c++ - QT C++ - OpenSSL AES - EVP.h

Question

过去几天我一直在尝试将 OpenSSL 与 QT 结合使用，但文档和示例很少或没有。

无论如何，我想出了这段代码:

void qkCrypto::AES_CBC(const unsigned char *string, const unsigned char *key, const unsigned char *iv)
{

    int outlen;
    unsigned char *out;

    EVP_CIPHER_CTX ctx;
    EVP_CIPHER_CTX_init(&ctx);
    const EVP_CIPHER *cipher = EVP_aes_128_cbc();

    EVP_EncryptInit(&ctx,cipher,key,iv);
    EVP_EncryptUpdate(&ctx,out,&outlen,string,strlen(string));

    EVP_EncryptFinal(&ctx,out,&outlen);

    EVP_CIPHER_CTX_cleanup(&ctx);

    qDebug() << out;

}

但是当我编译它时，我得到了一些错误...这是转换和强制转换错误，因为我不是那里最好的 C++ 程序员，我真的很感激能提供一些帮助来解决它们:

[...]/qkcrypto.cpp: In member function 'void qkCrypto::AES_CBC(const unsigned char*, const unsigned char*, const unsigned char*)':
[...]/qkcrypto.cpp:39: error: invalid conversion from 'const unsigned char*' to 'const char*'
[...]/qkcrypto.cpp:39: error: initializing argument 1 of 'size_t strlen(const char*)'

无论如何，我怎样才能使 QT 更友好地将字符转换为 QByteArrays？

最好的问候，谢谢大家 ;)

---

代码更新

我一直在“胡闹”，我正在努力做到这一点，但没有任何运气:

void qkCrypto::AES_CBC(QByteArray string, QByteArray key, QByteArray iv)
{

    int outlen;
    QByteArray out;

    EVP_CIPHER_CTX ctx;
    EVP_CIPHER_CTX_init(&ctx);
    const EVP_CIPHER *cipher = EVP_aes_128_cbc();

    EVP_EncryptInit(&ctx,cipher, key.constData() , iv.constData() );
    EVP_EncryptUpdate(&ctx, out.constData() ,&outlen, string.constData() ,strlen((const char*)string));

    EVP_EncryptFinal(&ctx, out.constData() ,&outlen);

    EVP_CIPHER_CTX_cleanup(&ctx);

    qDebug() << "OUT: "<< out;


}

我在转换方面遇到了很多错误:

[...]/qkcrypto.cpp: In member function 'void qkCrypto::AES_CBC(QByteArray, QByteArray, QByteArray)':
[...]/qkcrypto.cpp:38: error: invalid conversion from 'const char*' to 'const unsigned char*'
[...]/qkcrypto.cpp:38: error:   initializing argument 3 of 'int EVP_EncryptInit(EVP_CIPHER_CTX*, const EVP_CIPHER*, const unsigned char*, const unsigned char*)'
[...]/qkcrypto.cpp:38: error: invalid conversion from 'const char*' to 'const unsigned char*'
[...]/qkcrypto.cpp:38: error:   initializing argument 4 of 'int EVP_EncryptInit(EVP_CIPHER_CTX*, const EVP_CIPHER*, const unsigned char*, const unsigned char*)'
[...]/qkcrypto.cpp:39: error: invalid conversion from 'const char*' to 'unsigned char*'
[...]/qkcrypto.cpp:39: error:   initializing argument 2 of 'int EVP_EncryptUpdate(EVP_CIPHER_CTX*, unsigned char*, int*, const unsigned char*, int)'
[...]/qkcrypto.cpp:39: error: invalid conversion from 'const char*' to 'const unsigned char*'
[...]/qkcrypto.cpp:39: error:   initializing argument 4 of 'int EVP_EncryptUpdate(EVP_CIPHER_CTX*, unsigned char*, int*, const unsigned char*, int)'
[...]/qkcrypto.cpp:41: error: invalid conversion from 'const char*' to 'unsigned char*'
[...]/qkcrypto.cpp:41: error:   initializing argument 2 of 'int EVP_EncryptFinal(EVP_CIPHER_CTX*, unsigned char*, int*)'

谢谢。

Answer 1

好吧，正如错误所说，您正在尝试在指向 char 的指针和指向 unsigned char 的指针之间进行转换，这是不允许的。您必须添加一个明确的强制转换，例如

EVP_EncryptUpdate(&ctx, out, &outlen, string, strlen((const char*)string));
                                                     ^^^^^^^^^^^^^