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 13 SecureBlob::SecureBlob(const std::string& data) 14 : SecureBlob(data.begin(), data.end()) {} 15 16 SecureBlob::~SecureBlob() { 17 clear(); 18 } 19 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 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 34 void SecureBlob::clear() { 35 SecureMemset(data(), 0, capacity()); 36 Blob::clear(); 37 } 38 39 std::string SecureBlob::to_string() const { 40 return std::string(data(), data() + size()); 41 } 42 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 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 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 (at) root.org) of Root Labs. */ 69 while (n--) 70 result |= *us1++ ^ *us2++; 71 72 return result != 0; 73 } 74 75 } // namespace brillo 76
