hugo/tpl/crypto/crypto.go
2022-12-21 15:33:02 +01:00

137 lines
3.1 KiB
Go

// Copyright 2017 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 crypto provides template functions for cryptographic operations.
package crypto
import (
"crypto/hmac"
"crypto/md5"
"crypto/sha1"
"crypto/sha256"
"crypto/sha512"
"encoding/hex"
"fmt"
"hash"
"hash/fnv"
"github.com/spf13/cast"
)
// New returns a new instance of the crypto-namespaced template functions.
func New() *Namespace {
return &Namespace{}
}
// Namespace provides template functions for the "crypto" namespace.
type Namespace struct{}
// MD5 hashes the v and returns its MD5 checksum.
func (ns *Namespace) MD5(v any) (string, error) {
conv, err := cast.ToStringE(v)
if err != nil {
return "", err
}
hash := md5.Sum([]byte(conv))
return hex.EncodeToString(hash[:]), nil
}
// SHA1 hashes v and returns its SHA1 checksum.
func (ns *Namespace) SHA1(v any) (string, error) {
conv, err := cast.ToStringE(v)
if err != nil {
return "", err
}
hash := sha1.Sum([]byte(conv))
return hex.EncodeToString(hash[:]), nil
}
// SHA256 hashes v and returns its SHA256 checksum.
func (ns *Namespace) SHA256(v any) (string, error) {
conv, err := cast.ToStringE(v)
if err != nil {
return "", err
}
hash := sha256.Sum256([]byte(conv))
return hex.EncodeToString(hash[:]), nil
}
// FNV32a hashes v using fnv32a algorithm.
func (ns *Namespace) FNV32a(v any) (int, error) {
conv, err := cast.ToStringE(v)
if err != nil {
return 0, err
}
algorithm := fnv.New32a()
algorithm.Write([]byte(conv))
return int(algorithm.Sum32()), nil
}
// HMAC returns a cryptographic hash that uses a key to sign a message.
func (ns *Namespace) HMAC(h any, k any, m any, e ...any) (string, error) {
ha, err := cast.ToStringE(h)
if err != nil {
return "", err
}
var hash func() hash.Hash
switch ha {
case "md5":
hash = md5.New
case "sha1":
hash = sha1.New
case "sha256":
hash = sha256.New
case "sha512":
hash = sha512.New
default:
return "", fmt.Errorf("hmac: %s is not a supported hash function", ha)
}
msg, err := cast.ToStringE(m)
if err != nil {
return "", err
}
key, err := cast.ToStringE(k)
if err != nil {
return "", err
}
mac := hmac.New(hash, []byte(key))
_, err = mac.Write([]byte(msg))
if err != nil {
return "", err
}
var encoding = "hex"
if len(e) > 0 && e[0] != nil {
encoding, err = cast.ToStringE(e[0])
if err != nil {
return "", err
}
}
switch encoding {
case "binary":
return string(mac.Sum(nil)[:]), nil
case "hex":
return hex.EncodeToString(mac.Sum(nil)[:]), nil
default:
return "", fmt.Errorf("%q is not a supported encoding method", encoding)
}
}