Pre-requisites

1. Install libressl portable. The makefile assumes that libressl gets installed to /usr/local/lib.
2. Make sure you have boost installed (package libboost-dev on ubuntu).

Compilation

Run make.

Homework Problem 1

Implement the validate function for each transaction in txn_t::validate.

This function must check that:

1. SHA256(public_key) = source_addr
2. SHA256(public_key, source_addr, dest_addr, change_addr) = tx_hash
3. sign(tx_hash, tx_sign, public_key) is valid.

See the cryptotest.cpp file for examples of how we can use these functions.

Homework Problem 2

Implement the block_t::validate function. You will do this by removing the call to validate_block_helper and replacing it with your own code with a different function name my_validate_block_helper(). Appropriately declare this function in the appropriate file, and define the function in appropriate cpp file. Currently a helper.o file is provided with this distribution with implementation of validate_block_helper() (without the source code). DO NOT remove helper.o file from your distribution until you write
your own function my_validate_block_helper(). Replace all calls to the original validate_block_helper function with my_validate_block_helper function. If you remove helper.o, then remove any occurence of "helper.o" from the Makefile.

Running Tests

The program cryptotest.cpp contains unit tests for RSA signing and verification. Run these tests by invoking cryptotest.

$ ./cryptotest

The program readchain.cpp reads a blockchain and validates it. Example invocation:

$ ./readchain tests/t1.dat

There are three test input files: t1.dat, t2.dat and t3.dat provided in tests/ sub-folder. The expected output for these three files is shown in t1.txt, t2.txt and t3.txt.