GPG: support git config gpg.program

Add it to the GpgConfig. Change GpgConfig to load the values once only.
Add a parameter to the GpgObjectSigner interface's operations to pass
in a GpgConfig. Update CommitCommand and TagCommand to pass the value
to the signer. Let the signer decide whether it can actually produce
the wanted signature type (openpgp or x509).

No behavior change. But this makes it possible to implement different
signers that might support x509 signatures, or use gpg.program and
shell out to an external GPG executable for signing.

Change-Id: I427f83eb1ece81c310e1cddd85315f6f88cc99ea
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

1 files changed, 34 insertions, 2 deletions

diff --git a/org.eclipse.jgit.gpg.bc/src/org/eclipse/jgit/gpg/bc/internal/BouncyCastleGpgSigner.java b/org.eclipse.jgit.gpg.bc/src/org/eclipse/jgit/gpg/bc/internal/BouncyCastleGpgSigner.java
index 449c4a487b..f448d5e9e8 100644
--- a/org.eclipse.jgit.gpg.bc/src/org/eclipse/jgit/gpg/bc/internal/BouncyCastleGpgSigner.java
+++ b/org.eclipse.jgit.gpg.bc/src/org/eclipse/jgit/gpg/bc/internal/BouncyCastleGpgSigner.java
@@ -34,13 +34,17 @@ import org.eclipse.jgit.annotations.NonNull;
 import org.eclipse.jgit.annotations.Nullable;
 import org.eclipse.jgit.api.errors.CanceledException;
 import org.eclipse.jgit.api.errors.JGitInternalException;
+import org.eclipse.jgit.api.errors.UnsupportedSigningFormatException;
 import org.eclipse.jgit.errors.UnsupportedCredentialItem;
+import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.CommitBuilder;
+import org.eclipse.jgit.lib.GpgConfig;
 import org.eclipse.jgit.lib.GpgSignature;
 import org.eclipse.jgit.lib.GpgSigner;
 import org.eclipse.jgit.lib.GpgObjectSigner;
 import org.eclipse.jgit.lib.ObjectBuilder;
 import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.lib.GpgConfig.GpgFormat;
 import org.eclipse.jgit.transport.CredentialsProvider;
 import org.eclipse.jgit.util.StringUtils;
 
@@ -70,6 +74,24 @@ public class BouncyCastleGpgSigner extends GpgSigner
 	public boolean canLocateSigningKey(@Nullable String gpgSigningKey,
 			PersonIdent committer, CredentialsProvider credentialsProvider)
 			throws CanceledException {
+		try {
+			return canLocateSigningKey(gpgSigningKey, committer,
+					credentialsProvider, null);
+		} catch (UnsupportedSigningFormatException e) {
+			// Cannot occur with a null config
+			return false;
+		}
+	}
+
+	@Override
+	public boolean canLocateSigningKey(@Nullable String gpgSigningKey,
+			PersonIdent committer, CredentialsProvider credentialsProvider,
+			GpgConfig config)
+			throws CanceledException, UnsupportedSigningFormatException {
+		if (config != null && config.getKeyFormat() != GpgFormat.OPENPGP) {
+			throw new UnsupportedSigningFormatException(
+					JGitText.get().onlyOpenPgpSupportedForSigning);
+		}
 		try (BouncyCastleGpgKeyPassphrasePrompt passphrasePrompt = new BouncyCastleGpgKeyPassphrasePrompt(
 				credentialsProvider)) {
 			BouncyCastleGpgKey gpgKey = locateSigningKey(gpgSigningKey,
@@ -101,13 +123,23 @@ public class BouncyCastleGpgSigner extends GpgSigner
 	public void sign(@NonNull CommitBuilder commit,
 			@Nullable String gpgSigningKey, @NonNull PersonIdent committer,
 			CredentialsProvider credentialsProvider) throws CanceledException {
-		signObject(commit, gpgSigningKey, committer, credentialsProvider);
+		try {
+			signObject(commit, gpgSigningKey, committer, credentialsProvider,
+					null);
+		} catch (UnsupportedSigningFormatException e) {
+			// Cannot occur with a null config
+		}
 	}
 
 	@Override
 	public void signObject(@NonNull ObjectBuilder object,
 			@Nullable String gpgSigningKey, @NonNull PersonIdent committer,
-			CredentialsProvider credentialsProvider) throws CanceledException {
+			CredentialsProvider credentialsProvider, GpgConfig config)
+			throws CanceledException, UnsupportedSigningFormatException {
+		if (config != null && config.getKeyFormat() != GpgFormat.OPENPGP) {
+			throw new UnsupportedSigningFormatException(
+					JGitText.get().onlyOpenPgpSupportedForSigning);
+		}
 		try (BouncyCastleGpgKeyPassphrasePrompt passphrasePrompt = new BouncyCastleGpgKeyPassphrasePrompt(
 				credentialsProvider)) {
 			BouncyCastleGpgKey gpgKey = locateSigningKey(gpgSigningKey,