porting crypto functions

lang/funcs/crypto.go

@@ -190,6 +190,44 @@ var Sha1Func = function.New(&function.Spec{
 	},
 })
 
+// Sha256Func contructs a function that computes the SHA256 hash of a given string
+// and encodes it with hexadecimal digits.
+var Sha256Func = function.New(&function.Spec{
+	Params: []function.Parameter{
+		{
+			Name: "str",
+			Type: cty.String,
+		},
+	},
+	Type: function.StaticReturnType(cty.String),
+	Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
+		s := args[0].AsString()
+		h := sha256.New()
+		h.Write([]byte(s))
+		hash := hex.EncodeToString(h.Sum(nil))
+		return cty.StringVal(hash), nil
+	},
+})
+
+// Sha512Func contructs a function that computes the SHA256 hash of a given string
+// and encodes it with hexadecimal digits.
+var Sha512Func = function.New(&function.Spec{
+	Params: []function.Parameter{
+		{
+			Name: "str",
+			Type: cty.String,
+		},
+	},
+	Type: function.StaticReturnType(cty.String),
+	Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
+		s := args[0].AsString()
+		h := sha256.New()
+		h.Write([]byte(s))
+		hash := hex.EncodeToString(h.Sum(nil))
+		return cty.StringVal(hash), nil
+	},
+})
+
 // UUID generates and returns a Type-4 UUID in the standard hexadecimal string
 // format.
 //
@@ -245,3 +283,13 @@ func RsaDecrypt(ciphertext, privatekey cty.Value) (cty.Value, error) {
 func Sha1(str cty.Value) (cty.Value, error) {
 	return Sha1Func.Call([]cty.Value{str})
 }
+
+// Sha256 computes the SHA256 hash of a given string and encodes it with hexadecimal digits.
+func Sha256(str cty.Value) (cty.Value, error) {
+	return Sha256Func.Call([]cty.Value{str})
+}
+
+// Sha512 computes the SHA512 hash of a given string and encodes it with hexadecimal digits.
+func Sha512(str cty.Value) (cty.Value, error) {
+	return Sha512Func.Call([]cty.Value{str})
+}

lang/funcs/crypto_test.go

@@ -268,6 +268,39 @@ func TestSha1(t *testing.T) {
 	}
 }
 
+func TestSha256(t *testing.T) {
+	tests := []struct {
+		String cty.Value
+		Want   cty.Value
+		Err    bool
+	}{
+		{
+			cty.StringVal("test"),
+			cty.StringVal("9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08"),
+			false,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(fmt.Sprintf("sha256(%#v)", test.String), func(t *testing.T) {
+			got, err := Sha256(test.String)
+
+			if test.Err {
+				if err == nil {
+					t.Fatal("succeeded; want error")
+				}
+				return
+			} else if err != nil {
+				t.Fatalf("unexpected error: %s", err)
+			}
+
+			if !got.RawEquals(test.Want) {
+				t.Errorf("wrong result\ngot:  %#v\nwant: %#v", got, test.Want)
+			}
+		})
+	}
+}
+
 const (
 	CipherBase64 = "eczGaDhXDbOFRZGhjx2etVzWbRqWDlmq0bvNt284JHVbwCgObiuyX9uV0LSAMY707IEgMkExJqXmsB4OWKxvB7epRB9G/3+F+pcrQpODlDuL9oDUAsa65zEpYF0Wbn7Oh7nrMQncyUPpyr9WUlALl0gRWytOA23S+y5joa4M34KFpawFgoqTu/2EEH4Xl1zo+0fy73fEto+nfkUY+meuyGZ1nUx/+DljP7ZqxHBFSlLODmtuTMdswUbHbXbWneW51D7Jm7xB8nSdiA2JQNK5+Sg5x8aNfgvFTt/m2w2+qpsyFa5Wjeu6fZmXSl840CA07aXbk9vN4I81WmJyblD/ZA=="
 	PrivateKey   = `

lang/functions.go

@@ -79,9 +79,9 @@ func (s *Scope) Functions() map[string]function.Function {
 			"pow":          unimplFunc, // TODO
 			"replace":      unimplFunc, // TODO
 			"rsadecrypt":   funcs.RsaDecryptFunc,
-			"sha1":         unimplFunc, // TODO
-			"sha256":       unimplFunc, // TODO
-			"sha512":       unimplFunc, // TODO
+			"sha1":         funcs.Sha1Func,
+			"sha256":       funcs.Sha256Func,
+			"sha512":       funcs.Sha512Func,
 			"signum":       unimplFunc, // TODO
 			"slice":        unimplFunc, // TODO
 			"sort":         funcs.SortFunc,