Handle failed encryption and decryption attempts, return an error.

examples/pgp/PgpConnect.java

@@ -63,6 +63,11 @@ public class PgpConnect extends Fragment {
 		Log.d("gio", "onActivityResult(" + requestCode + "): " + resultCode);
 		super.onActivityResult(requestCode, resultCode, data);
 		//activityResult(requestCode, resultCode);
+		if (resultCode != Activity.RESULT_OK) {
+			Log.d("gio", "onActivityResult: not OK");
+			stringResult(requestCode, null);
+			return;
+		}
 		switch (data.getAction()) {
 			case OpenPgpApi.ACTION_DECRYPT_VERIFY: {
 				Log.d("gio", "action decrypt");

examples/pgp/jni_android.c

@@ -66,9 +66,13 @@ Decrypt(JNIEnv* env, jobject p, char* cdata, int datalen, int chint) {
 }
 
 void stringResult(JNIEnv* env, jclass cls, jint requestCode, jobject response) {
+	if (response == 0) {
+		goStringResult(env, cls, requestCode, 0);
+	} else {
 		char* str = (*env)->GetStringUTFChars(env, response, NULL);
 		goStringResult(env, cls, requestCode, str);
 	}
+}
 
 const char*
 Encrypt(JNIEnv* env, jobject p, char* cid, int idlen, char* cdata, int datalen, int chint) {

examples/pgp/jni_android.go

@@ -70,7 +70,7 @@ var (
 	chint int
 )
 
-func (p PGP) Decrypt(data string) string {
+func (p PGP) Decrypt(data string) (string, error) {
 	ch := make(chan string)
 	chmux.Lock()
 	if fragChans == nil {
@@ -87,10 +87,15 @@ func (p PGP) Decrypt(data string) string {
 		retc := C.Decrypt(env, (C.jobject)(p), (*C.char)(unsafe.Pointer(cdata)), (C.int)(len(data)), C.int(curint))
 		defer C.free(unsafe.Pointer(retc))
 	})
-	return <-ch
+	switch x := <-ch; {
+	case x == "":
+		return "", fmt.Errorf("Decryption failed")
+	default:
+		return x, nil
+	}
 }
 
-func (p PGP) Encrypt(id, data string) string {
+func (p PGP) Encrypt(id, data string) (string, error) {
 	ch := make(chan string)
 	chmux.Lock()
 	if fragChans == nil {
@@ -109,7 +114,12 @@ func (p PGP) Encrypt(id, data string) string {
 		retc := C.Encrypt(env, (C.jobject)(p), (*C.char)(unsafe.Pointer(cid)), (C.int)(len(id)), (*C.char)(unsafe.Pointer(cdata)), (C.int)(len(data)), C.int(curint))
 		defer C.free(unsafe.Pointer(retc))
 	})
-	return <-ch
+	switch x := <-ch; {
+	case x == "":
+		return "", fmt.Errorf("Encryption failed")
+	default:
+		return x, nil
+	}
 }
 
 func RunInJVM(f func(env *C.JNIEnv)) {

examples/pgp/os_android.go

@@ -47,10 +47,19 @@ func callJni() {
 	labchan <- fmt.Sprintf("Activity = %d", h.Activity)
 	time.Sleep(time.Second / 5)
 
-	val := pgp.Encrypt("greg_pomerantz@yahoo.com", "hi there")
+	val, err := pgp.Encrypt("greg_pomerantz@yahoo.com", "hi there")
-	//val := pgp.Encrypt("root@example.com", "hi there")
+	if err != nil {
+		fmt.Printf("Encryption error: %s", err)
+		labchan <- err.Error()
+		return
+	}
 	log.Print("val = ", val)
-	val2 := pgp.Decrypt(val)
+	val2, err := pgp.Decrypt(val)
+	if err != nil {
+		fmt.Printf("Decryption error: %s", err)
+		labchan <- err.Error()
+		return
+	}
 	labchan <- "result = " + val2
 }