Diff: platform-specific.h

Revision:

0:b6fdeddc0bc9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/platform-specific.h	Thu Sep 07 12:10:11 2017 +0000
@@ -0,0 +1,71 @@
+/* Copyright 2015, Kenneth MacKay. Licensed under the BSD 2-clause license. */
+
+#ifndef _UECC_PLATFORM_SPECIFIC_H_
+#define _UECC_PLATFORM_SPECIFIC_H_
+
+#include "types.h"
+
+#if (defined(_WIN32) || defined(_WIN64))
+/* Windows */
+
+// use pragma syntax to prevent tweaking the linker script for getting CryptXYZ function
+#pragma comment(lib, "crypt32.lib")
+#pragma comment(lib, "advapi32.lib")
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <wincrypt.h>
+
+static int default_RNG(uint8_t *dest, unsigned size) {
+    HCRYPTPROV prov;
+    if (!CryptAcquireContext(&prov, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) {
+        return 0;
+    }
+
+    CryptGenRandom(prov, size, (BYTE *)dest);
+    CryptReleaseContext(prov, 0);
+    return 1;
+}
+#define default_RNG_defined 1
+
+#elif defined(unix) || defined(__linux__) || defined(__unix__) || defined(__unix) || \
+    (defined(__APPLE__) && defined(__MACH__)) || defined(uECC_POSIX)
+
+/* Some POSIX-like system with /dev/urandom or /dev/random. */
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#ifndef O_CLOEXEC
+    #define O_CLOEXEC 0
+#endif
+
+static int default_RNG(uint8_t *dest, unsigned size) {
+    int fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC);
+    if (fd == -1) {
+        fd = open("/dev/random", O_RDONLY | O_CLOEXEC);
+        if (fd == -1) {
+            return 0;
+        }
+    }
+    
+    char *ptr = (char *)dest;
+    size_t left = size;
+    while (left > 0) {
+        ssize_t bytes_read = read(fd, ptr, left);
+        if (bytes_read <= 0) { // read failed
+            close(fd);
+            return 0;
+        }
+        left -= bytes_read;
+        ptr += bytes_read;
+    }
+    
+    close(fd);
+    return 1;
+}
+#define default_RNG_defined 1
+
+#endif /* platform */
+
+#endif /* _UECC_PLATFORM_SPECIFIC_H_ */