Add configurable keytext byte-limit guard for `/pks/add` and document proxy limits by Copilot · Pull Request #143 · bmarwell/java-keyserver

Copilot · 2026-05-25T18:16:01Z

POST /pks/add accepted unbounded keytext, allowing oversized payloads to be read and parsed fully in memory. This change adds an early byte-size guard before OpenPGP parsing and documents HTTP-layer limits for defense in depth.

Application-layer DoS guard in add command handler
- Added a UTF-8 byte-length check in AddKeyToVerificationQueueCommandHandler#doExecute.
- Rejects oversized submissions before Bouncy Castle parsing with:
  Key submission exceeds maximum allowed size.
- Introduced reusable config key:
  - keyserver.pks.max-key-bytes
  - default: 131072 (128 KiB)
- Added fallback to default when configured value is non-positive.
Config wiring
- Added microprofile-config-api as provided dependency where needed.
- Injected max-size via @ConfigProperty into the handler.
Focused tests for size-limit behavior
- Added tests that verify:
  - oversized payloads are rejected by size guard,
  - payloads exactly at the limit are not rejected by the guard (and proceed to normal parse path).
Operational documentation (defense in depth)
- Updated README.adoc with:
  - app-level limit property + env var mapping,
  - reverse-proxy examples for nginx and Caddy body-size limits.

int keyTextBytes = command.keyText().getBytes(StandardCharsets.UTF_8).length;
if (keyTextBytes > effectiveMaxKeyBytes()) {
    throw new KeyParsingException("Key submission exceeds maximum allowed size");
}

Agent-Logs-Url: https://github.com/bmarwell/java-keyserver/sessions/5c450da0-f6c9-49c8-839d-d5c15d84ca1b Co-authored-by: bmarwell <1413391+bmarwell@users.noreply.github.com>

codecov · 2026-05-25T18:23:49Z

Codecov Report

❌ Patch coverage is 71.42857% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 52.15%. Comparing base (33cba77) to head (8382bb3).
⚠️ Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
...ndler/AddKeyToVerificationQueueCommandHandler.java	71.42%	2 Missing and 4 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #143      +/-   ##
============================================
- Coverage     59.80%   52.15%   -7.65%     
- Complexity       58       69      +11     
============================================
  Files            16       21       +5     
  Lines           204      278      +74     
  Branches         22       32      +10     
============================================
+ Hits            122      145      +23     
- Misses           68      115      +47     
- Partials         14       18       +4

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Adds an application-layer byte-size guard for POST /pks/add key submissions (to reduce oversized-upload DoS risk) and documents complementary reverse-proxy request body limits.

Changes:

Enforces a configurable UTF-8 byte limit on keytext in AddKeyToVerificationQueueCommandHandler (default 128 KiB).
Wires MicroProfile Config (keyserver.pks.max-key-bytes) into the application-core module.
Adds unit tests for “over limit” and “exactly at limit” behavior; updates README with app + proxy limits.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
README.adoc	Documents the new application-level limit and recommends proxy body-size limits (nginx/Caddy examples).
pom.xml	Adds MicroProfile Config API to dependency management (provided scope).
application/application-core/pom.xml	Declares MicroProfile Config API dependency for application-core.
application/application-core/src/main/java/.../AddKeyToVerificationQueueCommandHandler.java	Implements the byte-size guard and config plumbing (with default + fallback).
application/application-core/src/test/java/.../AddKeyToVerificationQueueCommandHandlerTest.java	Adds focused tests covering over-limit rejection and equal-to-limit behavior.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

        if (command.keyText() == null || command.keyText().isBlank()) {
            throw new KeyParsingException("keytext must not be null or blank");
        }
+        int keyTextBytes = command.keyText().getBytes(StandardCharsets.UTF_8).length;
+        if (keyTextBytes > effectiveMaxKeyBytes()) {
+            throw new KeyParsingException("Key submission exceeds maximum allowed size");
+        }


+    @ConfigProperty(name = MAX_KEY_BYTES_CONFIG_KEY, defaultValue = "131072")
+    int maxKeyBytes = DEFAULT_MAX_KEY_BYTES;


+    void setMaxKeyBytes(int maxKeyBytes) {
+        this.maxKeyBytes = maxKeyBytes;
+    }
+
+    private int effectiveMaxKeyBytes() {
+        return maxKeyBytes > 0 ? maxKeyBytes : DEFAULT_MAX_KEY_BYTES;
+    }


Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

+        int maxKeyBytes = effectiveMaxKeyBytes();
+        if (keyText.length() > maxKeyBytes) {
+            throw new KeyParsingException("Key submission exceeds maximum allowed size");
+        }
+        byte[] keyTextBytes = keyText.getBytes(StandardCharsets.UTF_8);
+        if (keyTextBytes.length > maxKeyBytes) {


+For defense in depth, also enforce request/body limits at your reverse proxy.
+Example snippets:
+
+.nginx
+[source,nginx]
+----
+server {
+    client_max_body_size 128k;
+}
+----
+
+.Caddy
+[source,caddyfile]
+----
+example.com {
+    request_body {
+        max_size 128KB
+    }
+}


Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Initial plan

4983a7a

Copilot AI assigned Copilot and bmarwell May 25, 2026

Copilot started work on behalf of bmarwell May 25, 2026 18:16 View session

Copilot AI linked an issue May 25, 2026 that may be closed by this pull request

fix: add keytext size limit to guard against oversized upload DoS #135

Closed

fix: enforce configurable keytext size limit for /pks/add

e97ac47

Agent-Logs-Url: https://github.com/bmarwell/java-keyserver/sessions/5c450da0-f6c9-49c8-839d-d5c15d84ca1b Co-authored-by: bmarwell <1413391+bmarwell@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix keytext size limit to guard against oversized upload DoS~~ Add configurable keytext byte-limit guard for /pks/add and document proxy limits May 25, 2026

Copilot finished work on behalf of bmarwell May 25, 2026 18:21

Copilot AI requested a review from bmarwell May 25, 2026 18:21

fix: satisfy spotless import order for key size limit

74c1aff

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

bmarwell requested a review from Copilot May 25, 2026 19:58

Copilot started reviewing on behalf of bmarwell May 25, 2026 19:58 View session

Copilot AI reviewed May 25, 2026

View reviewed changes

fix: address key size guard review comments

f941b79

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

bmarwell requested a review from Copilot May 25, 2026 20:20

Copilot started reviewing on behalf of bmarwell May 25, 2026 20:20 View session

test: simplify key size limit coverage

c2d3de1

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot AI reviewed May 25, 2026

View reviewed changes

bmarwell and others added 2 commits May 25, 2026 22:26

fix: address latest key size review comments

02e9587

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

style: use this for instance field references

8382bb3

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

bmarwell marked this pull request as ready for review May 25, 2026 20:31

bmarwell merged commit db30827 into main May 25, 2026
5 of 6 checks passed

bmarwell deleted the copilot/fix-add-keytext-size-limit branch May 25, 2026 20:31

bmarwell mentioned this pull request May 25, 2026

Add subkey cap with template-method verification chain #147

Merged

Navigation Menu

Add configurable keytext byte-limit guard for `/pks/add` and document proxy limits - #143

Add configurable keytext byte-limit guard for `/pks/add` and document proxy limits#143
bmarwell merged 7 commits into
mainfrom
copilot/fix-add-keytext-size-limit

Copilot AI commented May 25, 2026 •

edited

Loading

Uh oh!

codecov Bot commented May 25, 2026 •

edited

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

		@ConfigProperty(name = MAX_KEY_BYTES_CONFIG_KEY, defaultValue = "131072")
		int maxKeyBytes = DEFAULT_MAX_KEY_BYTES;

Conversation

Copilot AI commented May 25, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

codecov Bot commented May 25, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Copilot AI commented May 25, 2026 •

edited

Loading

codecov Bot commented May 25, 2026 •

edited

Loading