passforios-gopenpgp/helper/mobile.go
marinthiercelin ada3fd0533
Signcryption (#82)
* added signcryption in the helpers

* changed the name of encrypted signature

* changed the name of an encrypted signature

Co-authored-by: marin thiercelin <marin.thiercelin@pm.me>
2020-10-07 15:26:36 +02:00

98 lines
3.1 KiB
Go

package helper
import (
"encoding/json"
"github.com/ProtonMail/gopenpgp/v2/crypto"
)
type ExplicitVerifyMessage struct {
Message *crypto.PlainMessage
SignatureVerificationError *crypto.SignatureVerificationError
}
// DecryptExplicitVerify decrypts an armored PGP message given a private key
// and its passphrase and verifies the embedded signature. Returns the plain
// data or an error on signature verification failure.
func DecryptExplicitVerify(
pgpMessage *crypto.PGPMessage,
privateKeyRing, publicKeyRing *crypto.KeyRing,
verifyTime int64,
) (*ExplicitVerifyMessage, error) {
var explicitVerify *ExplicitVerifyMessage
message, err := privateKeyRing.Decrypt(pgpMessage, publicKeyRing, verifyTime)
if err != nil {
castedErr, isType := err.(crypto.SignatureVerificationError)
if !isType {
return nil, err
}
explicitVerify = &ExplicitVerifyMessage{
Message: message,
SignatureVerificationError: &castedErr,
}
} else {
explicitVerify = &ExplicitVerifyMessage{
Message: message,
SignatureVerificationError: nil,
}
}
return explicitVerify, nil
}
// DecryptAttachment takes a keypacket and datpacket
// and returns a decrypted PlainMessage
// Specifically designed for attachments rather than text messages.
func DecryptAttachment(keyPacket []byte, dataPacket []byte, keyRing *crypto.KeyRing) (*crypto.PlainMessage, error) {
splitMessage := crypto.NewPGPSplitMessage(keyPacket, dataPacket)
decrypted, err := keyRing.DecryptAttachment(splitMessage)
if err != nil {
return nil, err
}
return decrypted, nil
}
// EncryptAttachment encrypts a file given a plainData and a fileName.
// Returns a PGPSplitMessage containing a session key packet and symmetrically
// encrypted data. Specifically designed for attachments rather than text
// messages.
func EncryptAttachment(plainData []byte, fileName string, keyRing *crypto.KeyRing) (*crypto.PGPSplitMessage, error) {
plainMessage := crypto.NewPlainMessage(plainData)
decrypted, err := keyRing.EncryptAttachment(plainMessage, fileName)
if err != nil {
return nil, err
}
return decrypted, nil
}
// GetJsonSHA256Fingerprints returns the SHA256 fingeprints of key and subkeys,
// encoded in JSON, since gomobile can not handle arrays.
func GetJsonSHA256Fingerprints(publicKey string) ([]byte, error) {
key, err := crypto.NewKeyFromArmored(publicKey)
if err != nil {
return nil, err
}
return json.Marshal(key.GetSHA256Fingerprints())
}
type EncryptSignArmoredDetachedMobileResult struct {
Ciphertext, EncryptedSignature string
}
// EncryptSignArmoredDetachedMobile wraps the EncryptSignArmoredDetached method
// to have only one return argument for mobile.
func EncryptSignArmoredDetachedMobile(
publicKey, privateKey string,
passphrase, plainData []byte,
) (wrappedTuple *EncryptSignArmoredDetachedMobileResult, err error) {
ciphertext, encryptedSignature, err := encryptSignArmoredDetached(publicKey, privateKey, passphrase, plainData)
if err != nil {
return nil, err
}
return &EncryptSignArmoredDetachedMobileResult{ciphertext, encryptedSignature}, nil
}