mc_ed25519.nim

#Include and link the Ed25519 library.
const currentFolder = currentSourcePath().substr(0, currentSourcePath().len - 15)

{.passC: "-I" & currentFolder & "ed25519/src/".}

{.compile: currentFolder & "ed25519/src/add_scalar.c".}
{.compile: currentFolder & "ed25519/src/fe.c".}
{.compile: currentFolder & "ed25519/src/ge.c".}
{.compile: currentFolder & "ed25519/src/key_exchange.c".}
{.compile: currentFolder & "ed25519/src/keypair.c".}
{.compile: currentFolder & "ed25519/src/sc.c".}
{.compile: currentFolder & "ed25519/src/seed.c".}
{.compile: currentFolder & "ed25519/src/sha512.c".}
{.compile: currentFolder & "ed25519/src/sign.c".}
{.compile: currentFolder & "ed25519/src/verify.c".}

type
  PrivateKey* = array[64, cuchar]
  PublicKey* = array[32, cuchar]

{.push header: "sc.h".}

proc mulAdd*(
  res: ptr cuchar,
  a: ptr cuchar,
  b: ptr cuchar,
  c: ptr cuchar
) {.importc: "sc_muladd".}

#Reduce a scalar.
proc reduceScalar*(
  scalar: ptr cuchar
) {.importc: "sc_reduce".}

{.pop.}

{.push header: "ge.h".}

#Define the Ed25519 objects.
type
  PointP1P1* {.
    header: "ge.h",
    importc: "ge_p1p1"
  .} = object
  Point2* {.
    header: "ge.h",
    importc: "ge_p2"
  .} = object
  Point3* {.
    header: "ge.h",
    importc: "ge_p3"
  .} = object
  PointCached* {.
    header: "ge.h",
    importc: "ge_cached"
  .} = object

#Convert a Public Key to a Point3.
proc keyToNegativePoint*(
  res: ptr Point3,
  bytes: ptr cuchar
) {.importc: "ge_frombytes_negate_vartime".}

proc p3ToCached*(
  cached: ptr PointCached,
  p3: ptr Point3
) {.importc: "ge_p3_to_cached".}

proc p1p1ToP3*(
  p3: ptr Point3,
  p1p1: ptr PointP1P1
) {.importc: "ge_p1p1_to_p3".}

#Add two points.
proc add*(
  res: ptr PointP1P1,
  p: ptr Point3,
  p2: ptr PointCached
) {.importc: "ge_add".}

#Multiply by Ed25519's base.
proc multiplyBase*(
  res: ptr Point3,
  point: ptr cuchar
) {.importc: "ge_scalarmult_base".}

#Multiply scalars.
proc multiplyScalar*(
  res: ptr Point2,
  scalar: ptr cuchar,
  point: ptr Point3,
  addScalar: ptr cuchar
) {.importc: "ge_double_scalarmult_vartime".}

#Serialize a Point2.
proc serialize*(
  res: ptr cuchar,
  point2: ptr Point2
) {.importc: "ge_tobytes".}

#Serialize a Point3.
proc serialize*(
  res: ptr cuchar,
  point: ptr Point3
) {.importc: "ge_p3_tobytes".}

{.pop.}

{.push header: "ed25519.h".}

#Sign a message.
proc sign*(
  sig: ptr cuchar,
  msg: ptr cuchar,
  msgLen: csize,
  pubKey: ptr cuchar,
  privKey: ptr cuchar
) {.importc: "ed25519_sign".}

#Verify a message.
proc verify*(
  sig: ptr cuchar,
  msg: ptr cuchar,
  msgLen: csize,
  pubKey: ptr cuchar
): int {.importc: "ed25519_verify".}

{.pop.}