Skip to content

Add Validation to DER Parser for Sequence Length that Exceeds Max Signed Integer #138683

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Nov 26, 2025
Merged

Add Validation to DER Parser for Sequence Length that Exceeds Max Signed Integer #138683

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
1d4ab14
Add validation to DerParser for sequence length that exceeds maximum …
ebarlas Nov 26, 2025
735d297
[CI] Auto commit changes from spotless
Nov 26, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 6 additions & 1 deletion libs/ssl-config/src/main/java/org/elasticsearch/common/ssl/DerParser.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -138,7 +138,12 @@ private int getLength() throws IOException {
int n = derInputStream.read(bytes);
if (n < num) throw new IOException("Invalid DER: length too short");

return new BigInteger(1, bytes).intValue();
int len = new BigInteger(1, bytes).intValue();
if (len < 0) {
throw new IOException("Invalid DER: length larger than max-int");
}

return len;
}

/**
Expand Down
13 changes: 13 additions & 0 deletions ...rity/src/test/java/org/elasticsearch/xpack/security/authc/pki/RdnFieldExtractorTests.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -88,6 +88,19 @@ public void testExtractWithMalformedDerData() {
assertThat(result, is(nullValue()));
}

public void testSeqLengthOutOfSignedIntRange() {
byte[] malformedBytes = {
(byte) 48, // SEQUENCE
(byte) 0x84, // Length byte indicating (1) long form with (2) 4 data bytes
(byte) 0xFF,
(byte) 0xFF,
(byte) 0xFF,
(byte) 0xFF };

String result = RdnFieldExtractor.extract(malformedBytes, OID_CN);
assertThat(result, is(nullValue()));
}

public void testExtractWithSpecialCharacters() {
assertExtractions("CN=Test\\, User, OU=R\\+D, O=Elastic\\\\Co", Map.of(OID_CN, "Test, User", OID_OU, "R+D", OID_O, "Elastic\\Co"));
}
Expand Down