1 files changed, 127 insertions, 0 deletions
diff --git a/src/common/random_string.cc b/src/common/random_string.cc
new file mode 100644
index 000000000..c72895618
--- /dev/null
+++ b/src/common/random_string.cc
@@ -0,0 +1,127 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab ft=cpp
+
+#include <string_view>
+#include "auth/Crypto.h"
+#include "common/armor.h"
+#include "common/ceph_context.h"
+#include "common/dout.h"
+#include "random_string.h"
+
+int gen_rand_base64(CephContext *cct, char *dest, size_t size) /* size should be the required string size + 1 */
+{
+  char buf[size];
+  char tmp_dest[size + 4]; /* so that there's space for the extra '=' characters, and some */
+  int ret;
+
+  cct->random()->get_bytes(buf, sizeof(buf));
+
+  ret = ceph_armor(tmp_dest, &tmp_dest[sizeof(tmp_dest)],
+		   (const char *)buf, ((const char *)buf) + ((size - 1) * 3 + 4 - 1) / 4);
+  if (ret < 0) {
+    lderr(cct) << "ceph_armor failed" << dendl;
+    return ret;
+  }
+  tmp_dest[ret] = '\0';
+  memcpy(dest, tmp_dest, size);
+  dest[size-1] = '\0';
+
+  return 0;
+}
+
+// choose 'size' random characters from the given string table
+static void choose_from(CryptoRandom* random, std::string_view table,
+                        char *dest, size_t size)
+{
+  random->get_bytes(dest, size);
+
+  for (size_t i = 0; i < size; i++) {
+    auto pos = static_cast<unsigned>(dest[i]);
+    dest[i] = table[pos % table.size()];
+  }
+}
+
+
+void gen_rand_alphanumeric(CephContext *cct, char *dest, size_t size) /* size should be the required string size + 1 */
+{
+  // this is basically a modified base64 charset, url friendly
+  static constexpr char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
+  choose_from(cct->random(), table, dest, size-1);
+  dest[size-1] = 0;
+}
+
+std::string gen_rand_alphanumeric(CephContext *cct, size_t size)
+{
+  std::string str;
+  str.resize(size + 1);
+  gen_rand_alphanumeric(cct, str.data(), str.size());
+  str.pop_back(); // pop the extra \0
+  return str;
+}
+
+void gen_rand_alphanumeric_lower(CephContext *cct, char *dest, size_t size) /* size should be the required string size + 1 */
+{
+  static constexpr char table[] = "0123456789abcdefghijklmnopqrstuvwxyz";
+  choose_from(cct->random(), table, dest, size-1);
+  dest[size-1] = 0;
+}
+
+std::string gen_rand_alphanumeric_lower(CephContext *cct, size_t size)
+{
+  std::string str;
+  str.resize(size + 1);
+  gen_rand_alphanumeric_lower(cct, str.data(), str.size());
+  str.pop_back(); // pop the extra \0
+  return str;
+}
+
+
+void gen_rand_alphanumeric_upper(CephContext *cct, char *dest, size_t size) /* size should be the required string size + 1 */
+{
+  static constexpr char table[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+  choose_from(cct->random(), table, dest, size-1);
+  dest[size-1] = 0;
+}
+
+std::string gen_rand_alphanumeric_upper(CephContext *cct, size_t size)
+{
+  std::string str;
+  str.resize(size + 1);
+  gen_rand_alphanumeric_upper(cct, str.data(), str.size());
+  str.pop_back(); // pop the extra \0
+  return str;
+}
+
+
+void gen_rand_alphanumeric_no_underscore(CephContext *cct, char *dest, size_t size) /* size should be the required string size + 1 */
+{
+  static constexpr char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-.";
+  choose_from(cct->random(), table, dest, size-1);
+  dest[size-1] = 0;
+}
+
+std::string gen_rand_alphanumeric_no_underscore(CephContext *cct, size_t size)
+{
+  std::string str;
+  str.resize(size + 1);
+  gen_rand_alphanumeric_no_underscore(cct, str.data(), str.size());
+  str.pop_back(); // pop the extra \0
+  return str;
+}
+
+
+void gen_rand_alphanumeric_plain(CephContext *cct, char *dest, size_t size) /* size should be the required string size + 1 */
+{
+  static constexpr char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+  choose_from(cct->random(), table, dest, size-1);
+  dest[size-1] = 0;
+}
+
+std::string gen_rand_alphanumeric_plain(CephContext *cct, size_t size)
+{
+  std::string str;
+  str.resize(size + 1);
+  gen_rand_alphanumeric_plain(cct, str.data(), str.size());
+  str.pop_back(); // pop the extra \0
+  return str;
+}