henrike@webrtc.org | 0e118e7 | 2013-07-10 00:45:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * libjingle |
| 3 | * Copyright 2004--2005, Google Inc. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions are met: |
| 7 | * |
| 8 | * 1. Redistributions of source code must retain the above copyright notice, |
| 9 | * this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| 11 | * this list of conditions and the following disclaimer in the documentation |
| 12 | * and/or other materials provided with the distribution. |
| 13 | * 3. The name of the author may not be used to endorse or promote products |
| 14 | * derived from this software without specific prior written permission. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 17 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 18 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
| 19 | * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 20 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 21 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 22 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 23 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 24 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 25 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | #ifndef _TALK_BASE_CRYPTSTRING_H_ |
| 29 | #define _TALK_BASE_CRYPTSTRING_H_ |
| 30 | |
pbos@webrtc.org | b951827 | 2014-03-07 15:22:04 +0000 | [diff] [blame] | 31 | #include <string.h> |
| 32 | |
henrike@webrtc.org | 0e118e7 | 2013-07-10 00:45:36 +0000 | [diff] [blame] | 33 | #include <string> |
| 34 | #include <vector> |
pbos@webrtc.org | b951827 | 2014-03-07 15:22:04 +0000 | [diff] [blame] | 35 | |
henrike@webrtc.org | 0e118e7 | 2013-07-10 00:45:36 +0000 | [diff] [blame] | 36 | #include "talk/base/linked_ptr.h" |
| 37 | #include "talk/base/scoped_ptr.h" |
| 38 | |
| 39 | namespace talk_base { |
| 40 | |
| 41 | class CryptStringImpl { |
| 42 | public: |
| 43 | virtual ~CryptStringImpl() {} |
| 44 | virtual size_t GetLength() const = 0; |
| 45 | virtual void CopyTo(char * dest, bool nullterminate) const = 0; |
| 46 | virtual std::string UrlEncode() const = 0; |
| 47 | virtual CryptStringImpl * Copy() const = 0; |
| 48 | virtual void CopyRawTo(std::vector<unsigned char> * dest) const = 0; |
| 49 | }; |
| 50 | |
| 51 | class EmptyCryptStringImpl : public CryptStringImpl { |
| 52 | public: |
| 53 | virtual ~EmptyCryptStringImpl() {} |
| 54 | virtual size_t GetLength() const { return 0; } |
| 55 | virtual void CopyTo(char * dest, bool nullterminate) const { |
| 56 | if (nullterminate) { |
| 57 | *dest = '\0'; |
| 58 | } |
| 59 | } |
| 60 | virtual std::string UrlEncode() const { return ""; } |
| 61 | virtual CryptStringImpl * Copy() const { return new EmptyCryptStringImpl(); } |
| 62 | virtual void CopyRawTo(std::vector<unsigned char> * dest) const { |
| 63 | dest->clear(); |
| 64 | } |
| 65 | }; |
| 66 | |
| 67 | class CryptString { |
| 68 | public: |
| 69 | CryptString() : impl_(new EmptyCryptStringImpl()) {} |
| 70 | size_t GetLength() const { return impl_->GetLength(); } |
| 71 | void CopyTo(char * dest, bool nullterminate) const { impl_->CopyTo(dest, nullterminate); } |
| 72 | CryptString(const CryptString & other) : impl_(other.impl_->Copy()) {} |
| 73 | explicit CryptString(const CryptStringImpl & impl) : impl_(impl.Copy()) {} |
| 74 | CryptString & operator=(const CryptString & other) { |
| 75 | if (this != &other) { |
| 76 | impl_.reset(other.impl_->Copy()); |
| 77 | } |
| 78 | return *this; |
| 79 | } |
| 80 | void Clear() { impl_.reset(new EmptyCryptStringImpl()); } |
| 81 | std::string UrlEncode() const { return impl_->UrlEncode(); } |
| 82 | void CopyRawTo(std::vector<unsigned char> * dest) const { |
| 83 | return impl_->CopyRawTo(dest); |
| 84 | } |
| 85 | |
| 86 | private: |
| 87 | scoped_ptr<const CryptStringImpl> impl_; |
| 88 | }; |
| 89 | |
| 90 | |
| 91 | // Used for constructing strings where a password is involved and we |
| 92 | // need to ensure that we zero memory afterwards |
| 93 | class FormatCryptString { |
| 94 | public: |
| 95 | FormatCryptString() { |
| 96 | storage_ = new char[32]; |
| 97 | capacity_ = 32; |
| 98 | length_ = 0; |
| 99 | storage_[0] = 0; |
| 100 | } |
| 101 | |
| 102 | void Append(const std::string & text) { |
| 103 | Append(text.data(), text.length()); |
| 104 | } |
| 105 | |
| 106 | void Append(const char * data, size_t length) { |
| 107 | EnsureStorage(length_ + length + 1); |
| 108 | memcpy(storage_ + length_, data, length); |
| 109 | length_ += length; |
| 110 | storage_[length_] = '\0'; |
| 111 | } |
| 112 | |
| 113 | void Append(const CryptString * password) { |
| 114 | size_t len = password->GetLength(); |
| 115 | EnsureStorage(length_ + len + 1); |
| 116 | password->CopyTo(storage_ + length_, true); |
| 117 | length_ += len; |
| 118 | } |
| 119 | |
| 120 | size_t GetLength() { |
| 121 | return length_; |
| 122 | } |
| 123 | |
| 124 | const char * GetData() { |
| 125 | return storage_; |
| 126 | } |
| 127 | |
| 128 | |
| 129 | // Ensures storage of at least n bytes |
| 130 | void EnsureStorage(size_t n) { |
| 131 | if (capacity_ >= n) { |
| 132 | return; |
| 133 | } |
| 134 | |
| 135 | size_t old_capacity = capacity_; |
| 136 | char * old_storage = storage_; |
| 137 | |
| 138 | for (;;) { |
| 139 | capacity_ *= 2; |
| 140 | if (capacity_ >= n) |
| 141 | break; |
| 142 | } |
| 143 | |
| 144 | storage_ = new char[capacity_]; |
| 145 | |
| 146 | if (old_capacity) { |
| 147 | memcpy(storage_, old_storage, length_); |
| 148 | |
| 149 | // zero memory in a way that an optimizer won't optimize it out |
| 150 | old_storage[0] = 0; |
| 151 | for (size_t i = 1; i < old_capacity; i++) { |
| 152 | old_storage[i] = old_storage[i - 1]; |
| 153 | } |
| 154 | delete[] old_storage; |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | ~FormatCryptString() { |
| 159 | if (capacity_) { |
| 160 | storage_[0] = 0; |
| 161 | for (size_t i = 1; i < capacity_; i++) { |
| 162 | storage_[i] = storage_[i - 1]; |
| 163 | } |
| 164 | } |
| 165 | delete[] storage_; |
| 166 | } |
| 167 | private: |
| 168 | char * storage_; |
| 169 | size_t capacity_; |
| 170 | size_t length_; |
| 171 | }; |
| 172 | |
| 173 | class InsecureCryptStringImpl : public CryptStringImpl { |
| 174 | public: |
| 175 | std::string& password() { return password_; } |
| 176 | const std::string& password() const { return password_; } |
| 177 | |
| 178 | virtual ~InsecureCryptStringImpl() {} |
| 179 | virtual size_t GetLength() const { return password_.size(); } |
| 180 | virtual void CopyTo(char * dest, bool nullterminate) const { |
| 181 | memcpy(dest, password_.data(), password_.size()); |
| 182 | if (nullterminate) dest[password_.size()] = 0; |
| 183 | } |
| 184 | virtual std::string UrlEncode() const { return password_; } |
| 185 | virtual CryptStringImpl * Copy() const { |
| 186 | InsecureCryptStringImpl * copy = new InsecureCryptStringImpl; |
| 187 | copy->password() = password_; |
| 188 | return copy; |
| 189 | } |
| 190 | virtual void CopyRawTo(std::vector<unsigned char> * dest) const { |
| 191 | dest->resize(password_.size()); |
| 192 | memcpy(&dest->front(), password_.data(), password_.size()); |
| 193 | } |
| 194 | private: |
| 195 | std::string password_; |
| 196 | }; |
| 197 | |
| 198 | } |
| 199 | |
| 200 | #endif // _TALK_BASE_CRYPTSTRING_H_ |