/* 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;
EVP_CIPHER_CTX_init(&dctx->cipher);
ret = EVP_CIPHER_CTX_copy(&dctx->cipher, &ctx->cipher);
if (ret)
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);
}
