5123321399

Committed 30 May 2023 04:06PM UTC coverage: 92.213% (+0.004%) from 92.209%

Build # 5123321399

Build Type

Pull #3558

github

Committed by

web-flow

Commit Message

Merge dd72f7389 into 057bcbc35

Pull Request Pull Request #3558: Add braces around all if/else statements

Run Details

75602 of 81986 relevant lines covered (92.21%)

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99.29

/src/lib/modes/mode_pad/mode_pad.cpp

/*
* CBC Padding Methods
* (C) 1999-2007,2013,2018,2020 Jack Lloyd
* (C) 2016 René Korthaus, Rohde & Schwarz Cybersecurity
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/internal/mode_pad.h>

#include <botan/exceptn.h>
#include <botan/internal/ct_utils.h>

namespace Botan {

/**
* Get a block cipher padding method by name
*/
std::unique_ptr<BlockCipherModePaddingMethod> BlockCipherModePaddingMethod::create(std::string_view algo_spec) {
   if(algo_spec == "NoPadding") {
      return std::make_unique<Null_Padding>();
   }

   if(algo_spec == "PKCS7") {
      return std::make_unique<PKCS7_Padding>();
   }

   if(algo_spec == "OneAndZeros") {
      return std::make_unique<OneAndZeros_Padding>();
   }

   if(algo_spec == "X9.23") {
      return std::make_unique<ANSI_X923_Padding>();
   }

   if(algo_spec == "ESP") {
      return std::make_unique<ESP_Padding>();
   }

   return nullptr;
}

/*
* Pad with PKCS #7 Method
*/
void PKCS7_Padding::add_padding(secure_vector<uint8_t>& buffer, size_t last_byte_pos, size_t BS) const {
   /*
   Padding format is
   01
   0202
   030303
   ...
   */
   BOTAN_DEBUG_ASSERT(last_byte_pos < BS);

   const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos);

   buffer.resize(buffer.size() + padding_len);

   CT::poison(&last_byte_pos, 1);
   CT::poison(buffer.data(), buffer.size());

   BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0);
   BOTAN_DEBUG_ASSERT(buffer.size() >= BS);

   const size_t start_of_last_block = buffer.size() - BS;
   const size_t end_of_last_block = buffer.size();
   const size_t start_of_padding = buffer.size() - padding_len;

   for(size_t i = start_of_last_block; i != end_of_last_block; ++i) {
      auto needs_padding = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gte(i, start_of_padding));
      buffer[i] = needs_padding.select(padding_len, buffer[i]);
   }

   CT::unpoison(buffer.data(), buffer.size());
   CT::unpoison(last_byte_pos);
}

/*
* Unpad with PKCS #7 Method
*/
size_t PKCS7_Padding::unpad(const uint8_t input[], size_t input_length) const {
   if(!valid_blocksize(input_length)) {
      return input_length;
   }

   CT::poison(input, input_length);

   const uint8_t last_byte = input[input_length - 1];

   /*
   The input should == the block size so if the last byte exceeds
   that then the padding is certainly invalid
   */
   auto bad_input = CT::Mask<size_t>::is_gt(last_byte, input_length);

   const size_t pad_pos = input_length - last_byte;

   for(size_t i = 0; i != input_length - 1; ++i) {
      // Does this byte equal the expected pad byte?
      const auto pad_eq = CT::Mask<size_t>::is_equal(input[i], last_byte);

      // Ignore values that are not part of the padding
      const auto in_range = CT::Mask<size_t>::is_gte(i, pad_pos);
      bad_input |= in_range & (~pad_eq);
   }

   CT::unpoison(input, input_length);

   return bad_input.select_and_unpoison(input_length, pad_pos);
}

/*
* Pad with ANSI X9.23 Method
*/
void ANSI_X923_Padding::add_padding(secure_vector<uint8_t>& buffer, size_t last_byte_pos, size_t BS) const {
   /*
   Padding format is
   01
   0002
   000003
   ...
   */
   BOTAN_DEBUG_ASSERT(last_byte_pos < BS);

   const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos);

   buffer.resize(buffer.size() + padding_len);

   CT::poison(&last_byte_pos, 1);
   CT::poison(buffer.data(), buffer.size());

   BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0);
   BOTAN_DEBUG_ASSERT(buffer.size() >= BS);

   const size_t start_of_last_block = buffer.size() - BS;
   const size_t end_of_zero_padding = buffer.size() - 1;
   const size_t start_of_padding = buffer.size() - padding_len;

   for(size_t i = start_of_last_block; i != end_of_zero_padding; ++i) {
      auto needs_padding = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gte(i, start_of_padding));
      buffer[i] = needs_padding.select(0, buffer[i]);
   }

   buffer[buffer.size() - 1] = padding_len;
   CT::unpoison(buffer.data(), buffer.size());
   CT::unpoison(last_byte_pos);
}

/*
* Unpad with ANSI X9.23 Method
*/
size_t ANSI_X923_Padding::unpad(const uint8_t input[], size_t input_length) const {
   if(!valid_blocksize(input_length)) {
      return input_length;
   }

   CT::poison(input, input_length);

   const size_t last_byte = input[input_length - 1];

   auto bad_input = CT::Mask<size_t>::is_gt(last_byte, input_length);

   const size_t pad_pos = input_length - last_byte;

   for(size_t i = 0; i != input_length - 1; ++i) {
      // Ignore values that are not part of the padding
      const auto in_range = CT::Mask<size_t>::is_gte(i, pad_pos);
      const auto pad_is_nonzero = CT::Mask<size_t>::expand(input[i]);
      bad_input |= pad_is_nonzero & in_range;
   }

   CT::unpoison(input, input_length);

   return bad_input.select_and_unpoison(input_length, pad_pos);
}

/*
* Pad with One and Zeros Method
*/
void OneAndZeros_Padding::add_padding(secure_vector<uint8_t>& buffer, size_t last_byte_pos, size_t BS) const {
   /*
   Padding format is
   80
   8000
   800000
   ...
   */

   BOTAN_DEBUG_ASSERT(last_byte_pos < BS);

   const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos);

   buffer.resize(buffer.size() + padding_len);

   CT::poison(&last_byte_pos, 1);
   CT::poison(buffer.data(), buffer.size());

   BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0);
   BOTAN_DEBUG_ASSERT(buffer.size() >= BS);

   const size_t start_of_last_block = buffer.size() - BS;
   const size_t end_of_last_block = buffer.size();
   const size_t start_of_padding = buffer.size() - padding_len;

   for(size_t i = start_of_last_block; i != end_of_last_block; ++i) {
      auto needs_80 = CT::Mask<uint8_t>(CT::Mask<size_t>::is_equal(i, start_of_padding));
      auto needs_00 = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gt(i, start_of_padding));
      buffer[i] = needs_00.select(0x00, needs_80.select(0x80, buffer[i]));
   }

   CT::unpoison(buffer.data(), buffer.size());
   CT::unpoison(last_byte_pos);
}

/*
* Unpad with One and Zeros Method
*/
size_t OneAndZeros_Padding::unpad(const uint8_t input[], size_t input_length) const {
   if(!valid_blocksize(input_length)) {
      return input_length;
   }

   CT::poison(input, input_length);

   auto bad_input = CT::Mask<uint8_t>::cleared();
   auto seen_0x80 = CT::Mask<uint8_t>::cleared();

   size_t pad_pos = input_length - 1;
   size_t i = input_length;

   while(i) {
      const auto is_0x80 = CT::Mask<uint8_t>::is_equal(input[i - 1], 0x80);
      const auto is_zero = CT::Mask<uint8_t>::is_zero(input[i - 1]);

      seen_0x80 |= is_0x80;
      pad_pos -= seen_0x80.if_not_set_return(1);
      bad_input |= ~seen_0x80 & ~is_zero;
      i--;
   }
   bad_input |= ~seen_0x80;

   CT::unpoison(input, input_length);

   return CT::Mask<size_t>::expand(bad_input).select_and_unpoison(input_length, pad_pos);
}

/*
* Pad with ESP Padding Method
*/
void ESP_Padding::add_padding(secure_vector<uint8_t>& buffer, size_t last_byte_pos, size_t BS) const {
   /*
   Padding format is
   01
   0102
   010203
   ...
   */
   BOTAN_DEBUG_ASSERT(last_byte_pos < BS);

   const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos);

   buffer.resize(buffer.size() + padding_len);

   CT::poison(&last_byte_pos, 1);
   CT::poison(buffer.data(), buffer.size());

   BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0);
   BOTAN_DEBUG_ASSERT(buffer.size() >= BS);

   const size_t start_of_last_block = buffer.size() - BS;
   const size_t end_of_last_block = buffer.size();
   const size_t start_of_padding = buffer.size() - padding_len;

   uint8_t pad_ctr = 0x01;

   for(size_t i = start_of_last_block; i != end_of_last_block; ++i) {
      auto needs_padding = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gte(i, start_of_padding));
      buffer[i] = needs_padding.select(pad_ctr, buffer[i]);
      pad_ctr = needs_padding.select(pad_ctr + 1, pad_ctr);
   }

   CT::unpoison(buffer.data(), buffer.size());
   CT::unpoison(last_byte_pos);
}

/*
* Unpad with ESP Padding Method
*/
size_t ESP_Padding::unpad(const uint8_t input[], size_t input_length) const {
   if(!valid_blocksize(input_length)) {
      return input_length;
   }

   CT::poison(input, input_length);

   const uint8_t input_length_8 = static_cast<uint8_t>(input_length);
   const uint8_t last_byte = input[input_length - 1];

   auto bad_input = CT::Mask<uint8_t>::is_zero(last_byte) | CT::Mask<uint8_t>::is_gt(last_byte, input_length_8);

   const uint8_t pad_pos = input_length_8 - last_byte;
   size_t i = input_length_8 - 1;
   while(i) {
      const auto in_range = CT::Mask<size_t>::is_gt(i, pad_pos);
      const auto incrementing = CT::Mask<uint8_t>::is_equal(input[i - 1], input[i] - 1);

      bad_input |= CT::Mask<uint8_t>(in_range) & ~incrementing;
      --i;
   }

   CT::unpoison(input, input_length);
   return bad_input.select_and_unpoison(input_length_8, pad_pos);
}

}  // namespace Botan

1	/*
2	* CBC Padding Methods
3	* (C) 1999-2007,2013,2018,2020 Jack Lloyd
4	* (C) 2016 René Korthaus, Rohde & Schwarz Cybersecurity
5	*
6	* Botan is released under the Simplified BSD License (see license.txt)
7	*/
8
9	#include <botan/internal/mode_pad.h>
10
11	#include <botan/exceptn.h>
12	#include <botan/internal/ct_utils.h>
13
14	namespace Botan {
15
16	/**
17	* Get a block cipher padding method by name
18	*/
19	std::unique_ptr<BlockCipherModePaddingMethod> BlockCipherModePaddingMethod::create(std::string_view algo_spec) {
20	if(algo_spec == "NoPadding") {
21	return std::make_unique<Null_Padding>();
22	}
23
24	if(algo_spec == "PKCS7") {
25	return std::make_unique<PKCS7_Padding>();
26	}
27
28	if(algo_spec == "OneAndZeros") {
29	return std::make_unique<OneAndZeros_Padding>();
30	}
31
32	if(algo_spec == "X9.23") {
33	return std::make_unique<ANSI_X923_Padding>();
34	}
35
36	if(algo_spec == "ESP") {
37	return std::make_unique<ESP_Padding>();
38	}
39
40	return nullptr;
41	}
42
43	/*
44	* Pad with PKCS #7 Method
45	*/
46	void PKCS7_Padding::add_padding(secure_vector<uint8_t>& buffer, size_t last_byte_pos, size_t BS) const {
47	/*
48	Padding format is
49	01
50	0202
51	030303
52	...
53	*/
54	BOTAN_DEBUG_ASSERT(last_byte_pos < BS);
55
56	const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos);
57
58	buffer.resize(buffer.size() + padding_len);
59
60	CT::poison(&last_byte_pos, 1);
61	CT::poison(buffer.data(), buffer.size());
62
63	BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0);
64	BOTAN_DEBUG_ASSERT(buffer.size() >= BS);
65
66	const size_t start_of_last_block = buffer.size() - BS;
67	const size_t end_of_last_block = buffer.size();
68	const size_t start_of_padding = buffer.size() - padding_len;
69
70	for(size_t i = start_of_last_block; i != end_of_last_block; ++i) {
71	auto needs_padding = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gte(i, start_of_padding));
72	buffer[i] = needs_padding.select(padding_len, buffer[i]);
73	}
74
75	CT::unpoison(buffer.data(), buffer.size());
76	CT::unpoison(last_byte_pos);
77	}
78
79	/*
80	* Unpad with PKCS #7 Method
81	*/
82	size_t PKCS7_Padding::unpad(const uint8_t input[], size_t input_length) const {
83	if(!valid_blocksize(input_length)) {
84	return input_length;
85	}
86
87	CT::poison(input, input_length);
88
89	const uint8_t last_byte = input[input_length - 1];
90
91	/*
92	The input should == the block size so if the last byte exceeds
93	that then the padding is certainly invalid
94	*/
95	auto bad_input = CT::Mask<size_t>::is_gt(last_byte, input_length);
96
97	const size_t pad_pos = input_length - last_byte;
98
99	for(size_t i = 0; i != input_length - 1; ++i) {
100	// Does this byte equal the expected pad byte?
101	const auto pad_eq = CT::Mask<size_t>::is_equal(input[i], last_byte);
102
103	// Ignore values that are not part of the padding
104	const auto in_range = CT::Mask<size_t>::is_gte(i, pad_pos);
105	bad_input \|= in_range & (~pad_eq);
106	}
107
108	CT::unpoison(input, input_length);
109
110	return bad_input.select_and_unpoison(input_length, pad_pos);
111	}
112
113	/*
114	* Pad with ANSI X9.23 Method
115	*/
116	void ANSI_X923_Padding::add_padding(secure_vector<uint8_t>& buffer, size_t last_byte_pos, size_t BS) const {
117	/*
118	Padding format is
119	01
120	0002
121	000003
122	...
123	*/
124	BOTAN_DEBUG_ASSERT(last_byte_pos < BS);
125
126	const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos);
127
128	buffer.resize(buffer.size() + padding_len);
129
130	CT::poison(&last_byte_pos, 1);
131	CT::poison(buffer.data(), buffer.size());
132
133	BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0);
134	BOTAN_DEBUG_ASSERT(buffer.size() >= BS);
135
136	const size_t start_of_last_block = buffer.size() - BS;
137	const size_t end_of_zero_padding = buffer.size() - 1;
138	const size_t start_of_padding = buffer.size() - padding_len;
139
140	for(size_t i = start_of_last_block; i != end_of_zero_padding; ++i) {
141	auto needs_padding = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gte(i, start_of_padding));
142	buffer[i] = needs_padding.select(0, buffer[i]);
143	}
144
145	buffer[buffer.size() - 1] = padding_len;
146	CT::unpoison(buffer.data(), buffer.size());
147	CT::unpoison(last_byte_pos);
148	}
149
150	/*
151	* Unpad with ANSI X9.23 Method
152	*/
153	size_t ANSI_X923_Padding::unpad(const uint8_t input[], size_t input_length) const {
154	if(!valid_blocksize(input_length)) {
155	return input_length;
156	}
157
158	CT::poison(input, input_length);
159
160	const size_t last_byte = input[input_length - 1];
161
162	auto bad_input = CT::Mask<size_t>::is_gt(last_byte, input_length);
163
164	const size_t pad_pos = input_length - last_byte;
165
166	for(size_t i = 0; i != input_length - 1; ++i) {
167	// Ignore values that are not part of the padding
168	const auto in_range = CT::Mask<size_t>::is_gte(i, pad_pos);
169	const auto pad_is_nonzero = CT::Mask<size_t>::expand(input[i]);
170	bad_input \|= pad_is_nonzero & in_range;
171	}
172
173	CT::unpoison(input, input_length);
174
175	return bad_input.select_and_unpoison(input_length, pad_pos);
176	}
177
178	/*
179	* Pad with One and Zeros Method
180	*/
181	void OneAndZeros_Padding::add_padding(secure_vector<uint8_t>& buffer, size_t last_byte_pos, size_t BS) const {
182	/*
183	Padding format is
184	80
185	8000
186	800000
187	...
188	*/
189
190	BOTAN_DEBUG_ASSERT(last_byte_pos < BS);
191
192	const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos);
193
194	buffer.resize(buffer.size() + padding_len);
195
196	CT::poison(&last_byte_pos, 1);
197	CT::poison(buffer.data(), buffer.size());
198
199	BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0);
200	BOTAN_DEBUG_ASSERT(buffer.size() >= BS);
201
202	const size_t start_of_last_block = buffer.size() - BS;
203	const size_t end_of_last_block = buffer.size();
204	const size_t start_of_padding = buffer.size() - padding_len;
205
206	for(size_t i = start_of_last_block; i != end_of_last_block; ++i) {
207	auto needs_80 = CT::Mask<uint8_t>(CT::Mask<size_t>::is_equal(i, start_of_padding));
208	auto needs_00 = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gt(i, start_of_padding));
209	buffer[i] = needs_00.select(0x00, needs_80.select(0x80, buffer[i]));
210	}
211
212	CT::unpoison(buffer.data(), buffer.size());
213	CT::unpoison(last_byte_pos);
214	}
215
216	/*
217	* Unpad with One and Zeros Method
218	*/
219	size_t OneAndZeros_Padding::unpad(const uint8_t input[], size_t input_length) const {
220	if(!valid_blocksize(input_length)) {
221	return input_length;
222	}
223
224	CT::poison(input, input_length);
225
226	auto bad_input = CT::Mask<uint8_t>::cleared();
227	auto seen_0x80 = CT::Mask<uint8_t>::cleared();
228
229	size_t pad_pos = input_length - 1;
230	size_t i = input_length;
231
232	while(i) {
233	const auto is_0x80 = CT::Mask<uint8_t>::is_equal(input[i - 1], 0x80);
234	const auto is_zero = CT::Mask<uint8_t>::is_zero(input[i - 1]);
235
236	seen_0x80 \|= is_0x80;
237	pad_pos -= seen_0x80.if_not_set_return(1);
238	bad_input \|= ~seen_0x80 & ~is_zero;
239	i--;
240	}
241	bad_input \|= ~seen_0x80;
242
243	CT::unpoison(input, input_length);
244
245	return CT::Mask<size_t>::expand(bad_input).select_and_unpoison(input_length, pad_pos);
246	}
247
248	/*
249	* Pad with ESP Padding Method
250	*/
251	void ESP_Padding::add_padding(secure_vector<uint8_t>& buffer, size_t last_byte_pos, size_t BS) const {
252	/*
253	Padding format is
254	01
255	0102
256	010203
257	...
258	*/
259	BOTAN_DEBUG_ASSERT(last_byte_pos < BS);
260
261	const uint8_t padding_len = static_cast<uint8_t>(BS - last_byte_pos);
262
263	buffer.resize(buffer.size() + padding_len);
264
265	CT::poison(&last_byte_pos, 1);
266	CT::poison(buffer.data(), buffer.size());
267
268	BOTAN_DEBUG_ASSERT(buffer.size() % BS == 0);
269	BOTAN_DEBUG_ASSERT(buffer.size() >= BS);
270
271	const size_t start_of_last_block = buffer.size() - BS;
272	const size_t end_of_last_block = buffer.size();
273	const size_t start_of_padding = buffer.size() - padding_len;
274
275	uint8_t pad_ctr = 0x01;
276
277	for(size_t i = start_of_last_block; i != end_of_last_block; ++i) {
278	auto needs_padding = CT::Mask<uint8_t>(CT::Mask<size_t>::is_gte(i, start_of_padding));
279	buffer[i] = needs_padding.select(pad_ctr, buffer[i]);
280	pad_ctr = needs_padding.select(pad_ctr + 1, pad_ctr);
281	}
282
283	CT::unpoison(buffer.data(), buffer.size());
284	CT::unpoison(last_byte_pos);
285	}
286
287	/*
288	* Unpad with ESP Padding Method
289	*/
290	size_t ESP_Padding::unpad(const uint8_t input[], size_t input_length) const {
291	if(!valid_blocksize(input_length)) {
292	return input_length;
293	}
294
295	CT::poison(input, input_length);
296
297	const uint8_t input_length_8 = static_cast<uint8_t>(input_length);
298	const uint8_t last_byte = input[input_length - 1];
299
300	auto bad_input = CT::Mask<uint8_t>::is_zero(last_byte) \| CT::Mask<uint8_t>::is_gt(last_byte, input_length_8);
301
302	const uint8_t pad_pos = input_length_8 - last_byte;
303	size_t i = input_length_8 - 1;
304	while(i) {
305	const auto in_range = CT::Mask<size_t>::is_gt(i, pad_pos);
306	const auto incrementing = CT::Mask<uint8_t>::is_equal(input[i - 1], input[i] - 1);
307
308	bad_input \|= CT::Mask<uint8_t>(in_range) & ~incrementing;
309	--i;
310	}
311
312	CT::unpoison(input, input_length);
313	return bad_input.select_and_unpoison(input_length_8, pad_pos);
314	}
315
316	} // namespace Botan

randombit / botan / 5123321399

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