[sshd] Log the full KEX negotiation result

Apache MINA sshd doesn't log all values, but it'd be very helpful to
debug KEX problems.

Change-Id: I5a19023c929f39caccde489d51a6fdca711fe5ff
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

1 files changed, 19 insertions, 0 deletions

diff --git a/org.eclipse.jgit.ssh.apache/src/org/eclipse/jgit/internal/transport/sshd/JGitClientSession.java b/org.eclipse.jgit.ssh.apache/src/org/eclipse/jgit/internal/transport/sshd/JGitClientSession.java
index 8183a92b9f..f9e80121ed 100644
--- a/org.eclipse.jgit.ssh.apache/src/org/eclipse/jgit/internal/transport/sshd/JGitClientSession.java
+++ b/org.eclipse.jgit.ssh.apache/src/org/eclipse/jgit/internal/transport/sshd/JGitClientSession.java
@@ -39,6 +39,7 @@ import org.apache.sshd.common.PropertyResolver;
 import org.apache.sshd.common.config.keys.KeyUtils;
 import org.apache.sshd.common.io.IoSession;
 import org.apache.sshd.common.io.IoWriteFuture;
+import org.apache.sshd.common.kex.KexProposalOption;
 import org.apache.sshd.common.util.Readable;
 import org.apache.sshd.common.util.buffer.Buffer;
 import org.eclipse.jgit.errors.InvalidPatternException;
@@ -201,6 +202,24 @@ public class JGitClientSession extends ClientSessionImpl {
 	}
 
 	@Override
+	protected Map<KexProposalOption, String> setNegotiationResult(
+			Map<KexProposalOption, String> guess) {
+		Map<KexProposalOption, String> result = super.setNegotiationResult(
+				guess);
+		// This should be doable with a SessionListener, too, but I don't see
+		// how to add a listener in time to catch the negotiation end for sure
+		// given that the super-constructor already starts KEX.
+		//
+		// TODO: This override can be removed once we use sshd 2.8.0.
+		if (log.isDebugEnabled()) {
+			result.forEach((option, value) -> log.debug(
+					"setNegotiationResult({}) Kex: {} = {}", this, //$NON-NLS-1$
+					option.getDescription(), value));
+		}
+		return result;
+	}
+
+	@Override
 	protected String resolveAvailableSignaturesProposal(
 			FactoryManager manager) {
 		List<String> defaultSignatures = getSignatureFactoriesNames();