empty
* buffer, so we should read in some more. */
while (outl > 0)
{
if (ctx->cont <= 0) break;
/* read in at IV offset, read the EVP_Cipher
* documentation about why */
i=BIO_read(b->next_bio,&(ctx->buf[BUF_OFFSET]),ENC_BLOCK_SIZE);
if (i <= 0)
{
/* Should be continue next time we are called? */
if (!BIO_should_retry(b->next_bio))
{
ctx->cont=i;
i=EVP_CipherFinal_ex(&(ctx->cipher),
(unsigned char *)ctx->buf,
&(ctx->buf_len));
ctx->ok=i;
ctx->buf_off=0;
}
else
{
ret=(ret == 0)?i:ret;
break;
}
}
else
{
EVP_CipherUpdate(&(ctx->cipher),
(unsigned char *)ctx->buf,&ctx->buf_len,
(unsigned char *)&(ctx->buf[BUF_OFFSET]),i);
ctx->cont=1;
/* Note: it is possible for EVP_CipherUpdate to
* decrypt zero bytes because this is or looks like
* the final block: if this happens we should retry
* and either read more data or decrypt the final
* block
*/
if(ctx->buf_len == 0) continue;
}
if (ctx->buf_len <= outl)
i=ctx->buf_len;
else
i=outl;
if (i <= 0) break;
memcpy(out,ctx->buf,i);
ret+=i;
ctx->buf_off=i;
outl-=i;
out+=i;
}
BIO_clear_retry_flags(b);
BIO_copy_next_retry(b);
return((ret == 0)?ctx->cont:ret);
}
static int enc_write(BIO *b, const char *in, int inl)
{
int ret=0,n,i;
BIO_ENC_CTX *ctx;
ctx=(BIO_ENC_CTX *)b->ptr;
ret=inl;
BIO_clear_retry_flags(b);
n=ctx->buf_len-ctx->buf_off;
while (n > 0)
{
i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
if (i <= 0)
{
BIO_copy_next_retry(b);
return(i);
}
ctx->buf_off+=i;
n-=i;
}
/* at this point all pending data has been written */
if ((in == NULL) || (inl <= 0)) return(0);
ctx->buf_off=0;
while (inl > 0)
{
n=(inl > ENC_BLOCK_SIZE)?ENC_BLOCK_SIZE:inl;
EVP_CipherUpdate(&(ctx->cipher),
(unsigned char *)ctx->buf,&ctx->buf_len,
(unsigned char *)in,n);
inl-=n;
in+=n;
ctx->buf_off=0;
n=ctx->buf_len;
while (n > 0)
{
i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
if (i <= 0)
{
BIO_copy_next_retry(b);
return (ret == inl) ? i : ret - inl;
}
n-=i;
ctx->buf_off+=i;
}
ctx->buf_len=0;
ctx->buf_off=0;
}
BIO_copy_next_retry(b);
return(ret);
}
static long enc_ctrl(BIO *b, int cmd, long num, void *ptr)
{
BIO *dbio;
BIO_ENC_CTX *ctx,*dctx;
long ret=1;
int i;
EVP_CIPHER_CTX **c_ctx;
ctx=(BIO_ENC_CTX *)b->ptr;
switch (cmd)
{
case BIO_CTRL_RESET:
ctx->ok=1;
ctx->finished=0;
EVP_CipherInit_ex(&(ctx->cipher),NULL,NULL,NULL,NULL,
ctx->cipher.encrypt);
ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
break;
case BIO_CTRL_EOF: /* More to read */
if (ctx->cont <= 0)
ret=1;
else
ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
break;
case BIO_CTRL_WPENDING:
ret=ctx->buf_len-ctx->buf_off;
if (ret <= 0)
ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
break;
case BIO_CTRL_PENDING: /* More to read in buffer */
ret=ctx->buf_len-ctx->buf_off;
if (ret <= 0)
ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
break;
case BIO_CTRL_FLUSH:
/* do a final write */
again:
while (ctx->buf_len != ctx->buf_off)
{
i=enc_write(b,NULL,0);
if (i < 0)
return i;
}
if (!ctx->finished)
{
ctx->finished=1;
ctx->buf_off=0;
ret=EVP_CipherFinal_ex(&(ctx->cipher),
(unsigned char *)ctx->buf,
&(ctx->buf_len));
ctx->ok=(int)ret;
if (ret <= 0) break;
/* push out the bytes */
goto again;
}
/* Finally flush the underlying BIO */
ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
break;
case BIO_C_GET_CIPHER_STATUS:
ret=(long)ctx->ok;
break;
case BIO_C_DO_STATE_MACHINE:
BIO_clear_retry_flags(b);
ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
BIO_copy_next_retry(b);
break;
case BIO_C_GET_CIPHER_CTX:
c_ctx=(EVP_CIPHER_CTX **)ptr;
(*c_ctx)= &(ctx->cipher);
b->init=1;
break;
case BIO_CTRL_DUP:
dbio=(BIO *)ptr;
dctx=(BIO_ENC_CTX *)dbio->ptr;
memcpy(&(dctx->cipher),&(ctx->cipher),sizeof(ctx->cipher));
dbio->init=1;
break;
default:
ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
break;
}
return(ret);
}
static long enc_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
{
long ret=1;
if (b->next_bio == NULL) return(0);
switch (cmd)
{
default:
ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
break;
}
return(ret);
}
/*
void BIO_set_cipher_ctx(b,c)
BIO *b;
EVP_CIPHER_ctx *c;
{
if (b == NULL) return;
if ((b->callback != NULL) &&
(b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0))
return;
b->init=1;
ctx=(BIO_ENC_CTX *)b->ptr;
memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX));
if (b->callback != NULL)
b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);
}
*/
void BIO_set_cipher(BIO *b, const EVP_CIPHER *c, const unsigned char *k,
const unsigned char *i, int e)
{
BIO_ENC_CTX *ctx;
if (b == NULL) return;
if ((b->callback != NULL) &&
(b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,0L) <= 0))
return;
b->init=1;
ctx=(BIO_ENC_CTX *)b->ptr;
EVP_CipherInit_ex(&(ctx->cipher),c,NULL, k,i,e);
if (b->callback != NULL)
b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,1L);
}