http://git.community.i2p/PurpleI2P/i2pd/commit/3c8f859169cb3c51807a814ae2e336c2ae124c5b
Encode ( zeroPadding ? encrypted + 1 : encrypted , 256 ) ; uint8_t m [ 255 ] ; m [ 0 ] = 0xFF ; memcpy ( m + 33 , data , len ) ; CryptoPP : : SHA256 ( ) . CalculateDigest ( m + 1 , m + 33 , 222 ) ; a_times_b_mod_c ( a_exp_b_mod_c ( y , k , elgp ) , CryptoPP : : Integer ( m , 255 ) , elgp ) .