generator: implement do_sha()

* link against cryptopp
* use both sha2 and sha3 generation functions
* try calling do_sha() directly
* call reseed() that in turn calls do_sha()
* return a bogus number, not the proper digest for now (see TODOs)

cryptopp needed to be installed to archlinux for the valgrind step to
pass successfully

.drone.starlark

@@ -58,7 +58,7 @@ def main(ctx):
 				"depends_on": ["build debug"],
 				"commands": [
 					"uname -r",
-					"pacman -Sy gcc cmake ninja valgrind --noconfirm --needed",
+					"pacman -Sy gcc cmake crypto++ ninja valgrind --noconfirm --needed",
 					"valgrind --version",
 					"make valgrind"
 				]
@@ -70,7 +70,7 @@ def main(ctx):
 				"depends_on": ["build release"],
 				"commands": [
 					"uname -r",
-					"pacman -Sy gcc cmake ninja valgrind --noconfirm --needed",
+					"pacman -Sy gcc cmake crypto++ ninja valgrind --noconfirm --needed",
 					"valgrind --version",
 					"make valgrind-release"
 				]

Makefile

@@ -1,6 +1,6 @@
 cppch = cppcheck
 cppch_args = --language=c++ --std=c++20 --enable=all --verbose ./*.{cpp,h}
-cpp_flags = CMAKE_CXX_FLAGS=
+cpp_flags = CMAKE_CXX_FLAGS=-lcryptopp
 c = cmake
 c_args = -G Ninja -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=
 n = ninja

generator.cpp

@@ -2,6 +2,14 @@
 #include <cassert>
 #include <cstdint>
 #include <stdexcept>
+#include <iostream>
+#include <algorithm>
+
+#include <cryptopp/hex.h>
+#include <cryptopp/filters.h>
+#include <cryptopp/sha.h>
+#include <cryptopp/sha3.h>
+
 #include "generator.h"
 
 #ifndef FORTUNA_GENERATOR_CPP
@@ -23,6 +31,10 @@ void Generator::initialize_generator(){
 	G->k = 0;
 	G->ctr = 0;
 	printf("Generator initialized\n");
+	// TODO(me): rm this, it's here just so it's called
+	do_sha("fortuna");
+	// TODO(me): bogus call of reseed just so it's called
+	reseed("");
 	delete(G);
 };
 
@@ -33,14 +45,47 @@ auto Generator::get_state() -> G_state {
 auto Generator::reseed(const string& s) -> void {
 	G_state G = get_state();
 	string to_be_hashed = std::to_string(G.k) + s;
-	G.k = do_sha(stoul(to_be_hashed));
+	// TODO(me): wrap do_sha in a try-catch
+	string a = do_sha(to_be_hashed);
+	// str, size, base
+	G.k = stol(a,nullptr,10);
 	G.ctr++;
 }
 
-auto Generator::do_sha(int64_t key_with_seed) -> int64_t {
+auto Generator::do_sha(const string& k_n_s) -> string {
 	/* do sha256 */
-	int64_t shastring = key_with_seed + 1;
-	return shastring;
+	using std::cout;
+	using std::endl;
+	using CryptoPP::HexEncoder;
+	using CryptoPP::HashFilter;
+	using CryptoPP::StringSink;
+
+	string digest;
+
+	CryptoPP::SHA256 sha2_256;
+	CryptoPP::SHA3_256 sha3_256;
+
+	digest.erase();
+	CryptoPP::StringSource foo(k_n_s,true,
+		new HashFilter(sha2_256,new HexEncoder(new StringSink(digest)))
+	);
+	digest = strtolowerpls(digest);
+	cout << digest << endl;
+
+	digest.erase();
+
+	CryptoPP::StringSource bar(k_n_s,true,
+		new HashFilter(sha3_256,new HexEncoder(new StringSink(digest)))
+	);
+	digest = strtolowerpls(digest);
+	cout << digest << endl;
+
+	// return digest;
+	// TODO(me)
+	// do not return the proper digest just yet, too long to fit into
+	// int64_t. G.k has to be a 256bit-wide type. for now just return a
+	// small enough number
+	return "42";
 }
 
 auto Generator::do_crypto(int64_t k, unsigned __int128 ctr) -> string {

generator.h

@@ -18,7 +18,7 @@ private:
 
 	auto reseed(const string& s) -> void;
 
-	auto do_sha(int64_t key_with_seed) -> int64_t;
+	auto do_sha(const string& k_n_s) -> string;
 
 	auto do_crypto(int64_t k, unsigned __int128 ctr) -> string;