sodium.cr/THREAD_SAFETY.md

Tested and provably thread safe.

• Sodium::CryptoBox::*
• Sodium::Cipher::Aead::XChaCha20Poly1305Ietf
• Sodium::SecretBox
• Sodium::Sign::*

Notes:

• Only uses stack allocation. Keys are stored in readonly memory.

Thread safe when hashing, deriving or creating keys after setting parameters.

• Sodium::Password::Hash
• Sodium::Password::Key
• Sodium::Password::Key::Create

Notes:

• Don't change parameters between threads without a Mutex.

Keeps state.

• Sodium::Cipher::Chalsa subclasses.
• Sodium::Cipher::SecretStream
• Sodium::Digest::Blake2b
• Sodium::Kdf

Notes:

• Use one instance per thread or wrap in a Mutex.

Not thread safe.

• Sodium::Nonce

Notes:

• Use Nonce.random with multiple threads or let the API provide the nonce's for you.
• #increment isn't safe, not even when wrapped in a mutex unless you also wrap #encrypt/#decrypt within the same #synchronize call.