From 3951521a16cda008881440d0575f74e465544e5d Mon Sep 17 00:00:00 2001
From: Ruslan Mustakov <r.mustakov@gmail.com>
Date: Thu, 15 Sep 2016 20:35:01 +0700
Subject: [PATCH] First version

---
 .gitignore            |  8 +++++
 .vscode/settings.json | 15 ++++++++
 LICENSE               | 20 +++++++++++
 README.md             | 33 +++++++++++++++++
 src/urandom.nim       | 65 +++++++++++++++++++++++++++++++++
 src/uuids.nim         | 83 +++++++++++++++++++++++++++++++++++++++++++
 uuids.nimble          |  7 ++++
 7 files changed, 231 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 .vscode/settings.json
 create mode 100644 LICENSE
 create mode 100644 README.md
 create mode 100644 src/urandom.nim
 create mode 100644 src/uuids.nim
 create mode 100644 uuids.nimble

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..4532471
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,8 @@
+**/uuids
+
+.vscode/.browse.*
+nimsuggest.log
+
+**/nimcache/**
+
+.DS_Store
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..55a52c2
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,15 @@
+{
+  "files.exclude": {
+    "**/nimcache/**": true
+  },
+  "files.trimTrailingWhitespace": true,
+  "editor.tabSize": 2,
+  "editor.insertSpaces": true,
+  "editor.rulers": [80],
+  "editor.renderIndentGuides": true,
+  "files.autoSave": "afterDelay",
+  "nim.licenseString": "# Copyright 2016 Xored Software, Inc.\n\n",
+  "nim.buildOnSave": false,
+  "nim.lintOnSave": true,
+  "nim.project": ["uuids.nim"]
+}
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..d943066
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,20 @@
+uuids - UUID library for Nim
+
+The MIT License
+
+Copyright (c) 2016 Xored Software Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial
+portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH
+THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..bc06028
--- /dev/null
+++ b/README.md
@@ -0,0 +1,33 @@
+# uuids
+
+UUID library for Nim.
+
+API:
+```nim
+type UUID* = object
+  ## 128-bit UUID compliant with RFC-4122
+
+proc `$`*(uuid: UUID): string
+  ## Returns a string representation of the UUID in canonical form.
+
+proc hash*(uuid: UUID): Hash
+  ## Computes hash of the specified UUID.
+
+proc `==`*(x, y: UUID): bool
+  ## Returns true when the specified UUIDs are equal, false otherwise.
+
+proc genUUID*(): UUID =
+  ## Returns a random (v4) UUID.
+  ## Uses random values obtained from system source (e.g. urandom).
+  ## In the future this will use a cryptographically secure PRNG for efficiency.
+
+proc toUUID*(s: string): UUID {.raises: [ValueError].}
+  ## Converts string representation of an UUID to UUID object.
+  ## Raises ValueError if invalid format is provided.
+```
+
+## License
+This library is licensed under the MIT license.
+Read [LICENSE](https://github.com/pragmagic/uuids/blob/master/LICENSE) file for details.
+
+Copyright (c) 2016 Xored Software, Inc.
diff --git a/src/urandom.nim b/src/urandom.nim
new file mode 100644
index 0000000..25dcf9f
--- /dev/null
+++ b/src/urandom.nim
@@ -0,0 +1,65 @@
+# Source: https://github.com/BlaXpirit/nim-random/blob/master/src/random/urandom.nim
+
+when defined(windows):
+  import winlean
+
+  type ULONG_PTR = int
+  type HCRYPTPROV = ULONG_PTR
+  var PROV_RSA_FULL {.importc, header: "<windows.h>".}: DWORD
+  var CRYPT_VERIFYCONTEXT {.importc, header: "<windows.h>".}: DWORD
+
+  {.push, stdcall, dynlib: "Advapi32.dll".}
+
+  when useWinUnicode:
+    proc CryptAcquireContext(
+      phProv: ptr HCRYPTPROV, pszContainer: WideCString,
+      pszProvider: WideCString, dwProvType: DWORD, dwFlags: DWORD
+    ): WinBool {.importc: "CryptAcquireContextW".}
+  else:
+    proc CryptAcquireContext(
+      phProv: ptr HCRYPTPROV, pszContainer: cstring, pszProvider: cstring,
+      dwProvType: DWORD, dwFlags: DWORD
+    ): WinBool {.importc: "CryptAcquireContextA".}
+
+  proc CryptGenRandom(
+    hProv: HCRYPTPROV, dwLen: DWORD, pbBuffer: pointer
+  ): WinBool {.importc: "CryptGenRandom".}
+
+  {.pop.}
+
+  var cryptProv: HCRYPTPROV = 0
+
+  proc urandomInit() =
+    let success = CryptAcquireContext(
+      addr cryptProv, nil, nil, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT
+    )
+    if success == 0:
+      raise newException(OSError, "Call to CryptAcquireContext failed")
+
+template urandomImpl() =
+  when defined(windows):
+    if cryptProv == 0:
+      urandomInit()
+
+    let success = CryptGenRandom(cryptProv, DWORD(size), addr result[0])
+    if success == 0:
+      raise newException(OSError, "Call to CryptGenRandom failed")
+
+  else:
+    var file: File
+    if not file.open("/dev/urandom"):
+      raise newException(OSError, "/dev/urandom is not available")
+    try:
+      var index = 0
+      while index < size:
+        let bytesRead = file.readBuffer(addr result[index], size-index)
+        if bytesRead <= 0:
+          raise newException(OSError, "Can't read enough bytes from /dev/urandom")
+        index += bytesRead
+    finally:
+      file.close()
+
+proc urandom*(size: static[Natural]): array[size, uint8] =
+  ## Returns an ``array`` of random integers ``0 <= n < 256`` provided by
+  ## the operating system's cryptographic source.
+  urandomImpl()
diff --git a/src/uuids.nim b/src/uuids.nim
new file mode 100644
index 0000000..69bc6c9
--- /dev/null
+++ b/src/uuids.nim
@@ -0,0 +1,83 @@
+import strutils, hashes
+import urandom
+
+type
+  UUID* = object
+    ## 128-bit UUID compliant with RFC-4122
+    mostSigBits: int64
+    leastSigBits: int64
+
+template toHex(s: string, start: Natural,
+               x: BiggestInt, len: Positive) =
+  const HexChars = "0123456789abcdef"
+  var n = x
+  for j in countdown(len - 1, 0):
+    s[start + j] = HexChars[n and 0xF]
+    n = n shr 4
+    # handle negative overflow
+    if n == 0 and x < 0: n = -1
+
+proc `$`*(uuid: UUID): string =
+  ## Returns a string representation of the UUID in canonical form.
+  result = newString(36)
+  toHex(result, 0, uuid.mostSigBits shr 32, 8)
+  result[8] = '-'
+  toHex(result, 9, uuid.mostSigBits shr 16, 4)
+  result[13] = '-'
+  toHex(result, 14, uuid.mostSigBits, 4)
+  result[18] = '-'
+  toHex(result, 19, uuid.leastSigBits shr 48, 4)
+  result[23] = '-'
+  toHex(result, 24, uuid.leastSigBits, 12)
+
+proc hash*(uuid: UUID): Hash =
+  ## Computes hash of the specified UUID.
+  result = uuid.mostSigBits.hash() !& uuid.leastSigBits.hash()
+  result = !$result
+
+proc `==`*(x, y: UUID): bool =
+  ## Returns ``true`` when the specified UUIDs are equal, ``false`` otherwise.
+  x.mostSigBits == y.mostSigBits and x.leastSigBits == y.leastSigBits
+
+proc genUUID*(): UUID =
+  ## Returns a random (v4) UUID.
+  ## Uses random values obtained from system source (e.g. urandom).
+  ## In the future this will use a cryptographically secure PRNG for efficiency.
+  var randBytes: array[16, uint8] = urandom(16)
+  copyMem(addr result.mostSigBits, addr randBytes[0], 8)
+  copyMem(addr result.leastSigBits, addr randBytes[8], 8)
+
+  # set version to 4
+  result.mostSigBits = (result.mostSigBits and 0xFFFFFFFFFFFF0FFF'i64) or
+                       0x0000000000004000'i64
+  # set IETF variant
+  result.leastSigBits = (result.leastSigBits and 0x3FFFFFFFFFFFFFFF'i64) or
+                        0x8000000000004000'i64
+
+proc toUUID*(s: string): UUID {.raises: [ValueError].} =
+  ## Converts string representation of an UUID to UUID object.
+  ## Raises ``ValueError`` if invalid format is provided.
+  let parts = s.split('-')
+  if parts.len != 5:
+    raise newException(ValueError,
+                       "UUID must consist of 5 parts separated with `-`")
+  var mostSigBits: int64 = parseHexInt(parts[0])
+  mostSigBits = mostSigBits shl 16
+  mostSigBits = mostSigBits or parseHexInt(parts[1])
+  mostSigBits = mostSigBits shl 16
+  mostSigBits = mostSigBits or parseHexInt(parts[2])
+
+  var leastSigBits: int64 = parseHexInt(parts[3])
+  leastSigBits = leastSigBits shl 48
+  leastSigBits = leastSigBits or parseHexInt(parts[4])
+
+  result = UUID(mostSigBits: mostSigBits, leastSigBits: leastSigBits)
+
+when isMainModule:
+  let uuid = genUUID()
+  let uuidStr = $uuid
+  assert(uuidStr.len == 36)
+  assert(uuidStr[14] == '4') # version
+  assert(uuidStr[19] in {'8', '9', 'a', 'b'}) # variant (2 bits)
+  assert(uuidStr.toUUID() == uuid)
+  assert(uuidStr.toUUID().hash() == uuid.hash())
diff --git a/uuids.nimble b/uuids.nimble
new file mode 100644
index 0000000..538bdaa
--- /dev/null
+++ b/uuids.nimble
@@ -0,0 +1,7 @@
+[Package]
+name: "uuids"
+version: "0.1.0"
+author: "Xored Software, Inc."
+description: "UUID library"
+license: "MIT"
+srcDir: "src"