GPG: handle extended private key format

Add detection for the key-value pair format that was available in
gpg-agent for some time already and that has become the default since
gpg-agent 2.2.20. If a secret key in the .gnupg/private-keys-v1.d
directory is found to have this format, extract the human-readable key
from it, convert it to the binary serialized form and hand that to
BouncyCastle.

Encrypted keys in the new format may use AES/OCB. OCB is a patent-
encumbered algorithm; although there is a license for open-source
software, that may not be good enough and OCB may not be available in
Java. It is not available in the default security provider in Java,
and it is also not available in the BouncyCastle version included in
Eclipse.

Implement AES/OCB decryption, throwing a PGPException with a nice
message if the algorithm is not available. Include a copy of the normal
s-expression parser of BouncyCastle and fix it to properly handle data
from such keys: such keys do not contain an internal hash since the
AES/OCB cipher includes and checks a MAC already.

Bug: 570501
Change-Id: Ifa6391a809a84cfc6ae7c6610af6a79204b4143b
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

1 files changed, 12 insertions, 0 deletions

diff --git a/org.eclipse.jgit.gpg.bc/resources/org/eclipse/jgit/gpg/bc/internal/BCText.properties b/org.eclipse.jgit.gpg.bc/resources/org/eclipse/jgit/gpg/bc/internal/BCText.properties
index f2aa014d6b..e4b1baba1f 100644
--- a/org.eclipse.jgit.gpg.bc/resources/org/eclipse/jgit/gpg/bc/internal/BCText.properties
+++ b/org.eclipse.jgit.gpg.bc/resources/org/eclipse/jgit/gpg/bc/internal/BCText.properties
@@ -1,5 +1,7 @@
 corrupt25519Key=Ed25519/Curve25519 public key has wrong length: {0}
 credentialPassphrase=Passphrase
+cryptCipherError=Cannot create cipher to decrypt: {0}
+cryptWrongDecryptedLength=Decrypted key has wrong length; expected {0} bytes, got only {1} bytes
 gpgFailedToParseSecretKey=Failed to parse secret key file {0}. Is the entered passphrase correct?
 gpgNoCredentialsProvider=missing credentials provider
 gpgNoKeygrip=Cannot find key {0}: cannot determine key grip
@@ -7,10 +9,20 @@ gpgNoKeyring=neither pubring.kbx nor secring.gpg files found
 gpgNoKeyInLegacySecring=no matching secret key found in legacy secring.gpg for key or user id: {0}
 gpgNoPublicKeyFound=Unable to find a public-key with key or user id: {0}
 gpgNoSecretKeyForPublicKey=unable to find associated secret key for public key: {0}
+gpgNoSuchAlgorithm=Cannot decrypt encrypted secret key: encryption algorithm {0} is not available
 gpgNotASigningKey=Secret key ({0}) is not suitable for signing
 gpgKeyInfo=GPG Key (fingerprint {0})
 gpgSigningCancelled=Signing was cancelled
 nonSignatureError=Signature does not decode into a signature object
+secretKeyTooShort=Secret key file corrupt; only {0} bytes read
+sexprHexNotClosed=Hex number in s-expression not closed
+sexprHexOdd=Hex number in s-expression has an odd number of digits
+sexprStringInvalidEscape=Invalid escape {0} in s-expression
+sexprStringInvalidEscapeAtEnd=Invalid s-expression: quoted string ends with escape character
+sexprStringInvalidHexEscape=Invalid hex escape in s-expression
+sexprStringInvalidOctalEscape=Invalid octal escape in s-expression
+sexprStringNotClosed=String in s-expression not closed
+sexprUnhandled=Unhandled token {0} in s-expression
 signatureInconsistent=Inconsistent signature; key ID {0} does not match issuer fingerprint {1}
 signatureKeyLookupError=Error occurred while looking for public key
 signatureNoKeyInfo=No way to determine a public key from the signature