Add golang support for ripemd160 and bitcoin hashes

Author: ethanfrey

go.mod

@@ -1,3 +1,6 @@
 module github.com/confio/proofs
 
-require github.com/gogo/protobuf v1.2.1
+require (
+	github.com/gogo/protobuf v1.2.1
+	golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734
+)

go.sum

@@ -2,4 +2,11 @@ github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
 github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734 h1:p/H982KKEjUnLJkM3tt/LemDnOc1GiZL5FCVlORJ5zo=
+golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

go/ops.go

@@ -7,6 +7,8 @@ import (
 	// adds sha512 capability to crypto.SHA512
 	_ "crypto/sha512"
 	fmt "fmt"
+	// adds ripemd160 capability to crypto.RIPEMD160
+	_ "golang.org/x/crypto/ripemd160"
 )
 
 func WrapLeaf(leaf *LeafOp) *ProofOp {
@@ -103,6 +105,18 @@ func doHash(hashOp HashOp, preimage []byte) ([]byte, error) {
 		hash := crypto.SHA512.New()
 		hash.Write(preimage)
 		return hash.Sum(nil), nil
+	case HashOp_RIPEMD160:
+		hash := crypto.RIPEMD160.New()
+		hash.Write(preimage)
+		return hash.Sum(nil), nil
+	case HashOp_BITCOIN:
+		// ripemd160(sha256(x))
+		sha := crypto.SHA256.New()
+		sha.Write(preimage)
+		tmp := sha.Sum(nil)
+		hash := crypto.RIPEMD160.New()
+		hash.Write(tmp)
+		return hash.Sum(nil), nil
 	}
 	return nil, fmt.Errorf("Unsupported hashop: %d", hashOp)
 }

go/ops_test.go

@@ -175,6 +175,46 @@ func TestInnerOp(t *testing.T) {
 	}
 }
 
+func TestDoHash(t *testing.T) {
+	cases := map[string]struct {
+		hashOp       HashOp
+		preimage     string
+		expectedHash string
+	}{
+		"sha256": {
+			hashOp:   HashOp_SHA256,
+			preimage: "food",
+			// echo -n food | sha256sum
+			expectedHash: "c1f026582fe6e8cb620d0c85a72fe421ddded756662a8ec00ed4c297ad10676b",
+		},
+		"ripemd160": {
+			hashOp:   HashOp_RIPEMD160,
+			preimage: "food",
+			// echo -n food | openssl dgst -rmd160 -hex | cut -d' ' -f2
+			expectedHash: "b1ab9988c7c7c5ec4b2b291adfeeee10e77cdd46",
+		},
+		"bitcoin": {
+			hashOp:   HashOp_BITCOIN,
+			preimage: "food",
+			// echo -n c1f026582fe6e8cb620d0c85a72fe421ddded756662a8ec00ed4c297ad10676b | xxd -r -p | openssl dgst -rmd160 -hex
+			expectedHash: "0bcb587dfb4fc10b36d57f2bba1878f139b75d24",
+		},
+	}
+
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			res, err := doHash(tc.hashOp, []byte(tc.preimage))
+			if err != nil {
+				t.Fatal(err)
+			}
+			hexRes := hex.EncodeToString(res)
+			if hexRes != tc.expectedHash {
+				t.Fatalf("Expected %s got %s", tc.expectedHash, hexRes)
+			}
+		})
+	}
+}
+
 func fromHex(data string) []byte {
 	res, err := hex.DecodeString(data)
 	if err != nil {