*thread

1 files changed, 90 insertions, 0 deletions

diff --git a/source/3rd-party/uuid4/uuid4.c b/source/3rd-party/uuid4/uuid4.c
new file mode 100644
index 0000000..1b60188
--- /dev/null
+++ b/source/3rd-party/uuid4/uuid4.c
@@ -0,0 +1,90 @@
+/**
+ * Copyright (c) 2018 rxi
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+
+#if defined(_WIN32)
+#include <windows.h>
+#include <wincrypt.h>
+#endif
+
+#include "uuid4.h"
+
+
+static uint64_t seed[2];
+
+
+static uint64_t xorshift128plus(uint64_t *s) {
+  /* http://xorshift.di.unimi.it/xorshift128plus.c */
+  uint64_t s1 = s[0];
+  const uint64_t s0 = s[1];
+  s[0] = s0;
+  s1 ^= s1 << 23;
+  s[1] = s1 ^ s0 ^ (s1 >> 18) ^ (s0 >> 5);
+  return s[1] + s0;
+}
+
+
+int uuid4_init(void) {
+#if defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__)
+  int res;
+  FILE *fp = fopen("/dev/urandom", "rb");
+  if (!fp) {
+    return UUID4_EFAILURE;
+  }
+  res = fread(seed, 1, sizeof(seed), fp);
+  fclose(fp);
+  if ( res != sizeof(seed) ) {
+    return UUID4_EFAILURE;
+  }
+
+#elif defined(_WIN32)
+  int res;
+  HCRYPTPROV hCryptProv;
+  res = CryptAcquireContext(
+    &hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
+  if (!res) {
+    return UUID4_EFAILURE;
+  }
+  res = CryptGenRandom(hCryptProv, (DWORD) sizeof(seed), (PBYTE) seed);
+  CryptReleaseContext(hCryptProv, 0);
+  if (!res) {
+    return UUID4_EFAILURE;
+  }
+
+#else
+  #error "unsupported platform"
+#endif
+  return UUID4_ESUCCESS;
+}
+
+
+void uuid4_generate(char *dst) {
+  static const char *template = "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";
+  static const char *chars = "0123456789abcdef";
+  union { unsigned char b[16]; uint64_t word[2]; } s;
+  const char *p;
+  int i, n;
+  /* get random */
+  s.word[0] = xorshift128plus(seed);
+  s.word[1] = xorshift128plus(seed);
+  /* build string */
+  p = template;
+  i = 0;
+  while (*p) {
+    n = s.b[i >> 1];
+    n = (i & 1) ? (n >> 4) : (n & 0xf);
+    switch (*p) {
+      case 'x'  : *dst = chars[n];              i++;  break;
+      case 'y'  : *dst = chars[(n & 0x3) + 8];  i++;  break;
+      default   : *dst = *p;
+    }
+    dst++, p++;
+  }
+  *dst = '\0';
+}