module Noble::Ed25519

Extended Modules

• Noble::Ed25519

Defined in:

noble-ed25519.cr

Constant Summary

BigInt256 = BigInt.new(255)

CURVE_ORDER = (Two ** (BigInt.new(252))) + (BigInt.new("27742317777372353535851937790883648493"))

D_MINUS_ONE_SQ = BigInt.new("40440834346308536858101042469323190826248399146238708352240133220865137265952")

(d-1)²

Hexes = (0..255).each.with_index.map do |v, i| (i.to_s(16)).rjust(2, '0') end.to_a

Convert between types

INVSQRT_A_MINUS_D = BigInt.new("54469307008909316920995813868745141605393597292927456921205312896311721017578")

1 / √(a-d)

MAX_256B = Noble::Ed25519::Two ** (BigInt.new(256))

One = BigInt.new(1)

ONE_MINUS_D_SQ = BigInt.new("1159843021668779879193775521855586647937357759715417654439879720876111806838")

1-d²

PointPrecomputes = Hash(Point, Array(ExtendedPoint)).new()

Stores precomputed values for points.

SQRT_AD_MINUS_ONE = BigInt.new("25063068953384623474111414158702152701244531502492656460079210482610430750235")

√(ad - 1)

SQRT_D = BigInt.new("6853475219497561581579357271197624642482790079785650197046958215289687604742")

√d aka sqrt(-486664)

SQRT_M1 = BigInt.new("19681161376707505956807079304988542015446066515923890162744021073123829784752")

√(-1) aka √(a) aka 2^((p-1)/4)

Two = BigInt.new(2)

Zero = BigInt.new(0)

Class Method Summary

• .normalizeScalar(num : Int, max : BigInt, strict = true) : BigInt

  ** Checks for num to be in range: For strict == true: 0 < num < max.

Instance Method Summary

• #adjustBytes25519(bytes : Bytes) : Bytes
• #bytes255ToNumberLE(bytes : Bytes) : BigInt
• #bytesToHex(uint8a : Bytes) : String
• #bytesToNumberLE(uint8a : Bytes) : BigInt

  Little Endian

• #concatBytes(*arrays) : Bytes
• #cswap(swap : BigInt, x_2 : BigInt, x_3 : BigInt) : Tuple(BigInt, BigInt)

  cswap from RFC7748

• #decodeScalar25519(n : Hex) : BigInt
• #decodeUCoordinate(uEnc : Hex) : BigInt
• #edIsNegative(num : BigInt)

  Little-endian check for first LE bit (last BE bit)

• #encodeUCoordinate(u : BigInt) : Bytes
• #ensureBytes(hex : Hex, expectedLength : Int32 | Nil = nil) : Bytes
• #equalBytes(b1 : Bytes, b2 : Bytes)
• #getExtendedPublicKey(key : PrivKey)

  Private convenience method RFC8032 5.1.5

• #getPublicKey(privateKey : PrivKey) : Bytes

  ** Calculates ed25519 public key.

• #getSharedSecret(privateKey : PrivKey, publicKey : Hex) : Bytes

  ** Calculates X25519 DH shared secret from ed25519 private & public keys.

• #hexToBytes(hex : String) : Bytes

  Caching slows it down 2-3x

• #invert(number : BigInt, modulo : BigInt = Curve::P) : BigInt

  Note: this egcd-based invert is 50% faster than powMod-based one.

• #invertBatch(nums : Array(BigInt), p : BigInt = Curve::P) : Array(BigInt)

  ** Takes a list of numbers, efficiently inverts all of them.

• #invertSqrt(number : BigInt)

  Calculates 1/√(number)

• #mod(a : BigInt, b : BigInt = Curve::P) : BigInt
• #montgomeryLadder(pointU : BigInt, scalar : BigInt) : BigInt

  x25519 from 4 **

• #numberTo32BytesBE(num : BigInt) : Bytes
• #numberTo32BytesLE(num : BigInt) : Bytes
• #pow2(x : BigInt, power : BigInt) : BigInt

  Does x ^ (2 ^ power) mod p.

• #pow_2_252_3(x : BigInt)

  Power to (p-5)/8 aka x^(2^252-3) Used to calculate y - the square root of y².

• #sha512ModqLE(*args) : BigInt

  Little-endian SHA512 with modulo n

• #sign(message : Hex, privateKey : Hex) : Bytes

  ** Signs message with privateKey.

• #uvRatio(u : BigInt, v : BigInt) : NamedTuple(isValid: Bool, value: BigInt)

  Ratio of u to v.

• #verify(sig : SigType, message : Hex, publicKey : PubKey) : Bool

  ** Verifies ed25519 signature against message and public key.

Class Method Detail

Instance Method Detail