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-rw-r--r--base/rand_util.h15
-rw-r--r--base/rand_util_posix.cc1
-rw-r--r--base/rand_util_win.cc3
-rw-r--r--crypto/crypto.gyp3
-rw-r--r--crypto/openpgp_symmetric_encryption.cc9
-rw-r--r--crypto/p224_spake.cc6
-rw-r--r--crypto/random.cc19
-rw-r--r--crypto/random.h21
-rw-r--r--crypto/random_unittest.cc27
-rw-r--r--sync/util/nigori.cc14
10 files changed, 95 insertions, 23 deletions
diff --git a/base/rand_util.h b/base/rand_util.h
index c5c4ef8..4f4765b 100644
--- a/base/rand_util.h
+++ b/base/rand_util.h
@@ -32,14 +32,21 @@ BASE_EXPORT double RandDouble();
// the range [0, 1). Thread-safe.
BASE_EXPORT double BitsToOpenEndedUnitInterval(uint64 bits);
-// Fills |output_length| bytes of |output| with cryptographically strong random
-// data.
+// Fills |output_length| bytes of |output| with random data.
+//
+// WARNING:
+// Do not use for security-sensitive purposes.
+// See crypto/ for cryptographically secure random number generation APIs.
BASE_EXPORT void RandBytes(void* output, size_t output_length);
-// Fills a string of length |length| with with cryptographically strong random
-// data and returns it. |length| should be nonzero.
+// Fills a string of length |length| with with random data and returns it.
+// |length| should be nonzero.
//
// Note that this is a variation of |RandBytes| with a different return type.
+//
+// WARNING:
+// Do not use for security-sensitive purposes.
+// See crypto/ for cryptographically secure random number generation APIs.
BASE_EXPORT std::string RandBytesAsString(size_t length);
#ifdef OS_POSIX
diff --git a/base/rand_util_posix.cc b/base/rand_util_posix.cc
index abb404a..d65ddae 100644
--- a/base/rand_util_posix.cc
+++ b/base/rand_util_posix.cc
@@ -41,6 +41,7 @@ base::LazyInstance<URandomFd> g_urandom_fd = LAZY_INSTANCE_INITIALIZER;
namespace base {
+// NOTE: This function must be cryptographically secure. http://crbug.com/140076
uint64 RandUint64() {
uint64 number;
diff --git a/base/rand_util_win.cc b/base/rand_util_win.cc
index ec0411e..391fe5b 100644
--- a/base/rand_util_win.cc
+++ b/base/rand_util_win.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
@@ -21,6 +21,7 @@ uint32 RandUint32() {
namespace base {
+// NOTE: This function must be cryptographically secure. http://crbug.com/140076
uint64 RandUint64() {
uint32 first_half = RandUint32();
uint32 second_half = RandUint32();
diff --git a/crypto/crypto.gyp b/crypto/crypto.gyp
index 287b53c..e124423 100644
--- a/crypto/crypto.gyp
+++ b/crypto/crypto.gyp
@@ -197,6 +197,8 @@
'openssl_util.h',
'p224.cc',
'p224.h',
+ 'random.h',
+ 'random.cc',
'rsa_private_key.cc',
'rsa_private_key.h',
'rsa_private_key_mac.cc',
@@ -242,6 +244,7 @@
'nss_util_unittest.cc',
'p224_unittest.cc',
'p224_spake_unittest.cc',
+ 'random_unittest.cc',
'rsa_private_key_unittest.cc',
'rsa_private_key_nss_unittest.cc',
'secure_hash_unittest.cc',
diff --git a/crypto/openpgp_symmetric_encryption.cc b/crypto/openpgp_symmetric_encryption.cc
index 3f37d4c..7eb6737 100644
--- a/crypto/openpgp_symmetric_encryption.cc
+++ b/crypto/openpgp_symmetric_encryption.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
@@ -12,7 +12,7 @@
#include <vector>
#include "base/logging.h"
-#include "base/rand_util.h"
+#include "crypto/random.h"
#include "crypto/scoped_nss_types.h"
#include "crypto/nss_util.h"
@@ -680,7 +680,8 @@ class Encrypter {
ske.push_back(3); // iterated and salted S2K
ske.push_back(2); // SHA-1
- uint64 salt64 = base::RandUint64();
+ uint64 salt64;
+ crypto::RandBytes(&salt64, sizeof(salt64));
ByteString salt(sizeof(salt64), 0);
// It's a random value, so endianness doesn't matter.
@@ -710,7 +711,7 @@ class Encrypter {
static const unsigned kBlockSize = 16; // AES block size
uint8 prefix[kBlockSize + 2], fre[kBlockSize], iv[kBlockSize];
- base::RandBytes(iv, kBlockSize);
+ crypto::RandBytes(iv, kBlockSize);
memset(fre, 0, sizeof(fre));
ScopedPK11Context aes_context;
diff --git a/crypto/p224_spake.cc b/crypto/p224_spake.cc
index af3c2b8..31109a4 100644
--- a/crypto/p224_spake.cc
+++ b/crypto/p224_spake.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
@@ -8,8 +8,8 @@
#include <crypto/p224_spake.h>
#include <base/logging.h>
-#include <base/rand_util.h>
#include <crypto/p224.h>
+#include <crypto/random.h>
#include <crypto/secure_util.h>
namespace {
@@ -103,7 +103,7 @@ P224EncryptedKeyExchange::P224EncryptedKeyExchange(
memset(&expected_authenticator_, 0, sizeof(expected_authenticator_));
// x_ is a random scalar.
- base::RandBytes(x_, sizeof(x_));
+ RandBytes(x_, sizeof(x_));
// X = g**x_
p224::Point X;
diff --git a/crypto/random.cc b/crypto/random.cc
new file mode 100644
index 0000000..a19bb1a
--- /dev/null
+++ b/crypto/random.cc
@@ -0,0 +1,19 @@
+// Copyright (c) 2012 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.
+
+#include "crypto/random.h"
+
+#include "base/rand_util.h"
+
+namespace crypto {
+
+void RandBytes(void *bytes, size_t length) {
+ // It's OK to call base::RandBytes(), because it's already strongly random.
+ // But _other_ code should go through this function to ensure that code which
+ // needs secure randomness is easily discoverable.
+ base::RandBytes(bytes, length);
+}
+
+} // namespace crypto
+
diff --git a/crypto/random.h b/crypto/random.h
new file mode 100644
index 0000000..cdbe8a9
--- /dev/null
+++ b/crypto/random.h
@@ -0,0 +1,21 @@
+// Copyright (c) 2012 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.
+
+#ifndef CRYPTO_RANDOM_H_
+#define CRYPTO_RANDOM_H_
+
+#include <stdlib.h>
+
+#include "crypto/crypto_export.h"
+
+namespace crypto {
+
+// Fills the given buffer with |length| random bytes of cryptographically
+// secure random numbers.
+// |length| must be positive.
+CRYPTO_EXPORT void RandBytes(void *bytes, size_t length);
+
+}
+
+#endif
diff --git a/crypto/random_unittest.cc b/crypto/random_unittest.cc
new file mode 100644
index 0000000..297f3cc
--- /dev/null
+++ b/crypto/random_unittest.cc
@@ -0,0 +1,27 @@
+// Copyright (c) 2012 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.
+
+#include "crypto/random.h"
+
+#include "base/string_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+// Basic functionality tests. Does NOT test the security of the random data.
+
+// Ensures we don't have all trivial data, i.e. that the data is indeed random.
+// Currently, that means the bytes cannot be all the same (e.g. all zeros).
+bool IsTrivial(const std::string& bytes) {
+ for (size_t i = 0; i < bytes.size(); i++) {
+ if (bytes[i] != bytes[0]) {
+ return false;
+ }
+ }
+ return true;
+}
+
+TEST(RandBytes, RandBytes) {
+ std::string bytes(16, '\0');
+ crypto::RandBytes(WriteInto(&bytes, bytes.size()), bytes.size());
+ EXPECT_TRUE(!IsTrivial(bytes));
+}
diff --git a/sync/util/nigori.cc b/sync/util/nigori.cc
index f2ee83d..60fc895 100644
--- a/sync/util/nigori.cc
+++ b/sync/util/nigori.cc
@@ -9,16 +9,15 @@
#include "base/base64.h"
#include "base/logging.h"
-#include "base/rand_util.h"
#include "base/string_util.h"
#include "base/sys_byteorder.h"
#include "crypto/encryptor.h"
#include "crypto/hmac.h"
+#include "crypto/random.h"
#include "crypto/symmetric_key.h"
using base::Base64Encode;
using base::Base64Decode;
-using base::RandInt;
using crypto::Encryptor;
using crypto::HMAC;
using crypto::SymmetricKey;
@@ -154,20 +153,13 @@ bool Nigori::Permute(Type type, const std::string& name,
return Base64Encode(output, permuted);
}
-std::string GenerateRandomString(size_t size) {
- // TODO(albertb): Use a secure random function.
- std::string random(size, 0);
- for (size_t i = 0; i < size; ++i)
- random[i] = RandInt(0, 0xff);
- return random;
-}
-
// Enc[Kenc,Kmac](value)
bool Nigori::Encrypt(const std::string& value, std::string* encrypted) const {
if (0U >= value.size())
return false;
- std::string iv = GenerateRandomString(kIvSize);
+ std::string iv;
+ crypto::RandBytes(WriteInto(&iv, kIvSize + 1), kIvSize);
Encryptor encryptor;
if (!encryptor.Init(encryption_key_.get(), Encryptor::CBC, iv))
generated by cgit v1.1 at 2025-02-19 12:03:39 +0000