Crypto Tools

Inspect keys, certificates and signatures locally in the browser.

Crypto Tools is a standalone local-first application in the add·ideas Toolbox. Inputs are processed in the browser and are not uploaded.

Current scope

• Bounded PEM and DER inspection for X.509 certificates, CSRs and CRLs
• PBES2/PBKDF2 encrypted PKCS #8 parameter inspection and password-gated in-memory decryption for WebCrypto-supported AES-CBC/AES-GCM profiles
• Bounded PKCS #12/PFX AuthenticatedSafe, SafeContents and nested bag inventory, including friendly names, local key IDs, X.509 certificates and private-key container metadata
• Password-gated PKCS #12 MacData verification for SHA-1/SHA-2 plus modern PBES2/PBKDF2 AES-CBC/AES-GCM decryption for encrypted SafeContents and shrouded PKCS #8 keys
• Identification and fingerprinting of public/private PEM key material
• JWK/JWKS inspection, private-member warnings and RFC 7638 SHA-256 thumbprints
• Explicit certificate-path analysis across supplied certificates: issuer DN, AKI/SKI, signature, CA/keyCertSign, path-length and time checks, without claiming trust
• DNS SAN hostname checks
• Concrete, fixed-profile WebCrypto sign/verify operations (RSA-PSS, RSASSA-PKCS1-v1_5, ECDSA P-256 and browser-supported Ed25519)
• Concrete RSA-OAEP SHA-256 and AES-256-GCM text encryption/decryption, with authenticated AES envelopes and explicit size/encoding limits
• A local JSON inspection report with an explicit non-trust model

This is not complete RFC 5280 validation, certificate trust, revocation checking, issuance, CMS/JWS tooling, legacy PKCS #1/SEC1 conversion or general-purpose file cryptography. PKCS #12 support intentionally rejects legacy PKCS #12 PBE/RC2/3DES, unknown CMS content, unsupported certificate types and excessive/malformed nesting; it does not implicitly export bag values. Inputs are bounded to 8 MiB and 256 PEM blocks, and password-gated inspection has a shared PBKDF2 work budget. See docs/ARCHITECTURE.md and docs/PRIVACY-SECURITY.md.

Development

Requires Node.js 22 and npm 11.

npm ci
npm run check
npm run test:browser

Release

npm run release:artifact creates a deterministic release/crypto-tools-0.2.0.zip and checksum sidecar.

Licence

GPL-3.0-or-later. Runtime dependencies retain their own licences; see THIRD_PARTY_NOTICES.md.