[7.0.0] Emit actual hash in same format as expected hash (#20189)

Work towards #17803

Closes #20155.

Commit
651c185

PiperOrigin-RevId: 582237355
Change-Id: I65dfabe0b3a7a87c5d85a9d0383d3831bbb56590

Co-authored-by: Fabian Meumertzheim <fabian@meumertzhe.im>

src/main/java/com/google/devtools/build/lib/bazel/repository/downloader/Checksum.java

@@ -34,18 +34,26 @@ private InvalidChecksumException(String msg) {
 
   private final KeyType keyType;
   private final HashCode hashCode;
+  private final boolean useSubresourceIntegrity;
 
-  private Checksum(KeyType keyType, HashCode hashCode) {
+  private Checksum(KeyType keyType, HashCode hashCode, boolean useSubresourceIntegrity) {
     this.keyType = keyType;
     this.hashCode = hashCode;
+    this.useSubresourceIntegrity = useSubresourceIntegrity;
   }
 
   /** Constructs a new Checksum for a given key type and hash, in hex format. */
   public static Checksum fromString(KeyType keyType, String hash) throws InvalidChecksumException {
+    return fromString(keyType, hash, /* useSubresourceIntegrity= */ false);
+  }
+
+  private static Checksum fromString(KeyType keyType, String hash, boolean useSubresourceIntegrity)
+      throws InvalidChecksumException {
     if (!keyType.isValid(hash)) {
       throw new InvalidChecksumException(keyType, hash);
     }
-    return new Checksum(keyType, HashCode.fromString(Ascii.toLowerCase(hash)));
+    return new Checksum(
+        keyType, HashCode.fromString(Ascii.toLowerCase(hash)), useSubresourceIntegrity);
   }
 
   /** Constructs a new Checksum from a hash in Subresource Integrity format. */
@@ -89,14 +97,19 @@ public static Checksum fromSubresourceIntegrity(String integrity)
           "Invalid " + keyType + " SRI checksum '" + integrity + "'");
     }
 
-    return Checksum.fromString(keyType, HashCode.fromBytes(hash).toString());
+    return Checksum.fromString(
+        keyType, HashCode.fromBytes(hash).toString(), /* useSubresourceIntegrity= */ true);
   }
 
-  public String toSubresourceIntegrity() {
+  private static String toSubresourceIntegrity(KeyType keyType, HashCode hashCode) {
     String encoded = Base64.getEncoder().encodeToString(hashCode.asBytes());
     return keyType.getHashName() + "-" + encoded;
   }
 
+  public String toSubresourceIntegrity() {
+    return toSubresourceIntegrity(keyType, hashCode);
+  }
+
   @Override
   public String toString() {
     return hashCode.toString();
@@ -109,4 +122,12 @@ public HashCode getHashCode() {
   public KeyType getKeyType() {
     return keyType;
   }
+
+  public String emitOtherHashInSameFormat(HashCode otherHash) {
+    if (useSubresourceIntegrity) {
+      return toSubresourceIntegrity(keyType, otherHash);
+    } else {
+      return otherHash.toString();
+    }
+  }
 }

src/main/java/com/google/devtools/build/lib/bazel/repository/downloader/HashInputStream.java

@@ -37,13 +37,13 @@ final class HashInputStream extends InputStream {
 
   private final InputStream delegate;
   private final Hasher hasher;
-  private final HashCode code;
+  private final Checksum checksum;
   @Nullable private volatile HashCode actual;
 
   HashInputStream(@WillCloseWhenClosed InputStream delegate, Checksum checksum) {
     this.delegate = delegate;
     this.hasher = checksum.getKeyType().newHasher();
-    this.code = checksum.getHashCode();
+    this.checksum = checksum;
   }
 
   @Override
@@ -83,9 +83,12 @@ private void check() throws IOException {
     if (actual == null) {
       actual = hasher.hash();
     }
-    if (!code.equals(actual)) {
+    if (!checksum.getHashCode().equals(actual)) {
       throw new UnrecoverableHttpException(
-          String.format("Checksum was %s but wanted %s", actual, code));
+          String.format(
+              "Checksum was %s but wanted %s",
+              checksum.emitOtherHashInSameFormat(actual),
+              checksum.emitOtherHashInSameFormat(checksum.getHashCode())));
     }
   }
 }

src/main/java/com/google/devtools/build/lib/bazel/repository/downloader/HashOutputStream.java

@@ -39,13 +39,13 @@ public final class HashOutputStream extends OutputStream {
 
   private final OutputStream delegate;
   private final Hasher hasher;
-  private final HashCode code;
+  private final Checksum checksum;
   @Nullable private volatile HashCode actual;
 
   public HashOutputStream(@WillCloseWhenClosed OutputStream delegate, Checksum checksum) {
     this.delegate = delegate;
     this.hasher = checksum.getKeyType().newHasher();
-    this.code = checksum.getHashCode();
+    this.checksum = checksum;
   }
 
   @Override
@@ -81,9 +81,12 @@ private void check() throws IOException {
     if (actual == null) {
       actual = hasher.hash();
     }
-    if (!code.equals(actual)) {
+    if (!checksum.getHashCode().equals(actual)) {
       throw new UnrecoverableHttpException(
-          String.format("Checksum was %s but wanted %s", actual, code));
+          String.format(
+              "Checksum was %s but wanted %s",
+              checksum.emitOtherHashInSameFormat(actual),
+              checksum.emitOtherHashInSameFormat(checksum.getHashCode())));
     }
   }
 }

src/test/shell/bazel/external_integration_test.sh

@@ -1104,6 +1104,7 @@ function test_integrity_incorrect() {
   create_workspace_with_default_repos WORKSPACE
   touch BUILD
   zip -r repo.zip *
+  integrity="sha256-$(cat repo.zip | openssl dgst -sha256 -binary | openssl base64 -A)"
   startup_server $PWD
   cd -
 
@@ -1118,7 +1119,7 @@ EOF
   bazel build @repo//... &> $TEST_log 2>&1 && fail "Expected to fail"
   expect_log "Error downloading \\[http://127.0.0.1:$fileserver_port/repo.zip\\] to"
   # Bazel translates the integrity value back to the sha256 checksum.
-  expect_log "but wanted 61a6f762aaf60652cbf332879b8dcc2cfd81be2129a061da957d039eae77f0b0"
+  expect_log "Checksum was $integrity but wanted sha256-Yab3Yqr2BlLL8zKHm43MLP2BviEpoGHalX0Dnq538LA="
   shutdown_server
 }
 

src/test/shell/bazel/external_patching_test.sh

@@ -291,7 +291,7 @@ EOF
 
   bazel build @ext//... &> $TEST_log 2>&1 && fail "Expected to fail"
   expect_log "Error downloading \\[.*/remote.patch\\] to"
-  expect_log "but wanted 61a6f762aaf60652cbf332879b8dcc2cfd81be2129a061da957d039eae77f0b0"
+  expect_log "but wanted sha256-Yab3Yqr2BlLL8zKHm43MLP2BviEpoGHalX0Dnq538LA="
 }
 
 test_remote_patches_with_same_base_name() {