TargetData should work on sha256 or sha512

Only of them is required by spec, so if one's missing we should
continue to work and determine the target file correctly based
on the available hash.

Signed-off-by: Appu Goundan <appu@google.com>

Author: loosebazooka

.github/workflows/ci.yaml

@@ -54,9 +54,9 @@ jobs:
     - name: Setup Gradle
       uses: gradle/actions/setup-gradle@af1da67850ed9a4cedd57bfd976089dd991e2582 # v4.0.0
 
-    # tests that hit staging are current disabled due to flakiness (-PskipStaging)
+    # if you need to skip staging due to flakiness use "-PskipStaging"
     - name: Test sigstore-java
-      run: ./gradlew build -PskipStaging
+      run: ./gradlew build
 
     - name: Ensure sigstore-java self signing still works
       run: ./gradlew sigstore-java:publishToMavenLocal -Prelease -PskipPgpSigning

sigstore-java/src/main/java/dev/sigstore/tuf/Updater.java

@@ -438,14 +438,18 @@ void downloadTargets(Targets targets)
       String targetName = entry.getKey();
       // 8) If target is missing metadata fail.
       // Note: This can't actually happen due to the way GSON is setup the targets.json would fail
-      // to parse. Leaving
-      // this code in in-case we eventually allow it in de-serialization.
+      // to parse. Leaving this code in in-case we eventually allow it in de-serialization.
       if (entry.getValue() == null) {
         throw new TargetMetadataMissingException(targetName);
       }
       TargetMeta.TargetData targetData = entry.getValue();
       // 9) Download target up to length specified in bytes. verify against hash.
-      var versionedTargetName = targetData.getHashes().getSha512() + "." + targetName;
+      String versionedTargetName;
+      if (targetData.getHashes().getSha512() != null) {
+        versionedTargetName = targetData.getHashes().getSha512() + "." + targetName;
+      } else {
+        versionedTargetName = targetData.getHashes().getSha256() + "." + targetName;
+      }
 
       var targetBytes =
           fetcher.fetchResource("targets/" + versionedTargetName, targetData.getLength());

sigstore-java/src/main/java/dev/sigstore/tuf/model/TargetMeta.java

@@ -41,11 +41,22 @@ interface TargetData {
     /** Custom application specific metadata about the target. */
     Optional<Custom> getCustom();
 
-    /** Hash values of the target metadata. */
+    /**
+     * Hash values of the target metadata. One or both of sha256 or sha512 is required to be
+     * present.
+     */
     Hashes getHashes();
 
     /** Length in bytes of the metadata. */
     int getLength();
+
+    @Value.Check
+    default void check() {
+      if (getHashes().getSha256() == null && getHashes().getSha512() == null) {
+        throw new IllegalStateException(
+            "No hashes (sha256 or sha512) found for target data: " + this);
+      }
+    }
   }
 
   /** Field to store use-case specific labels/data. */

sigstore-java/src/test/java/dev/sigstore/tuf/UpdaterTest.java

@@ -17,6 +17,7 @@
 
 import static dev.sigstore.testkit.tuf.TestResources.UPDATER_REAL_TRUSTED_ROOT;
 import static dev.sigstore.testkit.tuf.TestResources.UPDATER_SYNTHETIC_TRUSTED_ROOT;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -658,6 +659,31 @@ public void testTargetsDownload_success()
     assertTrue(updater.getLocalStore().getTargetFile("test2.txt") != null);
   }
 
+  // Ensure we accept sha256 or sha512 on hashes for targets
+  @Test
+  public void testTargetsDownload_sha256Only()
+      throws IOException, NoSuchAlgorithmException, InvalidKeySpecException, InvalidKeyException {
+    setupMirror(
+        "synthetic/targets-sha256-or-sha512",
+        "1.root.json",
+        "2.root.json",
+        "2.snapshot.json",
+        "1.targets.json",
+        "timestamp.json",
+        "targets/2dff935df7d1e1221ef52c753091c487c6fdaabbb0b0e2b193764de8cd7c1222776c61d7ef21f20a4d031a6a6bfa631713df7c4f71b4ee21d362152d4618d514.test2.txt",
+        "targets/55f8718109829bf506b09d8af615b9f107a266e19f7a311039d1035f180b22d4.test.txt");
+    var UPDATER_ROOT =
+        Path.of(
+            Resources.getResource("dev/sigstore/tuf/synthetic/targets-sha256-or-sha512/root.json")
+                .getPath());
+    var updater = createTimeStaticUpdater(localStorePath, UPDATER_ROOT);
+    var root = updater.updateRoot();
+    var timestamp = updater.updateTimestamp(root);
+    var snapshot = updater.updateSnapshot(root, timestamp.get());
+    var targets = updater.updateTargets(root, snapshot);
+    assertDoesNotThrow(() -> updater.downloadTargets(targets));
+  }
+
   // End to end sanity test on the actual prod sigstore repo.
   @Test
   public void testUpdate_fromProdData()

sigstore-java/src/test/java/dev/sigstore/tuf/model/TestTufJsonLoading.java

@@ -20,12 +20,15 @@
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import com.google.common.io.Resources;
+import com.google.gson.JsonSyntaxException;
+import dev.sigstore.tuf.model.TargetMeta.TargetData;
 import java.io.IOException;
 import java.io.Reader;
 import java.nio.charset.Charset;
 import java.time.ZonedDateTime;
 import java.util.List;
 import java.util.Map;
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
 public class TestTufJsonLoading {
@@ -163,12 +166,37 @@ public void loadTargetsJson() throws IOException {
     assertEquals("Expired", custom.getSigstoreMeta().getStatus());
     assertEquals("https://fulcio.dev", custom.getSigstoreMeta().getUri().get());
     assertEquals("Fulcio", custom.getSigstoreMeta().getUsage());
-    assertEquals(
-        "f360c53b2e13495a628b9b8096455badcb6d375b185c4816d95a5d746ff29908",
-        targetData.getHashes().getSha256());
-    assertEquals(
-        "0713252a7fd17f7f3ab12f88a64accf2eb14b8ad40ca711d7fe8b4ecba3b24db9e9dffadb997b196d3867b8f9ff217faf930d80e4dab4e235c7fc3f07be69224",
-        targetData.getHashes().getSha512());
     assertEquals(744, targetData.getLength());
   }
+
+  @Test
+  public void loadTargetData_oneHash() {
+    Assertions.assertDoesNotThrow(
+        () ->
+            GSON.get()
+                .fromJson(
+                    "{\"custom\":{\"sigstore\":{\"status\":\"Active\",\"usage\":\"CTFE\"}},\"hashes\":{\"sha256\": \"7fcb94a5d0ed541260473b990b99a6c39864c1fb16f3f3e594a5a3cebbfe138a\"},\"length\":177}",
+                    TargetData.class));
+    Assertions.assertDoesNotThrow(
+        () ->
+            GSON.get()
+                .fromJson(
+                    "{\"custom\":{\"sigstore\":{\"status\":\"Active\",\"usage\":\"CTFE\"}},\"hashes\":{\"sha512\": \"4b20747d1afe2544238ad38cc0cc3010921b177d60ac743767e0ef675b915489bd01a36606c0ff83c06448622d7160f0d866c83d20f0c0f44653dcc3f9aa0bd4\"},\"length\":177}",
+                    TargetData.class));
+  }
+
+  @Test
+  public void loadTargetData_failNoHashes() {
+    var error =
+        Assertions.assertThrows(
+            JsonSyntaxException.class,
+            () ->
+                GSON.get()
+                    .fromJson(
+                        "{\"custom\":{\"sigstore\":{\"status\":\"Active\",\"usage\":\"CTFE\"}},\"hashes\":{},\"length\":177}",
+                        TargetData.class));
+    Assertions.assertEquals(
+        "No hashes (sha256 or sha512) found for target data: TargetData{custom=Custom{sigstoreMeta=SigstoreMeta{status=Active, usage=CTFE}}, hashes=Hashes{}, length=177}",
+        error.getCause().getMessage());
+  }
 }

sigstore-java/src/test/resources/dev/sigstore/tuf/synthetic/targets-sha256-or-sha512/1.root.json

@@ -0,0 +1 @@
+{"signed":{"_type":"root","spec_version":"1.0","version":1,"expires":"2024-11-20T19:22:57Z","keys":{"09511bfa91a3dc7186789e61110733724c18b8debf2255623ed3202b70acd759":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEZd80ry+aWsYUuNgxh6A9MqZX7I03\nnP0sEfTHTBKYn+mHvmd7iNE3jT6ccTmvSmPR593Y59zPxuxVxVxNluI/Sw==\n-----END PUBLIC KEY-----\n"}},"1dec63309978fb7e4f8264f403798fce160174c65ac85398ae39b07daeaa2482":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE+iObJwvwNaRlcYTWQm06PwkG/JXZ\nHbs3NbF6q88yX8/9cFWkPM7fe6ywqnUPvjB3SB/TRBA247JOorXq9GnkoA==\n-----END PUBLIC KEY-----\n"}},"5e284914a20f614e375b4f82808333a687afeee15d7f43d187dc173353682fd5":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEidXjF3GT4NNDHaqLnAHmKHNcYM+v\nCtWgjXPUxZ/ra6X3JWDIAxySTW8kIxqBDuZjdPx2Cb3iGsYKvv1uU2ACTw==\n-----END PUBLIC KEY-----\n"}},"f48d3de6cc0c9f9dbb6b8af8f3de96a1f12d24c9f5980f2d8ce7afdf19b07e03":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEDYVTdtFRilKwjrgFU4BmfC+3dN7B\nnxvAzhcHNKr1BtgjlbD4ih10lM3mMfMy6xXEIgHG08hpz12NePg1JPaHFw==\n-----END PUBLIC KEY-----\n"}}},"roles":{"root":{"keyids":["09511bfa91a3dc7186789e61110733724c18b8debf2255623ed3202b70acd759"],"threshold":1},"snapshot":{"keyids":["1dec63309978fb7e4f8264f403798fce160174c65ac85398ae39b07daeaa2482"],"threshold":1},"targets":{"keyids":["5e284914a20f614e375b4f82808333a687afeee15d7f43d187dc173353682fd5"],"threshold":1},"timestamp":{"keyids":["f48d3de6cc0c9f9dbb6b8af8f3de96a1f12d24c9f5980f2d8ce7afdf19b07e03"],"threshold":1}},"consistent_snapshot":false},"signatures":[{"keyid":"09511bfa91a3dc7186789e61110733724c18b8debf2255623ed3202b70acd759","sig":"304502203b45b43d7049423433231073438bead62726d99266a80c1ba5b3a7fb7866fca3022100a0b1e10b9c3d0b92e9d3277f36e3154485996f83be6463e530b622e5af74bcc7"}]}

sigstore-java/src/test/resources/dev/sigstore/tuf/synthetic/targets-sha256-or-sha512/1.targets.json

@@ -0,0 +1 @@
+{"signed":{"_type":"targets","spec_version":"1.0","version":1,"expires":"2024-11-22T21:34:24Z","targets":{"test.txt":{"length":10,"hashes":{"sha256":"55f8718109829bf506b09d8af615b9f107a266e19f7a311039d1035f180b22d4"}},"test2.txt":{"length":6,"hashes":{"sha512":"2dff935df7d1e1221ef52c753091c487c6fdaabbb0b0e2b193764de8cd7c1222776c61d7ef21f20a4d031a6a6bfa631713df7c4f71b4ee21d362152d4618d514"}}}},"signatures":[{"keyid":"5e284914a20f614e375b4f82808333a687afeee15d7f43d187dc173353682fd5","sig":"304602210092fbb2a4cfc04497f640314d41207d79a17ea5b3331faf157e24da738c124dbc022100b237f54ea3d3fb5687b3e47fbc3549a216dbda9c0ab05e94196f2ab6990894da"}]}

sigstore-java/src/test/resources/dev/sigstore/tuf/synthetic/targets-sha256-or-sha512/2.root.json

@@ -0,0 +1 @@
+{"signed":{"_type":"root","spec_version":"1.0","version":2,"expires":"2024-12-20T21:37:40Z","keys":{"09511bfa91a3dc7186789e61110733724c18b8debf2255623ed3202b70acd759":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEZd80ry+aWsYUuNgxh6A9MqZX7I03\nnP0sEfTHTBKYn+mHvmd7iNE3jT6ccTmvSmPR593Y59zPxuxVxVxNluI/Sw==\n-----END PUBLIC KEY-----\n"}},"1dec63309978fb7e4f8264f403798fce160174c65ac85398ae39b07daeaa2482":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE+iObJwvwNaRlcYTWQm06PwkG/JXZ\nHbs3NbF6q88yX8/9cFWkPM7fe6ywqnUPvjB3SB/TRBA247JOorXq9GnkoA==\n-----END PUBLIC KEY-----\n"}},"5e284914a20f614e375b4f82808333a687afeee15d7f43d187dc173353682fd5":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEidXjF3GT4NNDHaqLnAHmKHNcYM+v\nCtWgjXPUxZ/ra6X3JWDIAxySTW8kIxqBDuZjdPx2Cb3iGsYKvv1uU2ACTw==\n-----END PUBLIC KEY-----\n"}},"61491d12afe41a1fc2c2204046d0857f9950115b4f2dfff758bb556c8fa38b2c":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEwQbpOfC51o+7QQYdEKgRGyA53MAk\n+kpoHN4u+vBiRX6gtElBG+08uHZ+hYGVuZkrYS3RY2e4FE6S8V67aYVg2g==\n-----END PUBLIC KEY-----\n"}},"f48d3de6cc0c9f9dbb6b8af8f3de96a1f12d24c9f5980f2d8ce7afdf19b07e03":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEDYVTdtFRilKwjrgFU4BmfC+3dN7B\nnxvAzhcHNKr1BtgjlbD4ih10lM3mMfMy6xXEIgHG08hpz12NePg1JPaHFw==\n-----END PUBLIC KEY-----\n"}}},"roles":{"root":{"keyids":["09511bfa91a3dc7186789e61110733724c18b8debf2255623ed3202b70acd759","61491d12afe41a1fc2c2204046d0857f9950115b4f2dfff758bb556c8fa38b2c"],"threshold":2},"snapshot":{"keyids":["1dec63309978fb7e4f8264f403798fce160174c65ac85398ae39b07daeaa2482"],"threshold":1},"targets":{"keyids":["5e284914a20f614e375b4f82808333a687afeee15d7f43d187dc173353682fd5"],"threshold":1},"timestamp":{"keyids":["f48d3de6cc0c9f9dbb6b8af8f3de96a1f12d24c9f5980f2d8ce7afdf19b07e03"],"threshold":1}},"consistent_snapshot":false},"signatures":[{"keyid":"09511bfa91a3dc7186789e61110733724c18b8debf2255623ed3202b70acd759","sig":"3046022100aceb849b04e33e1ff3bfa2ed7ee9fee11bcfb1e2e99ebcb1b3ae945215b8a42c022100c157930d70bc3d94075f1bc7e2b0d42cee5ea5c0adca235e5f4ce16ce88b2c46"},{"keyid":"61491d12afe41a1fc2c2204046d0857f9950115b4f2dfff758bb556c8fa38b2c","sig":"304502204f83ccbcfaf1e086b02172f0d0d13bdf8fb96fda3b6e4c6e71934af30099211802210085ed4b98bb8f93784286dd80eb8d272686ac5a9c89c589f59bffa0dac4a1ce48"}]}

sigstore-java/src/test/resources/dev/sigstore/tuf/synthetic/targets-sha256-or-sha512/2.snapshot.json

@@ -0,0 +1 @@
+{"signed":{"_type":"snapshot","spec_version":"1.0","version":2,"expires":"2024-08-29T20:36:55Z","meta":{"targets.json":{"length":642,"hashes":{"sha512":"4cdbc10a77607ab1effe79645e367c61d1195af568995b9ce0dec5fd684af4359198add5597e92e61aa8f2c96598ed48552847ad14fe35354868446b60a0e498"},"version":1}}},"signatures":[{"keyid":"1dec63309978fb7e4f8264f403798fce160174c65ac85398ae39b07daeaa2482","sig":"30460221008fa6b790fb813c483b9672afc045b5bd3e0c719bb8ddf63ab7f97ae632015a3b022100bcaa73f6b2de9e67cdd1d336cb31a0d86f73ec935d3bd03a9fd0a08fbb516754"}]}

sigstore-java/src/test/resources/dev/sigstore/tuf/synthetic/targets-sha256-or-sha512/root.json

@@ -0,0 +1 @@
+{"signed":{"_type":"root","spec_version":"1.0","version":2,"expires":"2024-12-20T21:37:40Z","keys":{"09511bfa91a3dc7186789e61110733724c18b8debf2255623ed3202b70acd759":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEZd80ry+aWsYUuNgxh6A9MqZX7I03\nnP0sEfTHTBKYn+mHvmd7iNE3jT6ccTmvSmPR593Y59zPxuxVxVxNluI/Sw==\n-----END PUBLIC KEY-----\n"}},"1dec63309978fb7e4f8264f403798fce160174c65ac85398ae39b07daeaa2482":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE+iObJwvwNaRlcYTWQm06PwkG/JXZ\nHbs3NbF6q88yX8/9cFWkPM7fe6ywqnUPvjB3SB/TRBA247JOorXq9GnkoA==\n-----END PUBLIC KEY-----\n"}},"5e284914a20f614e375b4f82808333a687afeee15d7f43d187dc173353682fd5":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEidXjF3GT4NNDHaqLnAHmKHNcYM+v\nCtWgjXPUxZ/ra6X3JWDIAxySTW8kIxqBDuZjdPx2Cb3iGsYKvv1uU2ACTw==\n-----END PUBLIC KEY-----\n"}},"61491d12afe41a1fc2c2204046d0857f9950115b4f2dfff758bb556c8fa38b2c":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEwQbpOfC51o+7QQYdEKgRGyA53MAk\n+kpoHN4u+vBiRX6gtElBG+08uHZ+hYGVuZkrYS3RY2e4FE6S8V67aYVg2g==\n-----END PUBLIC KEY-----\n"}},"f48d3de6cc0c9f9dbb6b8af8f3de96a1f12d24c9f5980f2d8ce7afdf19b07e03":{"keytype":"ecdsa-sha2-nistp256","scheme":"ecdsa-sha2-nistp256","keyid_hash_algorithms":["sha256","sha512"],"keyval":{"public":"-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEDYVTdtFRilKwjrgFU4BmfC+3dN7B\nnxvAzhcHNKr1BtgjlbD4ih10lM3mMfMy6xXEIgHG08hpz12NePg1JPaHFw==\n-----END PUBLIC KEY-----\n"}}},"roles":{"root":{"keyids":["09511bfa91a3dc7186789e61110733724c18b8debf2255623ed3202b70acd759","61491d12afe41a1fc2c2204046d0857f9950115b4f2dfff758bb556c8fa38b2c"],"threshold":2},"snapshot":{"keyids":["1dec63309978fb7e4f8264f403798fce160174c65ac85398ae39b07daeaa2482"],"threshold":1},"targets":{"keyids":["5e284914a20f614e375b4f82808333a687afeee15d7f43d187dc173353682fd5"],"threshold":1},"timestamp":{"keyids":["f48d3de6cc0c9f9dbb6b8af8f3de96a1f12d24c9f5980f2d8ce7afdf19b07e03"],"threshold":1}},"consistent_snapshot":false},"signatures":[{"keyid":"09511bfa91a3dc7186789e61110733724c18b8debf2255623ed3202b70acd759","sig":"3046022100aceb849b04e33e1ff3bfa2ed7ee9fee11bcfb1e2e99ebcb1b3ae945215b8a42c022100c157930d70bc3d94075f1bc7e2b0d42cee5ea5c0adca235e5f4ce16ce88b2c46"},{"keyid":"61491d12afe41a1fc2c2204046d0857f9950115b4f2dfff758bb556c8fa38b2c","sig":"304502204f83ccbcfaf1e086b02172f0d0d13bdf8fb96fda3b6e4c6e71934af30099211802210085ed4b98bb8f93784286dd80eb8d272686ac5a9c89c589f59bffa0dac4a1ce48"}]}