16245054916

Committed 13 Jul 2025 03:51AM UTC coverage: 90.581% (+0.009%) from 90.572%

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Pull #4982

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Merge 11956826b into e87c8e33a

Pull Request Pull Request #4982: Enable and fix clang-tidy warning cert-err58-cpp

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/src/lib/pubkey/mce/mceliece_key.cpp

/*
 * (C) Copyright Projet SECRET, INRIA, Rocquencourt
 * (C) Bhaskar Biswas and  Nicolas Sendrier
 *
 * (C) 2014 cryptosource GmbH
 * (C) 2014 Falko Strenzke fstrenzke@cryptosource.de
 * (C) 2015 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 *
 */

#include <botan/mceliece.h>

#include <botan/ber_dec.h>
#include <botan/der_enc.h>
#include <botan/rng.h>
#include <botan/internal/bit_ops.h>
#include <botan/internal/code_based_util.h>
#include <botan/internal/loadstor.h>
#include <botan/internal/mce_internal.h>
#include <botan/internal/pk_ops_impl.h>
#include <botan/internal/polyn_gf2m.h>
#include <botan/internal/stl_util.h>

namespace Botan {

McEliece_PrivateKey::McEliece_PrivateKey(const McEliece_PrivateKey&) = default;
McEliece_PrivateKey::McEliece_PrivateKey(McEliece_PrivateKey&&) noexcept = default;
McEliece_PrivateKey& McEliece_PrivateKey::operator=(const McEliece_PrivateKey&) = default;
McEliece_PrivateKey& McEliece_PrivateKey::operator=(McEliece_PrivateKey&&) noexcept = default;
McEliece_PrivateKey::~McEliece_PrivateKey() = default;

McEliece_PrivateKey::McEliece_PrivateKey(const polyn_gf2m& goppa_polyn,
                                         const std::vector<uint32_t>& parity_check_matrix_coeffs,
                                         const std::vector<polyn_gf2m>& square_root_matrix,
                                         const std::vector<gf2m>& inverse_support,
                                         const std::vector<uint8_t>& public_matrix) :
      McEliece_PublicKey(public_matrix, goppa_polyn.get_degree(), inverse_support.size()),
      m_g{goppa_polyn},
      m_sqrtmod(square_root_matrix),
      m_Linv(inverse_support),
      m_coeffs(parity_check_matrix_coeffs),
      m_codimension(static_cast<size_t>(ceil_log2(inverse_support.size())) * goppa_polyn.get_degree()),
      m_dimension(inverse_support.size() - m_codimension) {}

// NOLINTNEXTLINE(*-member-init)
McEliece_PrivateKey::McEliece_PrivateKey(RandomNumberGenerator& rng, size_t code_length, size_t t) {
   uint32_t ext_deg = ceil_log2(code_length);
   *this = generate_mceliece_key(rng, ext_deg, code_length, t);
}

const polyn_gf2m& McEliece_PrivateKey::get_goppa_polyn() const {
   return m_g[0];
}

size_t McEliece_PublicKey::get_message_word_bit_length() const {
   size_t codimension = ceil_log2(m_code_length) * m_t;
   return m_code_length - codimension;
}

secure_vector<uint8_t> McEliece_PublicKey::random_plaintext_element(RandomNumberGenerator& rng) const {
   const size_t bits = get_message_word_bit_length();

   secure_vector<uint8_t> plaintext((bits + 7) / 8);
   rng.randomize(plaintext.data(), plaintext.size());

   // unset unused bits in the last plaintext byte
   if(uint32_t used = bits % 8) {
      const uint8_t mask = (1 << used) - 1;
      plaintext[plaintext.size() - 1] &= mask;
   }

   return plaintext;
}

AlgorithmIdentifier McEliece_PublicKey::algorithm_identifier() const {
   return AlgorithmIdentifier(object_identifier(), AlgorithmIdentifier::USE_EMPTY_PARAM);
}

std::vector<uint8_t> McEliece_PublicKey::raw_public_key_bits() const {
   return m_public_matrix;
}

std::vector<uint8_t> McEliece_PublicKey::public_key_bits() const {
   std::vector<uint8_t> output;
   DER_Encoder(output)
      .start_sequence()
      .start_sequence()
      .encode(get_code_length())
      .encode(get_t())
      .end_cons()
      .encode(m_public_matrix, ASN1_Type::OctetString)
      .end_cons();
   return output;
}

size_t McEliece_PublicKey::key_length() const {
   return m_code_length;
}

size_t McEliece_PublicKey::estimated_strength() const {
   return mceliece_work_factor(m_code_length, m_t);
}

McEliece_PublicKey::McEliece_PublicKey(std::span<const uint8_t> key_bits) {
   BER_Decoder dec(key_bits);
   size_t n = 0;
   size_t t = 0;
   dec.start_sequence()
      .start_sequence()
      .decode(n)
      .decode(t)
      .end_cons()
      .decode(m_public_matrix, ASN1_Type::OctetString)
      .end_cons();
   m_t = t;
   m_code_length = n;
}

secure_vector<uint8_t> McEliece_PrivateKey::private_key_bits() const {
   DER_Encoder enc;
   enc.start_sequence()
      .start_sequence()
      .encode(get_code_length())
      .encode(get_t())
      .end_cons()
      .encode(m_public_matrix, ASN1_Type::OctetString)
      .encode(m_g[0].encode(), ASN1_Type::OctetString);  // g as octet string
   enc.start_sequence();
   for(size_t i = 0; i < m_sqrtmod.size(); i++) {
      enc.encode(m_sqrtmod[i].encode(), ASN1_Type::OctetString);
   }
   enc.end_cons();
   secure_vector<uint8_t> enc_support;

   for(uint16_t Linv : m_Linv) {
      enc_support.push_back(get_byte<0>(Linv));
      enc_support.push_back(get_byte<1>(Linv));
   }
   enc.encode(enc_support, ASN1_Type::OctetString);
   secure_vector<uint8_t> enc_H;
   for(uint32_t coef : m_coeffs) {
      enc_H.push_back(get_byte<0>(coef));
      enc_H.push_back(get_byte<1>(coef));
      enc_H.push_back(get_byte<2>(coef));
      enc_H.push_back(get_byte<3>(coef));
   }
   enc.encode(enc_H, ASN1_Type::OctetString);
   enc.end_cons();
   return enc.get_contents();
}

bool McEliece_PrivateKey::check_key(RandomNumberGenerator& rng, bool /*unused*/) const {
   const secure_vector<uint8_t> plaintext = this->random_plaintext_element(rng);

   secure_vector<uint8_t> ciphertext;
   secure_vector<uint8_t> errors;
   mceliece_encrypt(ciphertext, errors, plaintext, *this, rng);

   secure_vector<uint8_t> plaintext_out;
   secure_vector<uint8_t> errors_out;
   mceliece_decrypt(plaintext_out, errors_out, ciphertext, *this);

   if(errors != errors_out || plaintext != plaintext_out) {
      return false;
   }

   return true;
}

McEliece_PrivateKey::McEliece_PrivateKey(std::span<const uint8_t> key_bits) {
   size_t n = 0;
   size_t t = 0;
   secure_vector<uint8_t> enc_g;
   BER_Decoder dec_base(key_bits);
   BER_Decoder dec = dec_base.start_sequence()
                        .start_sequence()
                        .decode(n)
                        .decode(t)
                        .end_cons()
                        .decode(m_public_matrix, ASN1_Type::OctetString)
                        .decode(enc_g, ASN1_Type::OctetString);

   if(t == 0 || n == 0) {
      throw Decoding_Error("invalid McEliece parameters");
   }

   uint32_t ext_deg = ceil_log2(n);
   m_code_length = n;
   m_t = t;
   m_codimension = (ext_deg * t);
   m_dimension = (n - m_codimension);

   auto sp_field = std::make_shared<GF2m_Field>(ext_deg);
   m_g = {polyn_gf2m(enc_g, sp_field)};
   if(m_g[0].get_degree() != static_cast<int>(t)) {
      throw Decoding_Error("degree of decoded Goppa polynomial is incorrect");
   }
   BER_Decoder dec2 = dec.start_sequence();
   for(uint32_t i = 0; i < t / 2; i++) {
      secure_vector<uint8_t> sqrt_enc;
      dec2.decode(sqrt_enc, ASN1_Type::OctetString);
      while(sqrt_enc.size() < (t * 2)) {
         // ensure that the length is always t
         sqrt_enc.push_back(0);
         sqrt_enc.push_back(0);
      }
      if(sqrt_enc.size() != t * 2) {
         throw Decoding_Error("length of square root polynomial entry is too large");
      }
      m_sqrtmod.push_back(polyn_gf2m(sqrt_enc, sp_field));
   }
   secure_vector<uint8_t> enc_support;
   BER_Decoder dec3 = dec2.end_cons().decode(enc_support, ASN1_Type::OctetString);
   if(enc_support.size() % 2) {
      throw Decoding_Error("encoded support has odd length");
   }
   if(enc_support.size() / 2 != n) {
      throw Decoding_Error("encoded support has length different from code length");
   }
   for(uint32_t i = 0; i < n * 2; i += 2) {
      gf2m el = (enc_support[i] << 8) | enc_support[i + 1];
      m_Linv.push_back(el);
   }
   secure_vector<uint8_t> enc_H;
   dec3.decode(enc_H, ASN1_Type::OctetString).end_cons();
   if(enc_H.size() % 4) {
      throw Decoding_Error("encoded parity check matrix has length which is not a multiple of four");
   }
   if(enc_H.size() / 4 != bit_size_to_32bit_size(m_codimension) * m_code_length) {
      throw Decoding_Error("encoded parity check matrix has wrong length");
   }

   for(uint32_t i = 0; i < enc_H.size(); i += 4) {
      uint32_t coeff = (enc_H[i] << 24) | (enc_H[i + 1] << 16) | (enc_H[i + 2] << 8) | enc_H[i + 3];
      m_coeffs.push_back(coeff);
   }
}

bool McEliece_PrivateKey::operator==(const McEliece_PrivateKey& other) const {
   if(*static_cast<const McEliece_PublicKey*>(this) != *static_cast<const McEliece_PublicKey*>(&other)) {
      return false;
   }
   if(m_g != other.m_g) {
      return false;
   }

   if(m_sqrtmod != other.m_sqrtmod) {
      return false;
   }
   if(m_Linv != other.m_Linv) {
      return false;
   }
   if(m_coeffs != other.m_coeffs) {
      return false;
   }

   if(m_codimension != other.m_codimension || m_dimension != other.m_dimension) {
      return false;
   }

   return true;
}

std::unique_ptr<Public_Key> McEliece_PrivateKey::public_key() const {
   return std::make_unique<McEliece_PublicKey>(get_public_matrix(), get_t(), get_code_length());
}

bool McEliece_PublicKey::operator==(const McEliece_PublicKey& other) const {
   if(m_public_matrix != other.m_public_matrix) {
      return false;
   }
   if(m_t != other.m_t) {
      return false;
   }
   if(m_code_length != other.m_code_length) {
      return false;
   }
   return true;
}

namespace {

class MCE_KEM_Encryptor final : public PK_Ops::KEM_Encryption_with_KDF {
   public:
      MCE_KEM_Encryptor(const McEliece_PublicKey& key, std::string_view kdf) :
            KEM_Encryption_with_KDF(kdf), m_key(key) {}

   private:
      size_t raw_kem_shared_key_length() const override {
         const size_t err_sz = (m_key.get_code_length() + 7) / 8;
         const size_t ptext_sz = (m_key.get_message_word_bit_length() + 7) / 8;
         return ptext_sz + err_sz;
      }

      size_t encapsulated_key_length() const override { return (m_key.get_code_length() + 7) / 8; }

      void raw_kem_encrypt(std::span<uint8_t> out_encapsulated_key,
                           std::span<uint8_t> raw_shared_key,
                           RandomNumberGenerator& rng) override {
         secure_vector<uint8_t> plaintext = m_key.random_plaintext_element(rng);

         secure_vector<uint8_t> ciphertext, error_mask;
         mceliece_encrypt(ciphertext, error_mask, plaintext, m_key, rng);

         // TODO: Perhaps avoid the copies below
         BOTAN_ASSERT_NOMSG(out_encapsulated_key.size() == ciphertext.size());
         std::copy(ciphertext.begin(), ciphertext.end(), out_encapsulated_key.begin());

         BOTAN_ASSERT_NOMSG(raw_shared_key.size() == plaintext.size() + error_mask.size());
         BufferStuffer bs(raw_shared_key);
         bs.append(plaintext);
         bs.append(error_mask);
      }

      const McEliece_PublicKey& m_key;
};

class MCE_KEM_Decryptor final : public PK_Ops::KEM_Decryption_with_KDF {
   public:
      MCE_KEM_Decryptor(const McEliece_PrivateKey& key, std::string_view kdf) :
            KEM_Decryption_with_KDF(kdf), m_key(key) {}

   private:
      size_t raw_kem_shared_key_length() const override {
         const size_t err_sz = (m_key.get_code_length() + 7) / 8;
         const size_t ptext_sz = (m_key.get_message_word_bit_length() + 7) / 8;
         return ptext_sz + err_sz;
      }

      size_t encapsulated_key_length() const override { return (m_key.get_code_length() + 7) / 8; }

      void raw_kem_decrypt(std::span<uint8_t> out_shared_key, std::span<const uint8_t> encapsulated_key) override {
         secure_vector<uint8_t> plaintext, error_mask;
         mceliece_decrypt(plaintext, error_mask, encapsulated_key.data(), encapsulated_key.size(), m_key);

         // TODO: perhaps avoid the copies below
         BOTAN_ASSERT_NOMSG(out_shared_key.size() == plaintext.size() + error_mask.size());
         BufferStuffer bs(out_shared_key);
         bs.append(plaintext);
         bs.append(error_mask);
      }

      const McEliece_PrivateKey& m_key;
};

}  // namespace

std::unique_ptr<Private_Key> McEliece_PublicKey::generate_another(RandomNumberGenerator& rng) const {
   return std::make_unique<McEliece_PrivateKey>(rng, get_code_length(), get_t());
}

std::unique_ptr<PK_Ops::KEM_Encryption> McEliece_PublicKey::create_kem_encryption_op(std::string_view params,
                                                                                     std::string_view provider) const {
   if(provider == "base" || provider.empty()) {
      return std::make_unique<MCE_KEM_Encryptor>(*this, params);
   }
   throw Provider_Not_Found(algo_name(), provider);
}

std::unique_ptr<PK_Ops::KEM_Decryption> McEliece_PrivateKey::create_kem_decryption_op(RandomNumberGenerator& /*rng*/,
                                                                                      std::string_view params,
                                                                                      std::string_view provider) const {
   if(provider == "base" || provider.empty()) {
      return std::make_unique<MCE_KEM_Decryptor>(*this, params);
   }
   throw Provider_Not_Found(algo_name(), provider);
}

}  // namespace Botan

1	/*
2	* (C) Copyright Projet SECRET, INRIA, Rocquencourt
3	* (C) Bhaskar Biswas and Nicolas Sendrier
4	*
5	* (C) 2014 cryptosource GmbH
6	* (C) 2014 Falko Strenzke fstrenzke@cryptosource.de
7	* (C) 2015 Jack Lloyd
8	*
9	* Botan is released under the Simplified BSD License (see license.txt)
10	*
11	*/
12
13	#include <botan/mceliece.h>
14
15	#include <botan/ber_dec.h>
16	#include <botan/der_enc.h>
17	#include <botan/rng.h>
18	#include <botan/internal/bit_ops.h>
19	#include <botan/internal/code_based_util.h>
20	#include <botan/internal/loadstor.h>
21	#include <botan/internal/mce_internal.h>
22	#include <botan/internal/pk_ops_impl.h>
23	#include <botan/internal/polyn_gf2m.h>
24	#include <botan/internal/stl_util.h>
25
26	namespace Botan {
27
28	McEliece_PrivateKey::McEliece_PrivateKey(const McEliece_PrivateKey&) = default;	×
29	McEliece_PrivateKey::McEliece_PrivateKey(McEliece_PrivateKey&&) noexcept = default;	×
30	McEliece_PrivateKey& McEliece_PrivateKey::operator=(const McEliece_PrivateKey&) = default;	×
31	McEliece_PrivateKey& McEliece_PrivateKey::operator=(McEliece_PrivateKey&&) noexcept = default;	93✔
32	McEliece_PrivateKey::~McEliece_PrivateKey() = default;	645✔
33
34	McEliece_PrivateKey::McEliece_PrivateKey(const polyn_gf2m& goppa_polyn,	93✔
35	const std::vector<uint32_t>& parity_check_matrix_coeffs,
36	const std::vector<polyn_gf2m>& square_root_matrix,
37	const std::vector<gf2m>& inverse_support,
38	const std::vector<uint8_t>& public_matrix) :	93✔
39	McEliece_PublicKey(public_matrix, goppa_polyn.get_degree(), inverse_support.size()),	93✔
40	m_g{goppa_polyn},	186✔
41	m_sqrtmod(square_root_matrix),	93✔
42	m_Linv(inverse_support),	93✔
43	m_coeffs(parity_check_matrix_coeffs),	93✔
44	m_codimension(static_cast<size_t>(ceil_log2(inverse_support.size())) * goppa_polyn.get_degree()),	186✔
45	m_dimension(inverse_support.size() - m_codimension) {}	186✔
46
47	// NOLINTNEXTLINE(*-member-init)
48	McEliece_PrivateKey::McEliece_PrivateKey(RandomNumberGenerator& rng, size_t code_length, size_t t) {	93✔
49	uint32_t ext_deg = ceil_log2(code_length);	93✔
50	*this = generate_mceliece_key(rng, ext_deg, code_length, t);	93✔
51	}	93✔
52
53	const polyn_gf2m& McEliece_PrivateKey::get_goppa_polyn() const {	10,564✔
54	return m_g[0];	10,564✔
55	}
56
57	size_t McEliece_PublicKey::get_message_word_bit_length() const {	10,394✔
58	size_t codimension = ceil_log2(m_code_length) * m_t;	10,394✔
59	return m_code_length - codimension;	10,394✔
60	}
61
62	secure_vector<uint8_t> McEliece_PublicKey::random_plaintext_element(RandomNumberGenerator& rng) const {	2,641✔
63	const size_t bits = get_message_word_bit_length();	2,641✔
64
65	secure_vector<uint8_t> plaintext((bits + 7) / 8);	2,641✔
66	rng.randomize(plaintext.data(), plaintext.size());	2,641✔
67
68	// unset unused bits in the last plaintext byte
69	if(uint32_t used = bits % 8) {	2,641✔
70	const uint8_t mask = (1 << used) - 1;	1,928✔
71	plaintext[plaintext.size() - 1] &= mask;	1,928✔
72	}
73
74	return plaintext;	2,641✔
75	}	×
76
77	AlgorithmIdentifier McEliece_PublicKey::algorithm_identifier() const {	13✔
78	return AlgorithmIdentifier(object_identifier(), AlgorithmIdentifier::USE_EMPTY_PARAM);	13✔
79	}
80
81	std::vector<uint8_t> McEliece_PublicKey::raw_public_key_bits() const {	×
82	return m_public_matrix;	×
83	}
84
85	std::vector<uint8_t> McEliece_PublicKey::public_key_bits() const {	267✔
86	std::vector<uint8_t> output;	267✔
87	DER_Encoder(output)	534✔
88	.start_sequence()	267✔
89	.start_sequence()	267✔
90	.encode(get_code_length())	267✔
91	.encode(get_t())	267✔
92	.end_cons()	267✔
93	.encode(m_public_matrix, ASN1_Type::OctetString)	267✔
94	.end_cons();	267✔
95	return output;	267✔
96	}	×
97
98	size_t McEliece_PublicKey::key_length() const {	×
99	return m_code_length;	×
100	}
101
102	size_t McEliece_PublicKey::estimated_strength() const {	2✔
103	return mceliece_work_factor(m_code_length, m_t);	2✔
104	}
105
106	McEliece_PublicKey::McEliece_PublicKey(std::span<const uint8_t> key_bits) {	86✔
107	BER_Decoder dec(key_bits);	86✔
108	size_t n = 0;	86✔
109	size_t t = 0;	86✔
110	dec.start_sequence()	172✔
111	.start_sequence()	172✔
112	.decode(n)	86✔
113	.decode(t)	86✔
114	.end_cons()	86✔
115	.decode(m_public_matrix, ASN1_Type::OctetString)	86✔
116	.end_cons();	86✔
117	m_t = t;	86✔
118	m_code_length = n;	86✔
119	}	86✔
120
121	secure_vector<uint8_t> McEliece_PrivateKey::private_key_bits() const {	270✔
122	DER_Encoder enc;	270✔
123	enc.start_sequence()	270✔
124	.start_sequence()	270✔
125	.encode(get_code_length())	270✔
126	.encode(get_t())	270✔
127	.end_cons()	270✔
128	.encode(m_public_matrix, ASN1_Type::OctetString)	270✔
129	.encode(m_g[0].encode(), ASN1_Type::OctetString); // g as octet string	540✔
130	enc.start_sequence();	270✔
131	for(size_t i = 0; i < m_sqrtmod.size(); i++) {	4,544✔
132	enc.encode(m_sqrtmod[i].encode(), ASN1_Type::OctetString);	12,822✔
133	}
134	enc.end_cons();	270✔
135	secure_vector<uint8_t> enc_support;	270✔
136
137	for(uint16_t Linv : m_Linv) {	387,758✔
138	enc_support.push_back(get_byte<0>(Linv));	387,488✔
139	enc_support.push_back(get_byte<1>(Linv));	387,488✔
140	}
141	enc.encode(enc_support, ASN1_Type::OctetString);	270✔
142	secure_vector<uint8_t> enc_H;	270✔
143	for(uint32_t coef : m_coeffs) {	8,999,790✔
144	enc_H.push_back(get_byte<0>(coef));	8,999,520✔
145	enc_H.push_back(get_byte<1>(coef));	8,999,520✔
146	enc_H.push_back(get_byte<2>(coef));	8,999,520✔
147	enc_H.push_back(get_byte<3>(coef));	8,999,520✔
148	}
149	enc.encode(enc_H, ASN1_Type::OctetString);	270✔
150	enc.end_cons();	270✔
151	return enc.get_contents();	540✔
152	}	540✔
153
154	bool McEliece_PrivateKey::check_key(RandomNumberGenerator& rng, bool /unused/) const {	85✔
155	const secure_vector<uint8_t> plaintext = this->random_plaintext_element(rng);	85✔
156
157	secure_vector<uint8_t> ciphertext;	85✔
158	secure_vector<uint8_t> errors;	85✔
159	mceliece_encrypt(ciphertext, errors, plaintext, *this, rng);	85✔
160
161	secure_vector<uint8_t> plaintext_out;	85✔
162	secure_vector<uint8_t> errors_out;	85✔
163	mceliece_decrypt(plaintext_out, errors_out, ciphertext, *this);	85✔
164
165	if(errors != errors_out \|\| plaintext != plaintext_out) {	85✔
166	return false;
167	}
168
169	return true;
170	}	425✔
171
172	McEliece_PrivateKey::McEliece_PrivateKey(std::span<const uint8_t> key_bits) {	89✔
173	size_t n = 0;	89✔
174	size_t t = 0;	89✔
175	secure_vector<uint8_t> enc_g;	89✔
176	BER_Decoder dec_base(key_bits);	89✔
177	BER_Decoder dec = dec_base.start_sequence()	178✔
178	.start_sequence()	178✔
179	.decode(n)	89✔
180	.decode(t)	89✔
181	.end_cons()	89✔
182	.decode(m_public_matrix, ASN1_Type::OctetString)	89✔
183	.decode(enc_g, ASN1_Type::OctetString);	89✔
184
185	if(t == 0 \|\| n == 0) {	89✔
186	throw Decoding_Error("invalid McEliece parameters");	×
187	}
188
189	uint32_t ext_deg = ceil_log2(n);	89✔
190	m_code_length = n;	89✔
191	m_t = t;	89✔
192	m_codimension = (ext_deg * t);	89✔
193	m_dimension = (n - m_codimension);	89✔
194
195	auto sp_field = std::make_shared<GF2m_Field>(ext_deg);	89✔
196	m_g = {polyn_gf2m(enc_g, sp_field)};	267✔
197	if(m_g[0].get_degree() != static_cast<int>(t)) {	89✔
198	throw Decoding_Error("degree of decoded Goppa polynomial is incorrect");	×
199	}
200	BER_Decoder dec2 = dec.start_sequence();	89✔
201	for(uint32_t i = 0; i < t / 2; i++) {	1,471✔
202	secure_vector<uint8_t> sqrt_enc;	1,382✔
203	dec2.decode(sqrt_enc, ASN1_Type::OctetString);	1,382✔
204	while(sqrt_enc.size() < (t * 2)) {	1,382✔
205	// ensure that the length is always t
206	sqrt_enc.push_back(0);	×
207	sqrt_enc.push_back(0);	×
208	}
209	if(sqrt_enc.size() != t * 2) {	1,382✔
210	throw Decoding_Error("length of square root polynomial entry is too large");	×
211	}
212	m_sqrtmod.push_back(polyn_gf2m(sqrt_enc, sp_field));	2,764✔
213	}	1,382✔
214	secure_vector<uint8_t> enc_support;	89✔
215	BER_Decoder dec3 = dec2.end_cons().decode(enc_support, ASN1_Type::OctetString);	89✔
216	if(enc_support.size() % 2) {	89✔
217	throw Decoding_Error("encoded support has odd length");	×
218	}
219	if(enc_support.size() / 2 != n) {	89✔
220	throw Decoding_Error("encoded support has length different from code length");	×
221	}
222	for(uint32_t i = 0; i < n * 2; i += 2) {	124,057✔
223	gf2m el = (enc_support[i] << 8) \| enc_support[i + 1];	123,968✔
224	m_Linv.push_back(el);	123,968✔
225	}
226	secure_vector<uint8_t> enc_H;	89✔
227	dec3.decode(enc_H, ASN1_Type::OctetString).end_cons();	89✔
228	if(enc_H.size() % 4) {	89✔
229	throw Decoding_Error("encoded parity check matrix has length which is not a multiple of four");	×
230	}
231	if(enc_H.size() / 4 != bit_size_to_32bit_size(m_codimension) * m_code_length) {	89✔
232	throw Decoding_Error("encoded parity check matrix has wrong length");	×
233	}
234
235	for(uint32_t i = 0; i < enc_H.size(); i += 4) {	2,801,081✔
236	uint32_t coeff = (enc_H[i] << 24) \| (enc_H[i + 1] << 16) \| (enc_H[i + 2] << 8) \| enc_H[i + 3];	2,800,992✔
237	m_coeffs.push_back(coeff);	2,800,992✔
238	}
239	}	445✔
240
241	bool McEliece_PrivateKey::operator==(const McEliece_PrivateKey& other) const {	×
242	if(static_cast<const McEliece_PublicKey>(this) != static_cast<const McEliece_PublicKey>(&other)) {	×
243	return false;
244	}
245	if(m_g != other.m_g) {	×
246	return false;
247	}
248
249	if(m_sqrtmod != other.m_sqrtmod) {	×
250	return false;
251	}
252	if(m_Linv != other.m_Linv) {	×
253	return false;
254	}
255	if(m_coeffs != other.m_coeffs) {	×
256	return false;
257	}
258
259	if(m_codimension != other.m_codimension \|\| m_dimension != other.m_dimension) {	×
260	return false;
261	}
262
263	return true;
264	}
265
266	std::unique_ptr<Public_Key> McEliece_PrivateKey::public_key() const {	2✔
267	return std::make_unique<McEliece_PublicKey>(get_public_matrix(), get_t(), get_code_length());	2✔
268	}
269
270	bool McEliece_PublicKey::operator==(const McEliece_PublicKey& other) const {	×
271	if(m_public_matrix != other.m_public_matrix) {	×
272	return false;
273	}
274	if(m_t != other.m_t) {	×
275	return false;
276	}
277	if(m_code_length != other.m_code_length) {	×
278	return false;	×
279	}
280	return true;
281	}
282
283	namespace {
284
285	class MCE_KEM_Encryptor final : public PK_Ops::KEM_Encryption_with_KDF {
286	public:
287	MCE_KEM_Encryptor(const McEliece_PublicKey& key, std::string_view kdf) :	91✔
288	KEM_Encryption_with_KDF(kdf), m_key(key) {}	91✔
289
290	private:
291	size_t raw_kem_shared_key_length() const override {	2,556✔
292	const size_t err_sz = (m_key.get_code_length() + 7) / 8;	2,556✔
293	const size_t ptext_sz = (m_key.get_message_word_bit_length() + 7) / 8;	2,556✔
294	return ptext_sz + err_sz;	2,556✔
295	}
296
297	size_t encapsulated_key_length() const override { return (m_key.get_code_length() + 7) / 8; }	7,668✔
298
299	void raw_kem_encrypt(std::span<uint8_t> out_encapsulated_key,	2,556✔
300	std::span<uint8_t> raw_shared_key,
301	RandomNumberGenerator& rng) override {
302	secure_vector<uint8_t> plaintext = m_key.random_plaintext_element(rng);	2,556✔
303
304	secure_vector<uint8_t> ciphertext, error_mask;	2,556✔
305	mceliece_encrypt(ciphertext, error_mask, plaintext, m_key, rng);	2,556✔
306
307	// TODO: Perhaps avoid the copies below
308	BOTAN_ASSERT_NOMSG(out_encapsulated_key.size() == ciphertext.size());	2,556✔
309	std::copy(ciphertext.begin(), ciphertext.end(), out_encapsulated_key.begin());	2,556✔
310
311	BOTAN_ASSERT_NOMSG(raw_shared_key.size() == plaintext.size() + error_mask.size());	2,556✔
312	BufferStuffer bs(raw_shared_key);	2,556✔
313	bs.append(plaintext);	2,556✔
314	bs.append(error_mask);	2,556✔
315	}	7,668✔
316
317	const McEliece_PublicKey& m_key;
318	};
319
320	class MCE_KEM_Decryptor final : public PK_Ops::KEM_Decryption_with_KDF {
321	public:
322	MCE_KEM_Decryptor(const McEliece_PrivateKey& key, std::string_view kdf) :	91✔
323	KEM_Decryption_with_KDF(kdf), m_key(key) {}	91✔
324
325	private:
326	size_t raw_kem_shared_key_length() const override {	2,556✔
327	const size_t err_sz = (m_key.get_code_length() + 7) / 8;	2,556✔
328	const size_t ptext_sz = (m_key.get_message_word_bit_length() + 7) / 8;	2,556✔
329	return ptext_sz + err_sz;	2,556✔
330	}
331
332	size_t encapsulated_key_length() const override { return (m_key.get_code_length() + 7) / 8; }	×
333
334	void raw_kem_decrypt(std::span<uint8_t> out_shared_key, std::span<const uint8_t> encapsulated_key) override {	2,556✔
335	secure_vector<uint8_t> plaintext, error_mask;	2,556✔
336	mceliece_decrypt(plaintext, error_mask, encapsulated_key.data(), encapsulated_key.size(), m_key);	2,556✔
337
338	// TODO: perhaps avoid the copies below
339	BOTAN_ASSERT_NOMSG(out_shared_key.size() == plaintext.size() + error_mask.size());	2,556✔
340	BufferStuffer bs(out_shared_key);	2,556✔
341	bs.append(plaintext);	2,556✔
342	bs.append(error_mask);	2,556✔
343	}	5,112✔
344
345	const McEliece_PrivateKey& m_key;
346	};
347
348	} // namespace
349
350	std::unique_ptr<Private_Key> McEliece_PublicKey::generate_another(RandomNumberGenerator& rng) const {	×
351	return std::make_unique<McEliece_PrivateKey>(rng, get_code_length(), get_t());	×
352	}
353
354	std::unique_ptr<PK_Ops::KEM_Encryption> McEliece_PublicKey::create_kem_encryption_op(std::string_view params,	91✔
355	std::string_view provider) const {
356	if(provider == "base" \|\| provider.empty()) {	91✔
357	return std::make_unique<MCE_KEM_Encryptor>(*this, params);	91✔
358	}
359	throw Provider_Not_Found(algo_name(), provider);	×
360	}
361
362	std::unique_ptr<PK_Ops::KEM_Decryption> McEliece_PrivateKey::create_kem_decryption_op(RandomNumberGenerator& /rng/,	91✔
363	std::string_view params,
364	std::string_view provider) const {
365	if(provider == "base" \|\| provider.empty()) {	91✔
366	return std::make_unique<MCE_KEM_Decryptor>(*this, params);	91✔
367	}
368	throw Provider_Not_Found(algo_name(), provider);	×
369	}
370
371	} // namespace Botan

randombit / botan / 16245054916

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