13 #include <botan/mceliece.h> 14 #include <botan/internal/mce_internal.h> 15 #include <botan/internal/bit_ops.h> 16 #include <botan/internal/code_based_util.h> 17 #include <botan/internal/pk_ops_impl.h> 18 #include <botan/loadstor.h> 19 #include <botan/der_enc.h> 20 #include <botan/ber_dec.h> 21 #include <botan/rng.h> 26 std::vector<uint32_t>
const& parity_check_matrix_coeffs,
27 std::vector<polyn_gf2m>
const& square_root_matrix,
28 std::vector<gf2m>
const& inverse_support,
29 std::vector<uint8_t>
const& public_matrix) :
32 m_sqrtmod(square_root_matrix),
33 m_Linv(inverse_support),
34 m_coeffs(parity_check_matrix_coeffs),
35 m_codimension(
ceil_log2(inverse_support.size()) * goppa_polyn.get_degree()),
36 m_dimension(inverse_support.size() - m_codimension)
57 rng.
randomize(plaintext.data(), plaintext.size());
60 if(uint32_t used = bits % 8)
62 const uint8_t mask = (1 << used) - 1;
63 plaintext[plaintext.size() - 1] &= mask;
76 std::vector<uint8_t> output;
125 for(
size_t i = 0; i < m_sqrtmod.size(); i++)
132 for(uint16_t Linv : m_Linv)
134 enc_support.push_back(
get_byte(0, Linv));
135 enc_support.push_back(
get_byte(1, Linv));
139 for(uint32_t coef : m_coeffs)
163 if(errors != errors_out || plaintext != plaintext_out)
188 m_codimension = (ext_deg * t);
189 m_dimension = (n - m_codimension);
191 std::shared_ptr<GF2m_Field> sp_field(
new GF2m_Field(ext_deg));
195 throw Decoding_Error(
"degree of decoded Goppa polynomial is incorrect");
198 for(uint32_t i = 0; i < t/2; i++)
202 while(sqrt_enc.size() < (t*2))
206 sqrt_enc.push_back(0);
208 if(sqrt_enc.size() != t*2)
210 throw Decoding_Error(
"length of square root polynomial entry is too large");
212 m_sqrtmod.push_back(
polyn_gf2m(sqrt_enc, sp_field));
217 if(enc_support.size() % 2)
221 if(enc_support.size() / 2 != n)
223 throw Decoding_Error(
"encoded support has length different from code length");
225 for(uint32_t i = 0; i < n*2; i+=2)
227 gf2m el = (enc_support[i] << 8) | enc_support[i+1];
228 m_Linv.push_back(el);
235 throw Decoding_Error(
"encoded parity check matrix has length which is not a multiple of four");
239 throw Decoding_Error(
"encoded parity check matrix has wrong length");
242 for(uint32_t i = 0; i < enc_H.size(); i+=4)
244 uint32_t coeff = (enc_H[i] << 24) | (enc_H[i+1] << 16) | (enc_H[i+2] << 8) | enc_H[i+3];
245 m_coeffs.push_back(coeff);
252 if(*static_cast<const McEliece_PublicKey*>(
this) != *static_cast<const McEliece_PublicKey*>(&other))
261 if( m_sqrtmod != other.m_sqrtmod)
265 if( m_Linv != other.m_Linv)
269 if( m_coeffs != other.m_coeffs)
274 if(m_codimension != other.m_codimension || m_dimension != other.m_dimension)
306 const std::string& kdf) :
307 KEM_Encryption_with_KDF(kdf), m_key(key) {}
310 void raw_kem_encrypt(secure_vector<uint8_t>& out_encapsulated_key,
311 secure_vector<uint8_t>& raw_shared_key,
314 secure_vector<uint8_t> plaintext = m_key.random_plaintext_element(rng);
316 secure_vector<uint8_t> ciphertext, error_mask;
319 raw_shared_key.clear();
320 raw_shared_key += plaintext;
321 raw_shared_key += error_mask;
323 out_encapsulated_key.swap(ciphertext);
326 const McEliece_PublicKey& m_key;
329 class MCE_KEM_Decryptor
final :
public PK_Ops::KEM_Decryption_with_KDF
333 MCE_KEM_Decryptor(
const McEliece_PrivateKey& key,
334 const std::string& kdf) :
335 KEM_Decryption_with_KDF(kdf), m_key(key) {}
338 secure_vector<uint8_t>
339 raw_kem_decrypt(
const uint8_t encap_key[],
size_t len)
override 341 secure_vector<uint8_t> plaintext, error_mask;
344 secure_vector<uint8_t> output;
345 output.reserve(plaintext.size() + error_mask.size());
346 output.insert(output.end(), plaintext.begin(), plaintext.end());
347 output.insert(output.end(), error_mask.begin(), error_mask.end());
351 const McEliece_PrivateKey& m_key;
356 std::unique_ptr<PK_Ops::KEM_Encryption>
358 const std::string& params,
359 const std::string& provider)
const 361 if(provider ==
"base" || provider.empty())
362 return std::unique_ptr<PK_Ops::KEM_Encryption>(
new MCE_KEM_Encryptor(*
this, params));
366 std::unique_ptr<PK_Ops::KEM_Decryption>
368 const std::string& params,
369 const std::string& provider)
const 371 if(provider ==
"base" || provider.empty())
372 return std::unique_ptr<PK_Ops::KEM_Decryption>(
new MCE_KEM_Decryptor(*
this, params));
std::vector< uint8_t > m_public_matrix
void mceliece_decrypt(secure_vector< uint8_t > &plaintext_out, secure_vector< uint8_t > &error_mask_out, const secure_vector< uint8_t > &ciphertext, const McEliece_PrivateKey &key)
secure_vector< uint8_t > private_key_bits() const override
void mceliece_encrypt(secure_vector< uint8_t > &ciphertext_out, secure_vector< uint8_t > &error_mask_out, const secure_vector< uint8_t > &plaintext, const McEliece_PublicKey &key, RandomNumberGenerator &rng)
bool operator==(const McEliece_PrivateKey &other) const
size_t bit_size_to_32bit_size(uint32_t bit_size)
virtual void randomize(uint8_t output[], size_t length)=0
int(* final)(unsigned char *, CTX *)
secure_vector< uint8_t > get_contents()
constexpr uint8_t get_byte(size_t byte_num, T input)
std::unique_ptr< PK_Ops::KEM_Encryption > create_kem_encryption_op(RandomNumberGenerator &rng, const std::string ¶ms, const std::string &provider) const override
std::unique_ptr< PK_Ops::KEM_Decryption > create_kem_decryption_op(RandomNumberGenerator &rng, const std::string ¶ms, const std::string &provider) const override
void push_back(const BER_Object &obj)
BER_Decoder & decode(bool &out)
bool check_key(RandomNumberGenerator &rng, bool strong) const override
DER_Encoder & encode(bool b)
virtual OID get_oid() const
size_t key_length() const override
std::string encode(const uint8_t der[], size_t length, const std::string &label, size_t width)
size_t mceliece_work_factor(size_t n, size_t t)
BER_Decoder start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
secure_vector< uint8_t > random_plaintext_element(RandomNumberGenerator &rng) const
McEliece_PrivateKey(RandomNumberGenerator &rng, size_t code_length, size_t t)
uint32_t get_code_length() const
AlgorithmIdentifier algorithm_identifier() const override
size_t estimated_strength() const override
DER_Encoder & start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
uint32_t get_message_word_bit_length() const
std::string algo_name() const override
bool operator==(const McEliece_PublicKey &other) const
std::vector< T, secure_allocator< T > > secure_vector
McEliece_PrivateKey generate_mceliece_key(RandomNumberGenerator &rng, size_t ext_deg, size_t code_length, size_t t)
secure_vector< uint8_t > encode() const
std::vector< uint8_t > public_key_bits() const override