Moved getting random bytes into a separate get_random_bytes() function.

[claws.git] / src / common / utils.c

diff --git a/src/common/utils.c b/src/common/utils.c
index 236a924a118daf330b8a0f03eccacd82b63478ef..eb41d5cf6c2b1959b547d44f2caad5524a18e203 100644 (file)
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -5408,3 +5408,57 @@ g_utf8_substring (const gchar *str,
   return out;
 }
 #endif
+
+/* Attempts to read count bytes from a PRNG into memory area starting at buf.
+ * It is up to the caller to make sure there is at least count bytes
+ * available at buf. */
+gboolean
+get_random_bytes(void *buf, size_t count)
+{
+       /* Open our prng source. */
+#if defined G_OS_WIN32
+       HCRYPTPROV rnd;
+
+       if (!CryptAcquireContext(&rnd, NULL, NULL, PROV_RSA_FULL, 0) &&
+                       !CryptAcquireContext(&rnd, NULL, NULL, PROV_RSA_FULL, CRYPT_NEWKEYSET)) {
+               debug_print("Could not acquire a CSP handle.\n");
+               return FALSE;
+       }
+#else
+       int rnd;
+       ssize_t ret;
+
+       rnd = open("/dev/urandom", O_RDONLY);
+       if (rnd == -1) {
+               perror("open on /dev/urandom");
+               debug_print("Could not open /dev/urandom.\n");
+               return FALSE;
+       }
+#endif
+
+       /* Read data from the source into buf. */
+#if defined G_OS_WIN32
+       if (!CryptGenRandom(rnd, count, buf)) {
+               debug_print("Could not read %d random bytes.\n", count);
+               CryptReleaseContext(rnd, 0);
+               return FALSE;
+       }
+#else
+       ret = read(rnd, buf, count);
+       if (ret != count) {
+               perror("read from /dev/urandom");
+               debug_print("Could not read enough data from /dev/urandom, read only %ld of %lu bytes.\n", ret, count);
+               close(rnd);
+               return FALSE;
+       }
+#endif
+
+       /* Close the prng source. */
+#if defined G_OS_WIN32
+       CryptReleaseContext(rnd, 0);
+#else
+       close(rnd);
+#endif
+
+       return TRUE;
+}