Some platforms (most notably Windows) do not have a $HOME by default.

For those, unless the environment variables RANDFILE or HOME are
defined (the default case!), RAND_file_name() will return NULL.
This change adds a default HOME for those platforms.

To add a default HOME for any platform, just define DEFAULT_HOME in
the proper place, wrapped in appropriate #ifdef..#endif, in e_os.h.

crypto/rand/randfile.c

@@ -211,6 +211,12 @@ const char *RAND_file_name(char *buf, size_t size)
 		{
 		if (OPENSSL_issetugid() == 0)
 			s=getenv("HOME");
+#ifdef DEFAULT_HOME
+		if (s == NULL)
+			{
+			s = DEFAULT_HOME;
+			}
+#endif
 		if (s != NULL && (strlen(s)+strlen(RFILE)+2 < size))
 			{
 			strcpy(buf,s);
@@ -220,7 +226,7 @@ const char *RAND_file_name(char *buf, size_t size)
 			strcat(buf,RFILE);
 			ret=buf;
 			}
-		  else
+		else
 		  	buf[0] = '\0'; /* no file name */
 		}
 	return(ret);

e_os.h

@@ -230,6 +230,7 @@ extern "C" {
 #  define SSLEAY_CONF	OPENSSL_CONF
 #  define NUL_DEV	"nul"
 #  define RFILE		".rnd"
+#  define DEFAULT_HOME  "C:"
 
 #else /* The non-microsoft world world */