crypto/evp/evp_enc.c

/* crypto/evp/evp_enc.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"

#ifdef OPENSSL_FIPS
# define M_do_cipher(ctx, out, in, inl) \
                EVP_Cipher(ctx,out,in,inl)
#else
# define M_do_cipher(ctx, out, in, inl) \
                ctx->cipher->do_cipher(ctx,out,in,inl)
#endif

const char EVP_version[] = "EVP" OPENSSL_VERSION_PTEXT;

EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void)
{
    EVP_CIPHER_CTX *ctx = OPENSSL_malloc(sizeof *ctx);
    if (ctx)
        EVP_CIPHER_CTX_init(ctx);
    return ctx;
}

int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                   const unsigned char *key, const unsigned char *iv, int enc)
{
    if (cipher)
        EVP_CIPHER_CTX_init(ctx);
    return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
}

int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                     const unsigned char *in, int inl)
{
    if (ctx->encrypt)
        return EVP_EncryptUpdate(ctx, out, outl, in, inl);
    else
        return EVP_DecryptUpdate(ctx, out, outl, in, inl);
}

int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    if (ctx->encrypt)
        return EVP_EncryptFinal_ex(ctx, out, outl);
    else
        return EVP_DecryptFinal_ex(ctx, out, outl);
}

int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    if (ctx->encrypt)
        return EVP_EncryptFinal(ctx, out, outl);
    else
        return EVP_DecryptFinal(ctx, out, outl);
}

int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                    const unsigned char *key, const unsigned char *iv)
{
    return EVP_CipherInit(ctx, cipher, key, iv, 1);
}

int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                       ENGINE *impl, const unsigned char *key,
                       const unsigned char *iv)
{
    return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
}

int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                    const unsigned char *key, const unsigned char *iv)
{
    return EVP_CipherInit(ctx, cipher, key, iv, 0);
}

int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                       ENGINE *impl, const unsigned char *key,
                       const unsigned char *iv)
{
    return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
}

int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                      const unsigned char *in, int inl)
{
    int i, j, bl;

    if (inl <= 0) {
        *outl = 0;
        return inl == 0;
    }

    if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
        if (M_do_cipher(ctx, out, in, inl)) {
            *outl = inl;
            return 1;
        } else {
            *outl = 0;
            return 0;
        }
    }
    i = ctx->buf_len;
    bl = ctx->cipher->block_size;
    OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
    if (i != 0) {
        if (i + inl < bl) {
            memcpy(&(ctx->buf[i]), in, inl);
            ctx->buf_len += inl;
            *outl = 0;
            return 1;
        } else {
            j = bl - i;
            memcpy(&(ctx->buf[i]), in, j);
            if (!M_do_cipher(ctx, out, ctx->buf, bl))
                return 0;
            inl -= j;
            in += j;
            out += bl;
            *outl = bl;
        }
    } else
        *outl = 0;
    i = inl & (bl - 1);
    inl -= i;
    if (inl > 0) {
        if (!M_do_cipher(ctx, out, in, inl))
            return 0;
        *outl += inl;
    }

    if (i != 0)
        memcpy(ctx->buf, &(in[inl]), i);
    ctx->buf_len = i;
    return 1;
}

int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    int ret;
    ret = EVP_EncryptFinal_ex(ctx, out, outl);
    return ret;
}

int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    int n, ret;
    unsigned int i, b, bl;

    b = ctx->cipher->block_size;
    OPENSSL_assert(b <= sizeof ctx->buf);
    if (b == 1) {
        *outl = 0;
        return 1;
    }
    bl = ctx->buf_len;
    if (ctx->flags & EVP_CIPH_NO_PADDING) {
        if (bl) {
            EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
                   EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
            return 0;
        }
        *outl = 0;
        return 1;
    }

    n = b - bl;
    for (i = bl; i < b; i++)
        ctx->buf[i] = n;
    ret = M_do_cipher(ctx, out, ctx->buf, b);

    if (ret)
        *outl = b;

    return ret;
}

int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                      const unsigned char *in, int inl)
{
    int fix_len;
    unsigned int b;

    if (inl <= 0) {
        *outl = 0;
        return inl == 0;
    }

    if (ctx->flags & EVP_CIPH_NO_PADDING)
        return EVP_EncryptUpdate(ctx, out, outl, in, inl);

    b = ctx->cipher->block_size;
    OPENSSL_assert(b <= sizeof ctx->final);

    if (ctx->final_used) {
        memcpy(out, ctx->final, b);
        out += b;
        fix_len = 1;
    } else
        fix_len = 0;

    if (!EVP_EncryptUpdate(ctx, out, outl, in, inl))
        return 0;

    /*
     * if we have 'decrypted' a multiple of block size, make sure we have a
     * copy of this last block
     */
    if (b > 1 && !ctx->buf_len) {
        *outl -= b;
        ctx->final_used = 1;
        memcpy(ctx->final, &out[*outl], b);
    } else
        ctx->final_used = 0;

    if (fix_len)
        *outl += b;

    return 1;
}

int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    int ret;
    ret = EVP_DecryptFinal_ex(ctx, out, outl);
    return ret;
}

int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    int i, n;
    unsigned int b;

    *outl = 0;
    b = ctx->cipher->block_size;
    if (ctx->flags & EVP_CIPH_NO_PADDING) {
        if (ctx->buf_len) {
            EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
                   EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
            return 0;
        }
        *outl = 0;
        return 1;
    }
    if (b > 1) {
        if (ctx->buf_len || !ctx->final_used) {
            EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
            return (0);
        }
        OPENSSL_assert(b <= sizeof ctx->final);
        n = ctx->final[b - 1];
        if (n == 0 || n > (int)b) {
            EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
            return (0);
        }
        for (i = 0; i < n; i++) {
            if (ctx->final[--b] != n) {
                EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
                return (0);
            }
        }
        n = ctx->cipher->block_size - n;
        for (i = 0; i < n; i++)
            out[i] = ctx->final[i];
        *outl = n;
    } else
        *outl = 0;
    return (1);
}

void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
{
    if (ctx) {
        EVP_CIPHER_CTX_cleanup(ctx);
        OPENSSL_free(ctx);
    }
}

int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
{
    if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
        return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
    if (c->key_len == keylen)
        return 1;
    if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
        c->key_len = keylen;
        return 1;
    }
    EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
    return 0;
}

int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
{
    if (pad)
        ctx->flags &= ~EVP_CIPH_NO_PADDING;
    else
        ctx->flags |= EVP_CIPH_NO_PADDING;
    return 1;
}

int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *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) <= 0)
        return 0;
    return 1;
}

#ifndef OPENSSL_NO_ENGINE

# ifdef OPENSSL_FIPS

static int do_evp_enc_engine_full(EVP_CIPHER_CTX *ctx,
                                  const EVP_CIPHER **pcipher, ENGINE *impl)
{
    if (impl) {
        if (!ENGINE_init(impl)) {
            EVPerr(EVP_F_DO_EVP_ENC_ENGINE_FULL, 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_FULL, 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;
}

void int_EVP_CIPHER_init_engine_callbacks(void)
{
    int_EVP_CIPHER_set_engine_callbacks(ENGINE_finish,
                                        do_evp_enc_engine_full);
}

# endif

#endif