#mooncry

#Highlights

• Correct — every algorithm is checked against FIPS / NIST / RFC test vectors (plus Python references for BLAKE2b/BLAKE3/Poly1305/CMAC/SipHash/scrypt). 311 tests, run with moon test --deny-warn.
• Broad — MD5, SHA-1, the SHA-2 and SHA-3 families, SHAKE XOFs, BLAKE2b, BLAKE3, HMAC (incl. HMAC-SHA3), Poly1305, CMAC-AES, AES-CBC/GCM/CTR/KW/SIV, ChaCha20, Salsa20, ChaCha20-Poly1305 AEAD, HKDF, PBKDF2, scrypt, Argon2, RSA (PKCS1-v1.5/OAEP/PSS), ECDSA P-256, Ed25519, X25519, HOTP/TOTP, SipHash-2-4, CRC32/CRC32C, a sealed-box AEAD envelope, Base64, Hex.
• Fast where it matters — hex / Base64 encoding are O(n); AES MixColumns uses precomputed GF(2^8) tables (~5x over bit-sliced math); throughput is measured by moon bench.
• Fail-fast input validation — AES / ChaCha20 / SHAKE / hex functions abort with a clear message on wrong key / IV / nonce / tag lengths instead of producing garbage. Graceful Result-returning variants (hex_to_bytes_or, base64_decode_or) are provided for callers that prefer to branch on error.
• Single source of truth — one-shot hash entry points delegate to the streaming hashers, so the incremental and one-shot paths share one implementation.

The implementations are correct and tested but have not been formally audited. See Security & performance boundaries.

#Repositories

• GitHub (canonical): https://github.com/cc06b/mooncry
• Gitlink (mirror): https://www.gitlink.org.cn/CC01/mooncry_mirror

git remote add gitlink https://www.gitlink.org.cn/CC01/mooncry_mirror.git
git push gitlink master

#Algorithms

#Hash functions

• MD5 (RFC 1321) — 128-bit digest
• SHA-224 / SHA-256 (FIPS 180-4) — 224 / 256-bit digest
• SHA-384 / SHA-512 (FIPS 180-4) — 384 / 512-bit digest
• SHA-3 (FIPS 202) — SHA3-224 / 256 / 384 / 512 (Keccak-f[1600] sponge)
• BLAKE2b (RFC 7693) — 1..64-byte digest
• BLAKE3 (BLAKE3 spec) — 32-byte default digest, XOF (arbitrary-length via tree-Merkle)

#Extendable-output functions (XOF)

• SHAKE128 / SHAKE256 (FIPS 202) — variable-length output

#Message authentication

• HMAC-SHA256 / HMAC-SHA512 (RFC 2104)
• HMAC-SHA3-256 / HMAC-SHA3-512 (RFC 2104 over FIPS 202)
• Poly1305 (RFC 8439) — one-time MAC
• AES-CMAC (NIST SP 800-38B) — 128-bit tag, 128/192/256-bit keys

#Symmetric ciphers / AEAD

• AES-CBC (NIST SP 800-38A) — PKCS#7 padding, 128/192/256-bit keys, IV prepended
• AES-GCM (NIST SP 800-38D) — authenticated encryption with AAD, 96-bit nonce
• AES-CTR (NIST SP 800-38A) — 128-bit big-endian counter, stream cipher
• ChaCha20 (RFC 8439) — 256-bit key, 96-bit nonce, stream cipher
• Salsa20 (eSTREAM, 20-round) — 16/32-byte key, 8-byte nonce, stream cipher
• ChaCha20-Poly1305 (RFC 8439) — AEAD (ciphertext || 16-byte tag)

#Key derivation

• HKDF-SHA256 (RFC 5869) — extract + expand
• HKDF-SHA3-256 (RFC 5869 over FIPS 202)
• PBKDF2-HMAC-SHA256 (RFC 8018) — password-based key derivation
• PBKDF2-HMAC-SHA3-256 (RFC 8018 over FIPS 202)
• scrypt (RFC 7914) — memory-hard password-based KDF (Salsa20/8 + BlockMix + ROMix)

#Checksums / PRFs

• CRC32 (IEEE 802.3, poly 0xEDB88320 reflected)
• CRC32C (Castagnoli, poly 0x82F63B78 reflected) — iSCSI / ext4
• SipHash-2-4 (Aumasson & Bernstein 2012) — 64-bit short-input PRF

#Composite envelope

• Sealed box — versioned AEAD envelope: HKDF-SHA256 (key derivation) + AES-256-GCM (AEAD). Wire format: version(1) ‖ nonce(12) ‖ ciphertext ‖ tag(16).

#Asymmetric (RSA)

• RSAES-PKCS1-v1.5 (RFC 8017 §7.2) — public-key encryption (decrypt is deterministic; encrypt takes caller-supplied padding randomness — no RNG)
• RSAES-OAEP (RFC 8017 §7.1) — SHA-256 + MGF1-SHA256 (decrypt deterministic; encrypt takes a caller-supplied 32-byte seed)
• RSASSA-PKCS1-v1.5 (RFC 8017 §8.2) — sign/verify over SHA-256 (deterministic)
• RSASSA-PSS (RFC 8017 §8.1) — SHA-256 + MGF1-SHA256, caller-supplied salt

#Asymmetric signatures (Ed25519)

• Ed25519 (RFC 8032, ed25519-sha-512) — deterministic sign/verify. Field arithmetic over GF(2^255-19) uses @bigint; the twisted-Edwards base point is recovered from y = 4/5. Signing is deterministic (no RNG).

#Key agreement (X25519)

• X25519 (RFC 7748) — Diffie-Hellman over Curve25519 via the x-coordinate-only Montgomery ladder. Reuses the GF(2^255-19) field ops.

#Encoding

• Base64 (RFC 4648) — standard alphabet with padding
• Hex — bytes ↔ lowercase hex

#Streaming API

#Installation

moon add cc06b/mooncry

#Quick start

moon new myapp
cd myapp
moon add cc06b/mooncry

import {
  "cc06b/mooncry/lib",
}

pkgtype(kind: "executable")

fn main {
  // SHA-256 one-shot
  let digest = @lib.sha256(b"Hello, world!")
  println("SHA-256: " + @lib.bytes_to_hex(digest))

  // AES-GCM round-trip (256-bit key, 96-bit nonce, with AAD)
  let key = Bytes::make(32, b'\x00')
  let iv = Bytes::make(12, b'\x00')
  let (ciphertext, tag) = @lib.aes_gcm_encrypt(b"secret data", key, iv, b"aad")
  let (plaintext, ok) = @lib.aes_gcm_decrypt(ciphertext, key, iv, b"aad", tag)
  let status = if ok { "OK" } else { "FAIL" }
  println("AES-GCM round-trip: " + status)
  println("Recovered: " + @lib.bytes_to_hex(plaintext))

  // Sealed-box envelope: HKDF-SHA256 derives the AES-256-GCM key from a
  // master key + context, then encrypts into a versioned envelope.
  let master = Bytes::make(32, b'\x07')
  let nonce = Bytes::make(12, b'\x01')
  let envelope = @lib.sealed_box_seal(master, nonce, b"plaintext", b"aad", b"tenant-1")
  match @lib.sealed_box_open(master, envelope, b"aad", b"tenant-1") {
    Ok(pt) => println("Sealed box: " + @lib.bytes_to_hex(pt))
    Err(msg) => println("Sealed box failed: " + msg)
  }
}

moon run cmd/main

SHA-256: 315f5bdb76d078c43b8ac0064e4a0164612b1fce77c869345bfc94c75894edd3
AES-GCM round-trip: OK
Recovered: 7365637265742064617461

#Public API

#Security & performance boundaries

• Not audited. The code is correct against known vectors but has had no formal security review. Do not use it to protect high-value assets without an independent audit.
• AES is not constant-time. MixColumns uses precomputed GF(2^8) lookup tables (mul2/3/9/11/13/14) for ~5x throughput. This leaks key-dependent table indices through the CPU cache — acceptable for many use cases but not side-channel-safe against a local attacker. (GHASH and the GCM tag / CBC PKCS#7 verification are still bit-sliced and constant-time.)
• Nonce reuse is catastrophic for AES-GCM and ChaCha20(-Poly1305). Never reuse a (key, nonce) pair. The library does not track nonces — generate a fresh one per message (e.g. a counter or CSPRNG).
• PBKDF2 is a KDF, not a password hasher. For interactive password storage prefer Argon2 / bcrypt / scrypt elsewhere; PBKDF2 is included for compatibility with existing protocols.
• MD5 is collision-broken. It is included for legacy compatibility only — do not sign or authenticate with it.
• BLAKE3 supports arbitrary-length input via the tree-Merkle mode (verified vs the reference blake3 Python package up to 5000 bytes).
• Inputs are validated, not silently padded. Wrong key / IV / nonce / tag lengths abort immediately rather than producing wrong output.
• No RNG. The library provides deterministic primitives; obtain keys, IVs, and nonces from a secure source.

#Performance

moon bench

#Testing

moon test

#Development

moon check --deny-warn
moon fmt --check
moon info
moon test --deny-warn
moon bench          # run the benchmark suite

#Publishing (maintainers)

moon login            # one time, with the account that owns cc06b
moon publish          # publishes the current version

#License