diff --git a/Utils.cpp b/Utils.cpp
index 395a890..b6c7bf8 100644
--- a/Utils.cpp
+++ b/Utils.cpp
@@ -351,18 +351,20 @@
 }
 
 status_t ReadRandomBytes(size_t bytes, std::string& out) {
-    out.clear();
+    out.resize(bytes);
+    return ReadRandomBytes(bytes, &out[0]);
+}
 
+status_t ReadRandomBytes(size_t bytes, char* buf) {
     int fd = TEMP_FAILURE_RETRY(open("/dev/urandom", O_RDONLY | O_CLOEXEC | O_NOFOLLOW));
     if (fd == -1) {
         return -errno;
     }
 
-    char buf[BUFSIZ];
     size_t n;
-    while ((n = TEMP_FAILURE_RETRY(read(fd, &buf[0], std::min(sizeof(buf), bytes)))) > 0) {
-        out.append(buf, n);
+    while ((n = TEMP_FAILURE_RETRY(read(fd, &buf[0], bytes))) > 0) {
         bytes -= n;
+        buf += n;
     }
     close(fd);
 
@@ -434,6 +436,15 @@
     return OK;
 }
 
+status_t StrToHex(const KeyBuffer& str, KeyBuffer& hex) {
+    hex.clear();
+    for (size_t i = 0; i < str.size(); i++) {
+        hex.push_back(kLookup[(str.data()[i] & 0xF0) >> 4]);
+        hex.push_back(kLookup[str.data()[i] & 0x0F]);
+    }
+    return OK;
+}
+
 status_t NormalizeHex(const std::string& in, std::string& out) {
     std::string tmp;
     if (HexToStr(in, tmp)) {