我试图使用OpenSSL库和ECB模式创建AES加密示例。在ECB模式下很难找到任何文档，所以我拿了一个使用CBC模式的代码示例并尝试将其修改为ECB模式。我去掉了ECB中不包含的初始化向量，并尽力修改了代码。完成后编译时遇到了一些问题：
AES-256-ECB-Encryption.cpp: In function ‘int encrypt(unsigned char*, int, unsigned char*, unsigned char*)’:
AES-256-ECB-Encryption.cpp:27:63: error: too few arguments to function ‘int EVP_EncryptInit_ex(EVP_CIPHER_CTX*, const EVP_CIPHER*, ENGINE*, const unsigned char*, const unsigned char*)’
if(1 != EVP_EncryptInit_ex(ctx, EVP_aes_256_ecb(), NULL, key))
错误提示说我在int encrypt函数中参数太少。同时，在int decrypt函数中也存在此错误。我想知道是否有人能帮我澄清问题。我知道ECB模式存在的漏洞，但我仍然希望熟悉它。另外，我知道密钥不应硬编码，但我只是想运行一个示例来确保我有正确的想法。我正在使用OpenSSL库中的libcrypto库中的EVP对称加密和解密。我在Ubuntu 16.0.4上运行，如果有关系的话。如果有人能为我的问题提供一些解决方案或更多的ECB文档，那将不胜感激。
谢谢
以下是代码的其余部分：
#include <openssl/conf.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <string.h>
void handleErrors(void)
{
ERR_print_errors_fp(stderr);
abort();
}
int encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key, 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
* In this example we are using 256 bit AES (i.e. a 256 bit key).
*/
if(1 != EVP_EncryptInit_ex(ctx, EVP_aes_256_ecb(), NULL, key))
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 *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
* In this example we are using 256 bit AES (i.e. a 256 bit key). The
*/
if(1 != EVP_DecryptInit_ex(ctx, EVP_aes_256_ecb(), NULL, key))
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;
}
int main (void)
{
/* A 256 bit key */
unsigned char *key = (unsigned char *)"01234567890123456789012345678901";
/* Message to be encrypted */
unsigned char *plaintext =
(unsigned char *)"This is a test.";
/* 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[128];
/* Buffer for the decrypted text */
unsigned char decryptedtext[128];
int decryptedtext_len, ciphertext_len;
/* Initialise the library */
ERR_load_crypto_strings();
OpenSSL_add_all_algorithms();
OPENSSL_config(NULL);
/* Encrypt the plaintext */
ciphertext_len = encrypt (plaintext, strlen ((char *)plaintext), key, ciphertext);
/* Do something useful with the ciphertext here */
printf("Ciphertext is:\n");
BIO_dump_fp (stdout, (const char *)ciphertext, ciphertext_len);
/* Decrypt the ciphertext */
decryptedtext_len = decrypt(ciphertext, ciphertext_len, key,
decryptedtext);
/* Add a NULL terminator. Expecting printable text */
decryptedtext[decryptedtext_len] = '\0';
/* Show the decrypted text */
printf("Decrypted text is:\n");
printf("%s\n", decryptedtext);
/* Clean up */
EVP_cleanup();
ERR_free_strings();
return 0;
}
EVP_EncryptInit_ex传递了4个参数，而应该传递5个参数。 - iRove