1 files changed, 109 insertions, 0 deletions
diff --git a/ports/winnt/libntp/randfile.c b/ports/winnt/libntp/randfile.c
new file mode 100644
index 0000000..7de80b8
--- /dev/null
+++ b/ports/winnt/libntp/randfile.c
@@ -0,0 +1,109 @@
+/*
+ * Make sure that there is a good source of random characters
+ * so that OpenSSL can work properly and securely.
+ */
+
+#include <config.h>
+#include <wincrypt.h>
+
+#include <stdio.h>
+
+unsigned int	getrandom_chars(int desired, unsigned char *buf, int lenbuf);
+BOOL		create_random_file(char *filename);
+
+BOOL
+init_randfile()
+{
+	FILE *rf;
+	char *randfile;
+	char *homedir;
+	char tmp[256];
+	/* See if the environmental variable RANDFILE is defined
+	 * and the file exists
+	 */
+	randfile = getenv("RANDFILE");
+	if (randfile != NULL) {
+		rf = fopen(randfile, "rb");
+		if (rf != NULL) {
+			fclose(rf);
+			return (TRUE);
+		}
+		else {
+			/* The environmental variable exists but not the file */
+			return (create_random_file(randfile));
+		}
+	}
+	/*
+	 * If the RANDFILE environmental variable does not exist,
+	 * see if the HOME enviromental variable exists and
+	 * a .rnd file is in there.
+	 */
+	homedir = getenv("HOME");
+	if (homedir != NULL &&
+	    (strlen(homedir) + 5 /* \.rnd */) < sizeof(tmp)) {
+		snprintf(tmp, sizeof(tmp), "%s\\.rnd", homedir);
+		rf = fopen(tmp, "rb");
+		if (rf != NULL) {
+			fclose(rf);
+			return (TRUE);
+		}
+		else {
+			/* The HOME environmental variable exists but not the file */
+			return (create_random_file(tmp));
+		}
+	}
+	/*
+	 * Final try. Look for it on the C:\ directory
+	 * NOTE: This is a really bad place for it security-wise
+	 * However, OpenSSL looks for it there if it can't find it elsewhere
+	 */
+	rf = fopen("C:\\.rnd", "rb");
+	if (rf != NULL) {
+		fclose(rf);
+		return (TRUE);
+	}
+	/* The file does not exist */
+	return (create_random_file("C:\\.rnd"));
+}
+/*
+ * Routine to create the random file with 1024 random characters
+ */
+BOOL
+create_random_file(char *filename) {
+	FILE *rf;
+	int nchars;
+	unsigned char buf[1025];
+
+	nchars = getrandom_chars(1024, buf, sizeof(buf));
+	rf = fopen(filename, "wb");
+	if (rf == NULL)
+		return (FALSE);
+	fwrite(buf, sizeof(unsigned char), nchars, rf);
+	fclose(rf);
+	return (TRUE);
+}
+
+unsigned int
+getrandom_chars(int desired, unsigned char *buf, int lenbuf) {
+	HCRYPTPROV hcryptprov;
+	BOOL err;
+
+	if (buf == NULL || lenbuf <= 0 || desired > lenbuf)
+		return (0);
+	/*
+	 * The first time we just try to acquire the context
+	 */
+	err = CryptAcquireContext(&hcryptprov, NULL, NULL, PROV_RSA_FULL,
+				  CRYPT_VERIFYCONTEXT);
+	if (!err){
+		return (0);
+	}
+	if (!CryptGenRandom(hcryptprov, desired, buf)) {
+		CryptReleaseContext(hcryptprov, 0);
+		return (0);
+	}
+
+	CryptReleaseContext(hcryptprov, 0);
+	return (desired);
+}
+