forked from Mirrorlandia_minetest/irrlicht
2ae2a551a6
GLES drivers adapted, but only did make compile-tests. git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/branches/ogl-es@6038 dfc29bdd-3216-0410-991c-e03cc46cb475
139 lines
4.9 KiB
C++
139 lines
4.9 KiB
C++
/*
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---------------------------------------------------------------------------
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Copyright (c) 2002, Dr Brian Gladman < >, Worcester, UK.
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All rights reserved.
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LICENSE TERMS
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The free distribution and use of this software in both source and binary
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form is allowed (with or without changes) provided that:
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1. distributions of this source code include the above copyright
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notice, this list of conditions and the following disclaimer;
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2. distributions in binary form include the above copyright
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notice, this list of conditions and the following disclaimer
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in the documentation and/or other associated materials;
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3. the copyright holder's name is not used to endorse products
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built using this software without specific written permission.
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ALTERNATIVELY, provided that this notice is retained in full, this product
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may be distributed under the terms of the GNU General Public License (GPL),
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in which case the provisions of the GPL apply INSTEAD OF those given above.
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DISCLAIMER
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This software is provided 'as is' with no explicit or implied warranties
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in respect of its properties, including, but not limited to, correctness
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and/or fitness for purpose.
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-------------------------------------------------------------------------
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Issue Date: 26/08/2003
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This file implements password based file encryption and authentication
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using AES in CTR mode, HMAC-SHA1 authentication and RFC2898 password
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based key derivation.
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*/
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#include <memory.h>
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#include "fileenc.h"
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/* subroutine for data encryption/decryption */
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/* this could be speeded up a lot by aligning */
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/* buffers and using 32 bit operations */
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static void encr_data(unsigned char data[], unsigned long d_len, fcrypt_ctx cx[1])
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{
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unsigned long i = 0, pos = cx->encr_pos;
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while(i < d_len)
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{
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if(pos == BLOCK_SIZE)
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{ unsigned int j = 0;
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/* increment encryption nonce */
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while(j < 8 && !++cx->nonce[j])
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++j;
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/* encrypt the nonce to form next xor buffer */
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aes_encrypt(cx->nonce, cx->encr_bfr, cx->encr_ctx);
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pos = 0;
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}
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data[i++] ^= cx->encr_bfr[pos++];
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}
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cx->encr_pos = pos;
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}
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int fcrypt_init(
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int mode, /* the mode to be used (input) */
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const unsigned char pwd[], /* the user specified password (input) */
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unsigned int pwd_len, /* the length of the password (input) */
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const unsigned char salt[], /* the salt (input) */
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#ifdef PASSWORD_VERIFIER
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unsigned char pwd_ver[PWD_VER_LENGTH], /* 2 byte password verifier (output) */
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#endif
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fcrypt_ctx cx[1]) /* the file encryption context (output) */
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{
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unsigned char kbuf[2 * MAX_KEY_LENGTH + PWD_VER_LENGTH];
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if(pwd_len > MAX_PWD_LENGTH)
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return PASSWORD_TOO_LONG;
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if(mode < 1 || mode > 3)
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return BAD_MODE;
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cx->mode = mode;
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cx->pwd_len = pwd_len;
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/* initialise the encryption nonce and buffer pos */
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cx->encr_pos = BLOCK_SIZE;
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/* if we need a random component in the encryption */
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/* nonce, this is where it would have to be set */
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memset(cx->nonce, 0, BLOCK_SIZE * sizeof(unsigned char));
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/* initialise for authentication */
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hmac_sha_begin(cx->auth_ctx);
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/* derive the encryption and authetication keys and the password verifier */
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derive_key(pwd, pwd_len, salt, SALT_LENGTH(mode), KEYING_ITERATIONS,
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kbuf, 2 * KEY_LENGTH(mode) + PWD_VER_LENGTH);
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/* set the encryption key */
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aes_encrypt_key(kbuf, KEY_LENGTH(mode), cx->encr_ctx);
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/* set the authentication key */
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hmac_sha_key(kbuf + KEY_LENGTH(mode), KEY_LENGTH(mode), cx->auth_ctx);
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#ifdef PASSWORD_VERIFIER
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memcpy(pwd_ver, kbuf + 2 * KEY_LENGTH(mode), PWD_VER_LENGTH);
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#endif
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/* clear the buffer holding the derived key values */
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memset(kbuf, 0, 2 * KEY_LENGTH(mode) + PWD_VER_LENGTH);
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return GOOD_RETURN;
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}
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/* perform 'in place' encryption and authentication */
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void fcrypt_encrypt(unsigned char data[], unsigned int data_len, fcrypt_ctx cx[1])
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{
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encr_data(data, data_len, cx);
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hmac_sha_data(data, data_len, cx->auth_ctx);
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}
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/* perform 'in place' authentication and decryption */
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void fcrypt_decrypt(unsigned char data[], unsigned int data_len, fcrypt_ctx cx[1])
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{
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hmac_sha_data(data, data_len, cx->auth_ctx);
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encr_data(data, data_len, cx);
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}
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/* close encryption/decryption and return the MAC value */
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int fcrypt_end(unsigned char mac[], fcrypt_ctx cx[1])
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{
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hmac_sha_end(mac, MAC_LENGTH(cx->mode), cx->auth_ctx);
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memset(cx, 0, sizeof(fcrypt_ctx)); /* clear the encryption context */
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return MAC_LENGTH(cx->mode); /* return MAC length in bytes */
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}
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