passforios-gopenpgp/helper/cleartext.go
zugzwang ac8a49c114
Update lint (#44)
* Reduce complexity of SignatureCollector.Accept

* Add stylecheck linter, and lint accordingly

* Rephrase some comments

* godot - Top level comments should end with a dot.

* nestif - Reduce nested complexity of code

* Review changes

Co-authored-by: Aron Wussler <aron@wussler.it>
2020-04-28 13:55:36 +02:00

90 lines
2.7 KiB
Go

package helper
import (
"strings"
"github.com/ProtonMail/gopenpgp/v2/crypto"
"github.com/ProtonMail/gopenpgp/v2/internal"
)
// SignCleartextMessageArmored signs text given a private key and its
// passphrase, canonicalizes and trims the newlines, and returns the
// PGP-compliant special armoring.
func SignCleartextMessageArmored(privateKey string, passphrase []byte, text string) (string, error) {
signingKey, err := crypto.NewKeyFromArmored(privateKey)
if err != nil {
return "", err
}
unlockedKey, err := signingKey.Unlock(passphrase)
if err != nil {
return "", err
}
defer unlockedKey.ClearPrivateParams()
keyRing, err := crypto.NewKeyRing(unlockedKey)
if err != nil {
return "", err
}
return SignCleartextMessage(keyRing, text)
}
// VerifyCleartextMessageArmored verifies PGP-compliant armored signed plain
// text given the public key and returns the text or err if the verification
// fails.
func VerifyCleartextMessageArmored(publicKey, armored string, verifyTime int64) (string, error) {
signingKey, err := crypto.NewKeyFromArmored(publicKey)
if err != nil {
return "", err
}
verifyKeyRing, err := crypto.NewKeyRing(signingKey)
if err != nil {
return "", err
}
return VerifyCleartextMessage(verifyKeyRing, armored, verifyTime)
}
// SignCleartextMessage signs text given a private keyring, canonicalizes and
// trims the newlines, and returns the PGP-compliant special armoring.
func SignCleartextMessage(keyRing *crypto.KeyRing, text string) (string, error) {
text = canonicalizeAndTrim(text)
message := crypto.NewPlainMessageFromString(text)
signature, err := keyRing.SignDetached(message)
if err != nil {
return "", err
}
return crypto.NewClearTextMessage(message.GetBinary(), signature.GetBinary()).GetArmored()
}
// VerifyCleartextMessage verifies PGP-compliant armored signed plain text
// given the public keyring and returns the text or err if the verification
// fails.
func VerifyCleartextMessage(keyRing *crypto.KeyRing, armored string, verifyTime int64) (string, error) {
clearTextMessage, err := crypto.NewClearTextMessageFromArmored(armored)
if err != nil {
return "", err
}
message := crypto.NewPlainMessageFromString(clearTextMessage.GetString())
signature := crypto.NewPGPSignature(clearTextMessage.GetBinarySignature())
err = keyRing.VerifyDetached(message, signature, verifyTime)
if err != nil {
return "", err
}
return message.GetString(), nil
}
// ----- INTERNAL FUNCTIONS -----
// canonicalizeAndTrim alters a string canonicalizing and trimming the newlines.
func canonicalizeAndTrim(text string) string {
text = internal.TrimNewlines(text)
text = strings.Replace(strings.Replace(text, "\r\n", "\n", -1), "\n", "\r\n", -1)
return text
}