If you discover a security vulnerability in ypcli, please report it responsibly. Do not open a public GitHub issue for security vulnerabilities.

Use GitHub Security Advisories to report the vulnerability privately. Include:

• Description of the vulnerability
• Steps to reproduce (if applicable)
• Affected versions
• Potential impact

ypcli performs client-side end-to-end encryption; the server never sees plaintext or the decryption key.

• Encryption (internal/crypto): OpenPGP symmetric encryption via github.com/ProtonMail/go-crypto — AES-256, SHA-256, AEAD GCM, with optional memory-hard Argon2id S2K when the server advertises it. The configuration is byte-for-byte identical to the yopass server and the openpgp.js frontend.
• Keys (internal/crypto): generated with crypto/rand. The random key lives only in the URL fragment (#/…), which browsers never transmit to the server. Manual keys are omitted from the URL entirely.
• Authentication (internal/api, internal/config): bearer tokens are read from --token, YPCLI_TOKEN, or a per-profile token_command, and are never persisted to the config file. The config file is written mode 0600.
• Transport (internal/api): all requests are context-bounded with a timeout; TLS verification uses the Go standard library defaults.

• The unsafe package is never used.
• Only crypto/rand is used for key and identifier generation.
• gosec runs in CI; govulncheck runs on every push and pull request.
• The shipped binary excludes the upstream jhaals/yopass module (test-only dependency), keeping the release supply chain to ProtonMail/go-crypto and the CLI framework.

The latest published release is supported. Pre-1.0 releases may include breaking changes per Semantic Versioning rule 4.