add simple hash functions, tests

hash.go

@@ -0,0 +1,27 @@
+package hash
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/hex"
+)
+
+// SHA256 creates a hex-encoded SHA256 checksum for a string input.
+func SHA256(value string) string {
+	b := sha256.Sum256([]byte(value))
+	hash := []byte{}
+	for _, byte := range b {
+		hash = append(hash, byte)
+	}
+	return hex.EncodeToString(hash)
+}
+
+// SHA512 creates a hex-encoded SHA512 checksum for a string input.
+func SHA512(value string) string {
+	b := sha512.Sum512([]byte(value))
+	hash := []byte{}
+	for _, byte := range b {
+		hash = append(hash, byte)
+	}
+	return hex.EncodeToString(hash)
+}