Orkuncakilkaya
9ae69e64b4
All checks were successful
docs / build-and-deploy (push) Successful in 3s
The security-sensitive counterpart to the fast, non-cryptographic Hash.* library: standard, test-vector-backed hashing for signed saves and message integrity, kept in its own namespace so nobody reaches for the wrong tool. Crypto.sha256(s) SHA-256 -> 64-char lowercase hex Crypto.hmac_sha256(key, msg) HMAC-SHA256 -> 64-char hex Crypto.verify_hmac(key, msg, mac) recompute + constant-time compare -> bool Crypto.hex(s) lowercase hex of a string's bytes Crypto.ct_equal(a, b) constant-time string equality The primitives are implemented from scratch in plain integer LLVM IR (FIPS 180-4 / RFC 2104): no libc crypto, no data-dependent branches in the compression rounds, so a given input hashes to the same 32 bytes on every platform and run. Digests are returned as hex strings, not raw bytes, because a `str` is null-terminated and a raw digest can contain a NUL. MAC checks use a non-short-circuiting compare so timing does not leak how much of a forged tag was correct. Emitted on demand via g_uses_cryptort, mirroring the emit_hash prelude gate. Scoped to the deterministic, known-answer-testable core; OS-backed random_bytes (the one piece that can't be validated by test vectors) is left for a follow-up. Tested against published SHA-256 vectors (empty/"abc"/fox + 55/56/64-byte multi-block padding) and HMAC-SHA256 vectors; wired into the self-host suite as `crypto`. Docs: a new Crypto section with honest "what this protects / does not" guidance, one page per method, all fences checked and in the inventory. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
1.2 KiB
1.2 KiB
| id | name | category | kind | tokens | sig | tip | order | ns | member |
|---|---|---|---|---|---|---|---|---|---|
| crypto-ct_equal | Crypto.ct_equal | crypto | namespace-method | Crypto.ct_equal | Crypto.ct_equal(a, b) -> bool | Constant-time string equality for secrets. | 5 | Crypto | ct_equal |
Compares two strings for equality without short-circuiting: every character is examined even once a difference is found, so the time taken does not reveal where — or whether — the strings first diverged. Reach for it whenever you compare a secret, token, or MAC that an attacker might be probing. For the common case of checking a message tag, Crypto.verify_hmac already does this for you; use ct_equal directly when you hold both values yourself. Strings of different length return false at once (length is not secret). For ordinary, non-secret text just use == — the constant-time guarantee is not free.
Parameters:
a— one stringb— the other string
program CompareToken {
entry {
if Crypto.ct_equal("abc", "abc") { print(1) } else { print(0) } # 1
if Crypto.ct_equal("abc", "abd") { print(1) } else { print(0) } # 0
}
}