5111374265

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/src/lib/math/bigint/bigint.cpp

/*
* BigInt Base
* (C) 1999-2011,2012,2014,2019 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/bigint.h>

#include <botan/internal/bit_ops.h>
#include <botan/internal/ct_utils.h>
#include <botan/internal/loadstor.h>
#include <botan/internal/mp_core.h>
#include <botan/internal/rounding.h>

namespace Botan {

BigInt::BigInt(uint64_t n) {
#if BOTAN_MP_WORD_BITS == 64
   m_data.set_word_at(0, n);
#else
   m_data.set_word_at(1, static_cast<word>(n >> 32));
   m_data.set_word_at(0, static_cast<word>(n));
#endif
}

//static
BigInt BigInt::from_u64(uint64_t n) {
   BigInt bn;

#if BOTAN_MP_WORD_BITS == 64
   bn.set_word_at(0, n);
#else
   bn.set_word_at(1, static_cast<word>(n >> 32));
   bn.set_word_at(0, static_cast<word>(n));
#endif

   return bn;
}

//static
BigInt BigInt::from_word(word n) {
   BigInt bn;
   bn.set_word_at(0, n);
   return bn;
}

//static
BigInt BigInt::from_s32(int32_t n) {
   if(n >= 0)
      return BigInt::from_u64(static_cast<uint64_t>(n));
   else
      return -BigInt::from_u64(static_cast<uint64_t>(-n));
}

//static
BigInt BigInt::with_capacity(size_t size) {
   BigInt bn;
   bn.grow_to(size);
   return bn;
}

/*
* Construct a BigInt from a string
*/
BigInt::BigInt(std::string_view str) {
   Base base = Decimal;
   size_t markers = 0;
   bool negative = false;

   if(str.length() > 0 && str[0] == '-') {
      markers += 1;
      negative = true;
   }

   if(str.length() > markers + 2 && str[markers] == '0' && str[markers + 1] == 'x') {
      markers += 2;
      base = Hexadecimal;
   }

   *this = decode(cast_char_ptr_to_uint8(str.data()) + markers, str.length() - markers, base);

   if(negative)
      set_sign(Negative);
   else
      set_sign(Positive);
}

BigInt::BigInt(const uint8_t input[], size_t length) { binary_decode(input, length); }

/*
* Construct a BigInt from an encoded BigInt
*/
BigInt::BigInt(const uint8_t input[], size_t length, Base base) { *this = decode(input, length, base); }

//static
BigInt BigInt::from_bytes_with_max_bits(const uint8_t input[], size_t length, size_t max_bits) {
   const size_t input_bits = 8 * length;

   BigInt bn;
   bn.binary_decode(input, length);

   if(input_bits > max_bits) {
      const size_t bits_to_shift = input_bits - max_bits;

      bn >>= bits_to_shift;
   }

   return bn;
}

/*
* Construct a BigInt from an encoded BigInt
*/
BigInt::BigInt(RandomNumberGenerator& rng, size_t bits, bool set_high_bit) { randomize(rng, bits, set_high_bit); }

uint8_t BigInt::byte_at(size_t n) const {
   return get_byte_var(sizeof(word) - (n % sizeof(word)) - 1, word_at(n / sizeof(word)));
}

int32_t BigInt::cmp_word(word other) const {
   if(is_negative())
      return -1;  // other is positive ...

   const size_t sw = this->sig_words();
   if(sw > 1)
      return 1;  // must be larger since other is just one word ...

   return bigint_cmp(this->data(), sw, &other, 1);
}

/*
* Comparison Function
*/
int32_t BigInt::cmp(const BigInt& other, bool check_signs) const {
   if(check_signs) {
      if(other.is_positive() && this->is_negative())
         return -1;

      if(other.is_negative() && this->is_positive())
         return 1;

      if(other.is_negative() && this->is_negative())
         return (-bigint_cmp(this->data(), this->size(), other.data(), other.size()));
   }

   return bigint_cmp(this->data(), this->size(), other.data(), other.size());
}

bool BigInt::is_equal(const BigInt& other) const {
   if(this->sign() != other.sign())
      return false;

   return bigint_ct_is_eq(this->data(), this->sig_words(), other.data(), other.sig_words()).is_set();
}

bool BigInt::is_less_than(const BigInt& other) const {
   if(this->is_negative() && other.is_positive())
      return true;

   if(this->is_positive() && other.is_negative())
      return false;

   if(other.is_negative() && this->is_negative()) {
      return bigint_ct_is_lt(other.data(), other.sig_words(), this->data(), this->sig_words()).is_set();
   }

   return bigint_ct_is_lt(this->data(), this->sig_words(), other.data(), other.sig_words()).is_set();
}

void BigInt::encode_words(word out[], size_t size) const {
   const size_t words = sig_words();

   if(words > size)
      throw Encoding_Error("BigInt::encode_words value too large to encode");

   clear_mem(out, size);
   copy_mem(out, data(), words);
}

size_t BigInt::Data::calc_sig_words() const {
   const size_t sz = m_reg.size();
   size_t sig = sz;

   word sub = 1;

   for(size_t i = 0; i != sz; ++i) {
      const word w = m_reg[sz - i - 1];
      sub &= ct_is_zero(w);
      sig -= sub;
   }

   /*
   * This depends on the data so is poisoned, but unpoison it here as
   * later conditionals are made on the size.
   */
   CT::unpoison(sig);

   return sig;
}

/*
* Return bits {offset...offset+length}
*/
uint32_t BigInt::get_substring(size_t offset, size_t length) const {
   if(length == 0 || length > 32)
      throw Invalid_Argument("BigInt::get_substring invalid substring length");

   const uint32_t mask = 0xFFFFFFFF >> (32 - length);

   const size_t word_offset = offset / BOTAN_MP_WORD_BITS;
   const size_t wshift = (offset % BOTAN_MP_WORD_BITS);

   /*
   * The substring is contained within one or at most two words. The
   * offset and length are not secret, so we can perform conditional
   * operations on those values.
   */
   const word w0 = word_at(word_offset);

   if(wshift == 0 || (offset + length) / BOTAN_MP_WORD_BITS == word_offset) {
      return static_cast<uint32_t>(w0 >> wshift) & mask;
   } else {
      const word w1 = word_at(word_offset + 1);
      return static_cast<uint32_t>((w0 >> wshift) | (w1 << (BOTAN_MP_WORD_BITS - wshift))) & mask;
   }
}

/*
* Convert this number to a uint32_t, if possible
*/
uint32_t BigInt::to_u32bit() const {
   if(is_negative())
      throw Encoding_Error("BigInt::to_u32bit: Number is negative");
   if(bits() > 32)
      throw Encoding_Error("BigInt::to_u32bit: Number is too big to convert");

   uint32_t out = 0;
   for(size_t i = 0; i != 4; ++i)
      out = (out << 8) | byte_at(3 - i);
   return out;
}

/*
* Clear bit number n
*/
void BigInt::clear_bit(size_t n) {
   const size_t which = n / BOTAN_MP_WORD_BITS;

   if(which < size()) {
      const word mask = ~(static_cast<word>(1) << (n % BOTAN_MP_WORD_BITS));
      m_data.set_word_at(which, word_at(which) & mask);
   }
}

size_t BigInt::bytes() const { return round_up(bits(), 8) / 8; }

size_t BigInt::top_bits_free() const {
   const size_t words = sig_words();

   const word top_word = word_at(words - 1);
   const size_t bits_used = high_bit(top_word);
   CT::unpoison(bits_used);
   return BOTAN_MP_WORD_BITS - bits_used;
}

size_t BigInt::bits() const {
   const size_t words = sig_words();

   if(words == 0)
      return 0;

   const size_t full_words = (words - 1) * BOTAN_MP_WORD_BITS;
   const size_t top_bits = BOTAN_MP_WORD_BITS - top_bits_free();

   return full_words + top_bits;
}

/*
* Return the negation of this number
*/
BigInt BigInt::operator-() const {
   BigInt x = (*this);
   x.flip_sign();
   return x;
}

size_t BigInt::reduce_below(const BigInt& p, secure_vector<word>& ws) {
   if(p.is_negative() || this->is_negative())
      throw Invalid_Argument("BigInt::reduce_below both values must be positive");

   const size_t p_words = p.sig_words();

   if(size() < p_words + 1)
      grow_to(p_words + 1);

   if(ws.size() < p_words + 1)
      ws.resize(p_words + 1);

   clear_mem(ws.data(), ws.size());

   size_t reductions = 0;

   for(;;) {
      word borrow = bigint_sub3(ws.data(), data(), p_words + 1, p.data(), p_words);
      if(borrow)
         break;

      ++reductions;
      swap_reg(ws);
   }

   return reductions;
}

void BigInt::ct_reduce_below(const BigInt& mod, secure_vector<word>& ws, size_t bound) {
   if(mod.is_negative() || this->is_negative())
      throw Invalid_Argument("BigInt::ct_reduce_below both values must be positive");

   const size_t mod_words = mod.sig_words();

   grow_to(mod_words);

   const size_t sz = size();

   ws.resize(sz);

   clear_mem(ws.data(), sz);

   for(size_t i = 0; i != bound; ++i) {
      word borrow = bigint_sub3(ws.data(), data(), sz, mod.data(), mod_words);

      CT::Mask<word>::is_zero(borrow).select_n(mutable_data(), ws.data(), data(), sz);
   }
}

/*
* Return the absolute value of this number
*/
BigInt BigInt::abs() const {
   BigInt x = (*this);
   x.set_sign(Positive);
   return x;
}

void BigInt::binary_encode(uint8_t buf[]) const { this->binary_encode(buf, bytes()); }

/*
* Encode this number into bytes
*/
void BigInt::binary_encode(uint8_t output[], size_t len) const {
   const size_t full_words = len / sizeof(word);
   const size_t extra_bytes = len % sizeof(word);

   for(size_t i = 0; i != full_words; ++i) {
      const word w = word_at(i);
      store_be(w, output + (len - (i + 1) * sizeof(word)));
   }

   if(extra_bytes > 0) {
      const word w = word_at(full_words);

      for(size_t i = 0; i != extra_bytes; ++i) {
         output[extra_bytes - i - 1] = get_byte_var(sizeof(word) - i - 1, w);
      }
   }
}

/*
* Set this number to the value in buf
*/
void BigInt::binary_decode(const uint8_t buf[], size_t length) {
   clear();

   const size_t full_words = length / sizeof(word);
   const size_t extra_bytes = length % sizeof(word);

   secure_vector<word> reg((round_up(full_words + (extra_bytes > 0 ? 1 : 0), 8)));

   for(size_t i = 0; i != full_words; ++i) {
      reg[i] = load_be<word>(buf + length - sizeof(word) * (i + 1), 0);
   }

   if(extra_bytes > 0) {
      for(size_t i = 0; i != extra_bytes; ++i)
         reg[full_words] = (reg[full_words] << 8) | buf[i];
   }

   m_data.swap(reg);
}

void BigInt::ct_cond_add(bool predicate, const BigInt& value) {
   if(this->is_negative() || value.is_negative())
      throw Invalid_Argument("BigInt::ct_cond_add requires both values to be positive");
   this->grow_to(1 + value.sig_words());

   bigint_cnd_add(static_cast<word>(predicate), this->mutable_data(), this->size(), value.data(), value.sig_words());
}

void BigInt::ct_cond_swap(bool predicate, BigInt& other) {
   const size_t max_words = std::max(size(), other.size());
   grow_to(max_words);
   other.grow_to(max_words);

   bigint_cnd_swap(predicate, this->mutable_data(), other.mutable_data(), max_words);
}

void BigInt::cond_flip_sign(bool predicate) {
   // This code is assuming Negative == 0, Positive == 1

   const auto mask = CT::Mask<uint8_t>::expand(predicate);

   const uint8_t current_sign = static_cast<uint8_t>(sign());

   const uint8_t new_sign = mask.select(current_sign ^ 1, current_sign);

   set_sign(static_cast<Sign>(new_sign));
}

void BigInt::ct_cond_assign(bool predicate, const BigInt& other) {
   const size_t t_words = size();
   const size_t o_words = other.size();

   if(o_words < t_words)
      grow_to(o_words);

   const size_t r_words = std::max(t_words, o_words);

   const auto mask = CT::Mask<word>::expand(predicate);

   for(size_t i = 0; i != r_words; ++i) {
      const word o_word = other.word_at(i);
      const word t_word = this->word_at(i);
      this->set_word_at(i, mask.select(o_word, t_word));
   }

   const bool different_sign = sign() != other.sign();
   cond_flip_sign(predicate && different_sign);
}

#if defined(BOTAN_HAS_VALGRIND)
void BigInt::const_time_poison() const { CT::poison(m_data.const_data(), m_data.size()); }

void BigInt::const_time_unpoison() const { CT::unpoison(m_data.const_data(), m_data.size()); }
#endif

}  // namespace Botan

1	/*
2	* BigInt Base
3	* (C) 1999-2011,2012,2014,2019 Jack Lloyd
4	*
5	* Botan is released under the Simplified BSD License (see license.txt)
6	*/
7
8	#include <botan/bigint.h>
9
10	#include <botan/internal/bit_ops.h>
11	#include <botan/internal/ct_utils.h>
12	#include <botan/internal/loadstor.h>
13	#include <botan/internal/mp_core.h>
14	#include <botan/internal/rounding.h>
15
16	namespace Botan {
17
18	BigInt::BigInt(uint64_t n) {	230,025✔
19	#if BOTAN_MP_WORD_BITS == 64
20	m_data.set_word_at(0, n);	230,025✔
21	#else
22	m_data.set_word_at(1, static_cast<word>(n >> 32));
23	m_data.set_word_at(0, static_cast<word>(n));
24	#endif
25	}	230,025✔
26
27	//static
28	BigInt BigInt::from_u64(uint64_t n) {	25,358✔
29	BigInt bn;	25,358✔
30
31	#if BOTAN_MP_WORD_BITS == 64
32	bn.set_word_at(0, n);	25,358✔
33	#else
34	bn.set_word_at(1, static_cast<word>(n >> 32));
35	bn.set_word_at(0, static_cast<word>(n));
36	#endif
37
38	return bn;	25,358✔
39	}	×
40
41	//static
42	BigInt BigInt::from_word(word n) {	572,098✔
43	BigInt bn;	572,098✔
44	bn.set_word_at(0, n);	572,098✔
45	return bn;	572,098✔
46	}	×
47
48	//static
49	BigInt BigInt::from_s32(int32_t n) {	2,655✔
50	if(n >= 0)	2,655✔
51	return BigInt::from_u64(static_cast<uint64_t>(n));	2✔
52	else
53	return -BigInt::from_u64(static_cast<uint64_t>(-n));	5,306✔
54	}
55
56	//static
57	BigInt BigInt::with_capacity(size_t size) {	13,057,972✔
58	BigInt bn;	13,057,972✔
59	bn.grow_to(size);	13,057,972✔
60	return bn;	13,057,972✔
61	}	×
62
63	/*
64	* Construct a BigInt from a string
65	*/
66	BigInt::BigInt(std::string_view str) {	44,410✔
67	Base base = Decimal;	44,410✔
68	size_t markers = 0;	44,410✔
69	bool negative = false;	44,410✔
70
71	if(str.length() > 0 && str[0] == '-') {	44,410✔
72	markers += 1;
73	negative = true;
74	}
75
76	if(str.length() > markers + 2 && str[markers] == '0' && str[markers + 1] == 'x') {	44,410✔
77	markers += 2;
78	base = Hexadecimal;
79	}
80
81	*this = decode(cast_char_ptr_to_uint8(str.data()) + markers, str.length() - markers, base);	44,410✔
82
83	if(negative)	44,410✔
84	set_sign(Negative);	445✔
85	else
86	set_sign(Positive);	43,965✔
87	}	44,410✔
88
89	BigInt::BigInt(const uint8_t input[], size_t length) { binary_decode(input, length); }	207,746✔
90
91	/*
92	* Construct a BigInt from an encoded BigInt
93	*/
94	BigInt::BigInt(const uint8_t input[], size_t length, Base base) { *this = decode(input, length, base); }	4✔
95
96	//static
97	BigInt BigInt::from_bytes_with_max_bits(const uint8_t input[], size_t length, size_t max_bits) {	21,288✔
98	const size_t input_bits = 8 * length;	21,288✔
99
100	BigInt bn;	21,288✔
101	bn.binary_decode(input, length);	21,288✔
102
103	if(input_bits > max_bits) {	21,288✔
104	const size_t bits_to_shift = input_bits - max_bits;	8,949✔
105
106	bn >>= bits_to_shift;	8,949✔
107	}
108
109	return bn;	21,288✔
110	}	×
111
112	/*
113	* Construct a BigInt from an encoded BigInt
114	*/
115	BigInt::BigInt(RandomNumberGenerator& rng, size_t bits, bool set_high_bit) { randomize(rng, bits, set_high_bit); }	22,367✔
116
117	uint8_t BigInt::byte_at(size_t n) const {	286,350✔
118	return get_byte_var(sizeof(word) - (n % sizeof(word)) - 1, word_at(n / sizeof(word)));	286,350✔
119	}
120
121	int32_t BigInt::cmp_word(word other) const {	4,018,367✔
122	if(is_negative())	4,018,367✔
123	return -1; // other is positive ...
124
125	const size_t sw = this->sig_words();	3,985,187✔
126	if(sw > 1)	3,985,187✔
127	return 1; // must be larger since other is just one word ...
128
129	return bigint_cmp(this->data(), sw, &other, 1);	1,845,168✔
130	}
131
132	/*
133	* Comparison Function
134	*/
135	int32_t BigInt::cmp(const BigInt& other, bool check_signs) const {	537,105✔
136	if(check_signs) {	537,105✔
137	if(other.is_positive() && this->is_negative())	536,978✔
138	return -1;
139
140	if(other.is_negative() && this->is_positive())	536,902✔
141	return 1;
142
143	if(other.is_negative() && this->is_negative())	536,856✔
144	return (-bigint_cmp(this->data(), this->size(), other.data(), other.size()));	64✔
145	}
146
147	return bigint_cmp(this->data(), this->size(), other.data(), other.size());	536,919✔
148	}
149
150	bool BigInt::is_equal(const BigInt& other) const {	391,481✔
151	if(this->sign() != other.sign())	391,481✔
152	return false;
153
154	return bigint_ct_is_eq(this->data(), this->sig_words(), other.data(), other.sig_words()).is_set();	585,091✔
155	}
156
157	bool BigInt::is_less_than(const BigInt& other) const {	2,756,057✔
158	if(this->is_negative() && other.is_positive())	2,756,057✔
159	return true;
160
161	if(this->is_positive() && other.is_negative())	2,755,995✔
162	return false;
163
164	if(other.is_negative() && this->is_negative()) {	2,755,936✔
165	return bigint_ct_is_lt(other.data(), other.sig_words(), this->data(), this->sig_words()).is_set();	63✔
166	}
167
168	return bigint_ct_is_lt(this->data(), this->sig_words(), other.data(), other.sig_words()).is_set();	5,269,763✔
169	}
170
171	void BigInt::encode_words(word out[], size_t size) const {	1,957,818✔
172	const size_t words = sig_words();	1,957,818✔
173
174	if(words > size)	1,957,818✔
175	throw Encoding_Error("BigInt::encode_words value too large to encode");	×
176
177	clear_mem(out, size);	1,957,818✔
178	copy_mem(out, data(), words);	1,957,818✔
179	}	1,957,818✔
180
181	size_t BigInt::Data::calc_sig_words() const {	108,248,676✔
182	const size_t sz = m_reg.size();	108,248,676✔
183	size_t sig = sz;	108,248,676✔
184
185	word sub = 1;	108,248,676✔
186
187	for(size_t i = 0; i != sz; ++i) {	1,850,144,108✔
188	const word w = m_reg[sz - i - 1];	1,741,895,432✔
189	sub &= ct_is_zero(w);	1,741,895,432✔
190	sig -= sub;	1,741,895,432✔
191	}
192
193	/*
194	* This depends on the data so is poisoned, but unpoison it here as
195	* later conditionals are made on the size.
196	*/
197	CT::unpoison(sig);	108,248,676✔
198
199	return sig;	108,248,676✔
200	}
201
202	/*
203	* Return bits {offset...offset+length}
204	*/
205	uint32_t BigInt::get_substring(size_t offset, size_t length) const {	16,588,117✔
206	if(length == 0 \|\| length > 32)	16,588,117✔
207	throw Invalid_Argument("BigInt::get_substring invalid substring length");	×
208
209	const uint32_t mask = 0xFFFFFFFF >> (32 - length);	16,588,117✔
210
211	const size_t word_offset = offset / BOTAN_MP_WORD_BITS;	16,588,117✔
212	const size_t wshift = (offset % BOTAN_MP_WORD_BITS);	16,588,117✔
213
214	/*
215	* The substring is contained within one or at most two words. The
216	* offset and length are not secret, so we can perform conditional
217	* operations on those values.
218	*/
219	const word w0 = word_at(word_offset);	16,588,117✔
220
221	if(wshift == 0 \|\| (offset + length) / BOTAN_MP_WORD_BITS == word_offset) {	16,588,117✔
222	return static_cast<uint32_t>(w0 >> wshift) & mask;	15,805,493✔
223	} else {
224	const word w1 = word_at(word_offset + 1);	782,624✔
225	return static_cast<uint32_t>((w0 >> wshift) \| (w1 << (BOTAN_MP_WORD_BITS - wshift))) & mask;	782,624✔
226	}
227	}
228
229	/*
230	* Convert this number to a uint32_t, if possible
231	*/
232	uint32_t BigInt::to_u32bit() const {	34,948✔
233	if(is_negative())	34,948✔
234	throw Encoding_Error("BigInt::to_u32bit: Number is negative");	×
235	if(bits() > 32)	34,948✔
236	throw Encoding_Error("BigInt::to_u32bit: Number is too big to convert");	15✔
237
238	uint32_t out = 0;
239	for(size_t i = 0; i != 4; ++i)	174,665✔
240	out = (out << 8) \| byte_at(3 - i);	139,732✔
241	return out;	34,933✔
242	}
243
244	/*
245	* Clear bit number n
246	*/
247	void BigInt::clear_bit(size_t n) {	20✔
248	const size_t which = n / BOTAN_MP_WORD_BITS;	20✔
249
250	if(which < size()) {	20✔
251	const word mask = ~(static_cast<word>(1) << (n % BOTAN_MP_WORD_BITS));	20✔
252	m_data.set_word_at(which, word_at(which) & mask);	20✔
253	}
254	}	20✔
255
256	size_t BigInt::bytes() const { return round_up(bits(), 8) / 8; }	213,442✔
257
258	size_t BigInt::top_bits_free() const {	4,392,512✔
259	const size_t words = sig_words();	4,392,512✔
260
261	const word top_word = word_at(words - 1);	35,140,096✔
262	const size_t bits_used = high_bit(top_word);	4,392,512✔
263	CT::unpoison(bits_used);	4,392,512✔
264	return BOTAN_MP_WORD_BITS - bits_used;	4,392,512✔
265	}
266
267	size_t BigInt::bits() const {	2,023,192✔
268	const size_t words = sig_words();	2,023,192✔
269
270	if(words == 0)	2,023,192✔
271	return 0;
272
273	const size_t full_words = (words - 1) * BOTAN_MP_WORD_BITS;	2,006,326✔
274	const size_t top_bits = BOTAN_MP_WORD_BITS - top_bits_free();	2,006,326✔
275
276	return full_words + top_bits;	2,006,326✔
277	}
278
279	/*
280	* Return the negation of this number
281	*/
282	BigInt BigInt::operator-() const {	2,877✔
283	BigInt x = (*this);	2,877✔
284	x.flip_sign();	2,877✔
285	return x;	2,877✔
286	}	×
287
288	size_t BigInt::reduce_below(const BigInt& p, secure_vector<word>& ws) {	25,085,352✔
289	if(p.is_negative() \|\| this->is_negative())	25,085,352✔
290	throw Invalid_Argument("BigInt::reduce_below both values must be positive");	×
291
292	const size_t p_words = p.sig_words();	25,085,352✔
293
294	if(size() < p_words + 1)	25,085,352✔
295	grow_to(p_words + 1);	11,117✔
296
297	if(ws.size() < p_words + 1)	25,085,352✔
298	ws.resize(p_words + 1);	652,392✔
299
300	clear_mem(ws.data(), ws.size());	25,085,352✔
301
302	size_t reductions = 0;
303
304	for(;;) {	64,827,419✔
305	word borrow = bigint_sub3(ws.data(), data(), p_words + 1, p.data(), p_words);	129,654,838✔
306	if(borrow)	64,827,419✔
307	break;
308
309	++reductions;	39,742,067✔
310	swap_reg(ws);	64,827,419✔
311	}
312
313	return reductions;	25,085,352✔
314	}
315
316	void BigInt::ct_reduce_below(const BigInt& mod, secure_vector<word>& ws, size_t bound) {	8,337,499✔
317	if(mod.is_negative() \|\| this->is_negative())	8,337,499✔
318	throw Invalid_Argument("BigInt::ct_reduce_below both values must be positive");	×
319
320	const size_t mod_words = mod.sig_words();	8,337,499✔
321
322	grow_to(mod_words);	8,337,499✔
323
324	const size_t sz = size();	8,337,499✔
325
326	ws.resize(sz);	8,337,499✔
327
328	clear_mem(ws.data(), sz);	8,337,499✔
329
330	for(size_t i = 0; i != bound; ++i) {	25,012,497✔
331	word borrow = bigint_sub3(ws.data(), data(), sz, mod.data(), mod_words);	16,674,998✔
332
333	CT::Mask<word>::is_zero(borrow).select_n(mutable_data(), ws.data(), data(), sz);	33,349,996✔
334	}
335	}	8,337,499✔
336
337	/*
338	* Return the absolute value of this number
339	*/
340	BigInt BigInt::abs() const {	958✔
341	BigInt x = (*this);	958✔
342	x.set_sign(Positive);	958✔
343	return x;	958✔
344	}
345
346	void BigInt::binary_encode(uint8_t buf[]) const { this->binary_encode(buf, bytes()); }	73,315✔
347
348	/*
349	* Encode this number into bytes
350	*/
351	void BigInt::binary_encode(uint8_t output[], size_t len) const {	105,352✔
352	const size_t full_words = len / sizeof(word);	105,352✔
353	const size_t extra_bytes = len % sizeof(word);	105,352✔
354
355	for(size_t i = 0; i != full_words; ++i) {	1,154,142✔
356	const word w = word_at(i);	1,048,790✔
357	store_be(w, output + (len - (i + 1) * sizeof(word)));	1,048,790✔
358	}
359
360	if(extra_bytes > 0) {	105,352✔
361	const word w = word_at(full_words);	47,623✔
362
363	for(size_t i = 0; i != extra_bytes; ++i) {	195,816✔
364	output[extra_bytes - i - 1] = get_byte_var(sizeof(word) - i - 1, w);	148,193✔
365	}
366	}
367	}	105,352✔
368
369	/*
370	* Set this number to the value in buf
371	*/
372	void BigInt::binary_decode(const uint8_t buf[], size_t length) {	585,383✔
373	clear();	585,383✔
374
375	const size_t full_words = length / sizeof(word);	585,383✔
376	const size_t extra_bytes = length % sizeof(word);	585,383✔
377
378	secure_vector<word> reg((round_up(full_words + (extra_bytes > 0 ? 1 : 0), 8)));	1,314,087✔
379
380	for(size_t i = 0; i != full_words; ++i) {	4,052,804✔
381	reg[i] = load_be<word>(buf + length - sizeof(word) * (i + 1), 0);	3,467,421✔
382	}
383
384	if(extra_bytes > 0) {	585,383✔
385	for(size_t i = 0; i != extra_bytes; ++i)	1,378,057✔
386	reg[full_words] = (reg[full_words] << 8) \| buf[i];	1,009,423✔
387	}
388
389	m_data.swap(reg);	585,383✔
390	}	585,383✔
391
392	void BigInt::ct_cond_add(bool predicate, const BigInt& value) {	7,914,509✔
393	if(this->is_negative() \|\| value.is_negative())	7,914,509✔
394	throw Invalid_Argument("BigInt::ct_cond_add requires both values to be positive");	×
395	this->grow_to(1 + value.sig_words());	13,276,500✔
396
397	bigint_cnd_add(static_cast<word>(predicate), this->mutable_data(), this->size(), value.data(), value.sig_words());	7,914,509✔
398	}	7,914,509✔
399
400	void BigInt::ct_cond_swap(bool predicate, BigInt& other) {	155,658,527✔
401	const size_t max_words = std::max(size(), other.size());	155,658,527✔
402	grow_to(max_words);	155,658,527✔
403	other.grow_to(max_words);	155,658,527✔
404
405	bigint_cnd_swap(predicate, this->mutable_data(), other.mutable_data(), max_words);	155,658,527✔
406	}	155,658,527✔
407
408	void BigInt::cond_flip_sign(bool predicate) {	21,983,896✔
409	// This code is assuming Negative == 0, Positive == 1
410
411	const auto mask = CT::Mask<uint8_t>::expand(predicate);	21,983,896✔
412
413	const uint8_t current_sign = static_cast<uint8_t>(sign());	21,983,896✔
414
415	const uint8_t new_sign = mask.select(current_sign ^ 1, current_sign);	21,983,896✔
416
417	set_sign(static_cast<Sign>(new_sign));	21,983,896✔
418	}	21,983,896✔
419
420	void BigInt::ct_cond_assign(bool predicate, const BigInt& other) {	1,762,090✔
421	const size_t t_words = size();	1,762,090✔
422	const size_t o_words = other.size();	1,762,090✔
423
424	if(o_words < t_words)	1,762,090✔
425	grow_to(o_words);	44,214✔
426
427	const size_t r_words = std::max(t_words, o_words);	1,762,090✔
428
429	const auto mask = CT::Mask<word>::expand(predicate);	1,762,090✔
430
431	for(size_t i = 0; i != r_words; ++i) {	28,080,443✔
432	const word o_word = other.word_at(i);	26,318,353✔
433	const word t_word = this->word_at(i);	26,318,353✔
434	this->set_word_at(i, mask.select(o_word, t_word));	26,318,353✔
435	}
436
437	const bool different_sign = sign() != other.sign();	1,762,090✔
438	cond_flip_sign(predicate && different_sign);	1,762,090✔
439	}	1,762,090✔
440
441	#if defined(BOTAN_HAS_VALGRIND)
442	void BigInt::const_time_poison() const { CT::poison(m_data.const_data(), m_data.size()); }
443
444	void BigInt::const_time_unpoison() const { CT::unpoison(m_data.const_data(), m_data.size()); }
445	#endif
446
447	} // namespace Botan

randombit / botan / 5111374265

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