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/der_enc.h>
19 #include <botan/ber_dec.h>
24 std::vector<uint32_t>
const& parity_check_matrix_coeffs,
25 std::vector<polyn_gf2m>
const& square_root_matrix,
26 std::vector<gf2m>
const& inverse_support,
27 std::vector<uint8_t>
const& public_matrix) :
30 m_sqrtmod(square_root_matrix),
31 m_Linv(inverse_support),
32 m_coeffs(parity_check_matrix_coeffs),
33 m_codimension(
ceil_log2(inverse_support.size()) * goppa_polyn.get_degree()),
34 m_dimension(inverse_support.size() - m_codimension)
40 uint32_t ext_deg =
ceil_log2(code_length);
55 rng.
randomize(plaintext.data(), plaintext.size());
58 if(uint32_t used = bits % 8)
60 const uint8_t mask = (1 << used) - 1;
61 plaintext[plaintext.size() - 1] &= mask;
122 for(uint32_t i = 0; i < m_sqrtmod.size(); i++)
128 for(uint32_t i = 0; i < m_Linv.size(); i++)
130 enc_support.push_back(m_Linv[i] >> 8);
131 enc_support.push_back(m_Linv[i]);
135 for(uint32_t i = 0; i < m_coeffs.size(); i++)
137 enc_H.push_back(m_coeffs[i] >> 24);
138 enc_H.push_back(m_coeffs[i] >> 16);
139 enc_H.push_back(m_coeffs[i] >> 8);
140 enc_H.push_back(m_coeffs[i]);
159 if(errors != errors_out || plaintext != plaintext_out)
184 m_codimension = (ext_deg * t);
185 m_dimension = (n - m_codimension);
187 std::shared_ptr<GF2m_Field> sp_field(
new GF2m_Field(ext_deg));
191 throw Decoding_Error(
"degree of decoded Goppa polynomial is incorrect");
194 for(uint32_t i = 0; i < t/2; i++)
198 while(sqrt_enc.size() < (t*2))
202 sqrt_enc.push_back(0);
204 if(sqrt_enc.size() != t*2)
206 throw Decoding_Error(
"length of square root polynomial entry is too large");
208 m_sqrtmod.push_back(
polyn_gf2m(sqrt_enc, sp_field));
213 if(enc_support.size() % 2)
217 if(enc_support.size() / 2 != n)
219 throw Decoding_Error(
"encoded support has length different from code length");
221 for(uint32_t i = 0; i < n*2; i+=2)
223 gf2m el = (enc_support[i] << 8) | enc_support[i+1];
224 m_Linv.push_back(el);
231 throw Decoding_Error(
"encoded parity check matrix has length which is not a multiple of four");
235 throw Decoding_Error(
"encoded parity check matrix has wrong length");
238 for(uint32_t i = 0; i < enc_H.size(); i+=4)
240 uint32_t coeff = (enc_H[i] << 24) | (enc_H[i+1] << 16) | (enc_H[i+2] << 8) | enc_H[i+3];
241 m_coeffs.push_back(coeff);
248 if(*static_cast<const McEliece_PublicKey*>(
this) != *static_cast<const McEliece_PublicKey*>(&other))
257 if( m_sqrtmod != other.m_sqrtmod)
261 if( m_Linv != other.m_Linv)
265 if( m_coeffs != other.m_coeffs)
270 if(m_codimension != other.m_codimension || m_dimension != other.m_dimension)
302 const std::string& kdf) :
303 KEM_Encryption_with_KDF(kdf),
m_key(key) {}
306 void raw_kem_encrypt(secure_vector<uint8_t>& out_encapsulated_key,
307 secure_vector<uint8_t>& raw_shared_key,
310 secure_vector<uint8_t> plaintext =
m_key.random_plaintext_element(rng);
312 secure_vector<uint8_t> ciphertext, error_mask;
315 raw_shared_key.clear();
316 raw_shared_key += plaintext;
317 raw_shared_key += error_mask;
319 out_encapsulated_key.swap(ciphertext);
325 class MCE_KEM_Decryptor :
public PK_Ops::KEM_Decryption_with_KDF
329 MCE_KEM_Decryptor(
const McEliece_PrivateKey& key,
330 const std::string& kdf) :
331 KEM_Decryption_with_KDF(kdf),
m_key(key) {}
334 secure_vector<uint8_t>
335 raw_kem_decrypt(
const uint8_t encap_key[],
size_t len)
override
337 secure_vector<uint8_t> plaintext, error_mask;
340 secure_vector<uint8_t> output;
341 output.reserve(plaintext.size() + error_mask.size());
342 output.insert(output.end(), plaintext.begin(), plaintext.end());
343 output.insert(output.end(), error_mask.begin(), error_mask.end());
347 const McEliece_PrivateKey&
m_key;
352 std::unique_ptr<PK_Ops::KEM_Encryption>
354 const std::string& params,
355 const std::string& provider)
const
357 if(provider ==
"base" || provider.empty())
358 return std::unique_ptr<PK_Ops::KEM_Encryption>(
new MCE_KEM_Encryptor(*
this, params));
362 std::unique_ptr<PK_Ops::KEM_Decryption>
364 const std::string& params,
365 const std::string& provider)
const
367 if(provider ==
"base" || provider.empty())
368 return std::unique_ptr<PK_Ops::KEM_Decryption>(
new MCE_KEM_Decryptor(*
this, params));
secure_vector< uint8_t > random_plaintext_element(RandomNumberGenerator &rng) const
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)
uint32_t bit_size_to_32bit_size(uint32_t bit_size)
std::vector< uint8_t > get_contents_unlocked()
virtual void randomize(uint8_t output[], size_t length)=0
std::string encode(const uint8_t der[], size_t length, const std::string &label, size_t width)
secure_vector< uint8_t > get_contents()
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 &v)
uint32_t get_code_length() const
uint32_t get_message_word_bit_length() const
bool check_key(RandomNumberGenerator &rng, bool strong) const override
virtual OID get_oid() const
secure_vector< uint8_t > encode() const
DER_Encoder & encode(bool b)
size_t key_length() const override
std::vector< T, secure_allocator< T >> secure_vector
McEliece_PrivateKey generate_mceliece_key(RandomNumberGenerator &rng, uint32_t ext_deg, uint32_t code_length, uint32_t t)
const McEliece_PublicKey & m_key
BER_Decoder start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
bool operator==(const McEliece_PrivateKey &other) const
bool operator==(const McEliece_PublicKey &other) const
McEliece_PrivateKey(RandomNumberGenerator &rng, size_t code_length, size_t t)
AlgorithmIdentifier algorithm_identifier() const override
size_t estimated_strength() const override
DER_Encoder & start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
std::string algo_name() const override
std::vector< uint8_t > public_key_bits() const override
size_t mceliece_work_factor(size_t n, size_t t)