QT+openssl 实现aes 的 ebc 加解密过程pkcs填充

以下是使用QT和openssl库实现AES的ECB加解密过程，以及PKCS填充的示例代码：

#include <QCoreApplication>
#include <openssl/evp.h>
#include <openssl/aes.h>
#include <openssl/rand.h>

void aes_encrypt(const unsigned char *plaintext, int plaintext_len,
                 const unsigned char *key, const unsigned char *iv,
                 unsigned char *ciphertext, int *ciphertext_len)
{
    EVP_CIPHER_CTX *ctx;

    int len;

    *ciphertext_len = 0;

    if(!(ctx = EVP_CIPHER_CTX_new()))
        return;

    if(1 != EVP_EncryptInit_ex(ctx, EVP_aes_128_ecb(), NULL, key, iv))
        return;

    if(1 != EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len))
        return;

    *ciphertext_len = len;

    if(1 != EVP_EncryptFinal_ex(ctx, ciphertext + len, &len))
        return;

    *ciphertext_len += len;

    EVP_CIPHER_CTX_free(ctx);
}

void aes_decrypt(const unsigned char *ciphertext, int ciphertext_len,
                 const unsigned char *key, const unsigned char *iv,
                 unsigned char *plaintext, int *plaintext_len)
{
    EVP_CIPHER_CTX *ctx;

    int len;

    *plaintext_len = 0;

    if(!(ctx = EVP_CIPHER_CTX_new()))
        return;

    if(1 != EVP_DecryptInit_ex(ctx, EVP_aes_128_ecb(), NULL, key, iv))
        return;

    if(1 != EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len))
        return;

    *plaintext_len = len;

    if(1 != EVP_DecryptFinal_ex(ctx, plaintext + len, &len))
        return;

    *plaintext_len += len;

    EVP_CIPHER_CTX_free(ctx);
}

void pkcs7_pad(const unsigned char *input, int input_len,
               unsigned char *output, int *output_len)
{
    int pad_len = AES_BLOCK_SIZE - (input_len % AES_BLOCK_SIZE);

    *output_len = input_len + pad_len;

    for(int i = 0; i < input_len; i++)
        output[i] = input[i];

    for(int i = input_len; i < *output_len; i++)
        output[i] = pad_len;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    const unsigned char *key = (const unsigned char *)"0123456789abcdef";
    const unsigned char *iv = (const unsigned char *)"0123456789abcdef";
    unsigned char plaintext[] = "Hello, world!";
    int plaintext_len = strlen((char *)plaintext);

    int ciphertext_len = 0;
    unsigned char ciphertext[plaintext_len + AES_BLOCK_SIZE];

    aes_encrypt(plaintext, plaintext_len, key, iv, ciphertext, &ciphertext_len);

    printf("Ciphertext: ");
    for(int i = 0; i < ciphertext_len; i++)
        printf("%02x", ciphertext[i]);
    printf("\n");

    int decrypted_len = 0;
    unsigned char decrypted[plaintext_len];

    aes_decrypt(ciphertext, ciphertext_len, key, iv, decrypted, &decrypted_len);

    printf("Plaintext: %s\n", decrypted);

    unsigned char padded_plaintext[AES_BLOCK_SIZE * (plaintext_len / AES_BLOCK_SIZE + 1)];
    int padded_plaintext_len = 0;

    pkcs7_pad(plaintext, plaintext_len, padded_plaintext, &padded_plaintext_len);

    printf("Padded plaintext: ");
    for(int i = 0; i < padded_plaintext_len; i++)
        printf("%02x", padded_plaintext[i]);
    printf("\n");

    return a.exec();
}

在这个示例代码中，我们使用了OpenSSL库提供的EVP API来实现AES的ECB加解密。我们还实现了PKCS#7填充，以确保输入数据的长度是AES块大小的整数倍。

在这个示例代码中，我们使用了128位AES密钥和IV。请注意，这些是示例值，您应该使用真正的随机密钥和IV来保护您的数据。

以上就是使用QT和openssl库实现AES的ECB加解密过程，以及PKCS#7填充的示例代码