Added AffinePoint[G1,G2] initalization procedures.

Added more tests from Paritytech fork.
Removed Coeff[T] type.

bncurve/arith.nim

@@ -8,9 +8,10 @@
 # those terms.
 import options, endians
 import nimcrypto/[utils, sysrand]
-
 export options
 
+{.deadCodeElim: on.}
+
 type
   BNU256* = array[4, uint64]
   BNU512* = array[8, uint64]

bncurve/fp.nim

@@ -8,6 +8,8 @@
 # those terms.
 import arith, options
 
+{.deadCodeElim: on.}
+
 template fieldImplementation(finame, fimodulus, firsquared, fircubed,
                              fionep, fiinv: untyped): untyped {.dirty.} =
   type finame* = distinct BNU256

bncurve/fq12.nim

@@ -9,6 +9,8 @@
 import options
 import fq6, fq2, fp, arith
 
+{.deadCodeElim: on.}
+
 const frobeniusCoeffsC1: array[4, FQ2] = [
   FQ2.one(),
   FQ2(

bncurve/fq2.nim

@@ -9,6 +9,8 @@
 import options
 import fp, arith
 
+{.deadCodeElim: on.}
+
 type
   FQ2* = object
     c0*: FQ

bncurve/fq6.nim

@@ -9,6 +9,8 @@
 import options
 import fq2, fp, arith
 
+{.deadCodeElim: on.}
+
 const frobeniusCoeffsC1: array[4, FQ2] = [
   FQ2.one(),
   FQ2(

bncurve/groups.nim

@@ -10,6 +10,8 @@ import fields, arith, options
 export fields, arith, options
 import nimcrypto/utils
 
+{.deadCodeElim: on.}
+
 type
   G1* = object
   G2* = object
@@ -26,12 +28,6 @@ type
     else:
       x*, y*: FQ2
 
-  Coeff*[T: G1|G2] = object
-    when T is G1:
-      b*: FQ
-    else:
-      b*: FQ2
-
   EllCoeffs* = object
     ell_0*: FQ2
     ell_vw*: FQ2
@@ -124,11 +120,11 @@ proc name*[T: G1|G2](t: typedesc[T]): string {.inline, noinit.} =
   else:
     result = "G2"
 
-proc coeff*[T: G1|G2](t: typedesc[T]): Coeff[T] {.inline, noinit.} =
-  when T is G1:
-    result = G1B
-  else:
-    result = G2B
+proc coeff*(t: typedesc[G1]): FQ {.inline, noinit.} =
+  result = G1B
+
+proc coeff*(t: typedesc[G2]): FQ2 {.inline, noinit.} =
+  result = G2B
 
 proc zero*[T: G1|G2](t: typedesc[T]): Point[T] {.inline, noinit.} =
   when T is G1:
@@ -377,6 +373,26 @@ proc pairing*(p: Point[G1], q: Point[G2]): FQ12 {.noinit, inline.} =
     if ores.isSome():
       result = ores.get()
 
+proc init*(p: var AffinePoint[G1], x: FQ, y: FQ): bool {.inline.} =
+  ## Initializes AffinePoint[G1] with coordinates ``x`` and ``y``.
+  ## Returns ``true`` if (x, y) is on curve and in the subgroup.
+  if y.squared() == (x.squared() * x) + G1B:
+    var point = Point[G1](x: x, y: y, z: FQ.one())
+    if (point * (-FR.one())) + point == G1.zero():
+      p.x = x
+      p.y = y
+      result = true
+
+proc init*(p: var AffinePoint[G2], x: FQ2, y: FQ2): bool {.inline.} =
+  ## Initializes AffinePoint[G2] with coordinates ``x`` and ``y``.
+  ## Returns ``true`` if (x, y) is on curve and in the subgroup.
+  if y.squared() == (x.squared() * x) + G2B:
+    var point = Point[G2](x: x, y: y, z: FQ2.one())
+    if (point * (-FR.one())) + point == G2.zero():
+      p.x = x
+      p.y = y
+      result = true
+
 proc toBytes*[T: G1|G2](p: AffinePoint[T], dst: var openarray[byte]): bool =
   ## Encode affine point coordinates (x, y) to big-endian bytes representation
   ## ``dst``.

tests/tpairing.nim

@@ -224,6 +224,44 @@ proc testJoux(): bool =
 
   result = (alice_ss == bob_ss and bob_ss == carol_ss)
 
+proc testPredefinedPair(): bool =
+  let fq2x = FQ2(
+    c0: FQ.fromString("10857046999023057135944570762232829481370756359578518086990519993285655852781"),
+    c1: FQ.fromString("11559732032986387107991004021392285783925812861821192530917403151452391805634")
+  )
+  let fq2y = FQ2(
+    c0: FQ.fromString("8495653923123431417604973247489272438418190587263600148770280649306958101930"),
+    c1: FQ.fromString("4082367875863433681332203403145435568316851327593401208105741076214120093531")
+  )
+  var g1a: AffinePoint[G1]
+  var g2a: AffinePoint[G2]
+  if g1a.init(FQ.fromString("1"), FQ.fromString("2")):
+    var g1 = g1a.toJacobian()
+    if g2a.init(fq2x, fq2y):
+      var g2 = g2a.toJacobian()
+      let p = pairing(g1, g2)
+      if not p.isZero():
+        result = true
+
+proc testInternals(): bool =
+  let p = G1.one()
+  let val = p
+  let affineOpt = val.toAffine()
+  if isSome(affineOpt):
+    let affine = affineOpt.get()
+    if affine.x == FQ.one():
+      result = true
+
+proc testAffineFail1(): bool =
+  var ap: AffinePoint[G1]
+  if not ap.init(FQ.one(), FQ.one()):
+    result = true
+
+proc testAffineFail2(): bool =
+  var ap: AffinePoint[G1]
+  if not ap.init(FQ.one(), G1.coeff()):
+    result = true
+
 when isMainModule:
   suite "Pairing test suite":
     test "Prepared G2 test":
@@ -238,3 +276,11 @@ when isMainModule:
       check testDH() == true
     test "Joux test":
       check testJoux() == true
+    test "[Paritytech] Predefined pair test":
+      check testPredefinedPair() == true
+    test "[Paritytech] Internals test":
+      check testInternals() == true
+    test "[Paritytech] Affine FAIL#1 test":
+      check testAffineFail1() == true
+    test "[Paritytech] Affine FAIL#2 test":
+      check testAffineFail2() == true