$key = '1234567890123456';
$iv = '1234567890123456';
$enc = openssl_encrypt("hello wolrd!", 'aes-256-cbc', $key, OPENSSL_RAW_DATA, $iv);
$decrypted = openssl_decrypt($enc, 'aes-256-cbc', $key, OPENSSL_RAW_DATA, $iv);
echo bin2hex($enc)."
";
echo $decrypted;
algo_aes.h
#ifndef ALGO_AES_H
#define ALGO_AES_H
int encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
unsigned char *iv, unsigned char *ciphertext);
int decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
unsigned char *iv, unsigned char *plaintext);
#endif
algo_aes.cpp
#include <stdlib.h>
#include <stdio.h>
//#include "algo_aes.h"
#include <openssl/evp.h>
#pragma comment(lib, "libeay32.lib")
void handleErrors(void)
{
//ERR_print_errors_fp(stderr);
abort();
}
int encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
unsigned char *iv, unsigned char *ciphertext)
{
EVP_CIPHER_CTX *ctx;
int len;
int ciphertext_len;
/* Create and initialise the context */
if (!(ctx = EVP_CIPHER_CTX_new())) handleErrors();
/* Initialise the encryption operation. IMPORTANT - ensure you use a key
* and IV size appropriate for your cipher
* In this example we are using 256 bit AES (i.e. a 256 bit key). The
* IV size for *most* modes is the same as the block size. For AES this
* is 128 bits */
if (1 != EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv))
handleErrors();
/* Provide the message to be encrypted, and obtain the encrypted output.
* EVP_EncryptUpdate can be called multiple times if necessary
*/
if (1 != EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len))
handleErrors();
ciphertext_len = len;
/* Finalise the encryption. Further ciphertext bytes may be written at
* this stage.
*/
if (1 != EVP_EncryptFinal_ex(ctx, ciphertext + len, &len)) handleErrors();
ciphertext_len += len;
/* Clean up */
EVP_CIPHER_CTX_free(ctx);
return ciphertext_len;
}
int decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
unsigned char *iv, unsigned char *plaintext)
{
EVP_CIPHER_CTX *ctx;
int len;
int plaintext_len;
/* Create and initialise the context */
if (!(ctx = EVP_CIPHER_CTX_new())) handleErrors();
/* Initialise the decryption operation. IMPORTANT - ensure you use a key
* and IV size appropriate for your cipher
* In this example we are using 256 bit AES (i.e. a 256 bit key). The
* IV size for *most* modes is the same as the block size. For AES this
* is 128 bits */
if (1 != EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv))
handleErrors();
/* Provide the message to be decrypted, and obtain the plaintext output.
* EVP_DecryptUpdate can be called multiple times if necessary
*/
if (1 != EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len))
handleErrors();
plaintext_len = len;
/* Finalise the decryption. Further plaintext bytes may be written at
* this stage.
*/
if (1 != EVP_DecryptFinal_ex(ctx, plaintext + len, &len)) handleErrors();
plaintext_len += len;
/* Clean up */
EVP_CIPHER_CTX_free(ctx);
return plaintext_len;
}
//#include "algo_aes.h"
#include <stdio.h>
#include <string.h>
//#include <openssl/evp.h>
int main(int arc, char *argv[])
{
/* Set up the key and iv. Do I need to say to not hard code these in a
* real application? :-)
*/
/* A 256 bit key */
unsigned char *key = (unsigned char*)"1234567890123456";
/* A 128 bit IV */
unsigned char *iv = (unsigned char*)"1234567890123456";
/* Message to be encrypted */
unsigned char *plaintext = (unsigned char*)"hello wolrd!";
/* Buffer for ciphertext. Ensure the buffer is long enough for the
* ciphertext which may be longer than the plaintext, dependant on the
* algorithm and mode
*/
unsigned char ciphertext[64];
/* Buffer for the decrypted text */
unsigned char decryptedtext[64];
int decryptedtext_len, ciphertext_len;
/* Initialise the library */
/* ERR_load_crypto_strings();
OpenSSL_add_all_algorithms();
OPENSSL_config(NULL);*/
printf("Plaintext is:
%s
", plaintext);
/* Encrypt the plaintext */
ciphertext_len = encrypt(plaintext, strlen((const char*)plaintext), key, iv,
ciphertext);
/* Do something useful with the ciphertext here */
printf("Ciphertext is %d bytes long:
", ciphertext_len);
BIO_dump_fp(stdout, (const char*)ciphertext, ciphertext_len);
/* Decrypt the ciphertext */
decryptedtext_len = decrypt(ciphertext, ciphertext_len, key, iv,
decryptedtext);
/* Add a NULL terminator. We are expecting printable text */
decryptedtext[decryptedtext_len] = ' ';
/* Show the decrypted text */
printf("Decrypted text is:
");
printf("%s
", decryptedtext);
/* Clean up */
EVP_cleanup();
//ERR_free_strings();
system("pause");
return 0;
}