zig/lib/std/crypto.zig
Frank Denis 27610b0a0f
std/crypto: add support for ECDSA signatures (#11855)
ECDSA is the most commonly used signature scheme today, mainly for
historical and conformance reasons. It is a necessary evil for
many standard protocols such as TLS and JWT.

It is tricky to implement securely and has been the root cause of
multiple security disasters, from the Playstation 3 hack to multiple
critical issues in OpenSSL and Java.

This implementation combines lessons learned from the past with
recent recommendations.

In Zig, the NIST curves that ECDSA is almost always instantied with
use formally verified field arithmetic, giving us peace of mind
even on edge cases. And the API rejects neutral elements where it
matters, and unconditionally checks for non-canonical encoding for
scalars and group elements. This automatically eliminates common
vulnerabilities such as https://sk.tl/2LpS695v .

ECDSA's security heavily relies on the security of the random number
generator, which is a concern in some environments.

This implementation mitigates this by computing deterministic
nonces using the conservative scheme from Pornin et al. with the
optional addition of randomness as proposed in Ericsson's
"Deterministic ECDSA and EdDSA Signatures with Additional Randomness"
document. This approach mitigates both the implications of a weak RNG
and the practical implications of fault attacks.

Project Wycheproof is a Google project to test crypto libraries against
known attacks by triggering edge cases. It discovered vulnerabilities
in virtually all major ECDSA implementations.

The entire set of ECDSA-P256-SHA256 test vectors from Project Wycheproof
is included here. Zero defects were found in this implementation.

The public API differs from the Ed25519 one. Instead of raw byte strings
for keys and signatures, we introduce Signature, PublicKey and SecretKey
structures.

The reason is that a raw byte representation would not be optimal.
There are multiple standard representations for keys and signatures,
and decoding/encoding them may not be cheap (field elements have to be
converted from/to the montgomery domain).

So, the intent is to eventually move ed25519 to the same API, which
is not going to introduce any performance regression, but will bring
us a consistent API, that we can also reuse for RSA.
2022-06-15 08:55:39 +02:00

304 lines
9.9 KiB
Zig

/// Authenticated Encryption with Associated Data
pub const aead = struct {
pub const aegis = struct {
pub const Aegis128L = @import("crypto/aegis.zig").Aegis128L;
pub const Aegis256 = @import("crypto/aegis.zig").Aegis256;
};
pub const aes_gcm = struct {
pub const Aes128Gcm = @import("crypto/aes_gcm.zig").Aes128Gcm;
pub const Aes256Gcm = @import("crypto/aes_gcm.zig").Aes256Gcm;
};
pub const aes_ocb = struct {
pub const Aes128Ocb = @import("crypto/aes_ocb.zig").Aes128Ocb;
pub const Aes256Ocb = @import("crypto/aes_ocb.zig").Aes256Ocb;
};
pub const Gimli = @import("crypto/gimli.zig").Aead;
pub const chacha_poly = struct {
pub const ChaCha20Poly1305 = @import("crypto/chacha20.zig").ChaCha20Poly1305;
pub const ChaCha12Poly1305 = @import("crypto/chacha20.zig").ChaCha12Poly1305;
pub const ChaCha8Poly1305 = @import("crypto/chacha20.zig").ChaCha8Poly1305;
pub const XChaCha20Poly1305 = @import("crypto/chacha20.zig").XChaCha20Poly1305;
pub const XChaCha12Poly1305 = @import("crypto/chacha20.zig").XChaCha12Poly1305;
pub const XChaCha8Poly1305 = @import("crypto/chacha20.zig").XChaCha8Poly1305;
};
pub const isap = @import("crypto/isap.zig");
pub const salsa_poly = struct {
pub const XSalsa20Poly1305 = @import("crypto/salsa20.zig").XSalsa20Poly1305;
};
};
/// Authentication (MAC) functions.
pub const auth = struct {
pub const hmac = @import("crypto/hmac.zig");
pub const siphash = @import("crypto/siphash.zig");
};
/// Core functions, that should rarely be used directly by applications.
pub const core = struct {
pub const aes = @import("crypto/aes.zig");
pub const Gimli = @import("crypto/gimli.zig").State;
/// Modes are generic compositions to construct encryption/decryption functions from block ciphers and permutations.
///
/// These modes are designed to be building blocks for higher-level constructions, and should generally not be used directly by applications, as they may not provide the expected properties and security guarantees.
///
/// Most applications may want to use AEADs instead.
pub const modes = @import("crypto/modes.zig");
};
/// Diffie-Hellman key exchange functions.
pub const dh = struct {
pub const X25519 = @import("crypto/25519/x25519.zig").X25519;
};
/// Elliptic-curve arithmetic.
pub const ecc = struct {
pub const Curve25519 = @import("crypto/25519/curve25519.zig").Curve25519;
pub const Edwards25519 = @import("crypto/25519/edwards25519.zig").Edwards25519;
pub const P256 = @import("crypto/pcurves/p256.zig").P256;
pub const P384 = @import("crypto/pcurves/p384.zig").P384;
pub const Ristretto255 = @import("crypto/25519/ristretto255.zig").Ristretto255;
};
/// Hash functions.
pub const hash = struct {
pub const blake2 = @import("crypto/blake2.zig");
pub const Blake3 = @import("crypto/blake3.zig").Blake3;
pub const Gimli = @import("crypto/gimli.zig").Hash;
pub const Md5 = @import("crypto/md5.zig").Md5;
pub const Sha1 = @import("crypto/sha1.zig").Sha1;
pub const sha2 = @import("crypto/sha2.zig");
pub const sha3 = @import("crypto/sha3.zig");
};
/// Key derivation functions.
pub const kdf = struct {
pub const hkdf = @import("crypto/hkdf.zig");
};
/// MAC functions requiring single-use secret keys.
pub const onetimeauth = struct {
pub const Ghash = @import("crypto/ghash.zig").Ghash;
pub const Poly1305 = @import("crypto/poly1305.zig").Poly1305;
};
/// A password hashing function derives a uniform key from low-entropy input material such as passwords.
/// It is intentionally slow or expensive.
///
/// With the standard definition of a key derivation function, if a key space is small, an exhaustive search may be practical.
/// Password hashing functions make exhaustive searches way slower or way more expensive, even when implemented on GPUs and ASICs, by using different, optionally combined strategies:
///
/// - Requiring a lot of computation cycles to complete
/// - Requiring a lot of memory to complete
/// - Requiring multiple CPU cores to complete
/// - Requiring cache-local data to complete in reasonable time
/// - Requiring large static tables
/// - Avoiding precomputations and time/memory tradeoffs
/// - Requiring multi-party computations
/// - Combining the input material with random per-entry data (salts), application-specific contexts and keys
///
/// Password hashing functions must be used whenever sensitive data has to be directly derived from a password.
pub const pwhash = struct {
pub const Encoding = enum {
phc,
crypt,
};
pub const Error = HasherError || error{AllocatorRequired};
pub const HasherError = KdfError || phc_format.Error;
pub const KdfError = errors.Error || std.mem.Allocator.Error || std.Thread.SpawnError;
pub const argon2 = @import("crypto/argon2.zig");
pub const bcrypt = @import("crypto/bcrypt.zig");
pub const scrypt = @import("crypto/scrypt.zig");
pub const pbkdf2 = @import("crypto/pbkdf2.zig").pbkdf2;
pub const phc_format = @import("crypto/phc_encoding.zig");
};
/// Digital signature functions.
pub const sign = struct {
pub const Ed25519 = @import("crypto/25519/ed25519.zig").Ed25519;
pub const ecdsa = @import("crypto/ecdsa.zig");
};
/// Stream ciphers. These do not provide any kind of authentication.
/// Most applications should be using AEAD constructions instead of stream ciphers directly.
pub const stream = struct {
pub const chacha = struct {
pub const ChaCha20IETF = @import("crypto/chacha20.zig").ChaCha20IETF;
pub const ChaCha12IETF = @import("crypto/chacha20.zig").ChaCha12IETF;
pub const ChaCha8IETF = @import("crypto/chacha20.zig").ChaCha8IETF;
pub const ChaCha20With64BitNonce = @import("crypto/chacha20.zig").ChaCha20With64BitNonce;
pub const ChaCha12With64BitNonce = @import("crypto/chacha20.zig").ChaCha12With64BitNonce;
pub const ChaCha8With64BitNonce = @import("crypto/chacha20.zig").ChaCha8With64BitNonce;
pub const XChaCha20IETF = @import("crypto/chacha20.zig").XChaCha20IETF;
pub const XChaCha12IETF = @import("crypto/chacha20.zig").XChaCha12IETF;
pub const XChaCha8IETF = @import("crypto/chacha20.zig").XChaCha8IETF;
};
pub const salsa = struct {
pub const Salsa20 = @import("crypto/salsa20.zig").Salsa20;
pub const XSalsa20 = @import("crypto/salsa20.zig").XSalsa20;
};
};
pub const nacl = struct {
const salsa20 = @import("crypto/salsa20.zig");
pub const Box = salsa20.Box;
pub const SecretBox = salsa20.SecretBox;
pub const SealedBox = salsa20.SealedBox;
};
pub const utils = @import("crypto/utils.zig");
/// This is a thread-local, cryptographically secure pseudo random number generator.
pub const random = @import("crypto/tlcsprng.zig").interface;
const std = @import("std.zig");
pub const errors = @import("crypto/errors.zig");
test {
const please_windows_dont_oom = @import("builtin").os.tag == .windows;
if (please_windows_dont_oom) return error.SkipZigTest;
_ = aead.aegis.Aegis128L;
_ = aead.aegis.Aegis256;
_ = aead.aes_gcm.Aes128Gcm;
_ = aead.aes_gcm.Aes256Gcm;
_ = aead.aes_ocb.Aes128Ocb;
_ = aead.aes_ocb.Aes256Ocb;
_ = aead.Gimli;
_ = aead.chacha_poly.ChaCha20Poly1305;
_ = aead.chacha_poly.ChaCha12Poly1305;
_ = aead.chacha_poly.ChaCha8Poly1305;
_ = aead.chacha_poly.XChaCha20Poly1305;
_ = aead.chacha_poly.XChaCha12Poly1305;
_ = aead.chacha_poly.XChaCha8Poly1305;
_ = aead.isap;
_ = aead.salsa_poly.XSalsa20Poly1305;
_ = auth.hmac;
_ = auth.siphash;
_ = core.aes;
_ = core.Gimli;
_ = core.modes;
_ = dh.X25519;
_ = ecc.Curve25519;
_ = ecc.Edwards25519;
_ = ecc.P256;
_ = ecc.P384;
_ = ecc.Ristretto255;
_ = hash.blake2;
_ = hash.Blake3;
_ = hash.Gimli;
_ = hash.Md5;
_ = hash.Sha1;
_ = hash.sha2;
_ = hash.sha3;
_ = kdf.hkdf;
_ = onetimeauth.Ghash;
_ = onetimeauth.Poly1305;
_ = pwhash.Encoding;
_ = pwhash.Error;
_ = pwhash.HasherError;
_ = pwhash.KdfError;
_ = pwhash.argon2;
_ = pwhash.bcrypt;
_ = pwhash.scrypt;
_ = pwhash.pbkdf2;
_ = pwhash.phc_format;
_ = sign.Ed25519;
_ = sign.ecdsa;
_ = stream.chacha.ChaCha20IETF;
_ = stream.chacha.ChaCha12IETF;
_ = stream.chacha.ChaCha8IETF;
_ = stream.chacha.ChaCha20With64BitNonce;
_ = stream.chacha.ChaCha12With64BitNonce;
_ = stream.chacha.ChaCha8With64BitNonce;
_ = stream.chacha.XChaCha20IETF;
_ = stream.chacha.XChaCha12IETF;
_ = stream.chacha.XChaCha8IETF;
_ = stream.salsa.Salsa20;
_ = stream.salsa.XSalsa20;
_ = nacl.Box;
_ = nacl.SecretBox;
_ = nacl.SealedBox;
_ = utils;
_ = random;
_ = errors;
}
test "CSPRNG" {
const a = random.int(u64);
const b = random.int(u64);
const c = random.int(u64);
try std.testing.expect(a ^ b ^ c != 0);
}
test "issue #4532: no index out of bounds" {
const types = [_]type{
hash.Md5,
hash.Sha1,
hash.sha2.Sha224,
hash.sha2.Sha256,
hash.sha2.Sha384,
hash.sha2.Sha512,
hash.sha3.Sha3_224,
hash.sha3.Sha3_256,
hash.sha3.Sha3_384,
hash.sha3.Sha3_512,
hash.blake2.Blake2s128,
hash.blake2.Blake2s224,
hash.blake2.Blake2s256,
hash.blake2.Blake2b128,
hash.blake2.Blake2b256,
hash.blake2.Blake2b384,
hash.blake2.Blake2b512,
hash.Gimli,
};
inline for (types) |Hasher| {
var block = [_]u8{'#'} ** Hasher.block_length;
var out1: [Hasher.digest_length]u8 = undefined;
var out2: [Hasher.digest_length]u8 = undefined;
const h0 = Hasher.init(.{});
var h = h0;
h.update(block[0..]);
h.final(&out1);
h = h0;
h.update(block[0..1]);
h.update(block[1..]);
h.final(&out2);
try std.testing.expectEqual(out1, out2);
}
}