Question

伙计们，关于openssl的另一个问题：

我有以下命令：

openssl enc -aes-192-cbc -pbkdf2 -e -in <infile> -out <outfile> -pass pass:password

现在我只有该命令的密文，并且我知道密码，然后我也知道字符串“ Salted__”之后密文的前8个字节为salt。我也知道openssl作为默认参数需要1000次迭代计数和sha256作为摘要。我的问题是：我该如何返回到派生的键和从C语言派生的iv？

我的代码是这样，但它没有返回正确的值：

void decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *plaintext, const char *password, unsigned char* salt){
    EVP_CIPHER_CTX *ctx;

    int len;

    int plaintext_len;

    //unsigned char* key = "EF04020D6979FC09CC1859A2BFB832FFFCF57C64BA61F682"; right value
    //unsigned char* iv = "722EDDC813763C9AAB96A0A6885CE1DB"; right value
    unsigned char key[24], iv[16];

    int i;  

    PKCS5_PBKDF2_HMAC(password, strlen(password), (unsigned char*)salt, strlen(salt), 1000, EVP_sha256(), 16, key);

    EVP_BytesToKey(EVP_aes_192_cbc(), EVP_sha256(), (unsigned char*)salt, (unsigned char*)password, strlen(password), 1000, key+16, iv);

    printf("Key: "); for(i=0; i < 24; ++i){ printf("%02x", key[i]); } printf("\n");
    printf("IV: "); for(i=0; i < 16; ++i){ printf("%02x", iv[i]); } printf("\n\n");

    //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

    if(1 != EVP_DecryptInit_ex(ctx, EVP_aes_192_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);

}

正确的值被注释掉，我从终端拿走了...。但是我的C代码没有返回该值。我认为这取决于我不能很好地翻译-pbkdf2派生密钥的事实...请帮助我

Answer 1

我在GitHub上的openssl源代码中看到了解决的问题：

https://github.com/openssl/openssl/blob/master/apps/enc.c

如何在C语言中翻译openssl命令pbkdf2？

1 个答案: