From 9921fc6ff6fbde7783df7989b5a992f3a4c7f0cd Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Wed, 18 May 2022 14:19:08 +0200
Subject: [PATCH] Add and test OpenPgpFingerprint.parseFromBinary(bytes)

---
 .../pgpainless/key/OpenPgpFingerprint.java    | 11 +++++
 .../key/OpenPgpV4FingerprintTest.java         | 39 ++++++++++++++++++
 .../key/OpenPgpV5FingerprintTest.java         | 40 +++++++++++++++++++
 3 files changed, 90 insertions(+)

diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpFingerprint.java b/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpFingerprint.java
index d5a1daad..6abe207b 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpFingerprint.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpFingerprint.java
@@ -67,6 +67,17 @@ public abstract class OpenPgpFingerprint implements CharSequence, Comparable<Ope
         throw new IllegalArgumentException("Fingerprint does not appear to match any known fingerprint patterns.");
     }
 
+    /**
+     * Parse a binary OpenPGP fingerprint into an {@link OpenPgpFingerprint} object.
+     *
+     * @param binaryFingerprint
+     * @return
+     */
+    public static OpenPgpFingerprint parseFromBinary(byte[] binaryFingerprint) {
+        String hex = Hex.toHexString(binaryFingerprint).toUpperCase();
+        return parse(hex);
+    }
+
     public OpenPgpFingerprint(String fingerprint) {
         String fp = fingerprint.replace(" ", "").trim().toUpperCase();
         if (!isValid(fp)) {
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/OpenPgpV4FingerprintTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/OpenPgpV4FingerprintTest.java
index 811438af..d61aeedd 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/OpenPgpV4FingerprintTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/OpenPgpV4FingerprintTest.java
@@ -14,6 +14,7 @@ import java.net.URI;
 import java.net.URISyntaxException;
 
 import org.bouncycastle.openpgp.PGPPublicKey;
+import org.bouncycastle.util.encoders.Hex;
 import org.junit.jupiter.api.Test;
 
 
@@ -102,4 +103,42 @@ public class OpenPgpV4FingerprintTest {
         OpenPgpV4Fingerprint v4fp = (OpenPgpV4Fingerprint) parsed;
         assertEquals(prettyPrint, v4fp.prettyPrint());
     }
+
+    @Test
+    public void testParseFromBinary() {
+        String hex = "5448452043414B452049532041204C4945212121";
+        byte[] binary = Hex.decode(hex);
+
+        OpenPgpFingerprint fingerprint = OpenPgpFingerprint.parseFromBinary(binary);
+        assertTrue(fingerprint instanceof OpenPgpV4Fingerprint);
+        assertEquals(hex, fingerprint.toString());
+    }
+
+    @Test
+    public void testParseFromBinary_leadingZeros() {
+        String hex = "00000000000000000049532041204C4945212121";
+        byte[] binary = Hex.decode(hex);
+
+        OpenPgpFingerprint fingerprint = OpenPgpFingerprint.parseFromBinary(binary);
+        assertTrue(fingerprint instanceof OpenPgpV4Fingerprint);
+        assertEquals(hex, fingerprint.toString());
+    }
+
+    @Test
+    public void testParseFromBinary_trailingZeros() {
+        String hex = "49532041204C4945212121000000000000000000";
+        byte[] binary = Hex.decode(hex);
+
+        OpenPgpFingerprint fingerprint = OpenPgpFingerprint.parseFromBinary(binary);
+        assertTrue(fingerprint instanceof OpenPgpV4Fingerprint);
+        assertEquals(hex, fingerprint.toString());
+    }
+
+    @Test
+    public void testParseFromBinary_wrongLength() {
+        String hex = "5448452043414B452049532041204C49452121"; // 2 missing digits
+        byte[] binary = Hex.decode(hex);
+
+        assertThrows(IllegalArgumentException.class, () -> OpenPgpFingerprint.parseFromBinary(binary));
+    }
 }
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/OpenPgpV5FingerprintTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/OpenPgpV5FingerprintTest.java
index fffccfe0..2e657d72 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/OpenPgpV5FingerprintTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/OpenPgpV5FingerprintTest.java
@@ -4,9 +4,11 @@
 
 package org.pgpainless.key;
 
+import org.bouncycastle.util.encoders.Hex;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class OpenPgpV5FingerprintTest {
@@ -33,4 +35,42 @@ public class OpenPgpV5FingerprintTest {
         OpenPgpV5Fingerprint v5fp = (OpenPgpV5Fingerprint) parsed;
         assertEquals(prettyPrint, v5fp.prettyPrint());
     }
+
+    @Test
+    public void testParseFromBinary() {
+        String hex = "76543210ABCDEFAB01AB23CD1C0FFEE11EEFF0C1DC32BA10BAFEDCBA01234567";
+        byte[] binary = Hex.decode(hex);
+
+        OpenPgpFingerprint fingerprint = OpenPgpFingerprint.parseFromBinary(binary);
+        assertTrue(fingerprint instanceof OpenPgpV5Fingerprint);
+        assertEquals(hex, fingerprint.toString());
+    }
+
+    @Test
+    public void testParseFromBinary_leadingZeros() {
+        String hex = "000000000000000001AB23CD1C0FFEE11EEFF0C1DC32BA10BAFEDCBA01234567";
+        byte[] binary = Hex.decode(hex);
+
+        OpenPgpFingerprint fingerprint = OpenPgpFingerprint.parseFromBinary(binary);
+        assertTrue(fingerprint instanceof OpenPgpV5Fingerprint);
+        assertEquals(hex, fingerprint.toString());
+    }
+
+    @Test
+    public void testParseFromBinary_trailingZeros() {
+        String hex = "76543210ABCDEFAB01AB23CD1C0FFEE11EEFF0C1DC32BA100000000000000000";
+        byte[] binary = Hex.decode(hex);
+
+        OpenPgpFingerprint fingerprint = OpenPgpFingerprint.parseFromBinary(binary);
+        assertTrue(fingerprint instanceof OpenPgpV5Fingerprint);
+        assertEquals(hex, fingerprint.toString());
+    }
+
+    @Test
+    public void testParseFromBinary_wrongLength() {
+        String hex = "76543210ABCDEFAB01AB23CD1C0FFEE11EEFF0C1DC32BA10BAFEDCBA012345"; // missing 2 digits
+        byte[] binary = Hex.decode(hex);
+
+        assertThrows(IllegalArgumentException.class, () -> OpenPgpFingerprint.parseFromBinary(binary));
+    }
 }