macula_crypto_nif (macula v13.4.0)
View SourceCryptographic operations for Macula mesh.
This module provides ML-DSA signatures, BLAKE3 and SHA-256 hashing, base64 encoding and constant-time comparison, in a Rust NIF.
NIF vs Erlang
Hashing, encoding and comparison fall back to pure Erlang when the NIF cannot be loaded; the Rust NIF is faster (BLAKE3 about 20x, SHA-256 about 3x). ML-DSA has no fallback, below.
ML-DSA
ML-DSA (FIPS 204) signatures are made and checked by macula-mldsa (D7), and have no Erlang fallback: without the NIF they raise. Sets take OTP's names (mldsa44, mldsa65, mldsa87). A private key is {seed, Seed}, the 32-byte seed new keys are stored as (D6), or {expanded, Key}, the form OTP generates. Signing is hedged, with randomness from the OS, and takes a FIPS 204 context string of at most 255 bytes.
Summary
Functions
Decode URL-safe base64 data. Returns {ok, Data} or {error, invalid_base64}.
Encode data as URL-safe base64 (no padding).
Compute BLAKE3 hash. Returns 32-byte hash binary.
Compute BLAKE3 hash and return as hex string. Returns 64-character hex string.
Check if the NIF is loaded.
A new ML-DSA key, kept as its 32-byte seed.
The public key of an ML-DSA private key in either form. An expanded key whose parts disagree is inconsistent_private_key.
A hedged ML-DSA signature over Message under the context string Context.
Whether Signature is a valid ML-DSA signature over Message under Context. False for anything FIPS 204 rejects, a context over 255 bytes included.
Constant-time comparison of two binaries. Important for security - prevents timing attacks.
Compute SHA-256 hash. Returns 32-byte hash binary.
Compute SHA-256 hash and encode as URL-safe base64. Returns base64-encoded string (no padding).
Types
-type mldsa_private_key() :: {seed, <<_:256>>} | {expanded, binary()}.
-type mldsa_set() :: mldsa44 | mldsa65 | mldsa87.
Functions
Decode URL-safe base64 data. Returns {ok, Data} or {error, invalid_base64}.
Encode data as URL-safe base64 (no padding).
Compute BLAKE3 hash. Returns 32-byte hash binary.
Compute BLAKE3 hash and return as hex string. Returns 64-character hex string.
-spec is_nif_loaded() -> boolean().
Check if the NIF is loaded.
-spec mldsa_generate(mldsa_set()) -> {ok, {PublicKey :: binary(), Seed :: <<_:256>>}} | {error, randomness_unavailable}.
A new ML-DSA key, kept as its 32-byte seed.
-spec mldsa_public_key(mldsa_set(), mldsa_private_key()) -> {ok, PublicKey :: binary()} | {error, wrong_length | inconsistent_private_key}.
The public key of an ML-DSA private key in either form. An expanded key whose parts disagree is inconsistent_private_key.
-spec mldsa_sign(mldsa_set(), mldsa_private_key(), Message :: binary(), Context :: binary()) -> {ok, Signature :: binary()} | {error, wrong_length | context_too_long | randomness_unavailable}.
A hedged ML-DSA signature over Message under the context string Context.
-spec mldsa_verify(mldsa_set(), PublicKey :: binary(), Message :: binary(), Signature :: binary(), Context :: binary()) -> boolean().
Whether Signature is a valid ML-DSA signature over Message under Context. False for anything FIPS 204 rejects, a context over 255 bytes included.
-spec nif_effective_uid() -> non_neg_integer() | none.
Constant-time comparison of two binaries. Important for security - prevents timing attacks.
Compute SHA-256 hash. Returns 32-byte hash binary.
Compute SHA-256 hash and encode as URL-safe base64. Returns base64-encoded string (no padding).