going somewhere

helper/helper.go

@@ -1,6 +1,7 @@
 package helper
 
 import (
+	"crypto"
 	"errors"
 	"strings"
 )
@@ -21,3 +22,29 @@ func JoinErrors(errs []error) error {
 	}
 	return JoinAsError(msgs)
 }
+
+func GetHashFunctionByLowerCaseName(hashName string) (crypto.Hash, error) {
+	switch hashName {
+	case "md4":
+		return crypto.MD4, nil
+	case "md5":
+		return crypto.MD5, nil
+	case "sha1":
+		return crypto.SHA1, nil
+	case "sha224":
+		return crypto.SHA224, nil
+	case "sha256":
+		return crypto.SHA256, nil
+	case "sha384":
+		return crypto.SHA384, nil
+	case "sha512":
+		return crypto.SHA512, nil
+	case "md5sha1":
+		return crypto.MD5SHA1, nil
+	case "ripemd160":
+		return crypto.RIPEMD160, nil
+	default:
+		return 0, errors.New("unknown lowercase hash " + hashName)
+
+	}
+}

helper/helper_test.go

@@ -1,6 +1,7 @@
 package helper
 
 import (
+	"crypto"
 	"errors"
 	"testing"
 )
@@ -36,3 +37,24 @@ func TestJoinErrors(t *testing.T) {
 		t.Error("bad error")
 	}
 }
+
+func TestGetHashFunctionByLowerCaseName(t *testing.T) {
+	m := map[string]crypto.Hash{
+		"md4":       crypto.MD4,
+		"md5":       crypto.MD5,
+		"sha1":      crypto.SHA1,
+		"sha224":    crypto.SHA224,
+		"sha256":    crypto.SHA256,
+		"sha384":    crypto.SHA384,
+		"sha512":    crypto.SHA512,
+		"md5sha1":   crypto.MD5SHA1,
+		"ripemd160": crypto.RIPEMD160,
+	}
+	for hashName, exptedHash := range m {
+		if hash, err := GetHashFunctionByLowerCaseName(hashName); err != nil {
+			t.Error(err)
+		} else if hash != exptedHash {
+			t.Error("bad hash found for ", hashName)
+		}
+	}
+}