ssh: fix relogin with jumphosts

lib/client/api.go

@@ -469,15 +469,6 @@ func RetryWithRelogin(ctx context.Context, tc *TeleportClient, fn func() error)
 		log.Warningf("Failed to save profile: %v", err)
 		return trace.Wrap(err)
 	}
-	// Override client's auth methods, current cluster and user name
-	authMethod, err := key.AsAuthMethod()
-	if err != nil {
-		return trace.Wrap(err)
-	}
-	// After successful login we have local agent updated with latest
-	// and greatest auth information, setup client to try only this new
-	// method fetched from key, to isolate the retry
-	tc.Config.AuthMethods = []ssh.AuthMethod{authMethod}
 	return fn()
 }
 
@@ -1066,7 +1057,11 @@ func (tc *TeleportClient) LoadKeyForClusterWithReissue(ctx context.Context, clus
 		return trace.Wrap(err)
 	}
 	// Reissuing also loads the new key.
-	return tc.ReissueUserCerts(ctx, ReissueParams{RouteToCluster: clusterName})
+	err = tc.ReissueUserCerts(ctx, ReissueParams{RouteToCluster: clusterName})
+	if err != nil {
+		return trace.Wrap(err)
+	}
+	return nil
 }
 
 // accessPoint returns access point based on the cache policy
@@ -2208,7 +2203,18 @@ func (tc *TeleportClient) ActivateKey(ctx context.Context, key *Key) error {
 	// Connect to the Auth Server of the root cluster and fetch the known hosts.
 	rootClusterName := key.TrustedCA[0].ClusterName
 	if err := tc.UpdateTrustedCA(ctx, rootClusterName); err != nil {
-		return trace.Wrap(err)
+		if len(tc.JumpHosts) == 0 {
+			return trace.Wrap(err)
+		}
+		errViaJumphost := err
+		// If JumpHosts was pointing at the leaf cluster (e.g. during 'tsh ssh
+		// -J leaf.example.com'), this could've caused the above error. Try to
+		// fetch CAs without JumpHosts to force it to use the root cluster.
+		if err := tc.WithoutJumpHosts(func(tc *TeleportClient) error {
+			return tc.UpdateTrustedCA(ctx, rootClusterName)
+		}); err != nil {
+			return trace.NewAggregate(errViaJumphost, err)
+		}
 	}
 
 	return nil

lib/client/interfaces.go

@@ -370,6 +370,16 @@ func (k *Key) CheckCert() error {
 		return trace.Wrap(err)
 	}
 
+	// Check that the certificate was for the current public key. If not, the
+	// public/private key pair may have been rotated.
+	pub, _, _, _, err := ssh.ParseAuthorizedKey(k.Pub)
+	if err != nil {
+		return trace.Wrap(err)
+	}
+	if !sshutils.KeysEqual(cert.Key, pub) {
+		return trace.CompareFailed("public key in profile does not match the public key in SSH certificate")
+	}
+
 	// A valid principal is always passed in because the principals are not being
 	// checked here, but rather the validity period, signature, and algorithms.
 	certChecker := utils.CertChecker{