Fingerprinting and [SRI](https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity) can be applied to any asset file using `resources.Fingerpint` which takes two arguments, the resource object and a [hash function](https://en.wikipedia.org/wiki/Cryptographic_hash_function).
-The default hash function is `sha256`. Other available functions are `sha512` and `md5`.
+The default hash function is `sha256`. Other available functions are `sha384` (from Hugo `0.55`), `sha512` and `md5`.
Any so processed asset will bear a `.Data.Integrity` property containing an integrity string, which is made up of the name of the hash function, one hyphen and the base64-encoded hash sum.
"crypto/sha512"
"encoding/base64"
"encoding/hex"
- "fmt"
"hash"
"html/template"
"io"
+ "github.com/pkg/errors"
+
"github.com/gohugoio/hugo/resources"
"github.com/gohugoio/hugo/resources/resource"
)
// Transform creates a MD5 hash of the Resource content and inserts that hash before
// the extension in the filename.
func (t *fingerprintTransformation) Transform(ctx *resources.ResourceTransformationCtx) error {
- algo := t.algo
-
- var h hash.Hash
- switch algo {
- case "md5":
- h = md5.New()
- case "sha256":
- h = sha256.New()
- case "sha512":
- h = sha512.New()
- default:
- return fmt.Errorf("unsupported crypto algo: %q, use either md5, sha256 or sha512", algo)
+ h, err := newHash(t.algo)
+ if err != nil {
+ return err
}
io.Copy(io.MultiWriter(h, ctx.To), ctx.From)
return err
}
- ctx.Data["Integrity"] = integrity(algo, d)
+ ctx.Data["Integrity"] = integrity(t.algo, d)
ctx.AddOutPathIdentifier("." + hex.EncodeToString(d[:]))
return nil
}
+func newHash(algo string) (hash.Hash, error) {
+ switch algo {
+ case "md5":
+ return md5.New(), nil
+ case "sha256":
+ return sha256.New(), nil
+ case "sha384":
+ return sha512.New384(), nil
+ case "sha512":
+ return sha512.New(), nil
+ default:
+ return nil, errors.Errorf("unsupported crypto algo: %q, use either md5, sha256, sha384 or sha512", algo)
+ }
+}
+
// Fingerprint applies fingerprinting of the given resource and hash algorithm.
// It defaults to sha256 if none given, and the options are md5, sha256 or sha512.
// The same algo is used for both the fingerprinting part (aka cache busting) and
--- /dev/null
+// Copyright 2019 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package integrity
+
+import (
+ "testing"
+
+ "github.com/stretchr/testify/require"
+)
+
+func TestHashFromAlgo(t *testing.T) {
+
+ for _, algo := range []struct {
+ name string
+ bits int
+ }{
+ {"md5", 128},
+ {"sha256", 256},
+ {"sha384", 384},
+ {"sha512", 512},
+ {"shaman", -1},
+ } {
+
+ t.Run(algo.name, func(t *testing.T) {
+ assert := require.New(t)
+ h, err := newHash(algo.name)
+ if algo.bits > 0 {
+ assert.NoError(err)
+ assert.Equal(algo.bits/8, h.Size())
+ } else {
+ assert.Error(err)
+ assert.Contains(err.Error(), "use either md5, sha256, sha384 or sha512")
+ }
+
+ })
+ }
+}