13#include <botan/mceliece.h>
14#include <botan/polyn_gf2m.h>
15#include <botan/internal/mce_internal.h>
16#include <botan/internal/bit_ops.h>
17#include <botan/internal/code_based_util.h>
18#include <botan/internal/pk_ops_impl.h>
19#include <botan/loadstor.h>
20#include <botan/der_enc.h>
21#include <botan/ber_dec.h>
27 std::vector<uint32_t>
const& parity_check_matrix_coeffs,
28 std::vector<polyn_gf2m>
const& square_root_matrix,
29 std::vector<gf2m>
const& inverse_support,
30 std::vector<uint8_t>
const& public_matrix) :
33 m_sqrtmod(square_root_matrix),
34 m_Linv(inverse_support),
35 m_coeffs(parity_check_matrix_coeffs),
36 m_codimension(static_cast<size_t>(
ceil_log2(inverse_support.size())) * goppa_polyn.get_degree()),
37 m_dimension(inverse_support.size() - m_codimension)
43 uint32_t ext_deg =
ceil_log2(code_length);
65 rng.
randomize(plaintext.data(), plaintext.size());
68 if(uint32_t used = bits % 8)
70 const uint8_t mask = (1 << used) - 1;
71 plaintext[plaintext.size() - 1] &= mask;
84 std::vector<uint8_t> output;
133 for(
size_t i = 0; i < m_sqrtmod.size(); i++)
140 for(uint16_t Linv : m_Linv)
142 enc_support.push_back(
get_byte(0, Linv));
143 enc_support.push_back(
get_byte(1, Linv));
147 for(uint32_t coef : m_coeffs)
171 if(errors != errors_out || plaintext != plaintext_out)
196 m_codimension = (ext_deg * t);
197 m_dimension = (n - m_codimension);
199 std::shared_ptr<GF2m_Field> sp_field(
new GF2m_Field(ext_deg));
201 if(m_g[0].get_degree() !=
static_cast<int>(t))
203 throw Decoding_Error(
"degree of decoded Goppa polynomial is incorrect");
206 for(uint32_t i = 0; i < t/2; i++)
210 while(sqrt_enc.size() < (t*2))
214 sqrt_enc.push_back(0);
216 if(sqrt_enc.size() != t*2)
218 throw Decoding_Error(
"length of square root polynomial entry is too large");
220 m_sqrtmod.push_back(
polyn_gf2m(sqrt_enc, sp_field));
225 if(enc_support.size() % 2)
229 if(enc_support.size() / 2 != n)
231 throw Decoding_Error(
"encoded support has length different from code length");
233 for(uint32_t i = 0; i < n*2; i+=2)
235 gf2m el = (enc_support[i] << 8) | enc_support[i+1];
236 m_Linv.push_back(el);
243 throw Decoding_Error(
"encoded parity check matrix has length which is not a multiple of four");
247 throw Decoding_Error(
"encoded parity check matrix has wrong length");
250 for(uint32_t i = 0; i < enc_H.size(); i+=4)
252 uint32_t coeff = (enc_H[i] << 24) | (enc_H[i+1] << 16) | (enc_H[i+2] << 8) | enc_H[i+3];
253 m_coeffs.push_back(coeff);
269 if( m_sqrtmod != other.m_sqrtmod)
273 if( m_Linv != other.m_Linv)
277 if( m_coeffs != other.m_coeffs)
282 if(m_codimension != other.m_codimension || m_dimension != other.m_dimension)
314 const std::string& kdf) :
315 KEM_Encryption_with_KDF(kdf), m_key(key) {}
318 void raw_kem_encrypt(secure_vector<uint8_t>& out_encapsulated_key,
319 secure_vector<uint8_t>& raw_shared_key,
322 secure_vector<uint8_t> plaintext = m_key.random_plaintext_element(rng);
324 secure_vector<uint8_t> ciphertext, error_mask;
327 raw_shared_key.clear();
328 raw_shared_key += plaintext;
329 raw_shared_key += error_mask;
331 out_encapsulated_key.swap(ciphertext);
334 const McEliece_PublicKey& m_key;
337class MCE_KEM_Decryptor
final :
public PK_Ops::KEM_Decryption_with_KDF
341 MCE_KEM_Decryptor(
const McEliece_PrivateKey& key,
342 const std::string& kdf) :
343 KEM_Decryption_with_KDF(kdf), m_key(key) {}
346 secure_vector<uint8_t>
347 raw_kem_decrypt(
const uint8_t encap_key[],
size_t len)
override
349 secure_vector<uint8_t> plaintext, error_mask;
352 secure_vector<uint8_t> output;
353 output.reserve(plaintext.size() + error_mask.size());
354 output.insert(output.end(), plaintext.begin(), plaintext.end());
355 output.insert(output.end(), error_mask.begin(), error_mask.end());
359 const McEliece_PrivateKey& m_key;
364std::unique_ptr<PK_Ops::KEM_Encryption>
366 const std::string& params,
367 const std::string& provider)
const
369 if(provider ==
"base" || provider.empty())
370 return std::unique_ptr<PK_Ops::KEM_Encryption>(
new MCE_KEM_Encryptor(*
this, params));
374std::unique_ptr<PK_Ops::KEM_Decryption>
376 const std::string& params,
377 const std::string& provider)
const
379 if(provider ==
"base" || provider.empty())
380 return std::unique_ptr<PK_Ops::KEM_Decryption>(
new MCE_KEM_Decryptor(*
this, params));
BER_Decoder start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
void push_back(const BER_Object &obj)
BER_Decoder & decode(bool &out)
secure_vector< uint8_t > get_contents()
DER_Encoder & start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
DER_Encoder & encode(bool b)
secure_vector< uint8_t > private_key_bits() const override
McEliece_PrivateKey(RandomNumberGenerator &rng, size_t code_length, size_t t)
polyn_gf2m const & get_goppa_polyn() const
bool operator==(const McEliece_PrivateKey &other) const
std::unique_ptr< PK_Ops::KEM_Decryption > create_kem_decryption_op(RandomNumberGenerator &rng, const std::string ¶ms, const std::string &provider) const override
bool check_key(RandomNumberGenerator &rng, bool strong) const override
secure_vector< uint8_t > random_plaintext_element(RandomNumberGenerator &rng) const
size_t get_message_word_bit_length() const
std::string algo_name() const override
std::vector< uint8_t > public_key_bits() const override
std::vector< uint8_t > m_public_matrix
std::unique_ptr< PK_Ops::KEM_Encryption > create_kem_encryption_op(RandomNumberGenerator &rng, const std::string ¶ms, const std::string &provider) const override
size_t estimated_strength() const override
size_t get_code_length() const
bool operator==(const McEliece_PublicKey &other) const
AlgorithmIdentifier algorithm_identifier() const override
size_t key_length() const override
virtual OID get_oid() const
virtual void randomize(uint8_t output[], size_t length)=0
int(* final)(unsigned char *, CTX *)
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)
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)
McEliece_PrivateKey generate_mceliece_key(RandomNumberGenerator &rng, size_t ext_deg, size_t code_length, size_t t)
size_t mceliece_work_factor(size_t n, size_t t)
constexpr uint8_t get_byte(size_t byte_num, T input)
size_t bit_size_to_32bit_size(size_t bit_size)
std::vector< T, secure_allocator< T > > secure_vector