bio_enc.c
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- /* 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);
- }