diff --git a/src/frontends/android/app/src/main/java/org/strongswan/android/utils/Utils.java b/src/frontends/android/app/src/main/java/org/strongswan/android/utils/Utils.java
index b5c447f31..f2e8e0058 100644
--- a/src/frontends/android/app/src/main/java/org/strongswan/android/utils/Utils.java
+++ b/src/frontends/android/app/src/main/java/org/strongswan/android/utils/Utils.java
@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2014 Tobias Brunner
- * Hochschule fuer Technik Rapperswil
+ * Copyright (C) 2014-2017 Tobias Brunner
+ * HSR Hochschule fuer Technik Rapperswil
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -37,4 +37,13 @@ public class Utils
 		}
 		return new String(hex);
 	}
+
+	/**
+	 * Validate the given proposal string
+	 *
+	 * @param ike true for IKE, false for ESP
+	 * @param proposal proposal string
+	 * @return true if valid
+	 */
+	public native static boolean isProposalValid(boolean ike, String proposal);
 }
diff --git a/src/frontends/android/app/src/main/jni/libandroidbridge/charonservice.c b/src/frontends/android/app/src/main/jni/libandroidbridge/charonservice.c
index 2891eabe0..06c5cada4 100644
--- a/src/frontends/android/app/src/main/jni/libandroidbridge/charonservice.c
+++ b/src/frontends/android/app/src/main/jni/libandroidbridge/charonservice.c
@@ -716,3 +716,29 @@ JNI_METHOD(CharonVpnService, initiate, void,
 
 	initiate(settings);
 }
+
+/**
+ * Utility function to verify proposal strings (static, so `this` is the class)
+ */
+JNI_METHOD_P(org_strongswan_android_utils, Utils, isProposalValid, jboolean,
+	jboolean ike, jstring proposal)
+{
+	proposal_t *prop;
+	char *str;
+	bool valid;
+
+	dbg = dbg_android;
+
+	if (!library_init(NULL, "charon"))
+	{
+		library_deinit();
+		return FALSE;
+	}
+	str = androidjni_convert_jstring(env, proposal);
+	prop = proposal_create_from_string(ike ? PROTO_IKE : PROTO_ESP, str);
+	valid = prop != NULL;
+	DESTROY_IF(prop);
+	free(str);
+	library_deinit();
+	return valid;
+}