blob: b7b6694cf6234d188e7f6cf866e22e33d52d566e [file] [log] [blame]
/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef WEBRTC_RTC_BASE_CRYPTSTRING_H_
#define WEBRTC_RTC_BASE_CRYPTSTRING_H_
#include <string.h>
#include <memory>
#include <string>
#include <vector>
namespace rtc {
class CryptStringImpl {
public:
virtual ~CryptStringImpl() {}
virtual size_t GetLength() const = 0;
virtual void CopyTo(char * dest, bool nullterminate) const = 0;
virtual std::string UrlEncode() const = 0;
virtual CryptStringImpl * Copy() const = 0;
virtual void CopyRawTo(std::vector<unsigned char> * dest) const = 0;
};
class EmptyCryptStringImpl : public CryptStringImpl {
public:
~EmptyCryptStringImpl() override {}
size_t GetLength() const override;
void CopyTo(char* dest, bool nullterminate) const override;
std::string UrlEncode() const override;
CryptStringImpl* Copy() const override;
void CopyRawTo(std::vector<unsigned char>* dest) const override;
};
class CryptString {
public:
CryptString();
size_t GetLength() const { return impl_->GetLength(); }
void CopyTo(char * dest, bool nullterminate) const { impl_->CopyTo(dest, nullterminate); }
CryptString(const CryptString& other);
explicit CryptString(const CryptStringImpl& impl);
~CryptString();
CryptString & operator=(const CryptString & other) {
if (this != &other) {
impl_.reset(other.impl_->Copy());
}
return *this;
}
void Clear() { impl_.reset(new EmptyCryptStringImpl()); }
std::string UrlEncode() const { return impl_->UrlEncode(); }
void CopyRawTo(std::vector<unsigned char> * dest) const {
return impl_->CopyRawTo(dest);
}
private:
std::unique_ptr<const CryptStringImpl> impl_;
};
// Used for constructing strings where a password is involved and we
// need to ensure that we zero memory afterwards
class FormatCryptString {
public:
FormatCryptString() {
storage_ = new char[32];
capacity_ = 32;
length_ = 0;
storage_[0] = 0;
}
void Append(const std::string & text) {
Append(text.data(), text.length());
}
void Append(const char * data, size_t length) {
EnsureStorage(length_ + length + 1);
memcpy(storage_ + length_, data, length);
length_ += length;
storage_[length_] = '\0';
}
void Append(const CryptString * password) {
size_t len = password->GetLength();
EnsureStorage(length_ + len + 1);
password->CopyTo(storage_ + length_, true);
length_ += len;
}
size_t GetLength() {
return length_;
}
const char * GetData() {
return storage_;
}
// Ensures storage of at least n bytes
void EnsureStorage(size_t n) {
if (capacity_ >= n) {
return;
}
size_t old_capacity = capacity_;
char * old_storage = storage_;
for (;;) {
capacity_ *= 2;
if (capacity_ >= n)
break;
}
storage_ = new char[capacity_];
if (old_capacity) {
memcpy(storage_, old_storage, length_);
// zero memory in a way that an optimizer won't optimize it out
old_storage[0] = 0;
for (size_t i = 1; i < old_capacity; i++) {
old_storage[i] = old_storage[i - 1];
}
delete[] old_storage;
}
}
~FormatCryptString() {
if (capacity_) {
storage_[0] = 0;
for (size_t i = 1; i < capacity_; i++) {
storage_[i] = storage_[i - 1];
}
}
delete[] storage_;
}
private:
char * storage_;
size_t capacity_;
size_t length_;
};
class InsecureCryptStringImpl : public CryptStringImpl {
public:
std::string& password() { return password_; }
const std::string& password() const { return password_; }
~InsecureCryptStringImpl() override = default;
size_t GetLength() const override;
void CopyTo(char* dest, bool nullterminate) const override;
std::string UrlEncode() const override;
CryptStringImpl* Copy() const override;
void CopyRawTo(std::vector<unsigned char>* dest) const override;
private:
std::string password_;
};
}
#endif // WEBRTC_RTC_BASE_CRYPTSTRING_H_