cryptokitlisted

# CryptoKit Apple CryptoKit provides a Swift-native API for cryptographic operations: hashing, message authentication, symmetric encryption, public-key signing, key agreement, and Secure Enclave key storage. Available on iOS 13+. Prefer CryptoKit over CommonCrypto or raw Security framework APIs in all new code targeting Swift 6.3+. ## Contents - [Hashing](#hashing) - [HMAC](#hmac) - [Symmetric Encryption](#symmetric-encryption) - [Public-Key Signing](#public-key-signing) - [Key Agreement](#key-agreement) - [Secure Enclave](#secure-enclave) - [Common Mistakes](#common-mistakes) - [Review Checklist](#review-checklist) - [References](#references) ## Hashing CryptoKit provides SHA256, SHA384, and SHA512 hash functions. All conform to the `HashFunction` protocol. ### One-shot hashing ```swift import CryptoKit let data = Data("Hello, world!".utf8) let digest = SHA256.hash(data: data) let hex = digest.compactMap { String(format: "%02x", $0) }.joined() ``` SHA384 and SHA512 work identically -- substitute the type name. ### Incremental hashing For large data or streaming input, hash incrementally: ```swift var hasher = SHA256() hasher.update(data: chunk1) hasher.update(data: chunk2) let digest = hasher.finalize() ``` ### Digest comparison CryptoKit digests use constant-time comparison by default. Direct `==` checks between digests are safe against timing attacks. ```swift let expected = SHA256.hash(data: reference) let actual = SHA256.hash(data: received) if expected ==