first commit

pkg/address/crypto/hash.go

@@ -0,0 +1,44 @@
+package crypto
+
+import (
+	"crypto/sha256"
+
+	"golang.org/x/crypto/ripemd160"
+)
+
+func Checksum(input []byte) (cksum [4]byte) {
+	h := sha256.Sum256(input)
+	h2 := sha256.Sum256(h[:])
+	copy(cksum[:], h2[:4])
+	return
+}
+
+// Sha2Sum Returns hash: SHA256( SHA256( data ) )
+// Where possible, using ShaHash() should be a bit faster
+func Sha2Sum(b []byte) []byte {
+	tmp := sha256.Sum256(b)
+	tmp = sha256.Sum256(tmp[:])
+	return tmp[:]
+}
+
+// Rimp160 Returns hash: RIMP160( SHA256( data ) )
+// Where possible, using RimpHash() should be a bit faster
+func Rimp160(b []byte) []byte {
+	out := make([]byte, 20)
+	rimpHash(b, out[:])
+	return out[:]
+}
+
+func rimpHash(in []byte, out []byte) {
+	sha := sha256.New()
+	_, err := sha.Write(in)
+	if err != nil {
+		return
+	}
+	rim := ripemd160.New()
+	_, err = rim.Write(sha.Sum(nil)[:])
+	if err != nil {
+		return
+	}
+	copy(out, rim.Sum(nil))
+}