mirror of
https://github.com/go-gitea/gitea.git
synced 2024-12-12 07:09:36 +08:00
274149dd14
* Switch to keybase go-crypto (for some elliptic curve key) + test
* Use assert.NoError
and add a little more context to failing test description
* Use assert.(No)Error everywhere 🌈
and assert.Error in place of .Nil/.NotNil
903 lines
28 KiB
Go
903 lines
28 KiB
Go
// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package openpgp
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import (
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"crypto/hmac"
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"encoding/binary"
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"io"
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"time"
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"github.com/keybase/go-crypto/openpgp/armor"
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"github.com/keybase/go-crypto/openpgp/errors"
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"github.com/keybase/go-crypto/openpgp/packet"
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"github.com/keybase/go-crypto/rsa"
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)
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// PublicKeyType is the armor type for a PGP public key.
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var PublicKeyType = "PGP PUBLIC KEY BLOCK"
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// PrivateKeyType is the armor type for a PGP private key.
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var PrivateKeyType = "PGP PRIVATE KEY BLOCK"
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// An Entity represents the components of an OpenPGP key: a primary public key
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// (which must be a signing key), one or more identities claimed by that key,
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// and zero or more subkeys, which may be encryption keys.
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type Entity struct {
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PrimaryKey *packet.PublicKey
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PrivateKey *packet.PrivateKey
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Identities map[string]*Identity // indexed by Identity.Name
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Revocations []*packet.Signature
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// Revocations that are signed by designated revokers. Reading keys
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// will not verify these revocations, because it won't have access to
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// issuers' public keys, API consumers should do this instead (or
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// not, and just assume that the key is probably revoked).
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UnverifiedRevocations []*packet.Signature
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Subkeys []Subkey
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BadSubkeys []BadSubkey
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}
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// An Identity represents an identity claimed by an Entity and zero or more
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// assertions by other entities about that claim.
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type Identity struct {
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Name string // by convention, has the form "Full Name (comment) <email@example.com>"
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UserId *packet.UserId
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SelfSignature *packet.Signature
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Signatures []*packet.Signature
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Revocation *packet.Signature
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}
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// A Subkey is an additional public key in an Entity. Subkeys can be used for
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// encryption.
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type Subkey struct {
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PublicKey *packet.PublicKey
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PrivateKey *packet.PrivateKey
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Sig *packet.Signature
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Revocation *packet.Signature
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}
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// BadSubkey is one that failed reconstruction, but we'll keep it around for
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// informational purposes.
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type BadSubkey struct {
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Subkey
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Err error
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}
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// A Key identifies a specific public key in an Entity. This is either the
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// Entity's primary key or a subkey.
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type Key struct {
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Entity *Entity
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PublicKey *packet.PublicKey
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PrivateKey *packet.PrivateKey
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SelfSignature *packet.Signature
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KeyFlags packet.KeyFlagBits
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}
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// A KeyRing provides access to public and private keys.
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type KeyRing interface {
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// KeysById returns the set of keys that have the given key id.
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// fp can be optionally supplied, which is the full key fingerprint.
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// If it's provided, then it must match. This comes up in the case
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// of GPG subpacket 33.
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KeysById(id uint64, fp []byte) []Key
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// KeysByIdAndUsage returns the set of keys with the given id
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// that also meet the key usage given by requiredUsage.
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// The requiredUsage is expressed as the bitwise-OR of
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// packet.KeyFlag* values.
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// fp can be optionally supplied, which is the full key fingerprint.
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// If it's provided, then it must match. This comes up in the case
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// of GPG subpacket 33.
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KeysByIdUsage(id uint64, fp []byte, requiredUsage byte) []Key
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// DecryptionKeys returns all private keys that are valid for
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// decryption.
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DecryptionKeys() []Key
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}
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// primaryIdentity returns the Identity marked as primary or the first identity
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// if none are so marked.
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func (e *Entity) primaryIdentity() *Identity {
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var firstIdentity *Identity
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for _, ident := range e.Identities {
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if firstIdentity == nil {
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firstIdentity = ident
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}
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if ident.SelfSignature.IsPrimaryId != nil && *ident.SelfSignature.IsPrimaryId {
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return ident
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}
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}
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return firstIdentity
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}
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// encryptionKey returns the best candidate Key for encrypting a message to the
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// given Entity.
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func (e *Entity) encryptionKey(now time.Time) (Key, bool) {
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candidateSubkey := -1
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// Iterate the keys to find the newest key
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var maxTime time.Time
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for i, subkey := range e.Subkeys {
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// NOTE(maxtaco)
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// If there is a Flags subpacket, then we have to follow it, and only
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// use keys that are marked for Encryption of Communication. If there
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// isn't a Flags subpacket, and this is an Encrypt-Only key (right now only ElGamal
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// suffices), then we implicitly use it. The check for primary below is a little
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// more open-ended, but for now, let's be strict and potentially open up
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// if we see bugs in the wild.
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//
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// One more note: old DSA/ElGamal keys tend not to have the Flags subpacket,
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// so this sort of thing is pretty important for encrypting to older keys.
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//
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if ((subkey.Sig.FlagsValid && subkey.Sig.FlagEncryptCommunications) ||
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(!subkey.Sig.FlagsValid && subkey.PublicKey.PubKeyAlgo == packet.PubKeyAlgoElGamal)) &&
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subkey.PublicKey.PubKeyAlgo.CanEncrypt() &&
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!subkey.Sig.KeyExpired(now) &&
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subkey.Revocation == nil &&
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(maxTime.IsZero() || subkey.Sig.CreationTime.After(maxTime)) {
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candidateSubkey = i
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maxTime = subkey.Sig.CreationTime
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}
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}
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if candidateSubkey != -1 {
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subkey := e.Subkeys[candidateSubkey]
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return Key{e, subkey.PublicKey, subkey.PrivateKey, subkey.Sig, subkey.Sig.GetKeyFlags()}, true
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}
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// If we don't have any candidate subkeys for encryption and
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// the primary key doesn't have any usage metadata then we
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// assume that the primary key is ok. Or, if the primary key is
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// marked as ok to encrypt to, then we can obviously use it.
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//
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// NOTE(maxtaco) - see note above, how this policy is a little too open-ended
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// for my liking, but leave it for now.
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i := e.primaryIdentity()
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if (!i.SelfSignature.FlagsValid || i.SelfSignature.FlagEncryptCommunications) &&
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e.PrimaryKey.PubKeyAlgo.CanEncrypt() &&
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!i.SelfSignature.KeyExpired(now) {
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return Key{e, e.PrimaryKey, e.PrivateKey, i.SelfSignature, i.SelfSignature.GetKeyFlags()}, true
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}
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// This Entity appears to be signing only.
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return Key{}, false
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}
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// signingKey return the best candidate Key for signing a message with this
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// Entity.
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func (e *Entity) signingKey(now time.Time) (Key, bool) {
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candidateSubkey := -1
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for i, subkey := range e.Subkeys {
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if (!subkey.Sig.FlagsValid || subkey.Sig.FlagSign) &&
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subkey.PrivateKey.PrivateKey != nil &&
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subkey.PublicKey.PubKeyAlgo.CanSign() &&
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subkey.Revocation == nil &&
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!subkey.Sig.KeyExpired(now) {
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candidateSubkey = i
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break
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}
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}
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if candidateSubkey != -1 {
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subkey := e.Subkeys[candidateSubkey]
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return Key{e, subkey.PublicKey, subkey.PrivateKey, subkey.Sig, subkey.Sig.GetKeyFlags()}, true
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}
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// If we have no candidate subkey then we assume that it's ok to sign
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// with the primary key.
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i := e.primaryIdentity()
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if (!i.SelfSignature.FlagsValid || i.SelfSignature.FlagSign) &&
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e.PrimaryKey.PubKeyAlgo.CanSign() &&
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!i.SelfSignature.KeyExpired(now) &&
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e.PrivateKey.PrivateKey != nil {
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return Key{e, e.PrimaryKey, e.PrivateKey, i.SelfSignature, i.SelfSignature.GetKeyFlags()}, true
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}
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return Key{}, false
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}
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// An EntityList contains one or more Entities.
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type EntityList []*Entity
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func keyMatchesIdAndFingerprint(key *packet.PublicKey, id uint64, fp []byte) bool {
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if key.KeyId != id {
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return false
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}
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if fp == nil {
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return true
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}
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return hmac.Equal(fp, key.Fingerprint[:])
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}
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// KeysById returns the set of keys that have the given key id.
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// fp can be optionally supplied, which is the full key fingerprint.
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// If it's provided, then it must match. This comes up in the case
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// of GPG subpacket 33.
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func (el EntityList) KeysById(id uint64, fp []byte) (keys []Key) {
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for _, e := range el {
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if keyMatchesIdAndFingerprint(e.PrimaryKey, id, fp) {
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var selfSig *packet.Signature
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for _, ident := range e.Identities {
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if selfSig == nil {
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selfSig = ident.SelfSignature
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} else if ident.SelfSignature.IsPrimaryId != nil && *ident.SelfSignature.IsPrimaryId {
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selfSig = ident.SelfSignature
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break
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}
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}
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var keyFlags packet.KeyFlagBits
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for _, ident := range e.Identities {
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keyFlags.Merge(ident.SelfSignature.GetKeyFlags())
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}
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keys = append(keys, Key{e, e.PrimaryKey, e.PrivateKey, selfSig, keyFlags})
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}
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for _, subKey := range e.Subkeys {
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if keyMatchesIdAndFingerprint(subKey.PublicKey, id, fp) {
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// If there's both a a revocation and a sig, then take the
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// revocation. Otherwise, we can proceed with the sig.
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sig := subKey.Revocation
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if sig == nil {
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sig = subKey.Sig
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}
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keys = append(keys, Key{e, subKey.PublicKey, subKey.PrivateKey, sig, sig.GetKeyFlags()})
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}
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}
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}
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return
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}
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// KeysByIdAndUsage returns the set of keys with the given id that also meet
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// the key usage given by requiredUsage. The requiredUsage is expressed as
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// the bitwise-OR of packet.KeyFlag* values.
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// fp can be optionally supplied, which is the full key fingerprint.
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// If it's provided, then it must match. This comes up in the case
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// of GPG subpacket 33.
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func (el EntityList) KeysByIdUsage(id uint64, fp []byte, requiredUsage byte) (keys []Key) {
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for _, key := range el.KeysById(id, fp) {
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if len(key.Entity.Revocations) > 0 {
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continue
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}
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if key.SelfSignature.RevocationReason != nil {
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continue
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}
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if requiredUsage != 0 {
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var usage byte
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switch {
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case key.KeyFlags.Valid:
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usage = key.KeyFlags.BitField
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case key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoElGamal:
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// We also need to handle the case where, although the sig's
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// flags aren't valid, the key can is implicitly usable for
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// encryption by virtue of being ElGamal. See also the comment
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// in encryptionKey() above.
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usage |= packet.KeyFlagEncryptCommunications
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usage |= packet.KeyFlagEncryptStorage
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case key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoDSA ||
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key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoECDSA ||
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key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoEdDSA:
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usage |= packet.KeyFlagSign
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// For a primary RSA key without any key flags, be as permissiable
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// as possible.
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case key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoRSA &&
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keyMatchesIdAndFingerprint(key.Entity.PrimaryKey, id, fp):
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usage = (packet.KeyFlagCertify | packet.KeyFlagSign |
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packet.KeyFlagEncryptCommunications | packet.KeyFlagEncryptStorage)
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}
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if usage&requiredUsage != requiredUsage {
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continue
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}
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}
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keys = append(keys, key)
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}
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return
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}
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// DecryptionKeys returns all private keys that are valid for decryption.
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func (el EntityList) DecryptionKeys() (keys []Key) {
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for _, e := range el {
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for _, subKey := range e.Subkeys {
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if subKey.PrivateKey != nil && subKey.PrivateKey.PrivateKey != nil && (!subKey.Sig.FlagsValid || subKey.Sig.FlagEncryptStorage || subKey.Sig.FlagEncryptCommunications) {
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keys = append(keys, Key{e, subKey.PublicKey, subKey.PrivateKey, subKey.Sig, subKey.Sig.GetKeyFlags()})
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}
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}
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}
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return
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}
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// ReadArmoredKeyRing reads one or more public/private keys from an armor keyring file.
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func ReadArmoredKeyRing(r io.Reader) (EntityList, error) {
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block, err := armor.Decode(r)
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if err == io.EOF {
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return nil, errors.InvalidArgumentError("no armored data found")
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}
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if err != nil {
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return nil, err
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}
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if block.Type != PublicKeyType && block.Type != PrivateKeyType {
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return nil, errors.InvalidArgumentError("expected public or private key block, got: " + block.Type)
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}
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return ReadKeyRing(block.Body)
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}
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// ReadKeyRing reads one or more public/private keys. Unsupported keys are
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// ignored as long as at least a single valid key is found.
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func ReadKeyRing(r io.Reader) (el EntityList, err error) {
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packets := packet.NewReader(r)
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var lastUnsupportedError error
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for {
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var e *Entity
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e, err = ReadEntity(packets)
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if err != nil {
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// TODO: warn about skipped unsupported/unreadable keys
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if _, ok := err.(errors.UnsupportedError); ok {
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lastUnsupportedError = err
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err = readToNextPublicKey(packets)
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} else if _, ok := err.(errors.StructuralError); ok {
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// Skip unreadable, badly-formatted keys
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lastUnsupportedError = err
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err = readToNextPublicKey(packets)
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}
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if err == io.EOF {
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err = nil
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break
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}
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if err != nil {
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el = nil
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break
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}
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} else {
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el = append(el, e)
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}
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}
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if len(el) == 0 && err == nil {
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err = lastUnsupportedError
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}
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return
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}
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// readToNextPublicKey reads packets until the start of the entity and leaves
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// the first packet of the new entity in the Reader.
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func readToNextPublicKey(packets *packet.Reader) (err error) {
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var p packet.Packet
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for {
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p, err = packets.Next()
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if err == io.EOF {
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return
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} else if err != nil {
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if _, ok := err.(errors.UnsupportedError); ok {
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err = nil
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continue
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}
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return
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}
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if pk, ok := p.(*packet.PublicKey); ok && !pk.IsSubkey {
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packets.Unread(p)
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return
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}
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}
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panic("unreachable")
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}
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// ReadEntity reads an entity (public key, identities, subkeys etc) from the
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// given Reader.
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func ReadEntity(packets *packet.Reader) (*Entity, error) {
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e := new(Entity)
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e.Identities = make(map[string]*Identity)
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p, err := packets.Next()
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if err != nil {
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return nil, err
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}
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var ok bool
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if e.PrimaryKey, ok = p.(*packet.PublicKey); !ok {
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if e.PrivateKey, ok = p.(*packet.PrivateKey); !ok {
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packets.Unread(p)
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return nil, errors.StructuralError("first packet was not a public/private key")
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} else {
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e.PrimaryKey = &e.PrivateKey.PublicKey
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}
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}
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if !e.PrimaryKey.PubKeyAlgo.CanSign() {
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return nil, errors.StructuralError("primary key cannot be used for signatures")
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}
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var current *Identity
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var revocations []*packet.Signature
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designatedRevokers := make(map[uint64]bool)
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EachPacket:
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for {
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p, err := packets.Next()
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if err == io.EOF {
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break
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} else if err != nil {
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return nil, err
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}
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switch pkt := p.(type) {
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case *packet.UserId:
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// Make a new Identity object, that we might wind up throwing away.
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// We'll only add it if we get a valid self-signature over this
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// userID.
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current = new(Identity)
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current.Name = pkt.Id
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current.UserId = pkt
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case *packet.Signature:
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if pkt.SigType == packet.SigTypeKeyRevocation {
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// These revocations won't revoke UIDs (see
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// SigTypeIdentityRevocation). Handle these first,
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// because key might have revocation coming from
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// another key (designated revoke).
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revocations = append(revocations, pkt)
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continue
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}
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// These are signatures by other people on this key. Let's just ignore them
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// from the beginning, since they shouldn't affect our key decoding one way
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// or the other.
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if pkt.IssuerKeyId != nil && *pkt.IssuerKeyId != e.PrimaryKey.KeyId {
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continue
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}
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// If this is a signature made by the keyholder, and the signature has stubbed out
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// critical packets, then *now* we need to bail out.
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if e := pkt.StubbedOutCriticalError; e != nil {
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return nil, e
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}
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// Next handle the case of a self-signature. According to RFC8440,
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// Section 5.2.3.3, if there are several self-signatures,
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// we should take the newer one. If they were both created
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// at the same time, but one of them has keyflags specified and the
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// other doesn't, keep the one with the keyflags. We have actually
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// seen this in the wild (see the 'Yield' test in read_test.go).
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// If there is a tie, and both have the same value for FlagsValid,
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// then "last writer wins."
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//
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// HOWEVER! We have seen yet more keys in the wild (see the 'Spiros'
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// test in read_test.go), in which the later self-signature is a bunch
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// of junk, and doesn't even specify key flags. Does it really make
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// sense to overwrite reasonable key flags with the empty set? I'm not
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// sure what that would be trying to achieve, and plus GPG seems to be
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// ok with this situation, and ignores the later (empty) keyflag set.
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// So further tighten our overwrite rules, and only allow the later
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// signature to overwrite the earlier signature if so doing won't
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// trash the key flags.
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if current != nil &&
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(current.SelfSignature == nil ||
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(!pkt.CreationTime.Before(current.SelfSignature.CreationTime) &&
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(pkt.FlagsValid || !current.SelfSignature.FlagsValid))) &&
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(pkt.SigType == packet.SigTypePositiveCert || pkt.SigType == packet.SigTypeGenericCert) &&
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pkt.IssuerKeyId != nil &&
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|
*pkt.IssuerKeyId == e.PrimaryKey.KeyId {
|
|
|
|
if err = e.PrimaryKey.VerifyUserIdSignature(current.Name, e.PrimaryKey, pkt); err == nil {
|
|
|
|
current.SelfSignature = pkt
|
|
|
|
// NOTE(maxtaco) 2016.01.11
|
|
// Only register an identity once we've gotten a valid self-signature.
|
|
// It's possible therefore for us to throw away `current` in the case
|
|
// no valid self-signatures were found. That's OK as long as there are
|
|
// other identies that make sense.
|
|
//
|
|
// NOTE! We might later see a revocation for this very same UID, and it
|
|
// won't be undone. We've preserved this feature from the original
|
|
// Google OpenPGP we forked from.
|
|
e.Identities[current.Name] = current
|
|
} else {
|
|
// We really should warn that there was a failure here. Not raise an error
|
|
// since this really shouldn't be a fail-stop error.
|
|
}
|
|
} else if current != nil && pkt.SigType == packet.SigTypeIdentityRevocation {
|
|
if err = e.PrimaryKey.VerifyUserIdSignature(current.Name, e.PrimaryKey, pkt); err == nil {
|
|
// Note: we are not removing the identity from
|
|
// e.Identities. Caller can always filter by Revocation
|
|
// field to ignore revoked identities.
|
|
current.Revocation = pkt
|
|
}
|
|
} else if pkt.SigType == packet.SigTypeDirectSignature {
|
|
if err = e.PrimaryKey.VerifyRevocationSignature(e.PrimaryKey, pkt); err == nil {
|
|
if desig := pkt.DesignatedRevoker; desig != nil {
|
|
// If it's a designated revoker signature, take last 8 octects
|
|
// of fingerprint as Key ID and save it to designatedRevokers
|
|
// map. We consult this map later to see if a foreign
|
|
// revocation should be added to UnverifiedRevocations.
|
|
keyID := binary.BigEndian.Uint64(desig.Fingerprint[len(desig.Fingerprint)-8:])
|
|
designatedRevokers[keyID] = true
|
|
}
|
|
}
|
|
} else if current == nil {
|
|
// NOTE(maxtaco)
|
|
//
|
|
// See https://github.com/keybase/client/issues/2666
|
|
//
|
|
// There might have been a user attribute picture before this signature,
|
|
// in which case this is still a valid PGP key. In the future we might
|
|
// not ignore user attributes (like picture). But either way, it doesn't
|
|
// make sense to bail out here. Keep looking for other valid signatures.
|
|
//
|
|
// Used to be:
|
|
// return nil, errors.StructuralError("signature packet found before user id packet")
|
|
} else {
|
|
current.Signatures = append(current.Signatures, pkt)
|
|
}
|
|
case *packet.PrivateKey:
|
|
if pkt.IsSubkey == false {
|
|
packets.Unread(p)
|
|
break EachPacket
|
|
}
|
|
err = addSubkey(e, packets, &pkt.PublicKey, pkt)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
case *packet.PublicKey:
|
|
if pkt.IsSubkey == false {
|
|
packets.Unread(p)
|
|
break EachPacket
|
|
}
|
|
err = addSubkey(e, packets, pkt, nil)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
default:
|
|
// we ignore unknown packets
|
|
}
|
|
}
|
|
|
|
if len(e.Identities) == 0 {
|
|
return nil, errors.StructuralError("entity without any identities")
|
|
}
|
|
|
|
for _, revocation := range revocations {
|
|
if revocation.IssuerKeyId == nil || *revocation.IssuerKeyId == e.PrimaryKey.KeyId {
|
|
// Key revokes itself, something that we can verify.
|
|
err = e.PrimaryKey.VerifyRevocationSignature(e.PrimaryKey, revocation)
|
|
if err == nil {
|
|
e.Revocations = append(e.Revocations, revocation)
|
|
} else {
|
|
return nil, errors.StructuralError("revocation signature signed by alternate key")
|
|
}
|
|
} else if revocation.IssuerKeyId != nil {
|
|
if _, ok := designatedRevokers[*revocation.IssuerKeyId]; ok {
|
|
// Revocation is done by certified designated revoker,
|
|
// but we can't verify the revocation.
|
|
e.UnverifiedRevocations = append(e.UnverifiedRevocations, revocation)
|
|
}
|
|
}
|
|
}
|
|
|
|
return e, nil
|
|
}
|
|
|
|
func addSubkey(e *Entity, packets *packet.Reader, pub *packet.PublicKey, priv *packet.PrivateKey) error {
|
|
var subKey Subkey
|
|
subKey.PublicKey = pub
|
|
subKey.PrivateKey = priv
|
|
var lastErr error
|
|
for {
|
|
p, err := packets.Next()
|
|
if err == io.EOF {
|
|
break
|
|
}
|
|
if err != nil {
|
|
return errors.StructuralError("subkey signature invalid: " + err.Error())
|
|
}
|
|
sig, ok := p.(*packet.Signature)
|
|
if !ok {
|
|
// Hit a non-signature packet, so assume we're up to the next key
|
|
packets.Unread(p)
|
|
break
|
|
}
|
|
if st := sig.SigType; st != packet.SigTypeSubkeyBinding && st != packet.SigTypeSubkeyRevocation {
|
|
|
|
// Note(maxtaco):
|
|
// We used to error out here, but instead, let's fast-forward past
|
|
// packets that are in the wrong place (like misplaced 0x13 signatures)
|
|
// until we get to one that works. For a test case,
|
|
// see TestWithBadSubkeySignaturePackets.
|
|
|
|
continue
|
|
}
|
|
err = e.PrimaryKey.VerifyKeySignature(subKey.PublicKey, sig)
|
|
if err != nil {
|
|
// Non valid signature, so again, no need to abandon all hope, just continue;
|
|
// make a note of the error we hit.
|
|
lastErr = errors.StructuralError("subkey signature invalid: " + err.Error())
|
|
continue
|
|
}
|
|
switch sig.SigType {
|
|
case packet.SigTypeSubkeyBinding:
|
|
// Does the "new" sig set expiration to later date than
|
|
// "previous" sig?
|
|
if subKey.Sig == nil || subKey.Sig.ExpiresBeforeOther(sig) {
|
|
subKey.Sig = sig
|
|
}
|
|
case packet.SigTypeSubkeyRevocation:
|
|
// First writer wins
|
|
if subKey.Revocation == nil {
|
|
subKey.Revocation = sig
|
|
}
|
|
}
|
|
}
|
|
if subKey.Sig != nil {
|
|
e.Subkeys = append(e.Subkeys, subKey)
|
|
} else {
|
|
if lastErr == nil {
|
|
lastErr = errors.StructuralError("Subkey wasn't signed; expected a 'binding' signature")
|
|
}
|
|
e.BadSubkeys = append(e.BadSubkeys, BadSubkey{Subkey: subKey, Err: lastErr})
|
|
}
|
|
return nil
|
|
}
|
|
|
|
const defaultRSAKeyBits = 2048
|
|
|
|
// NewEntity returns an Entity that contains a fresh RSA/RSA keypair with a
|
|
// single identity composed of the given full name, comment and email, any of
|
|
// which may be empty but must not contain any of "()<>\x00".
|
|
// If config is nil, sensible defaults will be used.
|
|
func NewEntity(name, comment, email string, config *packet.Config) (*Entity, error) {
|
|
currentTime := config.Now()
|
|
|
|
bits := defaultRSAKeyBits
|
|
if config != nil && config.RSABits != 0 {
|
|
bits = config.RSABits
|
|
}
|
|
|
|
uid := packet.NewUserId(name, comment, email)
|
|
if uid == nil {
|
|
return nil, errors.InvalidArgumentError("user id field contained invalid characters")
|
|
}
|
|
signingPriv, err := rsa.GenerateKey(config.Random(), bits)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
encryptingPriv, err := rsa.GenerateKey(config.Random(), bits)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
e := &Entity{
|
|
PrimaryKey: packet.NewRSAPublicKey(currentTime, &signingPriv.PublicKey),
|
|
PrivateKey: packet.NewRSAPrivateKey(currentTime, signingPriv),
|
|
Identities: make(map[string]*Identity),
|
|
}
|
|
isPrimaryId := true
|
|
e.Identities[uid.Id] = &Identity{
|
|
Name: uid.Name,
|
|
UserId: uid,
|
|
SelfSignature: &packet.Signature{
|
|
CreationTime: currentTime,
|
|
SigType: packet.SigTypePositiveCert,
|
|
PubKeyAlgo: packet.PubKeyAlgoRSA,
|
|
Hash: config.Hash(),
|
|
IsPrimaryId: &isPrimaryId,
|
|
FlagsValid: true,
|
|
FlagSign: true,
|
|
FlagCertify: true,
|
|
IssuerKeyId: &e.PrimaryKey.KeyId,
|
|
},
|
|
}
|
|
|
|
e.Subkeys = make([]Subkey, 1)
|
|
e.Subkeys[0] = Subkey{
|
|
PublicKey: packet.NewRSAPublicKey(currentTime, &encryptingPriv.PublicKey),
|
|
PrivateKey: packet.NewRSAPrivateKey(currentTime, encryptingPriv),
|
|
Sig: &packet.Signature{
|
|
CreationTime: currentTime,
|
|
SigType: packet.SigTypeSubkeyBinding,
|
|
PubKeyAlgo: packet.PubKeyAlgoRSA,
|
|
Hash: config.Hash(),
|
|
FlagsValid: true,
|
|
FlagEncryptStorage: true,
|
|
FlagEncryptCommunications: true,
|
|
IssuerKeyId: &e.PrimaryKey.KeyId,
|
|
},
|
|
}
|
|
e.Subkeys[0].PublicKey.IsSubkey = true
|
|
e.Subkeys[0].PrivateKey.IsSubkey = true
|
|
|
|
return e, nil
|
|
}
|
|
|
|
// SerializePrivate serializes an Entity, including private key material, to
|
|
// the given Writer. For now, it must only be used on an Entity returned from
|
|
// NewEntity.
|
|
// If config is nil, sensible defaults will be used.
|
|
func (e *Entity) SerializePrivate(w io.Writer, config *packet.Config) (err error) {
|
|
err = e.PrivateKey.Serialize(w)
|
|
if err != nil {
|
|
return
|
|
}
|
|
for _, ident := range e.Identities {
|
|
err = ident.UserId.Serialize(w)
|
|
if err != nil {
|
|
return
|
|
}
|
|
if e.PrivateKey.PrivateKey != nil {
|
|
err = ident.SelfSignature.SignUserId(ident.UserId.Id, e.PrimaryKey, e.PrivateKey, config)
|
|
if err != nil {
|
|
return
|
|
}
|
|
}
|
|
err = ident.SelfSignature.Serialize(w)
|
|
if err != nil {
|
|
return
|
|
}
|
|
}
|
|
for _, subkey := range e.Subkeys {
|
|
err = subkey.PrivateKey.Serialize(w)
|
|
if err != nil {
|
|
return
|
|
}
|
|
// Workaround shortcoming of SignKey(), which doesn't work to reverse-sign
|
|
// sub-signing keys. So if requested, just reuse the signatures already
|
|
// available to us (if we read this key from a keyring).
|
|
if e.PrivateKey.PrivateKey != nil && !config.ReuseSignatures() {
|
|
err = subkey.Sig.SignKey(subkey.PublicKey, e.PrivateKey, config)
|
|
if err != nil {
|
|
return
|
|
}
|
|
}
|
|
|
|
if subkey.Revocation != nil {
|
|
err = subkey.Revocation.Serialize(w)
|
|
if err != nil {
|
|
return
|
|
}
|
|
}
|
|
|
|
err = subkey.Sig.Serialize(w)
|
|
if err != nil {
|
|
return
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Serialize writes the public part of the given Entity to w. (No private
|
|
// key material will be output).
|
|
func (e *Entity) Serialize(w io.Writer) error {
|
|
err := e.PrimaryKey.Serialize(w)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
for _, ident := range e.Identities {
|
|
err = ident.UserId.Serialize(w)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = ident.SelfSignature.Serialize(w)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
for _, sig := range ident.Signatures {
|
|
err = sig.Serialize(w)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
}
|
|
for _, subkey := range e.Subkeys {
|
|
err = subkey.PublicKey.Serialize(w)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if subkey.Revocation != nil {
|
|
err = subkey.Revocation.Serialize(w)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
err = subkey.Sig.Serialize(w)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// SignIdentity adds a signature to e, from signer, attesting that identity is
|
|
// associated with e. The provided identity must already be an element of
|
|
// e.Identities and the private key of signer must have been decrypted if
|
|
// necessary.
|
|
// If config is nil, sensible defaults will be used.
|
|
func (e *Entity) SignIdentity(identity string, signer *Entity, config *packet.Config) error {
|
|
if signer.PrivateKey == nil {
|
|
return errors.InvalidArgumentError("signing Entity must have a private key")
|
|
}
|
|
if signer.PrivateKey.Encrypted {
|
|
return errors.InvalidArgumentError("signing Entity's private key must be decrypted")
|
|
}
|
|
ident, ok := e.Identities[identity]
|
|
if !ok {
|
|
return errors.InvalidArgumentError("given identity string not found in Entity")
|
|
}
|
|
|
|
sig := &packet.Signature{
|
|
SigType: packet.SigTypeGenericCert,
|
|
PubKeyAlgo: signer.PrivateKey.PubKeyAlgo,
|
|
Hash: config.Hash(),
|
|
CreationTime: config.Now(),
|
|
IssuerKeyId: &signer.PrivateKey.KeyId,
|
|
}
|
|
if err := sig.SignUserId(identity, e.PrimaryKey, signer.PrivateKey, config); err != nil {
|
|
return err
|
|
}
|
|
ident.Signatures = append(ident.Signatures, sig)
|
|
return nil
|
|
}
|
|
|
|
// CopySubkeyRevocations copies subkey revocations from the src Entity over
|
|
// to the receiver entity. We need this because `gpg --export-secret-key` does
|
|
// not appear to output subkey revocations. In this case we need to manually
|
|
// merge with the output of `gpg --export`.
|
|
func (e *Entity) CopySubkeyRevocations(src *Entity) {
|
|
m := make(map[[20]byte]*packet.Signature)
|
|
for _, subkey := range src.Subkeys {
|
|
if subkey.Revocation != nil {
|
|
m[subkey.PublicKey.Fingerprint] = subkey.Revocation
|
|
}
|
|
}
|
|
for i, subkey := range e.Subkeys {
|
|
if r := m[subkey.PublicKey.Fingerprint]; r != nil {
|
|
e.Subkeys[i].Revocation = r
|
|
}
|
|
}
|
|
}
|
|
|
|
// CheckDesignatedRevokers will try to confirm any of designated
|
|
// revocation of entity. For this function to work, revocation
|
|
// issuer's key should be found in keyring. First successfully
|
|
// verified designated revocation is returned along with the key that
|
|
// verified it.
|
|
func FindVerifiedDesignatedRevoke(keyring KeyRing, entity *Entity) (*packet.Signature, *Key) {
|
|
for _, sig := range entity.UnverifiedRevocations {
|
|
if sig.IssuerKeyId == nil {
|
|
continue
|
|
}
|
|
|
|
issuerKeyId := *sig.IssuerKeyId
|
|
issuerFingerprint := sig.IssuerFingerprint
|
|
keys := keyring.KeysByIdUsage(issuerKeyId, issuerFingerprint, packet.KeyFlagSign)
|
|
if len(keys) == 0 {
|
|
continue
|
|
}
|
|
for _, key := range keys {
|
|
err := key.PublicKey.VerifyRevocationSignature(entity.PrimaryKey, sig)
|
|
if err == nil {
|
|
return sig, &key
|
|
}
|
|
}
|
|
}
|
|
|
|
return nil, nil
|
|
}
|