diff options
Diffstat (limited to 'src/lib/pubkey/mce/mceliece_key.cpp')
| -rw-r--r-- | src/lib/pubkey/mce/mceliece_key.cpp | 75 |
1 files changed, 43 insertions, 32 deletions
diff --git a/src/lib/pubkey/mce/mceliece_key.cpp b/src/lib/pubkey/mce/mceliece_key.cpp index 8cda0af89..8edbbf88a 100644 --- a/src/lib/pubkey/mce/mceliece_key.cpp +++ b/src/lib/pubkey/mce/mceliece_key.cpp @@ -9,15 +9,12 @@ * */ -#include <botan/mceliece_key.h> -#include <botan/internal/bit_ops.h> -#include <botan/gf2m_small_m.h> #include <botan/mceliece.h> -#include <botan/internal/code_based_key_gen.h> -#include <botan/code_based_util.h> +#include <botan/internal/mce_internal.h> +#include <botan/internal/bit_ops.h> +#include <botan/internal/code_based_util.h> #include <botan/der_enc.h> #include <botan/ber_dec.h> -#include <botan/workfactor.h> namespace Botan { @@ -42,12 +39,29 @@ McEliece_PrivateKey::McEliece_PrivateKey(RandomNumberGenerator& rng, size_t code *this = generate_mceliece_key(rng, ext_deg, code_length, t); } -unsigned McEliece_PublicKey::get_message_word_bit_length() const +u32bit McEliece_PublicKey::get_message_word_bit_length() const { u32bit codimension = ceil_log2(m_code_length) * m_t; return m_code_length - codimension; } +secure_vector<byte> McEliece_PublicKey::random_plaintext_element(RandomNumberGenerator& rng) const + { + const size_t bits = get_message_word_bit_length(); + + secure_vector<byte> plaintext((bits+7)/8); + rng.randomize(plaintext.data(), plaintext.size()); + + // unset unused bits in the last plaintext byte + if(u32bit used = bits % 8) + { + const byte mask = (1 << used) - 1; + plaintext[plaintext.size() - 1] &= mask; + } + + return plaintext; + } + AlgorithmIdentifier McEliece_PublicKey::algorithm_identifier() const { return AlgorithmIdentifier(get_oid(), std::vector<byte>()); @@ -55,16 +69,15 @@ AlgorithmIdentifier McEliece_PublicKey::algorithm_identifier() const std::vector<byte> McEliece_PublicKey::x509_subject_public_key() const { - // encode the public key - return unlock(DER_Encoder() - .start_cons(SEQUENCE) - .start_cons(SEQUENCE) - .encode(static_cast<size_t>(get_code_length())) - .encode(static_cast<size_t>(get_t())) - .end_cons() - .encode(m_public_matrix, OCTET_STRING) - .end_cons() - .get_contents()); + return DER_Encoder() + .start_cons(SEQUENCE) + .start_cons(SEQUENCE) + .encode(static_cast<size_t>(get_code_length())) + .encode(static_cast<size_t>(get_t())) + .end_cons() + .encode(m_public_matrix, OCTET_STRING) + .end_cons() + .get_contents_unlocked(); } McEliece_PublicKey::McEliece_PublicKey(const McEliece_PublicKey & other) : @@ -76,9 +89,7 @@ McEliece_PublicKey::McEliece_PublicKey(const McEliece_PublicKey & other) : size_t McEliece_PublicKey::estimated_strength() const { - const u32bit ext_deg = ceil_log2(m_code_length); - const size_t k = m_code_length - ext_deg * m_t; - return mceliece_work_factor(m_code_length, k, m_t); + return mceliece_work_factor(m_code_length, m_t); } McEliece_PublicKey::McEliece_PublicKey(const std::vector<byte>& key_bits) @@ -135,19 +146,20 @@ secure_vector<byte> McEliece_PrivateKey::pkcs8_private_key() const bool McEliece_PrivateKey::check_key(RandomNumberGenerator& rng, bool) const { - McEliece_Private_Operation priv_op(*this); - McEliece_Public_Operation pub_op(*this, get_code_length()); + const secure_vector<byte> plaintext = this->random_plaintext_element(rng); - secure_vector<byte> plaintext((this->get_message_word_bit_length()+7)/8); - rng.randomize(plaintext.data(), plaintext.size() - 1); - const secure_vector<gf2m> err_pos = create_random_error_positions(this->get_code_length(), this->get_t(), rng); + secure_vector<byte> ciphertext; + secure_vector<byte> errors; + mceliece_encrypt(ciphertext, errors, plaintext, *this, rng); - mceliece_message_parts parts(err_pos, plaintext, this->get_code_length()); - secure_vector<byte> message_and_error_input = parts.get_concat(); - secure_vector<byte> ciphertext = pub_op.encrypt(message_and_error_input.data(), message_and_error_input.size(), rng); - secure_vector<byte> message_and_error_output = priv_op.decrypt(ciphertext.data(), ciphertext.size()); + secure_vector<byte> plaintext_out; + secure_vector<byte> errors_out; + mceliece_decrypt(plaintext_out, errors_out, ciphertext, *this); - return (message_and_error_input == message_and_error_output); + if(errors != errors_out || plaintext != plaintext_out) + return false; + + return true; } McEliece_PrivateKey::McEliece_PrivateKey(const secure_vector<byte>& key_bits) @@ -172,7 +184,7 @@ McEliece_PrivateKey::McEliece_PrivateKey(const secure_vector<byte>& key_bits) m_codimension = (ext_deg * t); m_dimension = (n - m_codimension); - std::shared_ptr<gf2m_small_m::Gf2m_Field> sp_field(new gf2m_small_m::Gf2m_Field(ext_deg)); + std::shared_ptr<GF2m_Field> sp_field(new GF2m_Field(ext_deg)); m_g = polyn_gf2m(g_enc, sp_field); if(m_g.get_degree() != static_cast<int>(t)) { @@ -231,7 +243,6 @@ McEliece_PrivateKey::McEliece_PrivateKey(const secure_vector<byte>& key_bits) } - bool McEliece_PrivateKey::operator==(const McEliece_PrivateKey & other) const { if(*static_cast<const McEliece_PublicKey*>(this) != *static_cast<const McEliece_PublicKey*>(&other)) |