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[heimdal.git] / lib / hcrypto / evp.c

/*
 * Copyright (c) 2006 - 2008 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * 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. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE 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.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#define HC_DEPRECATED
#define HC_DEPRECATED_CRYPTO

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include <evp.h>
#include <evp-hcrypto.h>
#include <evp-cc.h>

#include <krb5-types.h>
#include <roken.h>

#ifndef HCRYPTO_DEF_PROVIDER
#define HCRYPTO_DEF_PROVIDER hcrypto
#endif

#define HC_CONCAT4(x,y,z,aa)    x ## y ## z ## aa


#define EVP_DEF_OP(_prov,_op) HC_CONCAT4(EVP_,_prov,_,_op)()

/**
 * @page page_evp EVP - generic crypto interface
 *
 * See the library functions here: @ref hcrypto_evp
 *
 * @section evp_cipher EVP Cipher
 *
 * The use of EVP_CipherInit_ex() and EVP_Cipher() is pretty easy to
 * understand forward, then EVP_CipherUpdate() and
 * EVP_CipherFinal_ex() really needs an example to explain @ref
 * example_evp_cipher.c .
 *
 * @example example_evp_cipher.c
 *
 * This is an example how to use EVP_CipherInit_ex(),
 * EVP_CipherUpdate() and EVP_CipherFinal_ex().
 */

struct hc_EVP_MD_CTX {
    const EVP_MD *md;
    ENGINE *engine;
    void *ptr;
};


/**
 * Return the output size of the message digest function.
 *
 * @param md the evp message
 *
 * @return size output size of the message digest function.
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_MD_size(const EVP_MD *md)
{
    return md->hash_size;
}

/**
 * Return the blocksize of the message digest function.
 *
 * @param md the evp message
 *
 * @return size size of the message digest block size
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_MD_block_size(const EVP_MD *md)
{
    return md->block_size;
}

/**
 * Allocate a messsage digest context object. Free with
 * EVP_MD_CTX_destroy().
 *
 * @return a newly allocated message digest context object.
 *
 * @ingroup hcrypto_evp
 */

EVP_MD_CTX *
EVP_MD_CTX_create(void)
{
    return calloc(1, sizeof(EVP_MD_CTX));
}

/**
 * Initiate a messsage digest context object. Deallocate with
 * EVP_MD_CTX_cleanup(). Please use EVP_MD_CTX_create() instead.
 *
 * @param ctx variable to initiate.
 *
 * @ingroup hcrypto_evp
 */

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

/**
 * Free a messsage digest context object.
 *
 * @param ctx context to free.
 *
 * @ingroup hcrypto_evp
 */

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

/**
 * Free the resources used by the EVP_MD context.
 *
 * @param ctx the context to free the resources from.
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx) HC_DEPRECATED
{
    if (ctx->md && ctx->md->cleanup)
        (ctx->md->cleanup)(ctx);
    else if (ctx->md)
        memset(ctx->ptr, 0, ctx->md->ctx_size);
    ctx->md = NULL;
    ctx->engine = NULL;
    free(ctx->ptr);
    memset(ctx, 0, sizeof(*ctx));
    return 1;
}

/**
 * Get the EVP_MD use for a specified context.
 *
 * @param ctx the EVP_MD context to get the EVP_MD for.
 *
 * @return the EVP_MD used for the context.
 *
 * @ingroup hcrypto_evp
 */

const EVP_MD *
EVP_MD_CTX_md(EVP_MD_CTX *ctx)
{
    return ctx->md;
}

/**
 * Return the output size of the message digest function.
 *
 * @param ctx the evp message digest context
 *
 * @return size output size of the message digest function.
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_MD_CTX_size(EVP_MD_CTX *ctx)
{
    return EVP_MD_size(ctx->md);
}

/**
 * Return the blocksize of the message digest function.
 *
 * @param ctx the evp message digest context
 *
 * @return size size of the message digest block size
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_MD_CTX_block_size(EVP_MD_CTX *ctx)
{
    return EVP_MD_block_size(ctx->md);
}

/**
 * Init a EVP_MD_CTX for use a specific message digest and engine.
 *
 * @param ctx the message digest context to init.
 * @param md the message digest to use.
 * @param engine the engine to use, NULL to use the default engine.
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *md, ENGINE *engine)
{
    if (ctx->md != md || ctx->engine != engine) {
        EVP_MD_CTX_cleanup(ctx);
        ctx->md = md;
        ctx->engine = engine;

        ctx->ptr = calloc(1, md->ctx_size);
        if (ctx->ptr == NULL)
            return 0;
    }
    (ctx->md->init)(ctx->ptr);
    return 1;
}

/**
 * Update the digest with some data.
 *
 * @param ctx the context to update
 * @param data the data to update the context with
 * @param size length of data
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t size)
{
    (ctx->md->update)(ctx->ptr, data, size);
    return 1;
}

/**
 * Complete the message digest.
 *
 * @param ctx the context to complete.
 * @param hash the output of the message digest function. At least
 * EVP_MD_size().
 * @param size the output size of hash.
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_DigestFinal_ex(EVP_MD_CTX *ctx, void *hash, unsigned int *size)
{
    (ctx->md->final)(hash, ctx->ptr);
    if (size)
        *size = ctx->md->hash_size;
    return 1;
}

/**
 * Do the whole EVP_MD_CTX_create(), EVP_DigestInit_ex(),
 * EVP_DigestUpdate(), EVP_DigestFinal_ex(), EVP_MD_CTX_destroy()
 * dance in one call.
 *
 * @param data the data to update the context with
 * @param dsize length of data
 * @param hash output data of at least EVP_MD_size() length.
 * @param hsize output length of hash.
 * @param md message digest to use
 * @param engine engine to use, NULL for default engine.
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_Digest(const void *data, size_t dsize, void *hash, unsigned int *hsize,
           const EVP_MD *md, ENGINE *engine)
{
    EVP_MD_CTX *ctx;
    int ret;

    ctx = EVP_MD_CTX_create();
    if (ctx == NULL)
        return 0;
    ret = EVP_DigestInit_ex(ctx, md, engine);
    if (ret != 1) {
        EVP_MD_CTX_destroy(ctx);
        return ret;
    }
    ret = EVP_DigestUpdate(ctx, data, dsize);
    if (ret != 1) {
        EVP_MD_CTX_destroy(ctx);
        return ret;
    }
    ret = EVP_DigestFinal_ex(ctx, hash, hsize);
    EVP_MD_CTX_destroy(ctx);
    return ret;
}

/**
 * The message digest SHA256
 *
 * @return the message digest type.
 *
 * @ingroup hcrypto_evp
 */

const EVP_MD *
EVP_sha256(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, sha256);
}

/**
 * The message digest SHA1
 *
 * @return the message digest type.
 *
 * @ingroup hcrypto_evp
 */

const EVP_MD *
EVP_sha1(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, sha1);
}

/**
 * The message digest SHA1
 *
 * @return the message digest type.
 *
 * @ingroup hcrypto_evp
 */

const EVP_MD *
EVP_sha(void) HC_DEPRECATED
    
{
    hcrypto_validate();
    return EVP_sha1();
}

/**
 * The message digest MD5
 *
 * @return the message digest type.
 *
 * @ingroup hcrypto_evp
 */

const EVP_MD *
EVP_md5(void) HC_DEPRECATED_CRYPTO
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, md5);
}

/**
 * The message digest MD4
 *
 * @return the message digest type.
 *
 * @ingroup hcrypto_evp
 */

const EVP_MD *
EVP_md4(void) HC_DEPRECATED_CRYPTO
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, md4);
}

/**
 * The message digest MD2
 *
 * @return the message digest type.
 *
 * @ingroup hcrypto_evp
 */

const EVP_MD *
EVP_md2(void) HC_DEPRECATED_CRYPTO
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, md2);
}

/*
 *
 */

static void
null_Init (void *m)
{
}
static void
null_Update (void *m, const void * data, size_t size)
{
}
static void
null_Final(void *res, void *m)
{
}

/**
 * The null message digest
 *
 * @return the message digest type.
 *
 * @ingroup hcrypto_evp
 */

const EVP_MD *
EVP_md_null(void)
{
    static const struct hc_evp_md null = {
        0,
        0,
        0,
        (hc_evp_md_init)null_Init,
        (hc_evp_md_update)null_Update,
        (hc_evp_md_final)null_Final,
        NULL
    };
    return &null;
}

/**
 * Return the block size of the cipher.
 *
 * @param c cipher to get the block size from.
 *
 * @return the block size of the cipher.
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_CIPHER_block_size(const EVP_CIPHER *c)
{
    return c->block_size;
}

/**
 * Return the key size of the cipher.
 *
 * @param c cipher to get the key size from.
 *
 * @return the key size of the cipher.
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_CIPHER_key_length(const EVP_CIPHER *c)
{
    return c->key_len;
}

/**
 * Return the IV size of the cipher.
 *
 * @param c cipher to get the IV size from.
 *
 * @return the IV size of the cipher.
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_CIPHER_iv_length(const EVP_CIPHER *c)
{
    return c->iv_len;
}

/**
 * Initiate a EVP_CIPHER_CTX context. Clean up with
 * EVP_CIPHER_CTX_cleanup().
 *
 * @param c the cipher initiate.
 *
 * @ingroup hcrypto_evp
 */

void
EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *c)
{
    memset(c, 0, sizeof(*c));
}

/**
 * Clean up the EVP_CIPHER_CTX context.
 *
 * @param c the cipher to clean up.
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
{
    if (c->cipher && c->cipher->cleanup)
        c->cipher->cleanup(c);
    if (c->cipher_data) {
        memset(c->cipher_data, 0, c->cipher->ctx_size);
        free(c->cipher_data);
        c->cipher_data = NULL;
    }
    return 1;
}

/**
 * If the cipher type supports it, change the key length
 *
 * @param c the cipher context to change the key length for
 * @param length new key length
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int length)
{
    if ((c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH) && length > 0) {
        c->key_len = length;
        return 1;
    }
    return 0;
}

#if 0
int
EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *c, int pad)
{
    return 0;
}
#endif

/**
 * Return the EVP_CIPHER for a EVP_CIPHER_CTX context.
 *
 * @param ctx the context to get the cipher type from.
 *
 * @return the EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_CIPHER_CTX_cipher(EVP_CIPHER_CTX *ctx)
{
    return ctx->cipher;
}

/**
 * Return the block size of the cipher context.
 *
 * @param ctx cipher context to get the block size from.
 *
 * @return the block size of the cipher context.
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_CIPHER_CTX_block_size(const EVP_CIPHER_CTX *ctx)
{
    return EVP_CIPHER_block_size(ctx->cipher);
}

/**
 * Return the key size of the cipher context.
 *
 * @param ctx cipher context to get the key size from.
 *
 * @return the key size of the cipher context.
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_CIPHER_CTX_key_length(const EVP_CIPHER_CTX *ctx)
{
    return EVP_CIPHER_key_length(ctx->cipher);
}

/**
 * Return the IV size of the cipher context.
 *
 * @param ctx cipher context to get the IV size from.
 *
 * @return the IV size of the cipher context.
 *
 * @ingroup hcrypto_evp
 */

size_t
EVP_CIPHER_CTX_iv_length(const EVP_CIPHER_CTX *ctx)
{
    return EVP_CIPHER_iv_length(ctx->cipher);
}

/**
 * Get the flags for an EVP_CIPHER_CTX context.
 *
 * @param ctx the EVP_CIPHER_CTX to get the flags from
 *
 * @return the flags for an EVP_CIPHER_CTX.
 *
 * @ingroup hcrypto_evp
 */

unsigned long
EVP_CIPHER_CTX_flags(const EVP_CIPHER_CTX *ctx)
{
    return ctx->cipher->flags;
}

/**
 * Get the mode for an EVP_CIPHER_CTX context.
 *
 * @param ctx the EVP_CIPHER_CTX to get the mode from
 *
 * @return the mode for an EVP_CIPHER_CTX.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_CIPHER_CTX_mode(const EVP_CIPHER_CTX *ctx)
{
    return EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_MODE;
}

/**
 * Get the app data for an EVP_CIPHER_CTX context.
 *
 * @param ctx the EVP_CIPHER_CTX to get the app data from
 *
 * @return the app data for an EVP_CIPHER_CTX.
 *
 * @ingroup hcrypto_evp
 */

void *
EVP_CIPHER_CTX_get_app_data(EVP_CIPHER_CTX *ctx)
{
    return ctx->app_data;
}

/**
 * Set the app data for an EVP_CIPHER_CTX context.
 *
 * @param ctx the EVP_CIPHER_CTX to set the app data for
 * @param data the app data to set for an EVP_CIPHER_CTX.
 *
 * @ingroup hcrypto_evp
 */

void
EVP_CIPHER_CTX_set_app_data(EVP_CIPHER_CTX *ctx, void *data)
{
    ctx->app_data = data;
}

/**
 * Initiate the EVP_CIPHER_CTX context to encrypt or decrypt data.
 * Clean up with EVP_CIPHER_CTX_cleanup().
 *
 * @param ctx context to initiate
 * @param c cipher to use.
 * @param engine crypto engine to use, NULL to select default.
 * @param key the crypto key to use, NULL will use the previous value.
 * @param iv the IV to use, NULL will use the previous value.
 * @param encp non zero will encrypt, -1 use the previous value.
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *c, ENGINE *engine,
                  const void *key, const void *iv, int encp)
{
    ctx->buf_len = 0;

    if (encp == -1)
        encp = ctx->encrypt;
    else
        ctx->encrypt = (encp ? 1 : 0);

    if (c && (c != ctx->cipher)) {
        EVP_CIPHER_CTX_cleanup(ctx);
        ctx->cipher = c;
        ctx->key_len = c->key_len;

        ctx->cipher_data = calloc(1, c->ctx_size);
        if (ctx->cipher_data == NULL && c->ctx_size != 0)
            return 0;

        /* assume block size is a multiple of 2 */
        ctx->block_mask = EVP_CIPHER_block_size(c) - 1;

    } else if (ctx->cipher == NULL) {
        /* reuse of cipher, but not any cipher ever set! */
        return 0;
    }

    switch (EVP_CIPHER_CTX_mode(ctx)) {
    case EVP_CIPH_CBC_MODE:

        assert(EVP_CIPHER_CTX_iv_length(ctx) <= sizeof(ctx->iv));

        if (iv)
            memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
        memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
        break;

    case EVP_CIPH_STREAM_CIPHER:
        break;
    case EVP_CIPH_CFB8_MODE:
        if (iv)
            memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
        break;

    default:
        return 0;
    }

    if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT))
        ctx->cipher->init(ctx, key, iv, encp);

    return 1;
}

/**
 * Encipher/decipher partial data
 *
 * @param ctx the cipher context.
 * @param out output data from the operation.
 * @param outlen output length
 * @param in input data to the operation.
 * @param inlen length of data.
 *
 * The output buffer length should at least be EVP_CIPHER_block_size()
 * byte longer then the input length.
 *
 * See @ref evp_cipher for an example how to use this function.
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, void *out, int *outlen,
                 void *in, size_t inlen)
{
    int ret, left, blocksize;

    *outlen = 0;

    /**
     * If there in no spare bytes in the left from last Update and the
     * input length is on the block boundery, the EVP_CipherUpdate()
     * function can take a shortcut (and preformance gain) and
     * directly encrypt the data, otherwise we hav to fix it up and
     * store extra it the EVP_CIPHER_CTX.
     */
    if (ctx->buf_len == 0 && (inlen & ctx->block_mask) == 0) {
        ret = (*ctx->cipher->do_cipher)(ctx, out, in, inlen);
        if (ret == 1)
            *outlen = inlen;
        else
            *outlen = 0;
        return ret;
    }


    blocksize = EVP_CIPHER_CTX_block_size(ctx);
    left = blocksize - ctx->buf_len;
    assert(left > 0);

    if (ctx->buf_len) {

        /* if total buffer is smaller then input, store locally */
        if (inlen < left) {
            memcpy(ctx->buf + ctx->buf_len, in, inlen);
            ctx->buf_len += inlen;
            return 1;
        }
        
        /* fill in local buffer and encrypt */
        memcpy(ctx->buf + ctx->buf_len, in, left);
        ret = (*ctx->cipher->do_cipher)(ctx, out, ctx->buf, blocksize);
        memset(ctx->buf, 0, blocksize);
        if (ret != 1)
            return ret;

        *outlen += blocksize;
        inlen -= left;
        in = ((unsigned char *)in) + left;
        out = ((unsigned char *)out) + blocksize;
        ctx->buf_len = 0;
    }

    if (inlen) {
        ctx->buf_len = (inlen & ctx->block_mask);
        inlen &= ~ctx->block_mask;
        
        ret = (*ctx->cipher->do_cipher)(ctx, out, in, inlen);
        if (ret != 1)
            return ret;

        *outlen += inlen;

        in = ((unsigned char *)in) + inlen;
        memcpy(ctx->buf, in, ctx->buf_len);
    }

    return 1;
}

/**
 * Encipher/decipher final data
 *
 * @param ctx the cipher context.
 * @param out output data from the operation.
 * @param outlen output length
 *
 * The input length needs to be at least EVP_CIPHER_block_size() bytes
 * long.
 *
 * See @ref evp_cipher for an example how to use this function.
 *
 * @return 1 on success.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, void *out, int *outlen)
{
    *outlen = 0;

    if (ctx->buf_len) {
        int ret, left, blocksize;

        blocksize = EVP_CIPHER_CTX_block_size(ctx);

        left = blocksize - ctx->buf_len;
        assert(left > 0);

        /* zero fill local buffer */
        memset(ctx->buf + ctx->buf_len, 0, left);
        ret = (*ctx->cipher->do_cipher)(ctx, out, ctx->buf, blocksize);
        memset(ctx->buf, 0, blocksize);
        if (ret != 1)
            return ret;

        *outlen += blocksize;
    }

    return 1;
}

/**
 * Encipher/decipher data
 *
 * @param ctx the cipher context.
 * @param out out data from the operation.
 * @param in in data to the operation.
 * @param size length of data.
 *
 * @return 1 on success.
 */

int
EVP_Cipher(EVP_CIPHER_CTX *ctx, void *out, const void *in,size_t size)
{
    return ctx->cipher->do_cipher(ctx, out, in, size);
}

/*
 *
 */

static int
enc_null_init(EVP_CIPHER_CTX *ctx,
                  const unsigned char * key,
                  const unsigned char * iv,
                  int encp)
{
    return 1;
}

static int
enc_null_do_cipher(EVP_CIPHER_CTX *ctx,
              unsigned char *out,
              const unsigned char *in,
              unsigned int size)
{
    memmove(out, in, size);
    return 1;
}

static int
enc_null_cleanup(EVP_CIPHER_CTX *ctx)
{
    return 1;
}

/**
 * The NULL cipher type, does no encryption/decryption.
 *
 * @return the null EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_enc_null(void)
{
    static const EVP_CIPHER enc_null = {
        0,
        0,
        0,
        0,
        EVP_CIPH_CBC_MODE,
        enc_null_init,
        enc_null_do_cipher,
        enc_null_cleanup,
        0,
        NULL,
        NULL,
        NULL,
        NULL
    };
    return &enc_null;
}

/**
 * The RC2 cipher type
 *
 * @return the RC2 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_rc2_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, rc2_cbc);
}

/**
 * The RC2 cipher type
 *
 * @return the RC2 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_rc2_40_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, rc2_40_cbc);
}

/**
 * The RC2 cipher type
 *
 * @return the RC2 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_rc2_64_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, rc2_64_cbc);
}

/**
 * The RC4 cipher type
 *
 * @return the RC4 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_rc4(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, rc4);
}

/**
 * The RC4-40 cipher type
 *
 * @return the RC4-40 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_rc4_40(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, rc4_40);
}

/**
 * The DES cipher type
 *
 * @return the DES-CBC EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_des_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, des_cbc);
}

/**
 * The tripple DES cipher type
 *
 * @return the DES-EDE3-CBC EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_des_ede3_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, des_ede3_cbc);
}

/**
 * The AES-128 cipher type
 *
 * @return the AES-128 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_aes_128_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, aes_128_cbc);
}

/**
 * The AES-192 cipher type
 *
 * @return the AES-192 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_aes_192_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, aes_192_cbc);
}

/**
 * The AES-256 cipher type
 *
 * @return the AES-256 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_aes_256_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, aes_256_cbc);
}

/**
 * The AES-128 cipher type
 *
 * @return the AES-128 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_aes_128_cfb8(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, aes_128_cfb8);
}

/**
 * The AES-192 cipher type
 *
 * @return the AES-192 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_aes_192_cfb8(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, aes_192_cfb8);
}

/**
 * The AES-256 cipher type
 *
 * @return the AES-256 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_aes_256_cfb8(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, aes_256_cfb8);
}

/**
 * The Camellia-128 cipher type
 *
 * @return the Camellia-128 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_camellia_128_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, camellia_128_cbc);
}

/**
 * The Camellia-198 cipher type
 *
 * @return the Camellia-198 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_camellia_192_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, camellia_192_cbc);
}

/**
 * The Camellia-256 cipher type
 *
 * @return the Camellia-256 EVP_CIPHER pointer.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_camellia_256_cbc(void)
{
    hcrypto_validate();
    return EVP_DEF_OP(HCRYPTO_DEF_PROVIDER, camellia_256_cbc);
}

/*
 *
 */

static const struct cipher_name {
    const char *name;
    const EVP_CIPHER *(*func)(void);
} cipher_name[] = {
    { "des-ede3-cbc", EVP_des_ede3_cbc },
    { "aes-128-cbc", EVP_aes_128_cbc },
    { "aes-192-cbc", EVP_aes_192_cbc },
    { "aes-256-cbc", EVP_aes_256_cbc },
    { "aes-128-cfb8", EVP_aes_128_cfb8 },
    { "aes-192-cfb8", EVP_aes_192_cfb8 },
    { "aes-256-cfb8", EVP_aes_256_cfb8 },
    { "camellia-128-cbc", EVP_camellia_128_cbc },
    { "camellia-192-cbc", EVP_camellia_192_cbc },
    { "camellia-256-cbc", EVP_camellia_256_cbc }
};

/**
 * Get the cipher type using their name.
 *
 * @param name the name of the cipher.
 *
 * @return the selected EVP_CIPHER pointer or NULL if not found.
 *
 * @ingroup hcrypto_evp
 */

const EVP_CIPHER *
EVP_get_cipherbyname(const char *name)
{
    int i;
    for (i = 0; i < sizeof(cipher_name)/sizeof(cipher_name[0]); i++) {
        if (strcasecmp(cipher_name[i].name, name) == 0)
            return (*cipher_name[i].func)();
    }
    return NULL;
}


/*
 *
 */

#ifndef min
#define min(a,b) (((a)>(b))?(b):(a))
#endif

/**
 * Provides a legancy string to key function, used in PEM files.
 *
 * New protocols should use new string to key functions like NIST
 * SP56-800A or PKCS#5 v2.0 (see PKCS5_PBKDF2_HMAC_SHA1()).
 *
 * @param type type of cipher to use
 * @param md message digest to use
 * @param salt salt salt string, should be an binary 8 byte buffer.
 * @param data the password/input key string.
 * @param datalen length of data parameter.
 * @param count iteration counter.
 * @param keydata output keydata, needs to of the size EVP_CIPHER_key_length().
 * @param ivdata output ivdata, needs to of the size EVP_CIPHER_block_size().
 *
 * @return the size of derived key.
 *
 * @ingroup hcrypto_evp
 */

int
EVP_BytesToKey(const EVP_CIPHER *type,
               const EVP_MD *md,
               const void *salt,
               const void *data, size_t datalen,
               unsigned int count,
               void *keydata,
               void *ivdata)
{
    int ivlen, keylen, first = 0;
    unsigned int mds = 0, i;
    unsigned char *key = keydata;
    unsigned char *iv = ivdata;
    unsigned char *buf;
    EVP_MD_CTX c;

    keylen = EVP_CIPHER_key_length(type);
    ivlen = EVP_CIPHER_iv_length(type);

    if (data == NULL)
        return keylen;

    buf = malloc(EVP_MD_size(md));
    if (buf == NULL)
        return -1;

    EVP_MD_CTX_init(&c);

    first = 1;
    while (1) {
        EVP_DigestInit_ex(&c, md, NULL);
        if (!first)
            EVP_DigestUpdate(&c, buf, mds);
        first = 0;
        EVP_DigestUpdate(&c,data,datalen);

#define PKCS5_SALT_LEN 8

        if (salt)
            EVP_DigestUpdate(&c, salt, PKCS5_SALT_LEN);

        EVP_DigestFinal_ex(&c, buf, &mds);
        assert(mds == EVP_MD_size(md));

        for (i = 1; i < count; i++) {
            EVP_DigestInit_ex(&c, md, NULL);
            EVP_DigestUpdate(&c, buf, mds);
            EVP_DigestFinal_ex(&c, buf, &mds);
            assert(mds == EVP_MD_size(md));
        }

        i = 0;
        if (keylen) {
            size_t sz = min(keylen, mds);
            if (key) {
                memcpy(key, buf, sz);
                key += sz;
            }
            keylen -= sz;
            i += sz;
        }
        if (ivlen && mds > i) {
            size_t sz = min(ivlen, (mds - i));
            if (iv) {
                memcpy(iv, &buf[i], sz);
                iv += sz;
            }
            ivlen -= sz;
        }
        if (keylen == 0 && ivlen == 0)
            break;
    }

    EVP_MD_CTX_cleanup(&c);
    free(buf);

    return EVP_CIPHER_key_length(type);
}

/**
 * Generate a random key for the specificed EVP_CIPHER.
 *
 * @param ctx EVP_CIPHER_CTX type to build the key for.
 * @param key return key, must be at least EVP_CIPHER_key_length() byte long.
 *
 * @return 1 for success, 0 for failure.
 *
 * @ingroup hcrypto_core
 */

int
EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, void *key)
{
    if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
        return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
    if (RAND_bytes(key, ctx->key_len) != 1)
        return 0;
    return 1;
}

/**
 * Perform a operation on a ctx
 *
 * @param ctx context to perform operation on.
 * @param type type of operation.
 * @param arg argument to operation.
 * @param data addition data to operation.

 * @return 1 for success, 0 for failure.
 *
 * @ingroup hcrypto_core
 */

int
EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *data)
{
    if (ctx->cipher == NULL || ctx->cipher->ctrl == NULL)
        return 0;
    return (*ctx->cipher->ctrl)(ctx, type, arg, data);
}

/**
 * Add all algorithms to the crypto core.
 *
 * @ingroup hcrypto_core
 */

void
OpenSSL_add_all_algorithms(void)
{
    return;
}

/**
 * Add all algorithms to the crypto core using configuration file.
 *
 * @ingroup hcrypto_core
 */

void
OpenSSL_add_all_algorithms_conf(void)
{
    return;
}

/**
 * Add all algorithms to the crypto core, but don't use the
 * configuration file.
 *
 * @ingroup hcrypto_core
 */

void
OpenSSL_add_all_algorithms_noconf(void)
{
    return;
}