3 files changed, 39 insertions, 5 deletions
diff --git a/base/rand_util.cc b/base/rand_util.cc
index ea6ffd3..d89f8b7 100644
--- a/base/rand_util.cc
+++ b/base/rand_util.cc
@@ -41,4 +41,20 @@ uint64 RandGenerator(uint64 max) {
   return base::RandUint64() % max;
 }
 
+std::string RandBytesAsString(size_t length) {
+  const size_t kBitsPerChar = 8;
+  const int kCharsPerInt64 = sizeof(uint64)/sizeof(char);
+
+  std::string result(length, '\0');
+  uint64 entropy = 0;
+  for (size_t i = 0; i < result.size(); ++i) {
+    if (i % kCharsPerInt64 == 0)
+      entropy = RandUint64();
+    result[i] = static_cast<char>(entropy);
+    entropy >>= kBitsPerChar;
+  }
+
+  return result;
+}
+
 }  // namespace base
diff --git a/base/rand_util.h b/base/rand_util.h
index a4ea479..4e902da 100644
--- a/base/rand_util.h
+++ b/base/rand_util.h
@@ -6,6 +6,8 @@
 #define BASE_RAND_UTIL_H_
 #pragma once
 
+#include <string>
+
 #include "base/base_api.h"
 #include "base/basictypes.h"
 
@@ -27,6 +29,9 @@ BASE_API uint64 RandGenerator(uint64 max);
 // Returns a random double in range [0, 1). Thread-safe.
 BASE_API double RandDouble();
 
+// Returns a random string of the specified length.
+BASE_API std::string RandBytesAsString(size_t length);
+
 }  // namespace base
 
 #endif  // BASE_RAND_UTIL_H_
diff --git a/base/rand_util_unittest.cc b/base/rand_util_unittest.cc
index cbc338a..3bdb815 100644
--- a/base/rand_util_unittest.cc
+++ b/base/rand_util_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -22,10 +22,23 @@ TEST(RandUtilTest, SameMinAndMax) {
 }
 
 TEST(RandUtilTest, RandDouble) {
- // Force 64-bit precision, making sure we're not in a 80-bit FPU register.
- volatile double number = base::RandDouble();
- EXPECT_GT(1.0, number);
- EXPECT_LE(0.0, number);
+  // Force 64-bit precision, making sure we're not in a 80-bit FPU register.
+  volatile double number = base::RandDouble();
+  EXPECT_GT(1.0, number);
+  EXPECT_LE(0.0, number);
+}
+
+TEST(RandUtilTest, RandBytesAsString) {
+  std::string random_string = base::RandBytesAsString(0);
+  EXPECT_EQ(0U, random_string.size());
+  random_string = base::RandBytesAsString(145);
+  EXPECT_EQ(145U, random_string.size());
+  char accumulator = 0;
+  for (size_t i = 0; i < random_string.size(); ++i)
+    accumulator |= random_string[i];
+  // In theory this test can fail, but it won't before the universe dies of
+  // heat death.
+  EXPECT_NE(0, accumulator);
 }
 
 // Make sure that it is still appropriate to use RandGenerator in conjunction