A Vala GCrypt.Hash example

gcrypt-hash-example.vala

using GCrypt;
using Posix;

void main () {
	Hash hash;
	GCrypt.Error err = Hash.open(out hash, Hash.Algorithm.SHA256, Hash.Flag.SECURE);
	if (err != 0) {
		print("Error: %s\n", err.to_string());
		Process.exit(EXIT_FAILURE);
	}

	string str = "Hello World!";
	hash.write(str.data);
	// hash.final(); // implicit in Hash.read(...)

	// Hash.read(...): [CCode (array_length = false)]
	unowned uchar[] ary = hash.read(Hash.Algorithm.SHA256);
	size_t len = hash.get_algo().get_digest_length();
	print("digest length: %zu\n", len);

	string result = Base64.encode(ary[0:len]);
	print("SHA256 digest: %s\n", result);

	hash.close();
	Process.exit(EXIT_SUCCESS);
}

// run:
// valac --pkg posix --pkg gcrypt -X -lgcrypt gcrypt-hash-example.vala
// ./gcrypt-hash-example