diff options
Diffstat (limited to 'src/crypto/cipher/derive_key.c')
| -rw-r--r-- | src/crypto/cipher/derive_key.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/src/crypto/cipher/derive_key.c b/src/crypto/cipher/derive_key.c new file mode 100644 index 0000000..9e1634a --- /dev/null +++ b/src/crypto/cipher/derive_key.c @@ -0,0 +1,154 @@ +/* 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 <openssl/cipher.h> + +#include <assert.h> + +#include <openssl/digest.h> +#include <openssl/mem.h> + +#include "internal.h" + + +#define PKCS5_SALT_LEN 8 + +int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md, + const uint8_t *salt, const uint8_t *data, size_t data_len, + unsigned count, uint8_t *key, uint8_t *iv) { + EVP_MD_CTX c; + uint8_t md_buf[EVP_MAX_MD_SIZE]; + unsigned niv, nkey, addmd = 0; + unsigned mds = 0, i; + int rv = 0; + + nkey = type->key_len; + niv = type->iv_len; + + assert(nkey <= EVP_MAX_KEY_LENGTH); + assert(niv <= EVP_MAX_IV_LENGTH); + + if (data == NULL) { + return nkey; + } + + EVP_MD_CTX_init(&c); + for (;;) { + if (!EVP_DigestInit_ex(&c, md, NULL)) { + return 0; + } + if (addmd++) { + if (!EVP_DigestUpdate(&c, md_buf, mds)) { + goto err; + } + } + if (!EVP_DigestUpdate(&c, data, data_len)) { + goto err; + } + if (salt != NULL) { + if (!EVP_DigestUpdate(&c, salt, PKCS5_SALT_LEN)) { + goto err; + } + } + if (!EVP_DigestFinal_ex(&c, md_buf, &mds)) { + goto err; + } + + for (i = 1; i < count; i++) { + if (!EVP_DigestInit_ex(&c, md, NULL) || + !EVP_DigestUpdate(&c, md_buf, mds) || + !EVP_DigestFinal_ex(&c, md_buf, &mds)) { + goto err; + } + } + + i = 0; + if (nkey) { + for (;;) { + if (nkey == 0 || i == mds) { + break; + } + if (key != NULL) { + *(key++) = md_buf[i]; + } + nkey--; + i++; + } + } + + if (niv && i != mds) { + for (;;) { + if (niv == 0 || i == mds) { + break; + } + if (iv != NULL) { + *(iv++) = md_buf[i]; + } + niv--; + i++; + } + } + if (nkey == 0 && niv == 0) { + break; + } + } + rv = type->key_len; + +err: + EVP_MD_CTX_cleanup(&c); + OPENSSL_cleanse(md_buf, EVP_MAX_MD_SIZE); + return rv; +} |