bio_md.c

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/* crypto/evp/bio_md.c */
/* Copyright (C) 1995-1998 Eric Young ([email protected])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([email protected]).
 * 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 ([email protected]).
 * 
 * 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 ([email protected])"
 *    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 ([email protected])"
 * 
 * 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>

/* BIO_put and BIO_get both add to the digest,
 * BIO_gets returns the digest */

static int md_write(BIO *h, char const *buf, int num);
static int md_read(BIO *h, char *buf, int size);
/*static int md_puts(BIO *h, const char *str); */
static int md_gets(BIO *h, char *str, int size);
static long md_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int md_new(BIO *h);
static int md_free(BIO *data);
static long md_callback_ctrl(BIO *h,int cmd,bio_info_cb *fp);

static BIO_METHOD methods_md=
    {
    BIO_TYPE_MD,"message digest",
    md_write,
    md_read,
    NULL, /* md_puts, */
    md_gets,
    md_ctrl,
    md_new,
    md_free,
    md_callback_ctrl,
    };

BIO_METHOD *BIO_f_md(void)
    {
    return(&methods_md);
    }

static int md_new(BIO *bi)
    {
    EVP_MD_CTX *ctx;

    ctx=EVP_MD_CTX_create();
    if (ctx == NULL) return(0);

    bi->init=0;
    bi->ptr=(char *)ctx;
    bi->flags=0;
    return(1);
    }

static int md_free(BIO *a)
    {
    if (a == NULL) return(0);
    EVP_MD_CTX_destroy(a->ptr);
    a->ptr=NULL;
    a->init=0;
    a->flags=0;
    return(1);
    }
    
static int md_read(BIO *b, char *out, int outl)
    {
    int ret=0;
    EVP_MD_CTX *ctx;

    if (out == NULL) return(0);
    ctx=b->ptr;

    if ((ctx == NULL) || (b->next_bio == NULL)) return(0);

    ret=BIO_read(b->next_bio,out,outl);
    if (b->init)
        {
        if (ret > 0)
            {
            if (EVP_DigestUpdate(ctx,(unsigned char *)out,
                (unsigned int)ret)<=0) return (-1);
            }
        }
    BIO_clear_retry_flags(b);
    BIO_copy_next_retry(b);
    return(ret);
    }

static int md_write(BIO *b, const char *in, int inl)
    {
    int ret=0;
    EVP_MD_CTX *ctx;

    if ((in == NULL) || (inl <= 0)) return(0);
    ctx=b->ptr;

    if ((ctx != NULL) && (b->next_bio != NULL))
        ret=BIO_write(b->next_bio,in,inl);
    if (b->init)
        {
        if (ret > 0)
            {
            if (!EVP_DigestUpdate(ctx,(const unsigned char *)in,
                (unsigned int)ret))
                {
                BIO_clear_retry_flags(b);
                return 0;
                }
            }
        }
    if(b->next_bio != NULL)
        {
        BIO_clear_retry_flags(b);
        BIO_copy_next_retry(b);
        }
    return(ret);
    }

static long md_ctrl(BIO *b, int cmd, long num, void *ptr)
    {
    EVP_MD_CTX *ctx,*dctx,**pctx;
    const EVP_MD **ppmd;
    EVP_MD *md;
    long ret=1;
    BIO *dbio;

    ctx=b->ptr;

    switch (cmd)
        {
    case BIO_CTRL_RESET:
        if (b->init)
            ret = EVP_DigestInit_ex(ctx,ctx->digest, NULL);
        else
            ret=0;
        if (ret > 0)
            ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
        break;
    case BIO_C_GET_MD:
        if (b->init)
            {
            ppmd=ptr;
            *ppmd=ctx->digest;
            }
        else
            ret=0;
        break;
    case BIO_C_GET_MD_CTX:
        pctx=ptr;
        *pctx=ctx;
        b->init = 1;
        break;
    case BIO_C_SET_MD_CTX:
        if (b->init)
            b->ptr=ptr;
        else
            ret=0;
        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_SET_MD:
        md=ptr;
        ret = EVP_DigestInit_ex(ctx,md, NULL);
        if (ret > 0)
            b->init=1;
        break;
    case BIO_CTRL_DUP:
        dbio=ptr;
        dctx=dbio->ptr;
        if (!EVP_MD_CTX_copy_ex(dctx,ctx))
            return 0;
        b->init=1;
        break;
    default:
        ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
        break;
        }
    return(ret);
    }

static long md_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);
    }

static int md_gets(BIO *bp, char *buf, int size)
    {
    EVP_MD_CTX *ctx;
    unsigned int ret;


    ctx=bp->ptr;
    if (size < ctx->digest->md_size)
        return(0);
    if (EVP_DigestFinal_ex(ctx,(unsigned char *)buf,&ret)<=0) 
        return -1;
        
    return((int)ret);
    }

/*
static int md_puts(bp,str)
BIO *bp;
char *str;
    {
    return(-1);
    }
*/