digest.c

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/* crypto/evp/digest.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.]
 */
/* ====================================================================
 * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
 *
 * 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 above 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 acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    [email protected].
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * ([email protected]).  This product includes software written by Tim
 * Hudson ([email protected]).
 *
 */

#include <stdio.h>
#include "cryptlib.h"
#include <openssl/objects.h>
#include <openssl/evp.h>
#ifndef OPENSSL_NO_ENGINE
#include <openssl/engine.h>
#endif

#ifdef OPENSSL_FIPS
#include <openssl/fips.h>
#endif

void EVP_MD_CTX_init(EVP_MD_CTX *ctx)
    {
    memset(ctx,'\0',sizeof *ctx);
    }

EVP_MD_CTX *EVP_MD_CTX_create(void)
    {
    EVP_MD_CTX *ctx=OPENSSL_malloc(sizeof *ctx);

    if (ctx)
        EVP_MD_CTX_init(ctx);

    return ctx;
    }

int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type)
    {
    EVP_MD_CTX_init(ctx);
    return EVP_DigestInit_ex(ctx, type, NULL);
    }

int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl)
    {
    EVP_MD_CTX_clear_flags(ctx,EVP_MD_CTX_FLAG_CLEANED);
#ifndef OPENSSL_NO_ENGINE
    /* Whether it's nice or not, "Inits" can be used on "Final"'d contexts
     * so this context may already have an ENGINE! Try to avoid releasing
     * the previous handle, re-querying for an ENGINE, and having a
     * reinitialisation, when it may all be unecessary. */
    if (ctx->engine && ctx->digest && (!type ||
            (type && (type->type == ctx->digest->type))))
        goto skip_to_init;
    if (type)
        {
        /* Ensure an ENGINE left lying around from last time is cleared
         * (the previous check attempted to avoid this if the same
         * ENGINE and EVP_MD could be used). */
        if(ctx->engine)
            ENGINE_finish(ctx->engine);
        if(impl)
            {
            if (!ENGINE_init(impl))
                {
                EVPerr(EVP_F_EVP_DIGESTINIT_EX,EVP_R_INITIALIZATION_ERROR);
                return 0;
                }
            }
        else
            /* Ask if an ENGINE is reserved for this job */
            impl = ENGINE_get_digest_engine(type->type);
        if(impl)
            {
            /* There's an ENGINE for this job ... (apparently) */
            const EVP_MD *d = ENGINE_get_digest(impl, type->type);
            if(!d)
                {
                /* Same comment from evp_enc.c */
                EVPerr(EVP_F_EVP_DIGESTINIT_EX,EVP_R_INITIALIZATION_ERROR);
                ENGINE_finish(impl);
                return 0;
                }
            /* We'll use the ENGINE's private digest definition */
            type = d;
            /* Store the ENGINE functional reference so we know
             * 'type' came from an ENGINE and we need to release
             * it when done. */
            ctx->engine = impl;
            }
        else
            ctx->engine = NULL;
        }
    else
    if(!ctx->digest)
        {
        EVPerr(EVP_F_EVP_DIGESTINIT_EX,EVP_R_NO_DIGEST_SET);
        return 0;
        }
#endif
    if (ctx->digest != type)
        {
        if (ctx->digest && ctx->digest->ctx_size)
            OPENSSL_free(ctx->md_data);
        ctx->digest=type;
        if (!(ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) && type->ctx_size)
            {
            ctx->update = type->update;
            ctx->md_data=OPENSSL_malloc(type->ctx_size);
            if (ctx->md_data == NULL)
                {
                EVPerr(EVP_F_EVP_DIGESTINIT_EX,
                            ERR_R_MALLOC_FAILURE);
                return 0;
                }
            }
        }
#ifndef OPENSSL_NO_ENGINE
skip_to_init:
#endif
    if (ctx->pctx)
        {
        int r;
        r = EVP_PKEY_CTX_ctrl(ctx->pctx, -1, EVP_PKEY_OP_TYPE_SIG,
                    EVP_PKEY_CTRL_DIGESTINIT, 0, ctx);
        if (r <= 0 && (r != -2))
            return 0;
        }
    if (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT)
        return 1;
#ifdef OPENSSL_FIPS
    if (FIPS_mode())
        {
        if (FIPS_digestinit(ctx, type))
            return 1;
        OPENSSL_free(ctx->md_data);
        ctx->md_data = NULL;
        return 0;
        }
#endif
    return ctx->digest->init(ctx);
    }

int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t count)
    {
#ifdef OPENSSL_FIPS
    return FIPS_digestupdate(ctx, data, count);
#else
    return ctx->update(ctx,data,count);
#endif
    }

/* The caller can assume that this removes any secret data from the context */
int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
    {
    int ret;
    ret = EVP_DigestFinal_ex(ctx, md, size);
    EVP_MD_CTX_cleanup(ctx);
    return ret;
    }

/* The caller can assume that this removes any secret data from the context */
int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
    {
#ifdef OPENSSL_FIPS
    return FIPS_digestfinal(ctx, md, size);
#else
    int ret;
    OPENSSL_assert(ctx->digest->md_size <= EVP_MAX_MD_SIZE);
    ret=ctx->digest->final(ctx,md);
    if (size != NULL)
        *size=ctx->digest->md_size;
    if (ctx->digest->cleanup)
        {
        ctx->digest->cleanup(ctx);
        EVP_MD_CTX_set_flags(ctx,EVP_MD_CTX_FLAG_CLEANED);
        }
    memset(ctx->md_data,0,ctx->digest->ctx_size);
    return ret;
#endif
    }

int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in)
    {
    EVP_MD_CTX_init(out);
    return EVP_MD_CTX_copy_ex(out, in);
    }

int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
    {
    unsigned char *tmp_buf;
    if ((in == NULL) || (in->digest == NULL))
        {
        EVPerr(EVP_F_EVP_MD_CTX_COPY_EX,EVP_R_INPUT_NOT_INITIALIZED);
        return 0;
        }
#ifndef OPENSSL_NO_ENGINE
    /* Make sure it's safe to copy a digest context using an ENGINE */
    if (in->engine && !ENGINE_init(in->engine))
        {
        EVPerr(EVP_F_EVP_MD_CTX_COPY_EX,ERR_R_ENGINE_LIB);
        return 0;
        }
#endif

    if (out->digest == in->digest)
        {
        tmp_buf = out->md_data;
            EVP_MD_CTX_set_flags(out,EVP_MD_CTX_FLAG_REUSE);
        }
    else tmp_buf = NULL;
    EVP_MD_CTX_cleanup(out);
    memcpy(out,in,sizeof *out);

    if (in->md_data && out->digest->ctx_size)
        {
        if (tmp_buf)
            out->md_data = tmp_buf;
        else
            {
            out->md_data=OPENSSL_malloc(out->digest->ctx_size);
            if (!out->md_data)
                {
                EVPerr(EVP_F_EVP_MD_CTX_COPY_EX,ERR_R_MALLOC_FAILURE);
                return 0;
                }
            }
        memcpy(out->md_data,in->md_data,out->digest->ctx_size);
        }

    out->update = in->update;

    if (in->pctx)
        {
        out->pctx = EVP_PKEY_CTX_dup(in->pctx);
        if (!out->pctx)
            {
            EVP_MD_CTX_cleanup(out);
            return 0;
            }
        }

    if (out->digest->copy)
        return out->digest->copy(out,in);
    
    return 1;
    }

int EVP_Digest(const void *data, size_t count,
        unsigned char *md, unsigned int *size, const EVP_MD *type, ENGINE *impl)
    {
    EVP_MD_CTX ctx;
    int ret;

    EVP_MD_CTX_init(&ctx);
    EVP_MD_CTX_set_flags(&ctx,EVP_MD_CTX_FLAG_ONESHOT);
    ret=EVP_DigestInit_ex(&ctx, type, impl)
      && EVP_DigestUpdate(&ctx, data, count)
      && EVP_DigestFinal_ex(&ctx, md, size);
    EVP_MD_CTX_cleanup(&ctx);

    return ret;
    }

void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx)
    {
    EVP_MD_CTX_cleanup(ctx);
    OPENSSL_free(ctx);
    }

/* This call frees resources associated with the context */
int EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx)
    {
#ifndef OPENSSL_FIPS
    /* Don't assume ctx->md_data was cleaned in EVP_Digest_Final,
     * because sometimes only copies of the context are ever finalised.
     */
    if (ctx->digest && ctx->digest->cleanup
        && !EVP_MD_CTX_test_flags(ctx,EVP_MD_CTX_FLAG_CLEANED))
        ctx->digest->cleanup(ctx);
    if (ctx->digest && ctx->digest->ctx_size && ctx->md_data
        && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_REUSE))
        {
        OPENSSL_cleanse(ctx->md_data,ctx->digest->ctx_size);
        OPENSSL_free(ctx->md_data);
        }
#endif
    if (ctx->pctx)
        EVP_PKEY_CTX_free(ctx->pctx);
#ifndef OPENSSL_NO_ENGINE
    if(ctx->engine)
        /* The EVP_MD we used belongs to an ENGINE, release the
         * functional reference we held for this reason. */
        ENGINE_finish(ctx->engine);
#endif
#ifdef OPENSSL_FIPS
    FIPS_md_ctx_cleanup(ctx);
#endif
    memset(ctx,'\0',sizeof *ctx);

    return 1;
    }