openssl/crypto/evp/e_rc2.c

/* crypto/evp/e_rc2.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"

#ifndef OPENSSL_NO_RC2

# include <openssl/evp.h>
# include <openssl/objects.h>
# include "evp_locl.h"
# include <openssl/rc2.h>

static int rc2_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
                        const unsigned char *iv, int enc);
static int rc2_meth_to_magic(EVP_CIPHER_CTX *ctx);
static int rc2_magic_to_meth(int i);
static int rc2_set_asn1_type_and_iv(EVP_CIPHER_CTX *c, ASN1_TYPE *type);
static int rc2_get_asn1_type_and_iv(EVP_CIPHER_CTX *c, ASN1_TYPE *type);
static int rc2_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr);

typedef struct {
    int key_bits;               /* effective key bits */
    RC2_KEY ks;                 /* key schedule */
} EVP_RC2_KEY;

# define data(ctx)       ((EVP_RC2_KEY *)(ctx)->cipher_data)

IMPLEMENT_BLOCK_CIPHER(rc2, ks, RC2, EVP_RC2_KEY, NID_rc2,
                       8,
                       RC2_KEY_LENGTH, 8, 64,
                       EVP_CIPH_VARIABLE_LENGTH | EVP_CIPH_CTRL_INIT,
                       rc2_init_key, NULL,
                       rc2_set_asn1_type_and_iv, rc2_get_asn1_type_and_iv,
                       rc2_ctrl)
# define RC2_40_MAGIC    0xa0
# define RC2_64_MAGIC    0x78
# define RC2_128_MAGIC   0x3a
static const EVP_CIPHER r2_64_cbc_cipher = {
    NID_rc2_64_cbc,
    8, 8 /* 64 bit */ , 8,
    EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | EVP_CIPH_CTRL_INIT,
    rc2_init_key,
    rc2_cbc_cipher,
    NULL,
    sizeof(EVP_RC2_KEY),
    rc2_set_asn1_type_and_iv,
    rc2_get_asn1_type_and_iv,
    rc2_ctrl,
    NULL
};

static const EVP_CIPHER r2_40_cbc_cipher = {
    NID_rc2_40_cbc,
    8, 5 /* 40 bit */ , 8,
    EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | EVP_CIPH_CTRL_INIT,
    rc2_init_key,
    rc2_cbc_cipher,
    NULL,
    sizeof(EVP_RC2_KEY),
    rc2_set_asn1_type_and_iv,
    rc2_get_asn1_type_and_iv,
    rc2_ctrl,
    NULL
};

const EVP_CIPHER *EVP_rc2_64_cbc(void)
{
    return (&r2_64_cbc_cipher);
}

const EVP_CIPHER *EVP_rc2_40_cbc(void)
{
    return (&r2_40_cbc_cipher);
}

static int rc2_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
                        const unsigned char *iv, int enc)
{
    RC2_set_key(&data(ctx)->ks, EVP_CIPHER_CTX_key_length(ctx),
                key, data(ctx)->key_bits);
    return 1;
}

static int rc2_meth_to_magic(EVP_CIPHER_CTX *e)
{
    int i;

    EVP_CIPHER_CTX_ctrl(e, EVP_CTRL_GET_RC2_KEY_BITS, 0, &i);
    if (i == 128)
        return (RC2_128_MAGIC);
    else if (i == 64)
        return (RC2_64_MAGIC);
    else if (i == 40)
        return (RC2_40_MAGIC);
    else
        return (0);
}

static int rc2_magic_to_meth(int i)
{
    if (i == RC2_128_MAGIC)
        return 128;
    else if (i == RC2_64_MAGIC)
        return 64;
    else if (i == RC2_40_MAGIC)
        return 40;
    else {
        EVPerr(EVP_F_RC2_MAGIC_TO_METH, EVP_R_UNSUPPORTED_KEY_SIZE);
        return (0);
    }
}

static int rc2_get_asn1_type_and_iv(EVP_CIPHER_CTX *c, ASN1_TYPE *type)
{
    long num = 0;
    int i = 0;
    int key_bits;
    unsigned int l;
    unsigned char iv[EVP_MAX_IV_LENGTH];

    if (type != NULL) {
        l = EVP_CIPHER_CTX_iv_length(c);
        OPENSSL_assert(l <= sizeof(iv));
        i = ASN1_TYPE_get_int_octetstring(type, &num, iv, l);
        if (i != (int)l)
            return (-1);
        key_bits = rc2_magic_to_meth((int)num);
        if (!key_bits)
            return (-1);
        if (i > 0)
            EVP_CipherInit_ex(c, NULL, NULL, NULL, iv, -1);
        EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_RC2_KEY_BITS, key_bits, NULL);
        EVP_CIPHER_CTX_set_key_length(c, key_bits / 8);
    }
    return (i);
}

static int rc2_set_asn1_type_and_iv(EVP_CIPHER_CTX *c, ASN1_TYPE *type)
{
    long num;
    int i = 0, j;

    if (type != NULL) {
        num = rc2_meth_to_magic(c);
        j = EVP_CIPHER_CTX_iv_length(c);
        i = ASN1_TYPE_set_int_octetstring(type, num, c->oiv, j);
    }
    return (i);
}

static int rc2_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
{
    switch (type) {
    case EVP_CTRL_INIT:
        data(c)->key_bits = EVP_CIPHER_CTX_key_length(c) * 8;
        return 1;

    case EVP_CTRL_GET_RC2_KEY_BITS:
        *(int *)ptr = data(c)->key_bits;
        return 1;

    case EVP_CTRL_SET_RC2_KEY_BITS:
        if (arg > 0) {
            data(c)->key_bits = arg;
            return 1;
        }
        return 0;

    default:
        return -1;
    }
}

#endif