/* clu_decrypt.c * * Copyright (C) 2006-2017 wolfSSL Inc. * * This file is part of wolfSSL. (formerly known as CyaSSL) * * wolfSSL is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * wolfSSL is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */ #include "clu_include/clu_header_main.h" #include "clu_include/genkey/clu_genkey.h" #define MAX_LEN 1024 int wolfCLU_decrypt(char* alg, char* mode, byte* pwdKey, byte* key, int size, char* in, char* out, byte* iv, int block, int keyType) { #ifndef NO_AES Aes aes; /* aes declaration */ #endif #ifndef NO_DES3 Des3 des3; /* 3des declaration */ #endif #ifdef HAVE_CAMELLIA Camellia camellia; /* camellia declaration */ #endif FILE* inFile; /* input file */ FILE* outFile; /* output file */ RNG rng; /* random number generator */ byte* input = NULL; /* input buffer */ byte* output = NULL; /* output buffer */ byte salt[SALT_SIZE] = {0}; /* salt variable */ int currLoopFlag = 1; /* flag to track the loop */ int lastLoopFlag = 0; /* flag for last loop */ int ret = 0; /* return variable */ int keyVerify = 0; /* verify the key is set */ int i = 0; /* loop variable */ int pad = 0; /* the length to pad */ int length; /* length of message */ int tempMax = MAX_LEN; /* equal to MAX_LEN until feof */ int sbSize = SALT_SIZE + block; /* size of salt and iv together */ /* opens input file */ inFile = fopen(in, "rb"); if (inFile == NULL) { printf("Input file does not exist.\n"); return DECRYPT_ERROR; } /* opens output file */ if ((outFile = fopen(out, "wb")) == NULL) { printf("Error creating output file.\n"); return DECRYPT_ERROR; } /* find end of file for length */ fseek(inFile, 0, SEEK_END); length = (int) ftell(inFile); fseek(inFile, 0, SEEK_SET); /* if there is a remainder, * round up else no round */ if (length % MAX_LEN > 0) { lastLoopFlag = (length/MAX_LEN) + 1; } else { lastLoopFlag = length/MAX_LEN; } input = (byte*) XMALLOC(MAX_LEN, HEAP_HINT, DYNAMIC_TYPE_TMP_BUFFER); if (input == NULL) return MEMORY_E; output = (byte*) XMALLOC(MAX_LEN, HEAP_HINT, DYNAMIC_TYPE_TMP_BUFFER); if (output == NULL) { wolfCLU_freeBins(input, NULL, NULL, NULL, NULL); } wc_InitRng(&rng); /* reads from inFile and writes whatever * is there to the input buffer */ while ( length > 0 ) { /* On first loop only read in salt and iv */ if (currLoopFlag == 1) { if ( (int) fread (salt, 1, SALT_SIZE, inFile) != SALT_SIZE) { printf("Error reading salt.\n"); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return FREAD_ERROR; } if ( (int) fread (iv, 1, block, inFile) != block) { printf("Error reading salt.\n"); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return FREAD_ERROR; } /* replicates old pwdKey if pwdKeys match */ if (keyType == 1) { if (wc_PBKDF2(key, pwdKey, (int) strlen((const char*)pwdKey), salt, SALT_SIZE, CLU_4K_TYPE, size, CLU_SHA256) != 0) { printf("pwdKey set error.\n"); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return ENCRYPT_ERROR; } } else if (keyType == 2) { for (i = 0; i < size; i++) { /* ensure key is set */ if (key[i] == 0 || key[i] == '\0') { continue; } else { keyVerify++; } } if (keyVerify == 0) { printf("the key is all zero's or not set.\n"); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return ENCRYPT_ERROR; } } } /* Read in 1kB */ if ((ret = (int) fread(input, 1, MAX_LEN, inFile)) != MAX_LEN) { if (feof(inFile)) { tempMax = ret; } else { printf("Input file does not exist.\n"); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return FREAD_ERROR; } } /* sets pwdKey decrypts the message to output from input length */ #ifndef NO_AES if (XSTRNCMP(alg, "aes", 3) == 0) { if (XSTRNCMP(mode, "cbc", 3) == 0) { ret = wc_AesSetKey(&aes, key, AES_BLOCK_SIZE, iv, AES_DECRYPTION); if (ret != 0) { fclose(inFile); fclose(outFile); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return ret; } ret = wc_AesCbcDecrypt(&aes, output, input, tempMax); if (ret != 0) { fclose(inFile); fclose(outFile); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return DECRYPT_ERROR; } } #ifdef WOLFSSL_AES_COUNTER else if (XSTRNCMP(mode, "ctr", 3) == 0) { /* if mode is ctr */ wc_AesSetKeyDirect(&aes, key, AES_BLOCK_SIZE, iv, AES_ENCRYPTION); wc_AesCtrEncrypt(&aes, output, input, tempMax); } #endif } #endif #ifndef NO_DES3 if (XSTRNCMP(alg, "3des", 4) == 0) { ret = wc_Des3_SetKey(&des3, key, iv, DES_DECRYPTION); if (ret != 0) { fclose(inFile); fclose(outFile); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return ret; } ret = wc_Des3_CbcDecrypt(&des3, output, input, tempMax); if (ret != 0){ fclose(inFile); fclose(outFile); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return DECRYPT_ERROR; } } #endif #ifdef HAVE_CAMELLIA if (XSTRNCMP(alg, "camellia", 8) == 0) { ret = wc_CamelliaSetKey(&camellia, key, block, iv); if (ret != 0) { fclose(inFile); fclose(outFile); wolfCLU_freeBins(input, output, NULL, NULL, NULL); return ret; } wc_CamelliaCbcDecrypt(&camellia, output, input, tempMax); } #endif if (currLoopFlag == lastLoopFlag) { if (salt[0] != 0) { /* reduces length based on number of padded elements */ pad = output[tempMax-1]; /* adjust length for padded bytes and salt size */ length -= pad + sbSize; /* reset tempMax for smaller decryption */ fwrite(output, 1, length, outFile); break; } else { fwrite(output, 1, tempMax, outFile); XMEMSET(input, 0, tempMax); XMEMSET(output, 0, tempMax); break; } } /* writes output to the outFile */ fwrite(output, 1, tempMax, outFile); XMEMSET(input, 0, tempMax); XMEMSET(output, 0, tempMax); currLoopFlag++; length -= tempMax; } /* closes the opened files and frees memory */ XMEMSET(input, 0, MAX_LEN); XMEMSET (output, 0, MAX_LEN); wolfCLU_freeBins(input, output, NULL, NULL, NULL); XMEMSET(key, 0, size); /* Use the wolfssl wc_FreeRng to free rng */ wc_FreeRng(&rng); fclose(inFile); fclose(outFile); return 0; }