Add encoding.HexDecode/Encode

Fixes #15068
See #15060

tpl/encoding/encoding.go

@@ -16,6 +16,7 @@ package encoding
 
 import (
 	"encoding/base64"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"html/template"
@@ -56,6 +57,28 @@ func (ns *Namespace) Base64Encode(content any) (string, error) {
 	return base64.StdEncoding.EncodeToString([]byte(conv)), nil
 }
 
+// HexDecode returns the hex decoding of the given content.
+func (ns *Namespace) HexDecode(content any) (string, error) {
+	conv, err := cast.ToStringE(content)
+	if err != nil {
+		return "", err
+	}
+	b, err := hex.DecodeString(conv)
+	if err != nil {
+		return "", err
+	}
+	return string(b), nil
+}
+
+// HexEncode returns the hex encoding of the given content.
+func (ns *Namespace) HexEncode(content any) (string, error) {
+	conv, err := cast.ToStringE(content)
+	if err != nil {
+		return "", err
+	}
+	return hex.EncodeToString([]byte(conv)), nil
+}
+
 // Jsonify encodes a given object to JSON.  To pretty print the JSON, pass a map
 // or dictionary of options as the first value in args.  Supported options are
 // "prefix" and "indent".  Each JSON element in the output will begin on a new

tpl/encoding/encoding_test.go

@@ -77,6 +77,60 @@ func TestBase64Encode(t *testing.T) {
 	}
 }
 
+func TestHexDecode(t *testing.T) {
+	t.Parallel()
+	c := qt.New(t)
+
+	ns := New()
+
+	for _, test := range []struct {
+		v      any
+		expect any
+	}{
+		{"616263313233213f242a2628292d3d407e", "abc123!?$*&()-=@~"},
+		// errors
+		{t, false},
+	} {
+
+		result, err := ns.HexDecode(test.v)
+
+		if b, ok := test.expect.(bool); ok && !b {
+			c.Assert(err, qt.Not(qt.IsNil))
+			continue
+		}
+
+		c.Assert(err, qt.IsNil)
+		c.Assert(result, qt.Equals, test.expect)
+	}
+}
+
+func TestHexEncode(t *testing.T) {
+	t.Parallel()
+	c := qt.New(t)
+
+	ns := New()
+
+	for _, test := range []struct {
+		v      any
+		expect any
+	}{
+		{"abc123!?$*&()-=@~", "616263313233213f242a2628292d3d407e"},
+		// errors
+		{t, false},
+	} {
+
+		result, err := ns.HexEncode(test.v)
+
+		if b, ok := test.expect.(bool); ok && !b {
+			c.Assert(err, qt.Not(qt.IsNil))
+			continue
+		}
+
+		c.Assert(err, qt.IsNil)
+		c.Assert(result, qt.Equals, test.expect)
+	}
+}
+
 func TestJsonify(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)

tpl/encoding/init.go

@@ -46,6 +46,20 @@ func init() {
 			},
 		)
 
+		ns.AddMethodMapping(ctx.HexDecode,
+			nil,
+			[][2]string{
+				{`{{ "48656c6c6f20776f726c64" | encoding.HexDecode }}`, `Hello world`},
+			},
+		)
+
+		ns.AddMethodMapping(ctx.HexEncode,
+			nil,
+			[][2]string{
+				{`{{ "Hello world" | encoding.HexEncode }}`, `48656c6c6f20776f726c64`},
+			},
+		)
+
 		ns.AddMethodMapping(ctx.Jsonify,
 			[]string{"jsonify"},
 			[][2]string{

tpl/templates/decorator_integration_test.go

@@ -453,3 +453,49 @@ Home. {{ partial "a" }}:Done.
 		}
 	}
 }
+
+func TestDecoratorFingerprintScript(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+baseURL = "https://example.org/"
+[outputs]
+home = ["html", "headers"]
+[mediaTypes]
+[mediaTypes."text/netlify"]
+delimiter = ""
+[outputFormats]
+[outputFormats.headers]
+baseName       = "_headers"
+isPlainText    = true
+mediatype      = "text/netlify"
+notAlternative = true
+-- layouts/_partials/script.html --
+{{ $s := (templates.Inner .) }}
+{{ $r := resources.FromString ($s | xxhash) $s | fingerprint }}
+{{ $hash := $s | crypto.SHA256 | encoding.HexDecode | encoding.Base64Encode }}
+{{ $sri := (printf "sha256-%s" $hash) }}
+{{ if ne $sri $r.Data.Integrity }}
+	{{ errorf "SRI hash mismatch: %s != %s" $sri $r.Data.Integrity }}
+{{ end }}
+{{ hugo.Store.SetInMap "srihashes" $sri true }}
+<script>{{ $s | safeJS }}</script>
+-- layouts/home.html --
+Home.
+{{ with partial "script.html" . }}
+console.log("Hello world");
+{{ end }}
+{{ with partial "script.html" . }}
+console.log("Hugo rocks!");
+{{ end }}
+-- layouts/home.headers --
+{{ $hashes := hugo.Store.Get "srihashes" -}}
+Content-Security-Policy: script-src 'self'{{ range $k, $v := $hashes }} '{{ $k }}'{{ end }};
+`
+
+	b := hugolib.Test(t, files)
+
+	b.AssertFileContentExact("public/index.html", "<script>\nconsole.log(\"Hello world\");\n</script>")
+	b.AssertFileContentExact("public/_headers", "Content-Security-Policy: script-src 'self' 'sha256-t6z9j4/CagmaDDbn6nHbntzt8PRk8HZ1TwrgdYuZjbE=' 'sha256-wVbS8f78ttoSSGU80KghGoPcTO8DXqT0Uc/87a7zMdk=';")
+}