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#include "cryptclassevp.h"
CryptClassEvp::CryptClassEvp()
: CryptClassBase()
{
ERR_load_crypto_strings();
OpenSSL_add_all_algorithms();
}
CryptClassEvp::~CryptClassEvp()
{
EVP_cleanup();
ERR_free_strings();
}
void CryptClassEvp::encrypt()
{
m_cryptText = QByteArray(m_clearText.size(), 0);
EVP_CIPHER_CTX *ctx;
int len = 0;
int ciphertext_len = 0;
/* Create and initialise the context */
if (!(ctx = EVP_CIPHER_CTX_new()))
{
handleOpenSslError();
}
/* Initialise the encryption operation. IMPORTANT - ensure you use a key
* and IV size appropriate for your cipher */
if (1 != EVP_EncryptInit_ex(ctx, algorithm(), NULL, (unsigned char *) getKey().data(), (unsigned char *) getIV().data()))
{
handleOpenSslError();
}
/* 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, (unsigned char *) m_cryptText.data(), &len,
(unsigned char *) m_clearText.data(), m_clearText.length()))
{
handleOpenSslError();
}
ciphertext_len = len;
/* Finalise the encryption. Further ciphertext bytes may be written at
* this stage.
*/
if (1 != EVP_EncryptFinal_ex(ctx, (unsigned char *)(m_cryptText.data() + len),
&len))
{
handleOpenSslError();
}
ciphertext_len += len;
m_cryptText.resize(ciphertext_len);
/* Clean up */
EVP_CIPHER_CTX_free(ctx);
}
void CryptClassEvp::decrypt()
{
m_clearText = QByteArray(m_cryptText.size(), 0);
EVP_CIPHER_CTX *ctx;
int len;
int plaintext_len;
/* Create and initialise the context */
if (!(ctx = EVP_CIPHER_CTX_new()))
{
handleOpenSslError();
}
/* Initialise the decryption operation. IMPORTANT - ensure you use a key
* and IV size appropriate for your cipher */
if (1 != EVP_DecryptInit_ex(ctx, algorithm(), NULL, (unsigned char *) getKey().data(), (unsigned char *) getIV().data()))
{
handleOpenSslError();
}
/* 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, (unsigned char*) m_clearText.data(), &len, (unsigned char*) m_cryptText.data(), m_cryptText.length()))
{
handleOpenSslError();
}
plaintext_len = len;
/* Finalise the decryption. Further plaintext bytes may be written at
* this stage.
*/
if (1 != EVP_DecryptFinal_ex(ctx, (unsigned char*) m_cryptText.data() + len, &len))
{
handleOpenSslError();
}
plaintext_len += len;
m_clearText.resize(plaintext_len);
/* Clean up */
EVP_CIPHER_CTX_free(ctx);
}
void CryptClassEvp::handleOpenSslError()
{
throw std::runtime_error(ERR_reason_error_string(ERR_get_error()));
}
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