forgejo/models/asymkey/gpg_key_common.go

137 lines
3.8 KiB
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package asymkey
import (
"bytes"
"crypto"
"encoding/base64"
"fmt"
"hash"
"io"
"strings"
"time"
"github.com/keybase/go-crypto/openpgp"
"github.com/keybase/go-crypto/openpgp/armor"
"github.com/keybase/go-crypto/openpgp/packet"
)
// __________________ ________ ____ __.
// / _____/\______ \/ _____/ | |/ _|____ ___.__.
// / \ ___ | ___/ \ ___ | <_/ __ < | |
// \ \_\ \| | \ \_\ \ | | \ ___/\___ |
// \______ /|____| \______ / |____|__ \___ > ____|
// \/ \/ \/ \/\/
// _________
// \_ ___ \ ____ _____ _____ ____ ____
// / \ \/ / _ \ / \ / \ / _ \ / \
// \ \___( <_> ) Y Y \ Y Y ( <_> ) | \
// \______ /\____/|__|_| /__|_| /\____/|___| /
// \/ \/ \/ \/
// This file provides common functions relating to GPG Keys
// checkArmoredGPGKeyString checks if the given key string is a valid GPG armored key.
// The function returns the actual public key on success
func checkArmoredGPGKeyString(content string) (openpgp.EntityList, error) {
list, err := openpgp.ReadArmoredKeyRing(strings.NewReader(content))
if err != nil {
return nil, ErrGPGKeyParsing{err}
}
return list, nil
}
// base64EncPubKey encode public key content to base 64
func base64EncPubKey(pubkey *packet.PublicKey) (string, error) {
var w bytes.Buffer
err := pubkey.Serialize(&w)
if err != nil {
return "", err
}
return base64.StdEncoding.EncodeToString(w.Bytes()), nil
}
func readerFromBase64(s string) (io.Reader, error) {
bs, err := base64.StdEncoding.DecodeString(s)
if err != nil {
return nil, err
}
return bytes.NewBuffer(bs), nil
}
// base64DecPubKey decode public key content from base 64
func base64DecPubKey(content string) (*packet.PublicKey, error) {
b, err := readerFromBase64(content)
if err != nil {
return nil, err
}
// Read key
p, err := packet.Read(b)
if err != nil {
return nil, err
}
// Check type
pkey, ok := p.(*packet.PublicKey)
if !ok {
return nil, fmt.Errorf("key is not a public key")
}
return pkey, nil
}
// getExpiryTime extract the expire time of primary key based on sig
func getExpiryTime(e *openpgp.Entity) time.Time {
expiry := time.Time{}
// Extract self-sign for expire date based on : https://github.com/golang/crypto/blob/master/openpgp/keys.go#L165
var selfSig *packet.Signature
for _, ident := range e.Identities {
if selfSig == nil {
selfSig = ident.SelfSignature
} else if ident.SelfSignature.IsPrimaryId != nil && *ident.SelfSignature.IsPrimaryId {
selfSig = ident.SelfSignature
break
}
}
if selfSig.KeyLifetimeSecs != nil {
expiry = e.PrimaryKey.CreationTime.Add(time.Duration(*selfSig.KeyLifetimeSecs) * time.Second)
}
return expiry
}
func populateHash(hashFunc crypto.Hash, msg []byte) (hash.Hash, error) {
h := hashFunc.New()
if _, err := h.Write(msg); err != nil {
return nil, err
}
return h, nil
}
// readArmoredSign read an armored signature block with the given type. https://sourcegraph.com/github.com/golang/crypto/-/blob/openpgp/read.go#L24:6-24:17
func readArmoredSign(r io.Reader) (body io.Reader, err error) {
block, err := armor.Decode(r)
if err != nil {
return
}
if block.Type != openpgp.SignatureType {
return nil, fmt.Errorf("expected '" + openpgp.SignatureType + "', got: " + block.Type)
}
return block.Body, nil
}
func extractSignature(s string) (*packet.Signature, error) {
r, err := readArmoredSign(strings.NewReader(s))
if err != nil {
return nil, fmt.Errorf("Failed to read signature armor")
}
p, err := packet.Read(r)
if err != nil {
return nil, fmt.Errorf("Failed to read signature packet")
}
sig, ok := p.(*packet.Signature)
if !ok {
return nil, fmt.Errorf("Packet is not a signature")
}
return sig, nil
}