1 // Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include <cstring> // memcpy
6
7 #include <base/stl_util.h>
8
9 #include "brillo/secure_blob.h"
10
11 namespace brillo {
12
SecureBlob(const std::string & data)13 SecureBlob::SecureBlob(const std::string& data)
14 : SecureBlob(data.begin(), data.end()) {}
15
~SecureBlob()16 SecureBlob::~SecureBlob() {
17 clear();
18 }
19
resize(size_type count)20 void SecureBlob::resize(size_type count) {
21 if (count < size()) {
22 SecureMemset(data() + count, 0, capacity() - count);
23 }
24 Blob::resize(count);
25 }
26
resize(size_type count,const value_type & value)27 void SecureBlob::resize(size_type count, const value_type& value) {
28 if (count < size()) {
29 SecureMemset(data() + count, 0, capacity() - count);
30 }
31 Blob::resize(count, value);
32 }
33
clear()34 void SecureBlob::clear() {
35 SecureMemset(data(), 0, capacity());
36 Blob::clear();
37 }
38
to_string() const39 std::string SecureBlob::to_string() const {
40 return std::string(data(), data() + size());
41 }
42
Combine(const SecureBlob & blob1,const SecureBlob & blob2)43 SecureBlob SecureBlob::Combine(const SecureBlob& blob1,
44 const SecureBlob& blob2) {
45 SecureBlob result;
46 result.reserve(blob1.size() + blob2.size());
47 result.insert(result.end(), blob1.begin(), blob1.end());
48 result.insert(result.end(), blob2.begin(), blob2.end());
49 return result;
50 }
51
SecureMemset(void * v,int c,size_t n)52 void* SecureMemset(void* v, int c, size_t n) {
53 volatile uint8_t* p = reinterpret_cast<volatile uint8_t*>(v);
54 while (n--)
55 *p++ = c;
56 return v;
57 }
58
SecureMemcmp(const void * s1,const void * s2,size_t n)59 int SecureMemcmp(const void* s1, const void* s2, size_t n) {
60 const uint8_t* us1 = reinterpret_cast<const uint8_t*>(s1);
61 const uint8_t* us2 = reinterpret_cast<const uint8_t*>(s2);
62 int result = 0;
63
64 if (0 == n)
65 return 1;
66
67 /* Code snippet without data-dependent branch due to
68 * Nate Lawson (nate@root.org) of Root Labs. */
69 while (n--)
70 result |= *us1++ ^ *us2++;
71
72 return result != 0;
73 }
74
75 } // namespace brillo
76