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author | Péter Szilágyi <peterke@gmail.com> | 2016-11-03 00:22:53 +0800 |
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committer | Péter Szilágyi <peterke@gmail.com> | 2016-11-03 16:32:57 +0800 |
commit | bad0de0dcbae82d96f68d1eec1701042d5dfa985 (patch) | |
tree | 7b6e585f47a0c4bb9f6e3a17d549ca1d0ddbd642 /vendor/golang.org/x/crypto/openpgp/keys.go | |
parent | 3b62c145f8d699767e13770d1bb21d07c2ba9b46 (diff) | |
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vendor: pull in azure sdk and openpgp signer
Diffstat (limited to 'vendor/golang.org/x/crypto/openpgp/keys.go')
-rw-r--r-- | vendor/golang.org/x/crypto/openpgp/keys.go | 639 |
1 files changed, 639 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/openpgp/keys.go b/vendor/golang.org/x/crypto/openpgp/keys.go new file mode 100644 index 000000000..fd9bbd29b --- /dev/null +++ b/vendor/golang.org/x/crypto/openpgp/keys.go @@ -0,0 +1,639 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package openpgp + +import ( + "crypto/rsa" + "io" + "time" + + "golang.org/x/crypto/openpgp/armor" + "golang.org/x/crypto/openpgp/errors" + "golang.org/x/crypto/openpgp/packet" +) + +// PublicKeyType is the armor type for a PGP public key. +var PublicKeyType = "PGP PUBLIC KEY BLOCK" + +// PrivateKeyType is the armor type for a PGP private key. +var PrivateKeyType = "PGP PRIVATE KEY BLOCK" + +// An Entity represents the components of an OpenPGP key: a primary public key +// (which must be a signing key), one or more identities claimed by that key, +// and zero or more subkeys, which may be encryption keys. +type Entity struct { + PrimaryKey *packet.PublicKey + PrivateKey *packet.PrivateKey + Identities map[string]*Identity // indexed by Identity.Name + Revocations []*packet.Signature + Subkeys []Subkey +} + +// An Identity represents an identity claimed by an Entity and zero or more +// assertions by other entities about that claim. +type Identity struct { + Name string // by convention, has the form "Full Name (comment) <email@example.com>" + UserId *packet.UserId + SelfSignature *packet.Signature + Signatures []*packet.Signature +} + +// A Subkey is an additional public key in an Entity. Subkeys can be used for +// encryption. +type Subkey struct { + PublicKey *packet.PublicKey + PrivateKey *packet.PrivateKey + Sig *packet.Signature +} + +// A Key identifies a specific public key in an Entity. This is either the +// Entity's primary key or a subkey. +type Key struct { + Entity *Entity + PublicKey *packet.PublicKey + PrivateKey *packet.PrivateKey + SelfSignature *packet.Signature +} + +// A KeyRing provides access to public and private keys. +type KeyRing interface { + // KeysById returns the set of keys that have the given key id. + KeysById(id uint64) []Key + // KeysByIdAndUsage returns the set of keys with the given id + // that also meet the key usage given by requiredUsage. + // The requiredUsage is expressed as the bitwise-OR of + // packet.KeyFlag* values. + KeysByIdUsage(id uint64, requiredUsage byte) []Key + // DecryptionKeys returns all private keys that are valid for + // decryption. + DecryptionKeys() []Key +} + +// primaryIdentity returns the Identity marked as primary or the first identity +// if none are so marked. +func (e *Entity) primaryIdentity() *Identity { + var firstIdentity *Identity + for _, ident := range e.Identities { + if firstIdentity == nil { + firstIdentity = ident + } + if ident.SelfSignature.IsPrimaryId != nil && *ident.SelfSignature.IsPrimaryId { + return ident + } + } + return firstIdentity +} + +// encryptionKey returns the best candidate Key for encrypting a message to the +// given Entity. +func (e *Entity) encryptionKey(now time.Time) (Key, bool) { + candidateSubkey := -1 + + // Iterate the keys to find the newest key + var maxTime time.Time + for i, subkey := range e.Subkeys { + if subkey.Sig.FlagsValid && + subkey.Sig.FlagEncryptCommunications && + subkey.PublicKey.PubKeyAlgo.CanEncrypt() && + !subkey.Sig.KeyExpired(now) && + (maxTime.IsZero() || subkey.Sig.CreationTime.After(maxTime)) { + candidateSubkey = i + maxTime = subkey.Sig.CreationTime + } + } + + if candidateSubkey != -1 { + subkey := e.Subkeys[candidateSubkey] + return Key{e, subkey.PublicKey, subkey.PrivateKey, subkey.Sig}, true + } + + // If we don't have any candidate subkeys for encryption and + // the primary key doesn't have any usage metadata then we + // assume that the primary key is ok. Or, if the primary key is + // marked as ok to encrypt to, then we can obviously use it. + i := e.primaryIdentity() + if !i.SelfSignature.FlagsValid || i.SelfSignature.FlagEncryptCommunications && + e.PrimaryKey.PubKeyAlgo.CanEncrypt() && + !i.SelfSignature.KeyExpired(now) { + return Key{e, e.PrimaryKey, e.PrivateKey, i.SelfSignature}, true + } + + // This Entity appears to be signing only. + return Key{}, false +} + +// signingKey return the best candidate Key for signing a message with this +// Entity. +func (e *Entity) signingKey(now time.Time) (Key, bool) { + candidateSubkey := -1 + + for i, subkey := range e.Subkeys { + if subkey.Sig.FlagsValid && + subkey.Sig.FlagSign && + subkey.PublicKey.PubKeyAlgo.CanSign() && + !subkey.Sig.KeyExpired(now) { + candidateSubkey = i + break + } + } + + if candidateSubkey != -1 { + subkey := e.Subkeys[candidateSubkey] + return Key{e, subkey.PublicKey, subkey.PrivateKey, subkey.Sig}, true + } + + // If we have no candidate subkey then we assume that it's ok to sign + // with the primary key. + i := e.primaryIdentity() + if !i.SelfSignature.FlagsValid || i.SelfSignature.FlagSign && + !i.SelfSignature.KeyExpired(now) { + return Key{e, e.PrimaryKey, e.PrivateKey, i.SelfSignature}, true + } + + return Key{}, false +} + +// An EntityList contains one or more Entities. +type EntityList []*Entity + +// KeysById returns the set of keys that have the given key id. +func (el EntityList) KeysById(id uint64) (keys []Key) { + for _, e := range el { + if e.PrimaryKey.KeyId == id { + 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 + } + } + keys = append(keys, Key{e, e.PrimaryKey, e.PrivateKey, selfSig}) + } + + for _, subKey := range e.Subkeys { + if subKey.PublicKey.KeyId == id { + keys = append(keys, Key{e, subKey.PublicKey, subKey.PrivateKey, subKey.Sig}) + } + } + } + return +} + +// KeysByIdAndUsage returns the set of keys with the given id that also meet +// the key usage given by requiredUsage. The requiredUsage is expressed as +// the bitwise-OR of packet.KeyFlag* values. +func (el EntityList) KeysByIdUsage(id uint64, requiredUsage byte) (keys []Key) { + for _, key := range el.KeysById(id) { + if len(key.Entity.Revocations) > 0 { + continue + } + + if key.SelfSignature.RevocationReason != nil { + continue + } + + if key.SelfSignature.FlagsValid && requiredUsage != 0 { + var usage byte + if key.SelfSignature.FlagCertify { + usage |= packet.KeyFlagCertify + } + if key.SelfSignature.FlagSign { + usage |= packet.KeyFlagSign + } + if key.SelfSignature.FlagEncryptCommunications { + usage |= packet.KeyFlagEncryptCommunications + } + if key.SelfSignature.FlagEncryptStorage { + usage |= packet.KeyFlagEncryptStorage + } + if usage&requiredUsage != requiredUsage { + continue + } + } + + keys = append(keys, key) + } + return +} + +// DecryptionKeys returns all private keys that are valid for decryption. +func (el EntityList) DecryptionKeys() (keys []Key) { + for _, e := range el { + for _, subKey := range e.Subkeys { + if subKey.PrivateKey != nil && (!subKey.Sig.FlagsValid || subKey.Sig.FlagEncryptStorage || subKey.Sig.FlagEncryptCommunications) { + keys = append(keys, Key{e, subKey.PublicKey, subKey.PrivateKey, subKey.Sig}) + } + } + } + return +} + +// ReadArmoredKeyRing reads one or more public/private keys from an armor keyring file. +func ReadArmoredKeyRing(r io.Reader) (EntityList, error) { + block, err := armor.Decode(r) + if err == io.EOF { + return nil, errors.InvalidArgumentError("no armored data found") + } + if err != nil { + return nil, err + } + if block.Type != PublicKeyType && block.Type != PrivateKeyType { + return nil, errors.InvalidArgumentError("expected public or private key block, got: " + block.Type) + } + + return ReadKeyRing(block.Body) +} + +// ReadKeyRing reads one or more public/private keys. Unsupported keys are +// ignored as long as at least a single valid key is found. +func ReadKeyRing(r io.Reader) (el EntityList, err error) { + packets := packet.NewReader(r) + var lastUnsupportedError error + + for { + var e *Entity + e, err = ReadEntity(packets) + if err != nil { + // TODO: warn about skipped unsupported/unreadable keys + if _, ok := err.(errors.UnsupportedError); ok { + lastUnsupportedError = err + err = readToNextPublicKey(packets) + } else if _, ok := err.(errors.StructuralError); ok { + // Skip unreadable, badly-formatted keys + lastUnsupportedError = err + err = readToNextPublicKey(packets) + } + if err == io.EOF { + err = nil + break + } + if err != nil { + el = nil + break + } + } else { + el = append(el, e) + } + } + + if len(el) == 0 && err == nil { + err = lastUnsupportedError + } + return +} + +// readToNextPublicKey reads packets until the start of the entity and leaves +// the first packet of the new entity in the Reader. +func readToNextPublicKey(packets *packet.Reader) (err error) { + var p packet.Packet + for { + p, err = packets.Next() + if err == io.EOF { + return + } else if err != nil { + if _, ok := err.(errors.UnsupportedError); ok { + err = nil + continue + } + return + } + + if pk, ok := p.(*packet.PublicKey); ok && !pk.IsSubkey { + packets.Unread(p) + return + } + } + + panic("unreachable") +} + +// ReadEntity reads an entity (public key, identities, subkeys etc) from the +// given Reader. +func ReadEntity(packets *packet.Reader) (*Entity, error) { + e := new(Entity) + e.Identities = make(map[string]*Identity) + + p, err := packets.Next() + if err != nil { + return nil, err + } + + var ok bool + if e.PrimaryKey, ok = p.(*packet.PublicKey); !ok { + if e.PrivateKey, ok = p.(*packet.PrivateKey); !ok { + packets.Unread(p) + return nil, errors.StructuralError("first packet was not a public/private key") + } else { + e.PrimaryKey = &e.PrivateKey.PublicKey + } + } + + if !e.PrimaryKey.PubKeyAlgo.CanSign() { + return nil, errors.StructuralError("primary key cannot be used for signatures") + } + + var current *Identity + var revocations []*packet.Signature +EachPacket: + for { + p, err := packets.Next() + if err == io.EOF { + break + } else if err != nil { + return nil, err + } + + switch pkt := p.(type) { + case *packet.UserId: + current = new(Identity) + current.Name = pkt.Id + current.UserId = pkt + e.Identities[pkt.Id] = current + + for { + p, err = packets.Next() + if err == io.EOF { + return nil, io.ErrUnexpectedEOF + } else if err != nil { + return nil, err + } + + sig, ok := p.(*packet.Signature) + if !ok { + return nil, errors.StructuralError("user ID packet not followed by self-signature") + } + + if (sig.SigType == packet.SigTypePositiveCert || sig.SigType == packet.SigTypeGenericCert) && sig.IssuerKeyId != nil && *sig.IssuerKeyId == e.PrimaryKey.KeyId { + if err = e.PrimaryKey.VerifyUserIdSignature(pkt.Id, e.PrimaryKey, sig); err != nil { + return nil, errors.StructuralError("user ID self-signature invalid: " + err.Error()) + } + current.SelfSignature = sig + break + } + current.Signatures = append(current.Signatures, sig) + } + case *packet.Signature: + if pkt.SigType == packet.SigTypeKeyRevocation { + revocations = append(revocations, pkt) + } else if pkt.SigType == packet.SigTypeDirectSignature { + // TODO: RFC4880 5.2.1 permits signatures + // directly on keys (eg. to bind additional + // revocation keys). + } else if current == nil { + 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 { + err = e.PrimaryKey.VerifyRevocationSignature(revocation) + if err == nil { + e.Revocations = append(e.Revocations, revocation) + } else { + // TODO: RFC 4880 5.2.3.15 defines revocation keys. + return nil, errors.StructuralError("revocation signature signed by alternate key") + } + } + + 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 + p, err := packets.Next() + if err == io.EOF { + return io.ErrUnexpectedEOF + } + if err != nil { + return errors.StructuralError("subkey signature invalid: " + err.Error()) + } + var ok bool + subKey.Sig, ok = p.(*packet.Signature) + if !ok { + return errors.StructuralError("subkey packet not followed by signature") + } + if subKey.Sig.SigType != packet.SigTypeSubkeyBinding && subKey.Sig.SigType != packet.SigTypeSubkeyRevocation { + return errors.StructuralError("subkey signature with wrong type") + } + err = e.PrimaryKey.VerifyKeySignature(subKey.PublicKey, subKey.Sig) + if err != nil { + return errors.StructuralError("subkey signature invalid: " + err.Error()) + } + e.Subkeys = append(e.Subkeys, subKey) + 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, + }, + } + + // If the user passes in a DefaultHash via packet.Config, + // set the PreferredHash for the SelfSignature. + if config != nil && config.DefaultHash != 0 { + e.Identities[uid.Id].SelfSignature.PreferredHash = []uint8{hashToHashId(config.DefaultHash)} + } + + 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 + } + 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 + } + err = subkey.Sig.SignKey(subkey.PublicKey, e.PrivateKey, config) + 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 + } + 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 +} |