Add seed-able cryptographic random.

hash.go

@@ -0,0 +1,18 @@
+package crypto
+
+import (
+	"crypto/sha256"
+	"golang.org/x/crypto/ripemd160"
+)
+
+func Sha256(bytes []byte) []byte {
+	hasher := sha256.New()
+	hasher.Write(bytes)
+	return hasher.Sum(nil)
+}
+
+func Ripemd160(bytes []byte) []byte {
+	hasher := ripemd160.New()
+	hasher.Write(bytes)
+	return hasher.Sum(nil)
+}