--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/dav/crypto.c Mon Aug 12 14:40:19 2013 +0200 @@ -0,0 +1,142 @@ +/* + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. + * + * Copyright 2013 Olaf Wintermann. All rights reserved. + * + * 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 above 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. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER 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. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "crypto.h" + +AESDecrypter* aes_decrypter_new(Key *key, void *stream, dav_write_func write_func) { + AESDecrypter *dec = malloc(sizeof(AESDecrypter)); + dec->stream = stream; + dec->write = write_func; + + EVP_CIPHER_CTX_init(&dec->ctx); + if(key->type == KEY_AES128) { + EVP_DecryptInit_ex(&dec->ctx, EVP_aes_128_cbc(), NULL, key->data, NULL); + } else if(key->type == KEY_AES256) { + EVP_DecryptInit_ex(&dec->ctx, EVP_aes_256_cbc(), NULL, key->data, NULL); + } else { + fprintf(stderr, "unknown key type\n"); + exit(-1); + } + return dec; +} + +size_t aes_write(const void *buf, size_t s, size_t n, AESDecrypter *dec) { + int len = s*n; + int outlen = len + AES_BLOCK_SIZE; + unsigned char *out = malloc(outlen); + EVP_DecryptUpdate(&dec->ctx, out, &len, buf, len); + dec->write(out, 1, len, dec->stream); + free(out); + return (s*n) / s; +} + +void aes_decrypter_close(AESDecrypter *dec) { + void *out = malloc(128); + int len = 0; + EVP_DecryptFinal_ex(&dec->ctx, out, &len); + dec->write(out, 1, len, dec->stream); + free(out); + EVP_CIPHER_CTX_cleanup(&dec->ctx); + free(dec); +} + + +AESEncrypter* aes_encrypter_new(Key *key, void *stream, dav_read_func read_func) { + AESEncrypter *enc = malloc(sizeof(AESEncrypter)); + enc->stream = stream; + enc->read = read_func; + enc->tmp = NULL; + enc->tmplen = 0; + enc->tmpoff = 0; + enc->end = 0; + + EVP_CIPHER_CTX_init(&enc->ctx); + if(key->type == KEY_AES128) { + EVP_EncryptInit_ex(&enc->ctx, EVP_aes_128_cbc(), NULL, key->data, NULL); + } else if(key->type == KEY_AES256) { + EVP_EncryptInit_ex(&enc->ctx, EVP_aes_256_cbc(), NULL, key->data, NULL); + } else { + fprintf(stderr, "unknown key type\n"); + exit(-1); + } + return enc; +} + +size_t aes_read(void *buf, size_t s, size_t n, AESEncrypter *enc) { + size_t len = s*n; + if(enc->tmp) { + size_t tmp_diff = enc->tmplen - enc->tmpoff; + size_t cp_len = tmp_diff > len ? len : tmp_diff; + memcpy(buf, enc->tmp + enc->tmpoff, cp_len); + enc->tmpoff += cp_len; + if(enc->tmpoff >= enc->tmplen) { + free(enc->tmp); + enc->tmp = NULL; + enc->tmplen = 0; + enc->tmpoff = 0; + } + return cp_len / s; + } + + if(enc->end) { + return 0; + } + + void *in = malloc(len); + size_t in_len = enc->read(in, 1, len, enc->stream); + + void *out = NULL; + int outlen = 0; + if(in_len != 0) { + outlen = len + AES_BLOCK_SIZE; + out = malloc(outlen); + EVP_EncryptUpdate(&enc->ctx, out, &outlen, in, in_len); + //out = (char*)aes_encrypt(enc->ctx, (unsigned char*)in, (int*)&in_len); + } else { + out = malloc(AES_BLOCK_SIZE); + EVP_EncryptFinal_ex(&enc->ctx, out, &outlen); + enc->end = 1; + } + enc->tmp = out; + enc->tmplen = outlen; + enc->tmpoff = 0; + + return aes_read(buf, s, n, enc); +} + +void aes_encrypter_close(AESEncrypter *enc) { + if(enc->tmp) { + free(enc->tmp); + } + EVP_CIPHER_CTX_cleanup(&enc->ctx); + free(enc); +}