Electroneum
wipeable_string.cpp
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28 
29 #include <boost/optional/optional.hpp>
30 #include <string.h>
31 #include "memwipe.h"
32 #include "misc_log_ex.h"
33 #include "wipeable_string.h"
34 #include <limits>
35 
36 static constexpr const char hex[] = u8"0123456789abcdef";
37 
38 namespace
39 {
40  int atolower(int c)
41  {
42  if (c >= 'A' && c <= 'Z')
43  c |= 32;
44  return c;
45  }
46 }
47 
48 namespace epee
49 {
50 
52  buffer(other.buffer)
53 {
54 }
55 
57 {
58  if (&other == this)
59  return;
60  buffer = std::move(other.buffer);
61 }
62 
64 {
65  grow(other.size());
66  if (size() > 0)
67  memcpy(buffer.data(), other.c_str(), size());
68 }
69 
71 {
72  grow(other.size());
73  if (size() > 0)
74  memcpy(buffer.data(), other.c_str(), size());
75  if (!other.empty())
76  {
77  memwipe(&other[0], other.size()); // we're kinda left with this again aren't we
78  other = std::string();
79  }
80 }
81 
83 {
84  grow(strlen(s));
85  if (size() > 0)
86  memcpy(buffer.data(), s, size());
87 }
88 
89 wipeable_string::wipeable_string(const char *s, size_t len)
90 {
91  grow(len);
92  memcpy(buffer.data(), s, len);
93 }
94 
96 {
97  wipe();
98 }
99 
101 {
102  if (!buffer.empty())
103  memwipe(buffer.data(), buffer.size() * sizeof(char));
104 }
105 
106 void wipeable_string::grow(size_t sz, size_t reserved)
107 {
108  if (reserved < sz)
109  reserved = sz;
110  if (reserved <= buffer.capacity())
111  {
112  if (sz < buffer.size())
113  memwipe(buffer.data() + sz, buffer.size() - sz);
114  buffer.resize(sz);
115  return;
116  }
117  size_t old_sz = buffer.size();
118  std::unique_ptr<char[]> tmp{new char[old_sz]};
119  if (old_sz > 0)
120  {
121  memcpy(tmp.get(), buffer.data(), old_sz * sizeof(char));
122  memwipe(buffer.data(), old_sz * sizeof(char));
123  }
124  buffer.reserve(reserved);
125  buffer.resize(sz);
126  if (old_sz > 0)
127  {
128  memcpy(buffer.data(), tmp.get(), old_sz * sizeof(char));
129  memwipe(tmp.get(), old_sz * sizeof(char));
130  }
131 }
132 
134 {
135  grow(size() + 1);
136  buffer.back() = c;
137 }
138 
140 {
141  push_back(c);
142 }
143 
144 void wipeable_string::append(const char *ptr, size_t len)
145 {
146  const size_t orgsz = size();
147  CHECK_AND_ASSERT_THROW_MES(orgsz < std::numeric_limits<size_t>::max() - len, "Appended data too large");
148  grow(orgsz + len);
149  if (len > 0)
150  memcpy(data() + orgsz, ptr, len);
151 }
152 
153 void wipeable_string::operator+=(const char *s)
154 {
155  append(s, strlen(s));
156 }
157 
159 {
160  append(s.data(), s.size());
161 }
162 
164 {
165  append(s.c_str(), s.size());
166 }
167 
169 {
170  size_t prefix = 0;
171  while (prefix < size() && data()[prefix] == ' ')
172  ++prefix;
173  if (prefix > 0)
174  memmove(buffer.data(), buffer.data() + prefix, size() - prefix);
175 
176  size_t suffix = 0;
177  while (suffix < size()-prefix && data()[size() - 1 - prefix - suffix] == ' ')
178  ++suffix;
179 
180  resize(size() - prefix - suffix);
181 }
182 
183 void wipeable_string::split(std::vector<wipeable_string> &fields) const
184 {
185  fields.clear();
186  size_t len = size();
187  const char *ptr = data();
188  bool space = true;
189  while (len--)
190  {
191  const char c = *ptr++;
192  if (c != ' ')
193  {
194  if (space)
195  fields.push_back({});
196  fields.back().push_back(c);
197  }
198  space = c == ' ';
199  }
200 }
201 
202 boost::optional<epee::wipeable_string> wipeable_string::parse_hexstr() const
203 {
204  if (size() % 2 != 0)
205  return boost::none;
206  boost::optional<epee::wipeable_string> res = epee::wipeable_string("");
207  const size_t len = size();
208  const char *d = data();
209  res->grow(0, len / 2);
210  for (size_t i = 0; i < len; i += 2)
211  {
212  char c = atolower(d[i]);
213  const char *ptr0 = strchr(hex, c);
214  if (!ptr0)
215  return boost::none;
216  c = atolower(d[i+1]);
217  const char *ptr1 = strchr(hex, c);
218  if (!ptr1)
219  return boost::none;
220  res->push_back(((ptr0-hex)<<4) | (ptr1-hex));
221  }
222  return res;
223 }
224 
226 {
227  const size_t sz = size();
228  CHECK_AND_ASSERT_THROW_MES(sz > 0, "Popping from an empty string");
229  const char c = buffer.back();
230  resize(sz - 1);
231  return c;
232 }
233 
234 void wipeable_string::resize(size_t sz)
235 {
236  grow(sz);
237 }
238 
240 {
241  grow(size(), sz);
242 }
243 
245 {
246  resize(0);
247 }
248 
250 {
251  if (&other != this)
252  buffer = std::move(other.buffer);
253  return *this;
254 }
255 
257 {
258  if (&other != this)
259  buffer = other.buffer;
260  return *this;
261 }
262 
263 }
const char * res
Definition: hmac_keccak.cpp:41
#define CHECK_AND_ASSERT_THROW_MES(expr, message)
Definition: misc_log_ex.h:173
boost::optional< wipeable_string > parse_hexstr() const
size_t size() const noexcept
::std::string string
Definition: gtest-port.h:1097
void append(const char *ptr, size_t len)
void split(std::vector< wipeable_string > &fields) const
wipeable_string & operator=(wipeable_string &&other)
const T & move(const T &t)
Definition: gtest-port.h:1317
void * memcpy(void *a, const void *b, size_t c)
void * memwipe(void *src, size_t n)
const char * data() const noexcept
void * memmove(void *a, const void *b, size_t c)
unsigned char u8
Definition: chacha_private.h:9