tb_digest.c

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/* ====================================================================
 * Copyright (c) 2000 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
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 *
 * 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
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 *    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/)"
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 *    [email protected].
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 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
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 *
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 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * ([email protected]).  This product includes software written by Tim
 * Hudson ([email protected]).
 *
 */

#include "eng_int.h"

/* If this symbol is defined then ENGINE_get_digest_engine(), the function that
 * is used by EVP to hook in digest code and cache defaults (etc), will display
 * brief debugging summaries to stderr with the 'nid'. */
/* #define ENGINE_DIGEST_DEBUG */

static ENGINE_TABLE *digest_table = NULL;

void ENGINE_unregister_digests(ENGINE *e)
    {
    engine_table_unregister(&digest_table, e);
    }

static void engine_unregister_all_digests(void)
    {
    engine_table_cleanup(&digest_table);
    }

int ENGINE_register_digests(ENGINE *e)
    {
    if(e->digests)
        {
        const int *nids;
        int num_nids = e->digests(e, NULL, &nids, 0);
        if(num_nids > 0)
            return engine_table_register(&digest_table,
                    engine_unregister_all_digests, e, nids,
                    num_nids, 0);
        }
    return 1;
    }

void ENGINE_register_all_digests()
    {
    ENGINE *e;

    for(e=ENGINE_get_first() ; e ; e=ENGINE_get_next(e))
        ENGINE_register_digests(e);
    }

int ENGINE_set_default_digests(ENGINE *e)
    {
    if(e->digests)
        {
        const int *nids;
        int num_nids = e->digests(e, NULL, &nids, 0);
        if(num_nids > 0)
            return engine_table_register(&digest_table,
                    engine_unregister_all_digests, e, nids,
                    num_nids, 1);
        }
    return 1;
    }

/* Exposed API function to get a functional reference from the implementation
 * table (ie. try to get a functional reference from the tabled structural
 * references) for a given digest 'nid' */
ENGINE *ENGINE_get_digest_engine(int nid)
    {
    return engine_table_select(&digest_table, nid);
    }

/* Obtains a digest implementation from an ENGINE functional reference */
const EVP_MD *ENGINE_get_digest(ENGINE *e, int nid)
    {
    const EVP_MD *ret;
    ENGINE_DIGESTS_PTR fn = ENGINE_get_digests(e);
    if(!fn || !fn(e, &ret, NULL, nid))
        {
        ENGINEerr(ENGINE_F_ENGINE_GET_DIGEST,
                ENGINE_R_UNIMPLEMENTED_DIGEST);
        return NULL;
        }
    return ret;
    }

/* Gets the digest callback from an ENGINE structure */
ENGINE_DIGESTS_PTR ENGINE_get_digests(const ENGINE *e)
    {
    return e->digests;
    }

/* Sets the digest callback in an ENGINE structure */
int ENGINE_set_digests(ENGINE *e, ENGINE_DIGESTS_PTR f)
    {
    e->digests = f;
    return 1;
    }