# aws/s2n-tls — health index 88/100 (Excellent)

> Inspection of the public repository aws/s2n-tls by inspect.software. It holds a health index of 88 out of 100, placing it in the Excellent band. The index is a signal derived from publicly visible practice, not a warranty, a security audit, or an endorsement, and it is independent of payment.

- Repository: https://github.com/aws/s2n-tls
- Report page: https://inspect.software/software/aws/s2n-tls
- Full JSON report: https://inspect.software/api/repositories/aws/s2n-tls/report
- Badge: https://raw.githubusercontent.com/inspect-software/badges/main/v1/a/aws/s2n-tls.svg
- Inspected: 2026-07-14
- Methodology: metrics 1.13.0, report schema 0.9.0 (https://inspect.software/methodology.md)

## Category summary

| Category | Weight | Index | Band |
|---|---|---|---|
| Vitality | 22% | 99/100 | Excellent |
| Community & Adoption | 18% | 94/100 | Excellent |
| Sustainability & Governance | 24% | 88/100 | Excellent |
| Engineering Quality | 20% | 86/100 | Excellent |
| Security | 16% | 70/100 | Good |
| AI Readiness | not counted | 56/100 | Moderate |

## Repository facts

| Field | Value |
|---|---|
| Description | An implementation of the TLS/SSL protocols |
| Homepage | https://aws.github.io/s2n-tls/usage-guide/ |
| Primary language | C |
| License | Apache-2.0 |
| Stars | 4,740 |
| Forks | 789 |
| Created | 2014-06-27 |
| Last push | 2026-07-14 |
| Latest release | v1.7.5 |
| Commits (last year) | 363 |
| Bus factor | 8 |
| Topics | c, c99, crypto, cryptography, encryption, s2n, ssl, tls |

## Vitality — 99/100 (Excellent)

Is the project alive — is code being written and are releases shipping? Weight: 22% of the overall index.

### Development activity — 99/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Push recency | met | 36 / 36 | last push 0 days ago |
| Commit cadence | partial | 35.3 / 36 | 51/52 weeks with commits |
| Commit volume | met | 18 / 18 | 363 commits in the last year |
| OpenSSF Scorecard: Maintained | met | 10 / 10 | 30 commit(s) and 0 issue activity found in the last 90 days -- score normalized to 10 |

### Release discipline — 100/100 (Excellent)

Excluded from scoring (no data or not applicable): OpenSSF Scorecard: Signed-Releases. Remaining weights renormalized.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Ships releases | met | 27 / 27 | 100 releases published |
| Release recency | met | 36 / 36 | latest release 18 days ago |
| Release cadence | met | 27 / 27 | a release every ~24.1 days |
| OpenSSF Scorecard: Signed-Releases | excluded | 0 / 10 | no releases found |

### Abandonment — 100/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Project is still maintained | met | 100 / 100 | maintenance record not established from the collected data |

## Community & Adoption — 94/100 (Excellent)

Does the project have users, downloads, attention, and a welcoming setup for contributors? Weight: 18% of the overall index.

### Popularity & adoption — 96/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Stars | partial | 59.6 / 60 | 4,740 stars |
| Forks | partial | 24.1 / 25 | 789 forks |
| Watchers | partial | 12.2 / 15 | 158 watchers |

### Community health — 92/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| README | met | 22.5 / 22.5 | — |
| License | met | 22.5 / 22.5 | recognized license (Apache-2.0) |
| CONTRIBUTING guide | met | 18 / 18 | — |
| Code of conduct | met | 13.5 / 13.5 | — |
| Issue template | not met | 0 / 7.2 | — |
| PR template | met | 6.3 / 6.3 | — |

## Sustainability & Governance — 88/100 (Excellent)

Will the project survive its people — bus factor, responsiveness, who backs it, and package upkeep? Weight: 24% of the overall index.

### Maintainer resilience (bus factor) — 98/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Bus factor | met | 54 / 54 | 8 contributor(s) cover half of all commits |
| Commit distribution | partial | 20 / 22.5 | top contributor authored 11% of commits |
| Contributor breadth | met | 13.5 / 13.5 | 100 contributors |
| OpenSSF Scorecard: Contributors | met | 10 / 10 | project has 27 contributing companies or organizations |

### Issue & PR responsiveness — 85/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Issue resolution | partial | 38.7 / 46.8 | 83% of issues closed |
| PR acceptance | partial | 31.1 / 38.2 | 3497/4297 decided PRs merged |
| OpenSSF Scorecard: Code-Review | met | 15 / 15 | all changesets reviewed |

### Ownership & stewardship — 80/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Ownership backing | met | 30 / 30 | organization-owned |
| Verified domain | not met | 0 / 20 | — |
| Owner reach | met | 25 / 25 | 16,054 followers of aws |
| Track record | met | 25 / 25 | 551 public repos, account ~13 yr old |

## Engineering Quality — 86/100 (Excellent)

Are baseline engineering and documentation practices in place? Weight: 20% of the overall index.

### Engineering practices — 84/100 (Good)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| CI workflows | met | 24 / 24 | 23 workflow(s) |
| Tests present | met | 24 / 24 | — |
| Linter config | met | 16 / 16 | tox.ini |
| Pre-commit hooks | not met | 0 / 9.6 | — |
| .editorconfig | not met | 0 / 6.4 | — |
| OpenSSF Scorecard: CI-Tests | met | 20 / 20 | 30 out of 30 merged PRs checked by a CI test -- score normalized to 10 |

### Documentation — 90/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| README | met | 30 / 30 | — |
| Documentation directory | met | 25 / 25 | — |
| Documentation / homepage site | met | 15 / 15 | https://aws.github.io/s2n-tls/usage-guide/ |
| Repository description | met | 10 / 10 | — |
| Topics | met | 10 / 10 | 8 topics |
| Wiki | not met | 0 / 10 | — |

## Security — 70/100 (Good)

Are visible security and supply-chain practices strong, with no malicious dependency and no unresolved high-risk jurisdiction exposure? Weight: 16% of the overall index.

### Security posture — 70/100 (Good)

Excluded from scoring (no data or not applicable): Packaging, Signed-Releases. Remaining weights renormalized.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Binary-Artifacts | met | 7.5 / 7.5 | no binaries found in the repo |
| Branch-Protection | partial | 6 / 7.5 | branch protection is not maximal on development and all release branches |
| CI-Tests | met | 2.5 / 2.5 | 30 out of 30 merged PRs checked by a CI test -- score normalized to 10 |
| CII-Best-Practices | not met | 0 / 2.5 | no effort to earn an OpenSSF best practices badge detected |
| Code-Review | met | 7.5 / 7.5 | all changesets reviewed |
| Contributors | met | 2.5 / 2.5 | project has 27 contributing companies or organizations |
| Dangerous-Workflow | met | 10 / 10 | no dangerous workflow patterns detected |
| Dependency-Update-Tool | met | 7.5 / 7.5 | update tool detected |
| Fuzzing | met | 5 / 5 | project is fuzzed |
| License | met | 2.5 / 2.5 | license file detected |
| Maintained | met | 7.5 / 7.5 | 30 commit(s) and 0 issue activity found in the last 90 days -- score normalized to 10 |
| Packaging | excluded | 0 / 5 | packaging workflow not detected |
| Pinned-Dependencies | not met | 0 / 5 | dependency not pinned by hash detected -- score normalized to 0 |
| SAST | partial | 0.5 / 5 | SAST tool is not run on all commits -- score normalized to 1 |
| Security-Policy | met | 5 / 5 | security policy file detected |
| Signed-Releases | excluded | 0 / 7.5 | no releases found |
| Token-Permissions | not met | 0 / 7.5 | detected GitHub workflow tokens with excessive permissions |
| Vulnerabilities | partial | 0.8 / 7.5 | 9 existing vulnerabilities detected |

### High-Risk Jurisdiction Exposure — 100/100 (Excellent)

Only high-confidence self-published location evidence affects this multiplier. Ambiguous matches are review-only; country evidence is not proof of nationality, citizenship, legal registration, malicious intent, or sanctions status.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Policy exposure multiplier | met | 100 / 100 | no confirmed policy-scope location match |

## AI Readiness — 56/100 (Moderate)

How well is the repo equipped to be developed and maintained with AI coding agents? An independent, experimental badge — weight 0.0, so it is surfaced on its own and does not affect the overall health score.

### Agent context & guidance — 1/100 (Critical)

Excluded from scoring (no data or not applicable): Legible commit history. Remaining weights renormalized.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Agent instructions | not met | 0 / 45 | no CLAUDE.md / AGENTS.md / editor rules |
| Machine-readable docs (llms.txt) | not met | 0 / 15 | — |
| Legible commit history | excluded | 0 / 40 | no data |

### Verify loop (build / test / typecheck) — 86/100 (Excellent)

Excluded from scoring (no data or not applicable): Demonstrated agent practice. Remaining weights renormalized.

| Criterion | Status | Points | Detail |
|---|---|---|---|
| One-command bootstrap | met | 18 / 18 | Makefile, bin/Makefile, bindings/rust/extended/Makefile, coverage/Makefile, crypto/Makefile, error/Makefile, lib/Makefile, stuffer/Makefile, tests/LD_PRELOAD/Makefile, tests/Makefile, tests/cbmc/proofs/s2n_add_overflow/Makefile, tests/cbmc/proofs/s2n_align_to/Makefile, tests/cbmc/proofs/s2n_alloc/Makefile, tests/cbmc/proofs/s2n_array_capacity/Makefile, tests/cbmc/proofs/s2n_array_free/Makefile, tests/cbmc/proofs/s2n_array_free_p/Makefile, tests/cbmc/proofs/s2n_array_get/Makefile, tests/cbmc/proofs/s2n_array_init/Makefile, tests/cbmc/proofs/s2n_array_insert/Makefile, tests/cbmc/proofs/s2n_array_insert_and_copy/Makefile, tests/cbmc/proofs/s2n_array_new/Makefile, tests/cbmc/proofs/s2n_array_num_elements/Makefile, tests/cbmc/proofs/s2n_array_pushback/Makefile, tests/cbmc/proofs/s2n_array_remove/Makefile, tests/cbmc/proofs/s2n_blob_char_to_lower/Makefile, tests/cbmc/proofs/s2n_blob_init/Makefile, tests/cbmc/proofs/s2n_blob_is_growable/Makefile, tests/cbmc/proofs/s2n_blob_slice/Makefile, tests/cbmc/proofs/s2n_blob_zero/Makefile, tests/cbmc/proofs/s2n_connection_get_last_message_name/Makefile, tests/cbmc/proofs/s2n_constant_time_copy_or_dont/Makefile, tests/cbmc/proofs/s2n_constant_time_equals/Makefile, tests/cbmc/proofs/s2n_constant_time_pkcs1_unpad_or_dont/Makefile, tests/cbmc/proofs/s2n_dh_compute_shared_secret_as_client/Makefile, tests/cbmc/proofs/s2n_dh_compute_shared_secret_as_server/Makefile, tests/cbmc/proofs/s2n_dh_generate_ephemeral_key/Makefile, tests/cbmc/proofs/s2n_dh_p_g_Ys_to_dh_params/Makefile, tests/cbmc/proofs/s2n_dh_params_check/Makefile, tests/cbmc/proofs/s2n_dh_params_copy/Makefile, tests/cbmc/proofs/s2n_dh_params_free/Makefile, tests/cbmc/proofs/s2n_dh_params_to_p_g_Ys/Makefile, tests/cbmc/proofs/s2n_dup/Makefile, tests/cbmc/proofs/s2n_free/Makefile, tests/cbmc/proofs/s2n_free_object/Makefile, tests/cbmc/proofs/s2n_free_or_wipe/Makefile, tests/cbmc/proofs/s2n_hash_copy/Makefile, tests/cbmc/proofs/s2n_hash_digest/Makefile, tests/cbmc/proofs/s2n_hash_digest_size/Makefile, tests/cbmc/proofs/s2n_hash_free/Makefile, tests/cbmc/proofs/s2n_hash_get_currently_in_hash_total/Makefile, tests/cbmc/proofs/s2n_hash_hmac_alg/Makefile, tests/cbmc/proofs/s2n_hash_init/Makefile, tests/cbmc/proofs/s2n_hash_is_available/Makefile, tests/cbmc/proofs/s2n_hash_is_ready_for_input/Makefile, tests/cbmc/proofs/s2n_hash_new/Makefile, tests/cbmc/proofs/s2n_hash_reset/Makefile, tests/cbmc/proofs/s2n_hash_update/Makefile, tests/cbmc/proofs/s2n_hmac_copy/Makefile, tests/cbmc/proofs/s2n_hmac_digest/Makefile, tests/cbmc/proofs/s2n_hmac_digest_size/Makefile, tests/cbmc/proofs/s2n_hmac_digest_two_compression_rounds/Makefile, tests/cbmc/proofs/s2n_hmac_digest_verify/Makefile, tests/cbmc/proofs/s2n_hmac_free/Makefile, tests/cbmc/proofs/s2n_hmac_hash_alg/Makefile, tests/cbmc/proofs/s2n_hmac_hash_block_size/Makefile, tests/cbmc/proofs/s2n_hmac_init/Makefile, tests/cbmc/proofs/s2n_hmac_new/Makefile, tests/cbmc/proofs/s2n_hmac_reset/Makefile, tests/cbmc/proofs/s2n_hmac_restore_evp_hash_state/Makefile, tests/cbmc/proofs/s2n_hmac_save_evp_hash_state/Makefile, tests/cbmc/proofs/s2n_hmac_update/Makefile, tests/cbmc/proofs/s2n_hmac_xor_pad_size/Makefile, tests/cbmc/proofs/s2n_is_base64_char/Makefile, tests/cbmc/proofs/s2n_is_hello_retry_handshake/Makefile, tests/cbmc/proofs/s2n_is_hello_retry_message/Makefile, tests/cbmc/proofs/s2n_mem_cleanup/Makefile, tests/cbmc/proofs/s2n_mem_init/Makefile, tests/cbmc/proofs/s2n_mul_overflow_harness/Makefile, tests/cbmc/proofs/s2n_pkcs3_to_dh_params/Makefile, tests/cbmc/proofs/s2n_pkcs3_to_dh_params_openssl_1_1_0/Makefile, tests/cbmc/proofs/s2n_realloc/Makefile, tests/cbmc/proofs/s2n_socket_quickack/Makefile, tests/cbmc/proofs/s2n_socket_read/Makefile, tests/cbmc/proofs/s2n_socket_read_restore/Makefile, tests/cbmc/proofs/s2n_socket_read_snapshot/Makefile, tests/cbmc/proofs/s2n_socket_was_corked/Makefile, tests/cbmc/proofs/s2n_socket_write/Makefile, tests/cbmc/proofs/s2n_socket_write_cork/Makefile, tests/cbmc/proofs/s2n_socket_write_restore/Makefile, tests/cbmc/proofs/s2n_socket_write_snapshot/Makefile, tests/cbmc/proofs/s2n_socket_write_uncork/Makefile, tests/cbmc/proofs/s2n_stuffer_alloc/Makefile, tests/cbmc/proofs/s2n_stuffer_alloc_ro_from_string/Makefile, tests/cbmc/proofs/s2n_stuffer_certificate_from_pem/Makefile, tests/cbmc/proofs/s2n_stuffer_copy/Makefile, tests/cbmc/proofs/s2n_stuffer_dhparams_from_pem/Makefile, tests/cbmc/proofs/s2n_stuffer_erase_and_read/Makefile, tests/cbmc/proofs/s2n_stuffer_erase_and_read_bytes/Makefile, tests/cbmc/proofs/s2n_stuffer_extract_blob/Makefile, tests/cbmc/proofs/s2n_stuffer_free/Makefile, tests/cbmc/proofs/s2n_stuffer_get_vector_size/Makefile, tests/cbmc/proofs/s2n_stuffer_growable_alloc/Makefile, tests/cbmc/proofs/s2n_stuffer_init/Makefile, tests/cbmc/proofs/s2n_stuffer_is_consumed/Makefile, tests/cbmc/proofs/s2n_stuffer_peek_char/Makefile, tests/cbmc/proofs/s2n_stuffer_peek_check_for_str/Makefile, tests/cbmc/proofs/s2n_stuffer_printf/Makefile, tests/cbmc/proofs/s2n_stuffer_private_key_from_pem/Makefile, tests/cbmc/proofs/s2n_stuffer_raw_read/Makefile, tests/cbmc/proofs/s2n_stuffer_raw_write/Makefile, tests/cbmc/proofs/s2n_stuffer_read/Makefile, tests/cbmc/proofs/s2n_stuffer_read_base64/Makefile, tests/cbmc/proofs/s2n_stuffer_read_bytes/Makefile, tests/cbmc/proofs/s2n_stuffer_read_expected_str/Makefile, tests/cbmc/proofs/s2n_stuffer_read_hex/Makefile, tests/cbmc/proofs/s2n_stuffer_read_line/Makefile, tests/cbmc/proofs/s2n_stuffer_read_token/Makefile, tests/cbmc/proofs/s2n_stuffer_read_uint16/Makefile, tests/cbmc/proofs/s2n_stuffer_read_uint16_hex/Makefile, tests/cbmc/proofs/s2n_stuffer_read_uint24/Makefile, tests/cbmc/proofs/s2n_stuffer_read_uint32/Makefile, tests/cbmc/proofs/s2n_stuffer_read_uint64/Makefile, tests/cbmc/proofs/s2n_stuffer_read_uint8/Makefile, tests/cbmc/proofs/s2n_stuffer_read_uint8_hex/Makefile, tests/cbmc/proofs/s2n_stuffer_reread/Makefile, tests/cbmc/proofs/s2n_stuffer_reserve/Makefile, tests/cbmc/proofs/s2n_stuffer_reserve_space/Makefile, tests/cbmc/proofs/s2n_stuffer_reserve_uint16/Makefile, tests/cbmc/proofs/s2n_stuffer_reserve_uint24/Makefile, tests/cbmc/proofs/s2n_stuffer_resize/Makefile, tests/cbmc/proofs/s2n_stuffer_resize_if_empty/Makefile, tests/cbmc/proofs/s2n_stuffer_rewind_read/Makefile, tests/cbmc/proofs/s2n_stuffer_rewrite/Makefile, tests/cbmc/proofs/s2n_stuffer_shift/Makefile, tests/cbmc/proofs/s2n_stuffer_skip_expected_char/Makefile, tests/cbmc/proofs/s2n_stuffer_skip_read/Makefile, tests/cbmc/proofs/s2n_stuffer_skip_read_until/Makefile, tests/cbmc/proofs/s2n_stuffer_skip_to_char/Makefile, tests/cbmc/proofs/s2n_stuffer_skip_whitespace/Makefile, tests/cbmc/proofs/s2n_stuffer_skip_write/Makefile, tests/cbmc/proofs/s2n_stuffer_wipe/Makefile, tests/cbmc/proofs/s2n_stuffer_wipe_n/Makefile, tests/cbmc/proofs/s2n_stuffer_write/Makefile, tests/cbmc/proofs/s2n_stuffer_write_base64/Makefile, tests/cbmc/proofs/s2n_stuffer_write_bytes/Makefile, tests/cbmc/proofs/s2n_stuffer_write_hex/Makefile, tests/cbmc/proofs/s2n_stuffer_write_network_order/Makefile, tests/cbmc/proofs/s2n_stuffer_write_reservation/Makefile, tests/cbmc/proofs/s2n_stuffer_write_uint16/Makefile, tests/cbmc/proofs/s2n_stuffer_write_uint16_hex/Makefile, tests/cbmc/proofs/s2n_stuffer_write_uint24/Makefile, tests/cbmc/proofs/s2n_stuffer_write_uint32/Makefile, tests/cbmc/proofs/s2n_stuffer_write_uint64/Makefile, tests/cbmc/proofs/s2n_stuffer_write_uint8/Makefile, tests/cbmc/proofs/s2n_stuffer_write_uint8_hex/Makefile, tests/cbmc/proofs/s2n_stuffer_write_vector_size/Makefile, tests/cbmc/proofs/s2n_stuffer_writev_bytes/Makefile, tests/cbmc/proofs/s2n_sub_overflow/Makefile, tests/ctverif/Makefile, tests/integrationv2/Makefile, tests/saw/Makefile, tests/saw/bitcode/Makefile, tests/saw/spec/extras/HMAC/Makefile, tests/sidetrail/Makefile, tests/sidetrail/working/s2n-cbc/Makefile, tests/sidetrail/working/s2n-record-read-aead/Makefile, tests/sidetrail/working/s2n-record-read-cbc-negative-test/Makefile, tests/sidetrail/working/s2n-record-read-cbc/Makefile, tests/sidetrail/working/s2n-record-read-composite/Makefile, tests/sidetrail/working/s2n-record-read-stream/Makefile, tests/testlib/Makefile, tests/unit/Makefile, tests/viz/Makefile, tls/Makefile, tls/extensions/Makefile, tls/policy/Makefile, utils/Makefile |
| Automated tests | met | 22 / 22 | — |
| Lint / format config | met | 11 / 11 | tox.ini |
| Static type checking | met | 11 / 11 | C (statically typed) |
| Reproducible environment | met | 10 / 10 | Nix |
| Demonstrated agent practice | excluded | 0 / 10 | no data |
| Automated maintenance | partial | 5 / 8 | dependency automation configured, none observed in the sampled commits |
| OpenSSF Scorecard: Pinned-Dependencies | not met | 0 / 10 | dependency not pinned by hash detected -- score normalized to 0 |

### Code legibility for models — 99/100 (Excellent)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| Type-checkable code | met | 45 / 45 | C (statically typed) |
| Manageable file sizes | partial | 53.8 / 55 | 24/1137 source files over 60KB |

### Machine-readable interfaces — 40/100 (At risk)

| Criterion | Status | Points | Detail |
|---|---|---|---|
| API schema (OpenAPI/GraphQL/proto) | not met | 0 / 40 | — |
| MCP server | not met | 0 / 20 | — |
| Runnable examples | met | 40 / 40 | examples |

## What this report is

inspect.software measures public repositories against a single published, versioned methodology and reports the result as a 1–100 health index. Findings are signals derived from what is visible in public repository data — they are not a security audit, a warranty, or an endorsement, and no result depends on payment.

- Methodology, formulas and weights: https://inspect.software/methodology.md
- What a result does and does not claim: https://inspect.software/wiki/signals-not-warranties.md
- Rating bands: https://inspect.software/wiki/scoring-bands.md
- Corrections: https://inspect.software/contact.md
- Index of all documents: https://inspect.software/llms.txt