fc::aes_encoder Class Reference

#include <aes.hpp>

Classes
struct	impl

Public Member Functions
void	init (const fc::sha256 &key, const fc::uint128 &init_value)
uint32_t	encode (const char *plaintxt, uint32_t len, char *ciphertxt)

Detailed Description

Definition at line 11 of file aes.hpp.

Member Function Documentation

encode()

uint32_t fc::aes_encoder::encode	(	const char *	plaintxt,
		uint32_t	len,
		char *	ciphertxt )

Definition at line 57 of file aes.cpp.

{
    int ciphertext_len = 0;
    /* Provide the message to be encrypted, and obtain the encrypted output.
    *    * EVP_EncryptUpdate can be called multiple times if necessary
    *       */
    if(1 != EVP_EncryptUpdate(my->ctx, (unsigned char*)ciphertxt, &ciphertext_len, (const unsigned char*)plaintxt, plaintext_len))
    {
        FC_THROW_EXCEPTION( aes_exception, "error during aes 256 cbc encryption update", 
                           ("s", ERR_error_string( ERR_get_error(), nullptr) ) );
    }
    FC_ASSERT( ciphertext_len == static_cast<int>(plaintext_len), "", ("ciphertext_len",ciphertext_len)("plaintext_len",plaintext_len) );
    return ciphertext_len;
}

init()

void fc::aes_encoder::init	(	const fc::sha256 &	key,
		const fc::uint128 &	init_value )

Definition at line 34 of file aes.cpp.

{
    my->ctx.obj = EVP_CIPHER_CTX_new();
    /* Create and initialise the context */
    if(!my->ctx)
    {
        FC_THROW_EXCEPTION( aes_exception, "error allocating evp cipher context", 
                           ("s", ERR_error_string( ERR_get_error(), nullptr) ) );
    }
 
    /* Initialise the encryption operation. IMPORTANT - ensure you use a key
    *    and IV size appropriate for your cipher
    *    In this example we are using 256 bit AES (i.e. a 256 bit key). The
    *    IV size for *most* modes is the same as the block size. For AES this
    *    is 128 bits */
    if(1 != EVP_EncryptInit_ex(my->ctx, EVP_aes_256_cbc(), NULL, (unsigned char*)&key, (unsigned char*)&init_value))
    {
        FC_THROW_EXCEPTION( aes_exception, "error during aes 256 cbc encryption init", 
                           ("s", ERR_error_string( ERR_get_error(), nullptr) ) );
    }
    EVP_CIPHER_CTX_set_padding( my->ctx, 0 );
}

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The documentation for this class was generated from the following files:

• libraries/fc/include/fc/crypto/aes.hpp
• libraries/fc/src/crypto/aes.cpp