go/src/crypto/internal/edwards25519/scalar_fiat.go

type fiatScalarUint1 …

type fiatScalarInt1 …

type fiatScalarMontgomeryDomainFieldElement …

type fiatScalarNonMontgomeryDomainFieldElement …

// fiatScalarCmovznzU64 is a single-word conditional move.
//
// Postconditions:
//
//	out1 = (if arg1 = 0 then arg2 else arg3)
//
// Input Bounds:
//
//	arg1: [0x0 ~> 0x1]
//	arg2: [0x0 ~> 0xffffffffffffffff]
//	arg3: [0x0 ~> 0xffffffffffffffff]
//
// Output Bounds:
//
//	out1: [0x0 ~> 0xffffffffffffffff]
func fiatScalarCmovznzU64(out1 *uint64, arg1 fiatScalarUint1, arg2 uint64, arg3 uint64) { … }

// fiatScalarMul multiplies two field elements in the Montgomery domain.
//
// Preconditions:
//
//	0 ≤ eval arg1 < m
//	0 ≤ eval arg2 < m
//
// Postconditions:
//
//	eval (from_montgomery out1) mod m = (eval (from_montgomery arg1) * eval (from_montgomery arg2)) mod m
//	0 ≤ eval out1 < m
func fiatScalarMul(out1 *fiatScalarMontgomeryDomainFieldElement, arg1 *fiatScalarMontgomeryDomainFieldElement, arg2 *fiatScalarMontgomeryDomainFieldElement) { … }

// fiatScalarAdd adds two field elements in the Montgomery domain.
//
// Preconditions:
//
//	0 ≤ eval arg1 < m
//	0 ≤ eval arg2 < m
//
// Postconditions:
//
//	eval (from_montgomery out1) mod m = (eval (from_montgomery arg1) + eval (from_montgomery arg2)) mod m
//	0 ≤ eval out1 < m
func fiatScalarAdd(out1 *fiatScalarMontgomeryDomainFieldElement, arg1 *fiatScalarMontgomeryDomainFieldElement, arg2 *fiatScalarMontgomeryDomainFieldElement) { … }

// fiatScalarSub subtracts two field elements in the Montgomery domain.
//
// Preconditions:
//
//	0 ≤ eval arg1 < m
//	0 ≤ eval arg2 < m
//
// Postconditions:
//
//	eval (from_montgomery out1) mod m = (eval (from_montgomery arg1) - eval (from_montgomery arg2)) mod m
//	0 ≤ eval out1 < m
func fiatScalarSub(out1 *fiatScalarMontgomeryDomainFieldElement, arg1 *fiatScalarMontgomeryDomainFieldElement, arg2 *fiatScalarMontgomeryDomainFieldElement) { … }

// fiatScalarOpp negates a field element in the Montgomery domain.
//
// Preconditions:
//
//	0 ≤ eval arg1 < m
//
// Postconditions:
//
//	eval (from_montgomery out1) mod m = -eval (from_montgomery arg1) mod m
//	0 ≤ eval out1 < m
func fiatScalarOpp(out1 *fiatScalarMontgomeryDomainFieldElement, arg1 *fiatScalarMontgomeryDomainFieldElement) { … }

// fiatScalarNonzero outputs a single non-zero word if the input is non-zero and zero otherwise.
//
// Preconditions:
//
//	0 ≤ eval arg1 < m
//
// Postconditions:
//
//	out1 = 0 ↔ eval (from_montgomery arg1) mod m = 0
//
// Input Bounds:
//
//	arg1: [[0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff]]
//
// Output Bounds:
//
//	out1: [0x0 ~> 0xffffffffffffffff]
func fiatScalarNonzero(out1 *uint64, arg1 *[4]uint64) { … }

// fiatScalarFromMontgomery translates a field element out of the Montgomery domain.
//
// Preconditions:
//
//	0 ≤ eval arg1 < m
//
// Postconditions:
//
//	eval out1 mod m = (eval arg1 * ((2^64)⁻¹ mod m)^4) mod m
//	0 ≤ eval out1 < m
func fiatScalarFromMontgomery(out1 *fiatScalarNonMontgomeryDomainFieldElement, arg1 *fiatScalarMontgomeryDomainFieldElement) { … }

// fiatScalarToMontgomery translates a field element into the Montgomery domain.
//
// Preconditions:
//
//	0 ≤ eval arg1 < m
//
// Postconditions:
//
//	eval (from_montgomery out1) mod m = eval arg1 mod m
//	0 ≤ eval out1 < m
func fiatScalarToMontgomery(out1 *fiatScalarMontgomeryDomainFieldElement, arg1 *fiatScalarNonMontgomeryDomainFieldElement) { … }

// fiatScalarToBytes serializes a field element NOT in the Montgomery domain to bytes in little-endian order.
//
// Preconditions:
//
//	0 ≤ eval arg1 < m
//
// Postconditions:
//
//	out1 = map (λ x, ⌊((eval arg1 mod m) mod 2^(8 * (x + 1))) / 2^(8 * x)⌋) [0..31]
//
// Input Bounds:
//
//	arg1: [[0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0x1fffffffffffffff]]
//
// Output Bounds:
//
//	out1: [[0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0x1f]]
func fiatScalarToBytes(out1 *[32]uint8, arg1 *[4]uint64) { … }

// fiatScalarFromBytes deserializes a field element NOT in the Montgomery domain from bytes in little-endian order.
//
// Preconditions:
//
//	0 ≤ bytes_eval arg1 < m
//
// Postconditions:
//
//	eval out1 mod m = bytes_eval arg1 mod m
//	0 ≤ eval out1 < m
//
// Input Bounds:
//
//	arg1: [[0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0xff], [0x0 ~> 0x1f]]
//
// Output Bounds:
//
//	out1: [[0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0xffffffffffffffff], [0x0 ~> 0x1fffffffffffffff]]
func fiatScalarFromBytes(out1 *[4]uint64, arg1 *[32]uint8) { … }