Add tests for ignoring marker packets when reading keys

pgpainless-core/src/test/java/org/pgpainless/key/parsing/KeyRingReaderTest.java

@@ -16,6 +16,7 @@
 package org.pgpainless.key.parsing;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
@@ -31,18 +32,27 @@ import java.security.InvalidAlgorithmParameterException;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 
+import org.bouncycastle.bcpg.ArmoredOutputStream;
+import org.bouncycastle.bcpg.BCPGOutputStream;
+import org.bouncycastle.bcpg.MarkerPacket;
 import org.bouncycastle.openpgp.PGPException;
 import org.bouncycastle.openpgp.PGPPublicKeyRing;
 import org.bouncycastle.openpgp.PGPPublicKeyRingCollection;
 import org.bouncycastle.openpgp.PGPSecretKeyRing;
 import org.bouncycastle.openpgp.PGPSecretKeyRingCollection;
+import org.bouncycastle.openpgp.PGPSignature;
 import org.bouncycastle.openpgp.PGPUtil;
 import org.junit.jupiter.api.Test;
 import org.pgpainless.PGPainless;
 import org.pgpainless.implementation.ImplementationFactory;
+import org.pgpainless.key.OpenPgpV4Fingerprint;
 import org.pgpainless.key.collection.PGPKeyRingCollection;
 import org.pgpainless.key.util.KeyRingUtils;
+import org.pgpainless.signature.SignatureUtils;
+import org.pgpainless.util.ArmoredOutputStreamFactory;
+import org.pgpainless.util.TestUtils;
 
 class KeyRingReaderTest {
 
@@ -245,4 +255,235 @@ class KeyRingReaderTest {
             throws IOException, URISyntaxException, PGPException {
         return PGPainless.readKeyRing().secretKeyRingCollection(getFileInputStreamFromResource(fileName));
     }
+
+    @Test
+    public void testReadSecretKeyIgnoresMarkerPacket() throws PGPException, IOException {
+        String markerAndKey = "-----BEGIN PGP PRIVATE KEY BLOCK-----\n" +
+                "Version: PGPainless\n" +
+                "Comment: Secret Key with prepended Marker Packet\n" +
+                "\n" +
+                "qANQR1CUWARg6WWBFgkrBgEEAdpHDwEBB0AyPTMeZL9XZtTedc9j8uX6igs+ZPGX\n" +
+                "KfJGSem/zCxrogABAMAXMTtEsEXDd90tgD2oasEQ9NNDKsHIxStLbhbu/W0GDzu0\n" +
+                "FGFsaWNlQHBncGFpbmxlc3Mub3JniHgEExYKACAFAmDpZYECGwEFFgIDAQAECwkI\n" +
+                "BwUVCgkICwIeAQIZAQAKCRBzXl6xxUHAzuckAP9j7FYdXB4y1G+qC8PxRWygnDLC\n" +
+                "3bgoJr+8mSBw8oGGowD/akhhuiU/EIFIG0A+kATN92AlJYLbq73sKF+1pIpPcA6c\n" +
+                "XQRg6WWBEgorBgEEAZdVAQUBAQdA1RexkLKsWJtxG82lsiaBpiUzjayFFlEpHhZv\n" +
+                "NemY+gQDAQgHAAD/ZluthWe9mBdbJxkq3+XGK3EBvFCSkTqEjAOeZpYRgOAPOIh1\n" +
+                "BBgWCgAdBQJg6WWBAhsMBRYCAwEABAsJCAcFFQoJCAsCHgEACgkQc15escVBwM4U\n" +
+                "HwEAjTd22074lQ4EsL/g6P6wVSrdIfxF6Sgx5652uKD2Cx0A/iR+3R1XlQd9+64G\n" +
+                "BDgLpvi4qox59RoXyLDZ1TDtnGQFnFgEYOllgRYJKwYBBAHaRw8BAQdA7+NE2Y83\n" +
+                "woDWXUIPQANQcskNOcwUU9hDw+qXxhCysesAAQDSgvEGDhoXcs8bJFrsTDrxugyl\n" +
+                "e1QRBde52d4PZfxOHw48iNUEGBYKAH0FAmDpZYECGwIFFgIDAQAECwkIBwUVCgkI\n" +
+                "CwIeAV8gBBkWCgAGBQJg6WWBAAoJEAZefiHacdJCCKYA/j+8mNlLNfeoBKx3vDxq\n" +
+                "PWB3C0n/RZdeV4pz3EsT46MyAP9fCBzLADQeSwNv4BCWl5EGv6YMlg0+S1Q0A3Cn\n" +
+                "lrtBCwAKCRBzXl6xxUHAzn9hAQCdTCa8P3aE8jbUav/eCSLsr5+ELi4ODg5ZAZaN\n" +
+                "GlNPVAD/byyQfgQgtxrdf7sHBEg2+CCEtac6vvTyq6o9ndW3owg=\n" +
+                "=9jtR\n" +
+                "-----END PGP PRIVATE KEY BLOCK-----";
+
+        PGPSecretKeyRing secretKey = PGPainless.readKeyRing().secretKeyRing(markerAndKey);
+        assertEquals(
+                new OpenPgpV4Fingerprint("562584F8730F39FCB02AACAE735E5EB1C541C0CE"),
+                new OpenPgpV4Fingerprint(secretKey));
+    }
+
+    @Test
+    public void testReadCertificateIgnoresMarkerPacket() throws IOException {
+        String markerAndCert = "-----BEGIN PGP PUBLIC KEY BLOCK-----\n" +
+                "Version: PGPainless\n" +
+                "Comment: Certificate with prepended Marker Packet\n" +
+                "\n" +
+                "qANQR1CYMwRg6WcmFgkrBgEEAdpHDwEBB0D33FQiRhS7lvYXVxYqHK5iFiXE9dO0\n" +
+                "rdNZ8i/YCVquLbQUYWxpY2VAcGdwYWlubGVzcy5vcmeIeAQTFgoAIAUCYOlnJgIb\n" +
+                "AQUWAgMBAAQLCQgHBRUKCQgLAh4BAhkBAAoJEPbyu9T10peTttsBAKYt4qWIcf+U\n" +
+                "J8rceVKr8WrbTbmYcMI948QKASqOmHQUAP0cBgIvJiTV6VPCzrr6y4DctgC2KmL2\n" +
+                "WLUVB5oKTVpnB7g4BGDpZyYSCisGAQQBl1UBBQEBB0CbvjPN9vqxth2ICQ2C8TEf\n" +
+                "VkSY44EghL9bs0aYfio1fgMBCAeIdQQYFgoAHQUCYOlnJgIbDAUWAgMBAAQLCQgH\n" +
+                "BRUKCQgLAh4BAAoJEPbyu9T10peTJCQBAIkIfsgWjvc1lBHjoqK1TG0uO2bR3+2x\n" +
+                "2fO2sB8s4ulAAQD/U5SWyx+2vw0Oi1GV6Do4xNKivJuNU5UgcbJj1SF+B7gzBGDp\n" +
+                "ZyYWCSsGAQQB2kcPAQEHQJbuNdOUc35ZOo6+8cYuV+d+Gu+AZIhkA7zFsyLMrGsC\n" +
+                "iNUEGBYKAH0FAmDpZyYCGwIFFgIDAQAECwkIBwUVCgkICwIeAV8gBBkWCgAGBQJg\n" +
+                "6WcmAAoJEAqPm07pCscSwX8BAJkVbDWA6FBHVqmU9Iis+ZeQpolmeRdyuKm6AkYp\n" +
+                "Z1jLAP9/MNtKOsbAvL1c7YXomytJAzgbx1hxWfFlD5rGSVuUBAAKCRD28rvU9dKX\n" +
+                "kxnQAQCe6sgVoCIWw2nFwlEBnwEH4OIsRya79mBps6UZPv8g9QD+K8imuYR9zOwT\n" +
+                "sFrPBVJ6f5HPPBEeQKMS0DBcg0NE3g4=\n" +
+                "=6XFh\n" +
+                "-----END PGP PUBLIC KEY BLOCK-----\n";
+
+        PGPPublicKeyRing certificate = PGPainless.readKeyRing().publicKeyRing(markerAndCert);
+
+        assertEquals(
+                new OpenPgpV4Fingerprint("4291C2BEF9B9209DF11128E7F6F2BBD4F5D29793"),
+                new OpenPgpV4Fingerprint(certificate));
+    }
+
+    @Test
+    public void testReadSecretKeyCollectionIgnoresMarkerPackets() throws PGPException, IOException {
+        // Marker
+        // Alice
+        // Marker
+        // Bob
+        // Marker
+        // Charlie
+        // Marker
+        String markersAndKeys = "-----BEGIN PGP PRIVATE KEY BLOCK-----\n" +
+                "Version: PGPainless\n" +
+                "Comment: Secret Keys with injected Marker Packets\n" +
+                "\n" +
+                "qANQR1CUWARg6WhFFgkrBgEEAdpHDwEBB0DjH2IBKwAhdm84ZRVuR6q7JeXRteRQ\n" +
+                "lf4QU7dbN3p3hQAA/iMLttV29lnH8K3FfcEcLVJ8ZjJJvDK0fbalvnf3zkXIEly0\n" +
+                "FGFsaWNlQHBncGFpbmxlc3Mub3JniHgEExYKACAFAmDpaEUCGwEFFgIDAQAECwkI\n" +
+                "BwUVCgkICwIeAQIZAQAKCRA6lTdYIKtst/3QAQDp4U2/4ntH3Fs5O1VHAK73WTO9\n" +
+                "zNXiKuC063A0P/v2bgD8DSDk1eCoyLQcOh/9DfN4tMZJ/6FIwb3WCkxSw97Z0wic\n" +
+                "XQRg6WhFEgorBgEEAZdVAQUBAQdAKxHYJTqkRCypuE7i4TsJbXXKN6Xmhbvmjhmd\n" +
+                "u1drcUsDAQgHAAD/cThN8gH2r5bsPOUvrt55l1tT14Oj+Qjap9EUwiesQmASRIh1\n" +
+                "BBgWCgAdBQJg6WhFAhsMBRYCAwEABAsJCAcFFQoJCAsCHgEACgkQOpU3WCCrbLew\n" +
+                "0QD+MY2b9/zRjacoMisomi2x+CYeSoYgUQqKdJKJrEAok/QA/256NyiPO/cNQEdL\n" +
+                "SzbUEZhme/DFg1rJN477Euo/hOMKnFcEYOloRRYJKwYBBAHaRw8BAQdAVKZYwF4Y\n" +
+                "PUD1hq1E3Ilnxoa6KCGKsh2FJxkctYOKR1sAAPYoiQHf3NHuBsScEqYDXHjTdy8v\n" +
+                "tYQzRmx+e9LDP4wHDz2I1QQYFgoAfQUCYOloRQIbAgUWAgMBAAQLCQgHBRUKCQgL\n" +
+                "Ah4BXyAEGRYKAAYFAmDpaEUACgkQSVw6Evq5JjqvEAD8CR7NcQKUy1CDQ+M84p4m\n" +
+                "nnbII6khqWoEq0bqazFPbKIBALwL6rhL5Ik/v8tW+JlRhDb4eBsWm5b4S1HaufxB\n" +
+                "XJ0EAAoJEDqVN1ggq2y33+4BAMtcL9lP87M1dNcuNsrZ1m0+gmmG5J+/oSqtsZlW\n" +
+                "SpxuAQDgI+IdPncg6nFCJMGwiL+qDb++c5o1pgflcGhVv2GlDqgDUEdQlFgEYOlo\n" +
+                "RRYJKwYBBAHaRw8BAQdA5vhJLr3c1QjPwfX9FTJ+ziVG9J8l/Z6QHKJuSBiaAlEA\n" +
+                "AQDm3Xt9X1YFRx//lSurYr7WRCBUHX3Ge1uOvlq9aomCNg84tBJib2JAcGdwYWlu\n" +
+                "bGVzcy5vcmeIeAQTFgoAIAUCYOloRQIbAQUWAgMBAAQLCQgHBRUKCQgLAh4BAhkB\n" +
+                "AAoJEMj0tCImK9SQ55cBAM8xAV/jDJN2lD18SbDPVZ+OJP/j9nrzZvQqb21Cds9C\n" +
+                "AP0R94jcyEx3FyyRBvDyqqeGUjXsPgcAQlp17AboXm03DpxdBGDpaEUSCisGAQQB\n" +
+                "l1UBBQEBB0B8eayqPueZm+rRCxnaxEXsUwhTL9UBaLtXJJK4Z1zEJAMBCAcAAP9N\n" +
+                "9fbs6BVTorTT26wtXnvNCvXlIsR8XsAV5f8f5fgxsBQwiHUEGBYKAB0FAmDpaEUC\n" +
+                "GwwFFgIDAQAECwkIBwUVCgkICwIeAQAKCRDI9LQiJivUkLbhAP9F7/xjyLvCRHtD\n" +
+                "pX/GfI29Kfb111iCT52BKyq/TT5WvQEA48K2XSvutAVK91JMBg5A34HK+5PPZPUV\n" +
+                "sG9Bb8RyRgucWARg6WhFFgkrBgEEAdpHDwEBB0CxEEGEc4hdT2qssJD0wWRY/ZsK\n" +
+                "WEhK7rbQJ71HnM8TEQAA/j0LCQr+Mn8bBnASusPzI3ye8xHVBPEFX4GLIUwOH14H\n" +
+                "DJWI1QQYFgoAfQUCYOloRQIbAgUWAgMBAAQLCQgHBRUKCQgLAh4BXyAEGRYKAAYF\n" +
+                "AmDpaEUACgkQRVTyVd6iXcyLagD/RHqcDj4n9M3wZABra+R2xESqnFjeivlirPDE\n" +
+                "4aRAsyIBAO5CN/BgUbAaPsjMgv9LK6lQKgdMCqWDpOyLxdeD33cFAAoJEMj0tCIm\n" +
+                "K9SQb7kA/16WbqBaoKCT86JR0fyRHnqv0OpkiLq/V0HshelcRhe2AQCM6QOO7fIr\n" +
+                "uPy0wh0YKJnERx4zZRbmsbh6sWjNaUiIBagDUEdQlFgEYOloRRYJKwYBBAHaRw8B\n" +
+                "AQdA9patkgJRlLYFoUHLXLADFhQ1BaQvX4MVbIZSiSO7BMQAAQCp6Cw8TyThR78B\n" +
+                "mCgF2Z4sN3Z0giB7Vt586eeJhJyejA9OtBZjaGFybGllQHBncGFpbmxlc3Mub3Jn\n" +
+                "iHgEExYKACAFAmDpaEUCGwEFFgIDAQAECwkIBwUVCgkICwIeAQIZAQAKCRCdtvZK\n" +
+                "TZDLyi7RAQDiFmvVuv9jCHbBfyjB7VpRVAW3FDRvuPdOXC9SWK4XBQD+PdLTljLw\n" +
+                "YT3lOr6SXfELd3fmJYMDImoBguN3CBDyjQWcXQRg6WhFEgorBgEEAZdVAQUBAQdA\n" +
+                "EBiuPXGJwy6w4QxWJPVo7aq7ZOWfZ46h6TZGwkK/FiYDAQgHAAD/WIN/9nM6taYW\n" +
+                "JHJMxFbmyQivCkos9R2zwJi0/7uyVOARwIh1BBgWCgAdBQJg6WhFAhsMBRYCAwEA\n" +
+                "BAsJCAcFFQoJCAsCHgEACgkQnbb2Sk2Qy8oKqgEAgVs1Zn7D8h7PFufOjbry2mbC\n" +
+                "xIY720qMUBjMJ3k6Up8BANs8So9Bza+PSSzkSl02FMO35mdSaTM0wN6FjC+p52cA\n" +
+                "nFgEYOloRRYJKwYBBAHaRw8BAQdAS0Hu07LjoCfmiRIRW+VuxI1lR6l5eeJ90yCd\n" +
+                "UEi00tkAAQDKneHa3lRE7pE16gK/h+EHeQ9aVs2qIp6XtM0Izu1ANBEliNUEGBYK\n" +
+                "AH0FAmDpaEUCGwIFFgIDAQAECwkIBwUVCgkICwIeAV8gBBkWCgAGBQJg6WhFAAoJ\n" +
+                "EBp7XFqQf6Zlh+sA/RDpmtiDmN03eF3e3LJiZsUd/sZDOU9D/Phkk6L8LjdRAQD/\n" +
+                "UMghkY6FoQgblW4jVUJ3JaLFJeTgZXJE2s8TxJj6CAAKCRCdtvZKTZDLypYsAP0R\n" +
+                "HqkNloRGvPXmbC44XsMe7oMu0DcJqu2En7UzxeLNmQEAhmYXXZXcGezCASlbwX7B\n" +
+                "ErE+7aqGe7NeySfX+Dq2JQ2oA1BHUA==\n" +
+                "=Jgh3\n" +
+                "-----END PGP PRIVATE KEY BLOCK-----";
+
+        PGPSecretKeyRingCollection secretKeys = PGPainless.readKeyRing().secretKeyRingCollection(markersAndKeys);
+        assertEquals(3, secretKeys.size());
+    }
+
+    @Test
+    public void testReadCertificateCollectionIgnoresMarkerPackets() throws PGPException, IOException {
+        String markersAndCerts = "-----BEGIN PGP PUBLIC KEY BLOCK-----\n" +
+                "Version: PGPainless\n" +
+                "Comment: Certificates with injected Marker Packets\n" +
+                "\n" +
+                "qANQR1CYMwRg6WlFFgkrBgEEAdpHDwEBB0D8DA8Ljt557GZn8wDFJPzeBv2A70fC\n" +
+                "h92MkTs17VoYILQUYWxpY2VAcGdwYWlubGVzcy5vcmeIeAQTFgoAIAUCYOlpRQIb\n" +
+                "AQUWAgMBAAQLCQgHBRUKCQgLAh4BAhkBAAoJEJB0aoL4SmmAukUA/igDja1VmFWc\n" +
+                "CIO5Usj+XT+mpWw/wBS2sJoUwVOBgNodAP9flvbOQsnYCtFcK8Zaixn2Y5MCGktg\n" +
+                "zPR4ViHqo3QrALg4BGDpaUUSCisGAQQBl1UBBQEBB0D2uMrObpVE1tLfcfC9Ol3k\n" +
+                "351KW9wfrVmgI76ckUuBdgMBCAeIdQQYFgoAHQUCYOlpRQIbDAUWAgMBAAQLCQgH\n" +
+                "BRUKCQgLAh4BAAoJEJB0aoL4SmmAW8sBAP42LkP5S/CwUhpiyfmMfydwG25g6nWv\n" +
+                "s413zKKIrDBNAP9UQShowbpRIhQkO3/fsmI+1kwujLXWEgV4ltuktmYKBrgzBGDp\n" +
+                "aUUWCSsGAQQB2kcPAQEHQOfCezOL4q6QbC4+6LmedQ8Ok4O1j+AS7FMTF/4jaEYr\n" +
+                "iNUEGBYKAH0FAmDpaUUCGwIFFgIDAQAECwkIBwUVCgkICwIeAV8gBBkWCgAGBQJg\n" +
+                "6WlFAAoJEJMPNY2nAmZ8aecA/3+Vx3jOX3ky+kxjIJgdpZV4zCK4+xxn7jc/K4gr\n" +
+                "BiKpAP9PZ9WPizfbbE3JX7ubLmDjLXAT0aDmiPESZB+tiiyADAAKCRCQdGqC+Epp\n" +
+                "gBx9AQD7zbQlhjs4W6HXoStlotRUjCSBuJA4Gb0EkQUyG8sTeAEA5EAb4JgFiloR\n" +
+                "Q2KOJvrzO0ESO+dKKDv+BtPXl49m0AyoA1BHUJgzBGDpaUUWCSsGAQQB2kcPAQEH\n" +
+                "QLhQd9y5pedCXnzvA0GJJgdp36JCmxrzI3Nxj0rZRLmHtBJib2JAcGdwYWlubGVz\n" +
+                "cy5vcmeIeAQTFgoAIAUCYOlpRQIbAQUWAgMBAAQLCQgHBRUKCQgLAh4BAhkBAAoJ\n" +
+                "EDJI0AtDs041jU0A/0QlLxkjwi0cYVGg62/rAJ9Hi3O/g1w9TS1eExboCeQZAP9c\n" +
+                "uQxnUgAAwnom8Mx7Rrydfb5nPS2a64AoNziw/zblD7g4BGDpaUUSCisGAQQBl1UB\n" +
+                "BQEBB0D8s6a+rQ/JHzQILoOr0yHxG5b428c+rF39frfnlInQcAMBCAeIdQQYFgoA\n" +
+                "HQUCYOlpRQIbDAUWAgMBAAQLCQgHBRUKCQgLAh4BAAoJEDJI0AtDs041yucBAKWG\n" +
+                "vCrvcM7l0O4VUADPuBz0JfxKsLibeSiB9J8wzpAtAQCA2fKdDpDqcyrWtGDiIuko\n" +
+                "Z6R6SdUquSCPPd/JuBCnCbgzBGDpaUUWCSsGAQQB2kcPAQEHQCtlUlAZuiXa1w6K\n" +
+                "SMybCOy7RZ9ouH560bYNVFryciI5iNUEGBYKAH0FAmDpaUUCGwIFFgIDAQAECwkI\n" +
+                "BwUVCgkICwIeAV8gBBkWCgAGBQJg6WlFAAoJEHasTR5i2pVLzhsBAMVbiy3J0OzK\n" +
+                "4KCwel+M+Kq/IaVaQFjmyu/zgWLVr04zAQCZ6w5aMAK7GmpBIvks/vlt7qgkxhZy\n" +
+                "E9V4pHGHcLD2BgAKCRAySNALQ7NONeQdAP9KBaYXbb/qcrqklTu7x1aYZNeAOnrZ\n" +
+                "zl4GTIh5aHZ25wD9FrgSO2ebavHe5vZmME6HIxzC3lADS+18fjo5taeS6gOoA1BH\n" +
+                "UJgzBGDpaUUWCSsGAQQB2kcPAQEHQAvooKeu5yJWMOH4QKXbNL+vtDtqckMNpM7o\n" +
+                "CEJWp85htBZjaGFybGllQHBncGFpbmxlc3Mub3JniHgEExYKACAFAmDpaUUCGwEF\n" +
+                "FgIDAQAECwkIBwUVCgkICwIeAQIZAQAKCRC4y4xSBWsKFSnzAQC5nGJaz0VAMbgt\n" +
+                "Z2ellsVO/wjRssCr3gHIsrGnW6E0ZAD/UVarkzwzk/h1IXQK8TGbx7dLb2gCoJ+v\n" +
+                "8smHe+3hawe4OARg6WlFEgorBgEEAZdVAQUBAQdAR4w1GbxLYm9V2kSq8ofRc6d8\n" +
+                "fseZ1zig1fNIxcv3njcDAQgHiHUEGBYKAB0FAmDpaUUCGwwFFgIDAQAECwkIBwUV\n" +
+                "CgkICwIeAQAKCRC4y4xSBWsKFXKAAQDyIqXxRmFozR6zP7/loI4YqfxDpwPFUevv\n" +
+                "CisDkaTaaAEA6Pyi0Y0T3yoyR00RLgJnyDBbf/vtWVGp0IcFWZcLZQS4MwRg6WlF\n" +
+                "FgkrBgEEAdpHDwEBB0DljpzDhVSzHgN2areAdxG1/1nZAkleDT/xyPUuXxbruYjV\n" +
+                "BBgWCgB9BQJg6WlFAhsCBRYCAwEABAsJCAcFFQoJCAsCHgFfIAQZFgoABgUCYOlp\n" +
+                "RQAKCRAYgL6ek003kO5bAP9vMBHKmn5GJIjrnvpwkog2TuLO/jcCnXwbes42EJ7t\n" +
+                "BgEAhIuNp1QnQPlgDabVSLJlJyiBWP3A+xIh0UHuLRyr2QQACgkQuMuMUgVrChXV\n" +
+                "1AD/dd5TWLYcbZJmLFW2gT0IslYVGZmZNO03WmKkahFoylIBANQ0Iu1y6j/vhGL6\n" +
+                "r1zIt4pkvfxrlrxvxlk80IqcTsYMqANQR1A=\n" +
+                "=aWCj\n" +
+                "-----END PGP PUBLIC KEY BLOCK-----\n";
+
+        PGPPublicKeyRingCollection certificates = PGPainless.readKeyRing().publicKeyRingCollection(markersAndCerts);
+        assertEquals(3, certificates.size());
+    }
+
+    @Test
+    public void testReadSignatureIgnoresMarkerPacket() throws PGPException, IOException {
+        String markerAndSignature = "-----BEGIN PGP SIGNATURE-----\n" +
+                "Version: PGPainless\n" +
+                "Comment: Signature with prepended Marker Packet\n" +
+                "\n" +
+                "qANQR1CIeAQTFgoAIAUCYOlqZgIbAQUWAgMBAAQLCQgHBRUKCQgLAh4BAhkBAAoJ\n" +
+                "EAJI18O3wl3pF3AA/3PcUODYUYfaFtwOjhRnbSVJDpRf271yNGkbuRPI9q7vAQCo\n" +
+                "nqxxfvd9VxfZCrdZc5gCbIxVUnbuBL2fjBqIoYQkDQ==\n" +
+                "=S1jF\n" +
+                "-----END PGP SIGNATURE-----";
+        List<PGPSignature> signatureList = SignatureUtils.readSignatures(markerAndSignature);
+        assertEquals(1, signatureList.size());
+    }
+
+    @Test
+    public void testReadSecretKeysIgnoresMultipleMarkers() throws PGPException, InvalidAlgorithmParameterException, NoSuchAlgorithmException, IOException {
+        PGPSecretKeyRing alice = PGPainless.generateKeyRing().modernKeyRing("alice@pgpainless.org", null);
+        PGPSecretKeyRing bob = PGPainless.generateKeyRing().modernKeyRing("bob@pgpainless.org", null);
+        MarkerPacket marker = TestUtils.getMarkerPacket();
+
+        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+        ArmoredOutputStream armor = ArmoredOutputStreamFactory.get(bytes);
+        armor.setHeader("Comment", "Secret Keys and an absurd amount of markers");
+        BCPGOutputStream outputStream = new BCPGOutputStream(armor);
+
+        for (int i = 0; i < 25; i++) {
+            marker.encode(outputStream);
+        }
+        alice.encode(outputStream);
+        for (int i = 0; i < 53; i++) {
+            marker.encode(outputStream);
+        }
+        bob.encode(outputStream);
+        for (int i = 0; i < 102; i++) {
+            marker.encode(outputStream);
+        }
+        outputStream.close();
+        armor.close();
+
+        String armoredMess = bytes.toString();
+
+        PGPSecretKeyRingCollection secretKeys = PGPainless.readKeyRing().secretKeyRingCollection(armoredMess);
+        assertEquals(2, secretKeys.size());
+        assertTrue(secretKeys.contains(alice.getSecretKey().getKeyID()));
+        assertTrue(secretKeys.contains(bob.getSecretKey().getKeyID()));
+    }
 }