1 files changed, 68 insertions, 0 deletions
diff --git a/wrappers/EduVpnCommon/src/eduvpncommon/Discovery.java b/wrappers/EduVpnCommon/src/eduvpncommon/Discovery.java
new file mode 100644
index 0000000..6c27eee
--- /dev/null
+++ b/wrappers/EduVpnCommon/src/eduvpncommon/Discovery.java
@@ -0,0 +1,68 @@
+package eduvpncommon;
+
+import com.sun.jna.*;
+
+import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.util.*;
+
+public class Discovery {
+    private static final String libName = "eduvpn_verify";
+    private static final NativeApi discovery = Native.load(libName, NativeApi.class);
+
+    /**
+     * Verifies the signature on the JSON server_list.json/organization_list.json file.
+     * If the function returns the signature is valid for the given file type.
+     *
+     * @param signature        .minisig signature file contents.
+     * @param signedJson       Signed .json file contents.
+     * @param expectedFileName The file type to be verified, one of {@code "server_list.json"} or {@code "organization_list.json"}.
+     * @param minSignTime      Minimum time for signature. Should be set to at least the time in a previously retrieved file.
+     * @throws VerifyException If signature verification fails.
+     */
+    public static void verify(byte[] signature, byte[] signedJson, String expectedFileName, Instant minSignTime) throws VerifyException {
+        long err = discovery.Verify(NativeApi.GoSlice.make(signature), NativeApi.GoSlice.make(signedJson),
+                NativeApi.GoSlice.make(expectedFileName.getBytes(StandardCharsets.UTF_8)),
+                minSignTime.getEpochSecond());
+        if (err != 0) throw new VerifyException();
+        //TODO throw new IllegalArgumentException()
+    }
+
+    /**
+     * Use for testing only, see Go documentation.
+     */
+    // package-private
+    static void insecureTestingSetExtraKey(String keyString) {
+        discovery.InsecureTestingSetExtraKey(NativeApi.GoSlice.make(keyString.getBytes(StandardCharsets.UTF_8)));
+    }
+
+    private interface NativeApi extends Library {
+        class GoSlice extends Structure implements Structure.ByValue {
+            public Pointer data;
+            public long len, cap;
+
+            public GoSlice(Pointer data, long len, long cap) {
+                this.data = data;
+                this.len = len;
+                this.cap = cap;
+            }
+
+            public static GoSlice make(byte[] bytes) {
+                Memory memory = new Memory(bytes.length);
+                memory.write(0, bytes, 0, bytes.length);
+                return new GoSlice(memory, bytes.length, bytes.length);
+            }
+
+            protected List<String> getFieldOrder() {
+                return Arrays.asList("data", "len", "cap");
+            }
+        }
+
+        long Verify(GoSlice signatureFileContent, GoSlice signedJson, GoSlice expectedFileName, long minSignTime);
+
+        void InsecureTestingSetExtraKey(GoSlice keyString);
+    }
+
+    private Discovery() {
+    }
+}