lib: add sha256 implementation

1 files changed, 31 insertions, 0 deletions

diff --git a/lib/sha256_test.go b/lib/sha256_test.go
new file mode 100644
index 0000000..ca429fd
--- /dev/null
+++ b/lib/sha256_test.go
@@ -0,0 +1,31 @@
+// Copyright © 2022 siddharth <s@ricketyspace.net>
+// SPDX-License-Identifier: ISC
+
+package lib
+
+import "testing"
+
+// Tests from
+// https://csrc.nist.gov/CSRC/media/Projects/Cryptographic-Standards-and-Guidelines/documents/examples/SHA256.pdf
+func TestSha256Hash(t *testing.T) {
+	sha256 := Sha256{}
+	sha256.Init([]uint32{})
+
+	// Test 1
+	m := "abc"
+	sha256.Message(StrToBytes(m))
+	h := sha256.Hash()
+	e := "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"
+	if BytesToHexStr(h) != e {
+		t.Errorf("sha256 test 1 failed: %x != %s\n", h, e)
+	}
+
+	// Test 2
+	m = "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
+	sha256.Message(StrToBytes(m))
+	h = sha256.Hash()
+	e = "248d6a61d20638b8e5c026930c3e6039a33ce45964ff2167f6ecedd419db06c1"
+	if BytesToHexStr(h) != e {
+		t.Errorf("sha256 test 1 failed: %x != %s\n", h, e)
+	}
+}