/* crypto/evp/enc_min.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 "cryptlib.h"
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#ifndef OPENSSL_NO_ENGINE
# include <openssl/engine.h>
#endif
#include "evp_locl.h"

void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
{
#ifdef OPENSSL_FIPS
    FIPS_selftest_check();
#endif
    memset(ctx, 0, sizeof(EVP_CIPHER_CTX));
    /* ctx->cipher=NULL; */
}

#ifdef OPENSSL_FIPS

/*
 * The purpose of these is to trap programs that attempt to use non FIPS
 * algorithms in FIPS mode and ignore the errors.
 */

static int bad_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
                    const unsigned char *iv, int enc)
{
    FIPS_ERROR_IGNORED("Cipher init");
    return 0;
}

static int bad_do_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
                         const unsigned char *in, unsigned int inl)
{
    FIPS_ERROR_IGNORED("Cipher update");
    return 0;
}

/* NB: no cleanup because it is allowed after failed init */

static int bad_set_asn1(EVP_CIPHER_CTX *ctx, ASN1_TYPE *typ)
{
    FIPS_ERROR_IGNORED("Cipher set_asn1");
    return 0;
}

static int bad_get_asn1(EVP_CIPHER_CTX *ctx, ASN1_TYPE *typ)
{
    FIPS_ERROR_IGNORED("Cipher get_asn1");
    return 0;
}

static int bad_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
{
    FIPS_ERROR_IGNORED("Cipher ctrl");
    return 0;
}

static const EVP_CIPHER bad_cipher = {
    0,
    0,
    0,
    0,
    0,
    bad_init,
    bad_do_cipher,
    NULL,
    0,
    bad_set_asn1,
    bad_get_asn1,
    bad_ctrl,
    NULL
};

#endif

#ifndef OPENSSL_NO_ENGINE

# ifdef OPENSSL_FIPS

static int do_engine_null(ENGINE *impl)
{
    return 0;
}

static int do_evp_enc_engine_null(EVP_CIPHER_CTX *ctx,
                                  const EVP_CIPHER **pciph, ENGINE *impl)
{
    return 1;
}

static int (*do_engine_finish) (ENGINE *impl)
    = do_engine_null;

static int (*do_evp_enc_engine)
 (EVP_CIPHER_CTX *ctx, const EVP_CIPHER **pciph, ENGINE *impl)
    = do_evp_enc_engine_null;

void int_EVP_CIPHER_set_engine_callbacks(int (*eng_ciph_fin) (ENGINE *impl),
                                         int (*eng_ciph_evp)
                                          (EVP_CIPHER_CTX *ctx,
                                           const EVP_CIPHER **pciph,
                                           ENGINE *impl))
{
    do_engine_finish = eng_ciph_fin;
    do_evp_enc_engine = eng_ciph_evp;
}

# else

#  define do_engine_finish ENGINE_finish

static int do_evp_enc_engine(EVP_CIPHER_CTX *ctx, const EVP_CIPHER **pcipher,
                             ENGINE *impl)
{
    if (impl) {
        if (!ENGINE_init(impl)) {
            EVPerr(EVP_F_DO_EVP_ENC_ENGINE, EVP_R_INITIALIZATION_ERROR);
            return 0;
        }
    } else
        /* Ask if an ENGINE is reserved for this job */
        impl = ENGINE_get_cipher_engine((*pcipher)->nid);
    if (impl) {
        /* There's an ENGINE for this job ... (apparently) */
        const EVP_CIPHER *c = ENGINE_get_cipher(impl, (*pcipher)->nid);
        if (!c) {
            /*
             * One positive side-effect of US's export control history, is
             * that we should at least be able to avoid using US mispellings
             * of "initialisation"?
             */
            EVPerr(EVP_F_DO_EVP_ENC_ENGINE, EVP_R_INITIALIZATION_ERROR);
            return 0;
        }
        /* We'll use the ENGINE's private cipher definition */
        *pcipher = c;
        /*
         * Store the ENGINE functional reference so we know 'cipher' came
         * from an ENGINE and we need to release it when done.
         */
        ctx->engine = impl;
    } else
        ctx->engine = NULL;
    return 1;
}

# endif

#endif

int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                      ENGINE *impl, const unsigned char *key,
                      const unsigned char *iv, int enc)
{
    if (enc == -1)
        enc = ctx->encrypt;
    else {
        if (enc)
            enc = 1;
        ctx->encrypt = enc;
    }
#ifdef OPENSSL_FIPS
    if (FIPS_selftest_failed()) {
        FIPSerr(FIPS_F_EVP_CIPHERINIT_EX, FIPS_R_FIPS_SELFTEST_FAILED);
        ctx->cipher = &bad_cipher;
        return 0;
    }
#endif
#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->cipher && (!cipher ||
                                       (cipher
                                        && (cipher->nid ==
                                            ctx->cipher->nid))))
        goto skip_to_init;
#endif
    if (cipher) {
        /*
         * Ensure a context left lying around from last time is cleared (the
         * previous check attempted to avoid this if the same ENGINE and
         * EVP_CIPHER could be used).
         */
        EVP_CIPHER_CTX_cleanup(ctx);

        /* Restore encrypt field: it is zeroed by cleanup */
        ctx->encrypt = enc;
#ifndef OPENSSL_NO_ENGINE
        if (!do_evp_enc_engine(ctx, &cipher, impl))
            return 0;
#endif

        ctx->cipher = cipher;
        if (ctx->cipher->ctx_size) {
            ctx->cipher_data = OPENSSL_malloc(ctx->cipher->ctx_size);
            if (!ctx->cipher_data) {
                EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
                return 0;
            }
        } else {
            ctx->cipher_data = NULL;
        }
        ctx->key_len = cipher->key_len;
        ctx->flags = 0;
        if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
            if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
                EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
                return 0;
            }
        }
    } else if (!ctx->cipher) {
        EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_NO_CIPHER_SET);
        return 0;
    }
#ifndef OPENSSL_NO_ENGINE
 skip_to_init:
#endif
    /* we assume block size is a power of 2 in *cryptUpdate */
    OPENSSL_assert(ctx->cipher->block_size == 1
                   || ctx->cipher->block_size == 8
                   || ctx->cipher->block_size == 16);

    if (!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
        switch (EVP_CIPHER_CTX_mode(ctx)) {

        case EVP_CIPH_STREAM_CIPHER:
        case EVP_CIPH_ECB_MODE:
            break;

        case EVP_CIPH_CFB_MODE:
        case EVP_CIPH_OFB_MODE:

            ctx->num = 0;
            /* fall-through */

        case EVP_CIPH_CBC_MODE:

            OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
                           (int)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;

        default:
            return 0;
            break;
        }
    }
#ifdef OPENSSL_FIPS
    /*
     * After 'key' is set no further parameters changes are permissible. So
     * only check for non FIPS enabling at this point.
     */
    if (key && FIPS_mode()) {
        if (!(ctx->cipher->flags & EVP_CIPH_FLAG_FIPS)
            & !(ctx->flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW)) {
            EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_DISABLED_FOR_FIPS);
# if 0
            ERR_add_error_data(2, "cipher=", EVP_CIPHER_name(ctx->cipher));
# endif
            ctx->cipher = &bad_cipher;
            return 0;
        }
    }
#endif

    if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
        if (!ctx->cipher->init(ctx, key, iv, enc))
            return 0;
    }
    ctx->buf_len = 0;
    ctx->final_used = 0;
    ctx->block_mask = ctx->cipher->block_size - 1;
    return 1;
}

int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
{
    if (c->cipher != NULL) {
        if (c->cipher->cleanup && !c->cipher->cleanup(c))
            return 0;
        /* Cleanse cipher context data */
        if (c->cipher_data)
            OPENSSL_cleanse(c->cipher_data, c->cipher->ctx_size);
    }
    if (c->cipher_data)
        OPENSSL_free(c->cipher_data);
#ifndef OPENSSL_NO_ENGINE
    if (c->engine)
        /*
         * The EVP_CIPHER we used belongs to an ENGINE, release the
         * functional reference we held for this reason.
         */
        do_engine_finish(c->engine);
#endif
    memset(c, 0, sizeof(EVP_CIPHER_CTX));
    return 1;
}

int EVP_Cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
               const unsigned char *in, unsigned int inl)
{
#ifdef OPENSSL_FIPS
    FIPS_selftest_check();
#endif
    return ctx->cipher->do_cipher(ctx, out, in, inl);
}

int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
{
    int ret;
    if (!ctx->cipher) {
        EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
        return 0;
    }

    if (!ctx->cipher->ctrl) {
        EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
        return 0;
    }

    ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
    if (ret == -1) {
        EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
               EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
        return 0;
    }
    return ret;
}

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

int EVP_CIPHER_CTX_iv_length(const EVP_CIPHER_CTX *ctx)
{
    return ctx->cipher->iv_len;
}

int EVP_CIPHER_nid(const EVP_CIPHER *cipher)
{
    return cipher->nid;
}
