go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/lucicfg/digest.go (about)

     1  // Copyright 2020 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package lucicfg
    16  
    17  import (
    18  	"crypto/sha256"
    19  	"fmt"
    20  	"hash"
    21  
    22  	"go.starlark.net/starlark"
    23  )
    24  
    25  // See also //internal/digest.star.
    26  func init() {
    27  	declNative("hash_digest", func(call nativeCall) (starlark.Value, error) {
    28  		var algo, blob starlark.String
    29  		if err := call.unpack(1, &algo, &blob); err != nil {
    30  			return nil, err
    31  		}
    32  
    33  		var h hash.Hash
    34  		switch algo.GoString() {
    35  		case "SHA256":
    36  			h = sha256.New()
    37  		default:
    38  			return nil, fmt.Errorf("digest.bytes: unknown hashing algorithm %q", algo.GoString())
    39  		}
    40  
    41  		h.Write([]byte(blob))
    42  		return starlark.String(h.Sum(nil)), nil
    43  	})
    44  }