/************************************************* * MDx Hash Function Source File * * (C) 1999-2007 Jack Lloyd * *************************************************/ #include #include namespace Botan { /************************************************* * MDx_HashFunction Constructor * *************************************************/ MDx_HashFunction::MDx_HashFunction(u32bit hash_len, u32bit block_len, bool byte_end, bool bit_end, u32bit cnt_size) : HashFunction(hash_len, block_len), buffer(block_len), BIG_BYTE_ENDIAN(byte_end), BIG_BIT_ENDIAN(bit_end), COUNT_SIZE(cnt_size) { if(COUNT_SIZE >= OUTPUT_LENGTH || COUNT_SIZE >= HASH_BLOCK_SIZE) throw Invalid_Argument("MDx_HashFunction: COUNT_SIZE is too big"); count = position = 0; } /************************************************* * Clear memory of sensitive data * *************************************************/ void MDx_HashFunction::clear() throw() { buffer.clear(); count = position = 0; } /************************************************* * Update the hash * *************************************************/ void MDx_HashFunction::add_data(const byte input[], u32bit length) { count += length; if(position) { buffer.copy(position, input, length); if(position + length >= HASH_BLOCK_SIZE) { hash(buffer.begin()); input += (HASH_BLOCK_SIZE - position); length -= (HASH_BLOCK_SIZE - position); position = 0; } } while(length >= HASH_BLOCK_SIZE) { hash(input); input += HASH_BLOCK_SIZE; length -= HASH_BLOCK_SIZE; } buffer.copy(position, input, length); position += length; } /************************************************* * Finalize a Hash * *************************************************/ void MDx_HashFunction::final_result(byte output[]) { buffer[position] = (BIG_BIT_ENDIAN ? 0x80 : 0x01); for(u32bit j = position+1; j != HASH_BLOCK_SIZE; ++j) buffer[j] = 0; if(position >= HASH_BLOCK_SIZE - COUNT_SIZE) { hash(buffer); buffer.clear(); } write_count(buffer + HASH_BLOCK_SIZE - COUNT_SIZE); hash(buffer); copy_out(output); clear(); } /************************************************* * Write the count bits to the buffer * *************************************************/ void MDx_HashFunction::write_count(byte out[]) { if(COUNT_SIZE < 8) throw Invalid_State("MDx_HashFunction::write_count: COUNT_SIZE < 8"); const u64bit bit_count = count * 8; if(BIG_BYTE_ENDIAN) store_be(bit_count, out + COUNT_SIZE - 8); else store_le(bit_count, out + COUNT_SIZE - 8); } }