/
verify_handle.go
270 lines (253 loc) · 8.79 KB
/
verify_handle.go
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package crypto
import (
"bytes"
"io"
"github.com/ProtonMail/go-crypto/openpgp/armor"
"github.com/ProtonMail/go-crypto/openpgp/clearsign"
"github.com/ProtonMail/go-crypto/openpgp/packet"
openpgp "github.com/ProtonMail/go-crypto/openpgp/v2"
"github.com/ProtonMail/gopenpgp/v3/constants"
"github.com/ProtonMail/gopenpgp/v3/internal"
"github.com/pkg/errors"
)
type verifyHandle struct {
VerifyKeyRing *KeyRing
VerificationContext *VerificationContext
DisableVerifyTimeCheck bool
DisableStrictMessageParsing bool
DisableAutomaticTextSanitize bool
IsUTF8 bool
clock Clock
profile SignProfile
}
// --- Default verification handle to build from
func defaultVerifyHandle(profile SignProfile, clock Clock) *verifyHandle {
return &verifyHandle{
clock: clock,
profile: profile,
}
}
// --- Implements VerifyHandle functions
// VerifyingReader wraps a reader with a signature verify reader.
// Once all data is read from the returned verify reader, the signature can be verified
// with (VerifyDataReader).VerifySignature().
// Note that an error is only returned if it is not a signature error.
// The encoding indicates if the input signature message should be unarmored or not,
// i.e., Bytes/Armor/Auto where Auto tries to detect it automatically.
// If detachedData is nil, signatureMessage is treated as an inline signature message.
// Thus, it is expected that signatureMessage contains the data to be verified.
// If detachedData is not nil, signatureMessage must contain a detached signature,
// which is verified against the detachedData.
func (vh *verifyHandle) VerifyingReader(detachedData, signatureMessage Reader, encoding int8) (reader *VerifyDataReader, err error) {
var armored bool
signatureMessage, armored = unarmorInput(encoding, signatureMessage)
if armored {
// Wrap with decode armor reader.
armoredBlock, err := armor.Decode(signatureMessage)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: unarmor failed")
}
signatureMessage = armoredBlock.Body
}
if detachedData != nil {
if vh.IsUTF8 {
detachedData = openpgp.NewCanonicalTextReader(detachedData)
}
reader, err = vh.verifyingDetachedReader(detachedData, signatureMessage)
} else {
reader, err = vh.verifyingReader(signatureMessage)
if err == nil && vh.IsUTF8 {
reader.internalReader = internal.NewSanitizeReader(reader.internalReader)
}
}
return
}
// VerifyDetached verifies a detached signature pgp message
// and returns a VerifyResult. The VerifyResult can be checked for failure
// and allows access to information about the signatures.
// Note that an error is only returned if it is not a signature error.
// The encoding indicates if the input signature message should be unarmored or not,
// i.e., Bytes/Armor/Auto where Auto tries to detect it automatically.
func (vh *verifyHandle) VerifyDetached(data, signature []byte, encoding int8) (verifyResult *VerifyResult, err error) {
signatureMessageReader := bytes.NewReader(signature)
detachedDataReader := bytes.NewReader(data)
ptReader, err := vh.VerifyingReader(detachedDataReader, signatureMessageReader, encoding)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: verifying signature failed")
}
_, err = io.Copy(io.Discard, ptReader)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: reading data to verify signature failed")
}
return ptReader.VerifySignature()
}
// VerifyInline verifies an inline signed pgp message
// and returns a VerifiedDataResult. The VerifiedDataResult can be checked for failure,
// allows access to information about the signatures, and includes the plain message.
// Note that an error is only returned if it is not a signature error.
// The encoding indicates if the input message should be unarmored or not, i.e., Bytes/Armor/Auto
// where Auto tries to detect it automatically.
func (vh *verifyHandle) VerifyInline(message []byte, encoding int8) (verifyDataResult *VerifiedDataResult, err error) {
var ptReader *VerifyDataReader
messageReader := bytes.NewReader(message)
ptReader, err = vh.VerifyingReader(nil, messageReader, encoding)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: verifying signature failed")
}
data, err := ptReader.ReadAll()
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: reading data to verify signature failed")
}
verifyResult, err := ptReader.VerifySignature()
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: verifying signature failed")
}
verifyDataResult = &VerifiedDataResult{
data: data,
metadata: ptReader.GetMetadata(),
VerifyResult: *verifyResult,
}
return
}
// VerifyCleartext verifies an armored cleartext message and returns a VerifyCleartextResult.
// The VerifyCleartextResult can be checked for failure and allows access the contained message.
// Note that an error is only returned if it is not a signature error.
func (vh *verifyHandle) VerifyCleartext(cleartext []byte) (*VerifyCleartextResult, error) {
return vh.verifyCleartext(cleartext)
}
// --- Private logic functions
func (vh *verifyHandle) validate() error {
if vh.VerifyKeyRing == nil {
return errors.New("gopenpgp: no verification key provided")
}
return nil
}
// verifyDetachedSignature verifies if a detached signature is valid with the entity list.
func (vh *verifyHandle) verifyDetachedSignature(
origText io.Reader,
signature []byte,
) (result *VerifyResult, err error) {
signatureReader := bytes.NewReader(signature)
ptReader, err := vh.verifyingDetachedReader(origText, signatureReader)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: verify signature failed")
}
_, err = io.Copy(io.Discard, ptReader)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: reading all data from plaintext reader failed")
}
return ptReader.VerifySignature()
}
func (vh *verifyHandle) verifyingReader(
signatureMessage io.Reader,
) (reader *VerifyDataReader, err error) {
checkPacketSequence := !vh.DisableStrictMessageParsing
config := vh.profile.SignConfig()
config.CheckPacketSequence = &checkPacketSequence
verifyTime := vh.clock().Unix()
config.Time = NewConstantClock(verifyTime)
if vh.VerificationContext != nil {
config.KnownNotations = map[string]bool{constants.SignatureContextName: true}
}
md, err := openpgp.ReadMessage(
signatureMessage,
vh.VerifyKeyRing.getEntities(),
nil,
config,
)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: initialize signature reader failed")
}
return &VerifyDataReader{
md,
md.UnverifiedBody,
vh.VerifyKeyRing,
verifyTime,
vh.DisableVerifyTimeCheck,
false,
vh.VerificationContext,
}, nil
}
func (vh *verifyHandle) verifyingDetachedReader(
data Reader,
signature Reader,
) (*VerifyDataReader, error) {
return verifyingDetachedReader(
data,
signature,
vh.VerifyKeyRing,
vh.VerificationContext,
vh.DisableVerifyTimeCheck,
vh.DisableAutomaticTextSanitize,
vh.profile.SignConfig(),
vh.clock,
)
}
func (vh *verifyHandle) verifyCleartext(cleartext []byte) (*VerifyCleartextResult, error) {
block, rest := clearsign.Decode(cleartext)
if block == nil {
return nil, errors.New("gopenpgp: not able to parse cleartext message")
}
if len(bytes.TrimSpace(rest)) > 0 {
return nil, errors.New("gopenpgp: cleartext message has trailing text")
}
signature, err := io.ReadAll(block.ArmoredSignature.Body)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: signature not parsable in cleartext")
}
reader := bytes.NewReader(block.Bytes)
result, err := vh.verifyDetachedSignature(
reader,
signature,
)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: cleartext verify failed with non-signature error")
}
return &VerifyCleartextResult{
VerifyResult: *result,
cleartext: block.Plaintext[:len(block.Plaintext)-1],
}, nil
}
func verifyingDetachedReader(
data Reader,
signature Reader,
verifyKeyRing *KeyRing,
verificationContext *VerificationContext,
disableVerifyTimeCheck bool,
disableAutomaticTextSanitize bool,
config *packet.Config,
clock Clock,
) (*VerifyDataReader, error) {
if config == nil {
config = &packet.Config{}
}
verifyTime := clock().Unix()
config.Time = NewConstantClock(verifyTime)
if verificationContext != nil {
config.KnownNotations = map[string]bool{constants.SignatureContextName: true}
}
md, err := openpgp.VerifyDetachedSignatureReader(
verifyKeyRing.getEntities(),
data,
signature,
config,
)
if err != nil {
return nil, errors.Wrap(err, "gopenpgp: verify signature reader failed")
}
internalReader := md.UnverifiedBody
if len(md.SignatureCandidates) > 0 &&
!disableAutomaticTextSanitize &&
md.SignatureCandidates[0].SigType == packet.SigTypeText {
internalReader = internal.NewSanitizeReader(internalReader)
}
return &VerifyDataReader{
md,
internalReader,
verifyKeyRing,
verifyTime,
disableVerifyTimeCheck,
false,
verificationContext,
}, nil
}