additional api with global kzg settings

kzg4844.nim

@@ -8,8 +8,9 @@
 # those terms.
 
 import
-  kzg4844/kzg
+  kzg4844/kzg,
+  kzg4844/kzg_ex
 
 export
-  kzg
-
+  kzg,
+  kzg_ex

kzg4844/kzg_ex.nim

@@ -0,0 +1,101 @@
+# nim-kzg4844
+# Copyright (c) 2023 Status Research & Development GmbH
+# Licensed under either of
+#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
+#  * MIT license ([LICENSE-MIT](LICENSE-MIT))
+# at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+import
+  stew/results,
+  ./kzg
+
+export
+  results,
+  kzg
+
+type
+  Kzg* = object
+  Bytes32 = array[32, byte]
+
+when (NimMajor, NimMinor) < (1, 4):
+  {.push raises: [Defect].}
+else:
+  {.push raises: [].}
+
+##############################################################
+# Private helpers
+##############################################################
+
+var gCtx: KzgCtx
+
+const
+  GlobalCtxErr = "kzg global context not loaded"
+
+template setupCtx(body: untyped): untyped =
+  let res = body
+  if res.isErr:
+    return err(res.error)
+  gCtx = res.get
+  ok()
+
+template verifyCtx(body: untyped): untyped =
+  if gCtx.isNil:
+    return err(GlobalCtxErr)
+  body
+
+##############################################################
+# Public functions
+##############################################################
+
+proc loadTrustedSetup*(_: type Kzg,
+                       input: File): Result[void, string] =
+  setupCtx:
+    kzg.loadTrustedSetup(input)
+
+proc loadTrustedSetup*(_: type Kzg,
+                       fileName: string): Result[void, string] =
+  setupCtx:
+    kzg.loadTrustedSetup(fileName)
+
+proc loadTrustedSetup*(_: type Kzg, g1: openArray[G1Data],
+                       g2: openArray[G2Data]):
+                           Result[void, string] =
+  setupCtx:
+    kzg.loadTrustedSetup(g1, g2)
+
+proc loadTrustedSetupFromString*(_: type Kzg,
+                                 input: string): Result[void, string] =
+  setupCtx:
+    kzg.loadTrustedSetupFromString(input)
+
+proc toCommitment*(blob: KzgBlob):
+                    Result[KzgCommitment, string] =
+  verifyCtx:
+    gCtx.toCommitment(blob)
+
+proc computeProof*(blobs: openArray[KzgBlob]):
+                     Result[KzgProof, string] =
+  verifyCtx:
+    gCtx.computeProof(blobs)
+
+proc verifyProof*(blobs: openArray[KzgBlob],
+                  commitments: openArray[KzgCommitment],
+                  proof: KzgProof): Result[void, string] =
+  verifyCtx:
+    gCtx.verifyProof(blobs, commitments, proof)
+
+proc computeProof*(blob: KzgBlob,
+                   z: Bytes32): Result[KzgProof, string] =
+  verifyCtx:
+    gCtx.computeProof(blob, z)
+
+proc verifyProof*(commitment: KzgCommitment,
+                  z: Bytes32, # Input Point
+                  y: Bytes32, # Claimed Value
+                  proof: KzgProof): Result[void, string] =
+  verifyCtx:
+    gCtx.verifyProof(commitment, z, y, proof)
+
+{. pop .}

tests/test_all.nim

@@ -9,4 +9,5 @@
 
 import
   test_abi,
-  test_kzg
+  test_kzg,
+  test_kzg_ex

tests/test_kzg.nim

@@ -31,9 +31,6 @@ proc createKateBlobs(ctx: KzgCtx, n: int): KateBlobs =
     result.kates.add(res.get)
 
 suite "verify proof (high-level)":
-  const
-    trustedSetup = staticRead("../" & trustedSetupFile)
-
   var ctx: KzgCtx
 
   test "load trusted setup from string":

tests/test_kzg_ex.nim

@@ -0,0 +1,63 @@
+# nim-kzg4844
+# Copyright (c) 2023 Status Research & Development GmbH
+# Licensed under either of
+#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
+#  * MIT license ([LICENSE-MIT](LICENSE-MIT))
+# at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+{.used.}
+
+import
+  std/[sysrand],
+  unittest2,
+  ../kzg4844/kzg_ex,
+  ./types
+
+proc createKateBlobs(n: int): KateBlobs =
+  var blob: KzgBlob
+  for i in 0..<n:
+    discard urandom(blob)
+    for i in 0..<len(blob):
+      # don't overflow modulus
+      if blob[i] > MAX_TOP_BYTE and i %% BYTES_PER_FIELD_ELEMENT == 31:
+        blob[i] = MAX_TOP_BYTE
+    result.blobs.add(blob)
+
+  for i in 0..<n:
+    let res = toCommitment(result.blobs[i])
+    doAssert res.isOk
+    result.kates.add(res.get)
+
+suite "verify proof (extended version)":
+  test "load trusted setup from string":
+    let res = Kzg.loadTrustedSetupFromString(trustedSetup)
+    check res.isOk
+
+  test "verify proof success":
+    let kb = createKateBlobs(nblobs)
+    let pres = computeProof(kb.blobs)
+    check pres.isOk
+    let res = verifyProof(kb.blobs, kb.kates, pres.get)
+    check res.isOk
+
+  test "verify proof failure":
+    let kb = createKateBlobs(nblobs)
+    let pres = computeProof(kb.blobs)
+    check pres.isOk
+
+    let other = createKateBlobs(nblobs)
+    let badProof = computeProof(other.blobs)
+    check badProof.isOk
+
+    let res = verifyProof(kb.blobs, kb.kates, badProof.get)
+    check res.isErr
+
+  test "verify proof":
+    let kp = computeProof(blob, inputPoint)
+    check kp.isOk
+    check kp.get == proof
+
+    let res = verifyProof(commitment, inputPoint, claimedValue, kp.get)
+    check res.isOk

tests/types.nim

@@ -27,3 +27,4 @@ const
   inputPoint* = hexToByteArray[32]("AD5570F5A3810B7AF9D4B24BC1C2EA670245DB2EAA49AAE654B8F7393A9A6214")
   claimedValue* = hexToByteArray[32]("17F10B3E7BFC7894E4150626380E226D7B1D0085550067787F259A7F55BB5D36")
   nblobs* = 5
+  trustedSetup* = staticRead("../" & trustedSetupFile)