Created
December 9, 2020 16:33
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#include <openssl/evp.h> | |
#include <openssl/sha.h> | |
#include <stdio.h> | |
#include <string.h> | |
enum { MAX_SIZE = 4096 }; | |
enum ErrorCodes {SUCCESS, BAD_ARG }; | |
int main(int argc, char* argv[]) | |
{ | |
if (argc - 1 < 1 ) { | |
return BAD_ARG; | |
} | |
unsigned char data[MAX_SIZE] = ""; | |
int num_read = 0; | |
num_read = fread(data, sizeof(data[0]), MAX_SIZE, stdin); | |
unsigned char key[32], iv[16]; | |
unsigned char* password = (unsigned char*)argv[1]; | |
size_t pass_len = strlen(argv[1]); | |
EVP_BytesToKey( | |
EVP_aes_256_cbc(), | |
EVP_sha256(), | |
data + 8, | |
password, | |
pass_len, | |
1, | |
key, | |
iv); | |
printf("Salt="); | |
for (size_t i = 0; i < 8; ++i) { | |
printf("%02x", (data + 8)[i]); | |
} | |
printf("!\n"); | |
printf("key="); | |
for (size_t i = 0; i < 32; ++i) { | |
printf("%02x", (key)[i]); | |
} | |
printf("!\n"); | |
printf("iv="); | |
for (size_t i = 0; i < 16; ++i) { | |
printf("%02x", (iv)[i]); | |
} | |
printf("!\n"); | |
EVP_CIPHER_CTX* ctx = EVP_CIPHER_CTX_new(); | |
int len = 0; | |
int plaintext_len = 0; | |
unsigned char plaintext[MAX_SIZE] = ""; | |
EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv); | |
EVP_CIPHER_CTX_set_key_length(ctx, EVP_MAX_KEY_LENGTH); | |
EVP_DecryptUpdate(ctx, plaintext, &len, data, num_read); | |
plaintext_len = len; | |
EVP_DecryptFinal_ex(ctx, plaintext + len, &len); | |
plaintext_len += len; | |
EVP_CIPHER_CTX_free(ctx); | |
fwrite(plaintext, sizeof(plaintext[0]), plaintext_len, stdout); | |
return 0; | |
} |
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