aws/s2n-tls

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An implementation of the TLS/SSL protocols

Stars: 4.8k
Forks: 802
Open beginner issues: 0
Indexed issues: 270
Avg merge: 5d 22h
Merged PRs (30d): 33

Dominant language: C
License: Apache-2.0
Last GitHub push: Sep 11, 2026
Latest indexed: Sep 14, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: good first issue

Open All

267 open issues indexed

SSLv3 s2n_hmac_test uses keys of the wrong lengths Open

priority/medium size/xsmall type/cleanup

aws/s2n-tls#644 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Reduce timing leakage from hash_digest_two_compression_rounds Open

priority/medium size/medium type/formal_verification type/investigation type/side_channel

aws/s2n-tls#685 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Make Public/Private Key Sanity Checking Optional Open

priority/medium s2n-core size/medium type/breaking_change type/performance

aws/s2n-tls#752 · 0 comments · 2 reactions · 0 assignees · Indexed Sep 14, 2026
Add a way to get specific s2n errors Open

priority/low size/medium type/debug type/usability

aws/s2n-tls#882 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Observability for TLS session resumption Open

priority/medium size/medium type/api

aws/s2n-tls#1002 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Audit and move s2n errors to a proper types Open

priority/medium size/large

aws/s2n-tls#1277 · 1 comment · 1 reaction · 0 assignees · Indexed Sep 14, 2026
Optimize usage of evp_pkey params for higher performance Open

priority/low s2n-core size/medium type/performance

aws/s2n-tls#1410 · 0 comments · 0 reactions · 1 assignee · Indexed Sep 14, 2026
Reduce code duplication in SSLv2 handshake handling Open

priority/low size/large

aws/s2n-tls#1601 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Test for a Client That Exceeds the Maximum Fragment Length Open

priority/medium size/small type/regression_test

aws/s2n-tls#1633 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
">= S2N_TLSX" vs "== S2N_TLSX" Open

priority/low s2n-core status/needs_team_discussion

aws/s2n-tls#1681 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Use non-zero to represent CLIENT_HELLO in state machine Open

priority/low size/medium type/refactor

aws/s2n-tls#1707 · 0 comments · 6 reactions · 0 assignees · Indexed Sep 14, 2026
LLVMFuzzerInitialize doesn't not error on Non Zero Open

ops-backlog priority/low size/small

aws/s2n-tls#1772 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Allow s2n_stuffer_raw_write() to be guarded Open

priority/low size/medium

aws/s2n-tls#1777 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Standardize how we exit tests Open

good first issue ops-backlog priority/low s2n-core size/small

aws/s2n-tls#1893 · 1 comment · 0 reactions · 1 assignee · Indexed Sep 14, 2026
Change return 0, 1 to return S2N_SUCCESS, S2N_FAILURE Open

ops-backlog priority/low s2n-core size/medium

aws/s2n-tls#1897 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
dev: Add CBMC support to nix devShell Open

ops-backlog priority/medium s2n-core size/small

aws/s2n-tls#1910 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Automatically convert safety check errors into another error type Open

priority/low s2n-core

aws/s2n-tls#1941 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
s2n_stuffer_wipe_n should wipe down from the `high_water_mark` Open

good first issue priority/medium size/small

aws/s2n-tls#2090 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
s2n_realloc can leak memory Open

priority/low size/medium

aws/s2n-tls#2257 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Security Policy Builder Open

priority/high s2n-core size/large status/needs_team_discussion type/design type/refactor

aws/s2n-tls#2380 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Using s2n_stuffer_data_available without validating the stuffer Open

priority/low s2n-core size/medium

aws/s2n-tls#2420 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Migrate codebase to use S2N_RESULT by default Open

ops-backlog priority/low s2n-core size/large

aws/s2n-tls#2425 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
We should ensure that CI runs unit/integration tests on both debug and prod builds Open

priority/low size/medium

aws/s2n-tls#2463 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
[0RTT] QUIC support Open

priority/low s2n-core size/large

aws/s2n-tls#2577 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Write a key log integration test Open

priority/medium s2n-core size/medium

aws/s2n-tls#2587 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Define a S2N convention for function arguments Open

priority/medium s2n-core size/small

aws/s2n-tls#2614 · 1 comment · 1 reaction · 1 assignee · Indexed Sep 14, 2026
Remove S2N_ERROR_IF macro Open

priority/low s2n-core size/medium

aws/s2n-tls#2635 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Potential improvements for combining PQ TLS with TLS 1.3 EarlyData and HelloRetryRequests Open

priority/low s2n-core size/large type/post-quantum

aws/s2n-tls#2640 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Call s2n_tls13_handle_secrets from s2n_advance_message Open

priority/low s2n-core size/small

aws/s2n-tls#2724 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Handshake Traces for TLS1.3 are for Stateful Session Resumption Open

priority/tracking s2n-core size/small

aws/s2n-tls#2742 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Safely resize blobs Open

CBMC priority/low s2n-core

aws/s2n-tls#2786 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Optimize parsing public_key in s2n_async_pkey Open

priority/medium size/large

aws/s2n-tls#2831 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Retrieving server certificate during a session resumption handshake Open

priority/low s2n-core size/large

aws/s2n-tls#2836 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Integrate s2n_handle_retry_state into s2n_negotiate better Open

priority/low s2n-core size/medium

aws/s2n-tls#2850 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Apply error blinding more widely Open

priority/low s2n-core size/medium

aws/s2n-tls#2851 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
TLS-RFC compliance Open

priority/low size/large

aws/s2n-tls#2880 · 3 comments · 1 reaction · 0 assignees · Indexed Sep 14, 2026
Add a new "SECURITY_CONSIDERATION" document to help customers manage External PSKs Open

priority/low s2n-core size/medium type/docs type/tls_1.3

aws/s2n-tls#2887 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Inefficient tls record creation with repeated small writes Open

priority/medium size/medium

aws/s2n-tls#2911 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Encrypt/Decrypt alerts with correct key when using early data Open

priority/low s2n-core size/medium

aws/s2n-tls#2921 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Early data freshness checks Open

priority/low s2n-core size/medium

aws/s2n-tls#2923 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Upgrade SMACK for sidetrail Open

priority/medium s2n-core size/large type/side_channel

aws/s2n-tls#2962 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Detect missing vs zero-length extensions Open

priority/low s2n-core size/medium type/api type/tls_extension

aws/s2n-tls#3001 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Support assertions about what integration test cases run Open

priority/low s2n-core size/large

aws/s2n-tls#3020 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Combinatorial Test Framework of all supported TLS Features Open

priority/medium s2n-core size/large status/needs_test type/test

aws/s2n-tls#3032 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
[RFC6962] Support SignedCertificateTimestamp validation in S2N_CLIENT mode Open

priority/low size/large

aws/s2n-tls#3037 · 0 comments · 0 reactions · 1 assignee · Indexed Sep 14, 2026
Validate early TLS1.3 handshake types in s2n_conn_set_tls13_handshake_type Open

priority/low s2n-core size/small

aws/s2n-tls#3047 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
handshake_io_lowlevel.saw: Avoid the use of an explicit `chosen_psk_null` boolean argument Open

priority/low size/large

aws/s2n-tls#3052 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Remove hard-coded assumptions about `use_tickets` and `client_session_resumed` in SAW proofs Open

priority/low size/large

aws/s2n-tls#3080 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Reduce s2n-tls + AWS-LC memory usage Open

priority/low size/medium type/optimization

aws/s2n-tls#3114 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026
Reduce s2n-tls binary size Open

priority/low s2n-core size/large type/optimization type/platform_support

aws/s2n-tls#3115 · 5 comments · 0 reactions · 0 assignees · Indexed Sep 14, 2026

aws/s2n-tls

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