AES-128 CBC模式解密输出乱码问题求助

尝试使用AES 128 CBC模式对字符串缓冲区进行加密和解密，选择CBC是因为它支持一次性加密整个数组。加密过程似乎正常，但解密失败，解密后的输出为无法识别的乱码。

测试代码 #

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>

#define AES_KEY_SIZE 128
#define AES_BLOCK_SIZE 16

void encryptMessage(const char *message, size_t messageLen, const unsigned char *key, const unsigned char *iv, unsigned char *ciphertext) {
    AES_KEY aesKey;
    AES_set_encrypt_key(key, AES_KEY_SIZE, &aesKey);

    AES_cbc_encrypt((unsigned char *)message, (unsigned char*)ciphertext, messageLen, &aesKey, (unsigned char *)iv, AES_ENCRYPT);
}

void decryptMessage(const unsigned char *ciphertext, size_t ciphertextLen, const unsigned char *key, const unsigned char *iv, char *decryptedMessage) {
    AES_KEY aesKey;
    AES_set_decrypt_key(key, AES_KEY_SIZE, &aesKey);

    AES_cbc_encrypt(ciphertext, (unsigned char *)decryptedMessage, ciphertextLen, &aesKey, (unsigned char *)iv, AES_DECRYPT);    
    //size_t paddingLen = decryptedMessage[ciphertextLen - 1];
    //decryptedMessage[ciphertextLen - paddingLen] = '\0';
}

int main() {
    const unsigned char key[AES_KEY_SIZE] = "mysecretkey1234";
    const unsigned char iv[AES_BLOCK_SIZE] = "abcdefghijklmnop";

    char message[1024];
    unsigned char ciphertext[1024];
    char decryptedMessage[1024];

    printf("Enter a message: ");
    fgets(message, sizeof(message), stdin);
    message[strcspn(message, "\n")] = '\0';

    size_t messageLen = strlen(message);

    encryptMessage(message, messageLen, key, iv, ciphertext);

    decryptMessage(ciphertext, messageLen, key, iv, decryptedMessage);

    printf("Original Message: %s\n", message);
    printf("Encrypted Message: ");
    for (size_t i = 0; i < messageLen; ++i) {
        printf("%02x", ciphertext[i]);
    }
    printf("\n");

    printf("Decrypted Message: %s\n", decryptedMessage);

    return 0;
}

运行结果 #

Enter a message: asdadfadfadfa
Original Message: asdadfadfadfa
Encrypted Message: 70bbb018fc29b4a5255938ea7a
Decrypted Message: p???)??*R7?v?%?

官方文档说明 #

AES_cbc_encrypt encrypts (or decrypts, if enc == AES_DECRYPT) len bytes from in to out. The length must be a multiple of the block size. This function may be called in-place with in equal to out, but otherwise the buffers may not partially overlap. A partial overlap may overwrite input data before it is read.

OPENSSL_EXPORT void AES_cbc_encrypt(const uint8_t *in, uint8_t *out, size_t len, const AES_KEY *key, uint8_t *ivec, const int enc);

已尝试的解决方法 #

• 在解密函数中添加空终止符（相关代码已注释），未解决问题
• 将解密结果从十六进制转ASCII，无效

已查找相关示例但未找到匹配项目需求的内容，希望得到技术帮助。

内容的提问来源于stack exchange，提问作者stan_the_man