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-rw-r--r--src/lib/pubkey/ecgdsa/ecgdsa.cpp148
-rw-r--r--src/lib/pubkey/ecgdsa/ecgdsa.h91
-rw-r--r--src/lib/pubkey/ecgdsa/info.txt13
3 files changed, 252 insertions, 0 deletions
diff --git a/src/lib/pubkey/ecgdsa/ecgdsa.cpp b/src/lib/pubkey/ecgdsa/ecgdsa.cpp
new file mode 100644
index 000000000..b28e3fe96
--- /dev/null
+++ b/src/lib/pubkey/ecgdsa/ecgdsa.cpp
@@ -0,0 +1,148 @@
+/*
+* ECGDSA (BSI-TR-03111, version 2.0)
+* (C) 2016 René Korthaus
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/internal/pk_utils.h>
+#include <botan/ecgdsa.h>
+#include <botan/keypair.h>
+
+namespace Botan {
+
+bool ECGDSA_PrivateKey::check_key(RandomNumberGenerator& rng,
+ bool strong) const
+ {
+ if(!public_point().on_the_curve())
+ return false;
+
+ if(!strong)
+ return true;
+
+ return KeyPair::signature_consistency_check(rng, *this, "EMSA1(SHA-1)");
+ }
+
+namespace {
+
+/**
+* ECGDSA signature operation
+*/
+class ECGDSA_Signature_Operation : public PK_Ops::Signature_with_EMSA
+ {
+ public:
+ typedef ECGDSA_PrivateKey Key_Type;
+
+ ECGDSA_Signature_Operation(const ECGDSA_PrivateKey& ecgdsa,
+ const std::string& emsa) :
+ PK_Ops::Signature_with_EMSA(emsa),
+ m_order(ecgdsa.domain().get_order()),
+ m_base_point(ecgdsa.domain().get_base_point(), m_order),
+ m_x(ecgdsa.private_value()),
+ m_mod_order(m_order)
+ {
+ }
+
+ secure_vector<byte> raw_sign(const byte msg[], size_t msg_len,
+ RandomNumberGenerator& rng) override;
+
+ size_t message_parts() const override { return 2; }
+ size_t message_part_size() const override { return m_order.bytes(); }
+ size_t max_input_bits() const override { return m_order.bits(); }
+
+ private:
+ const BigInt& m_order;
+ Blinded_Point_Multiply m_base_point;
+ const BigInt& m_x;
+ Modular_Reducer m_mod_order;
+ };
+
+secure_vector<byte>
+ECGDSA_Signature_Operation::raw_sign(const byte msg[], size_t msg_len,
+ RandomNumberGenerator& rng)
+ {
+ const BigInt m(msg, msg_len);
+
+ BigInt k = BigInt::random_integer(rng, 1, m_order);
+
+ const PointGFp k_times_P = m_base_point.blinded_multiply(k, rng);
+ const BigInt r = m_mod_order.reduce(k_times_P.get_affine_x());
+ const BigInt s = m_mod_order.multiply(m_x, mul_sub(k, r, m));
+
+ // With overwhelming probability, a bug rather than actual zero r/s
+ BOTAN_ASSERT(s != 0, "invalid s");
+ BOTAN_ASSERT(r != 0, "invalid r");
+
+ secure_vector<byte> output(2*m_order.bytes());
+ r.binary_encode(&output[output.size() / 2 - r.bytes()]);
+ s.binary_encode(&output[output.size() - s.bytes()]);
+ return output;
+ }
+
+/**
+* ECGDSA verification operation
+*/
+class ECGDSA_Verification_Operation : public PK_Ops::Verification_with_EMSA
+ {
+ public:
+ typedef ECGDSA_PublicKey Key_Type;
+
+ ECGDSA_Verification_Operation(const ECGDSA_PublicKey& ecgdsa,
+ const std::string& emsa) :
+ PK_Ops::Verification_with_EMSA(emsa),
+ m_base_point(ecgdsa.domain().get_base_point()),
+ m_public_point(ecgdsa.public_point()),
+ m_order(ecgdsa.domain().get_order()),
+ m_mod_order(m_order)
+ {
+ }
+
+ size_t message_parts() const override { return 2; }
+ size_t message_part_size() const override { return m_order.bytes(); }
+ size_t max_input_bits() const override { return m_order.bits(); }
+
+ bool with_recovery() const override { return false; }
+
+ bool verify(const byte msg[], size_t msg_len,
+ const byte sig[], size_t sig_len) override;
+ private:
+ const PointGFp& m_base_point;
+ const PointGFp& m_public_point;
+ const BigInt& m_order;
+ // FIXME: should be offered by curve
+ Modular_Reducer m_mod_order;
+ };
+
+bool ECGDSA_Verification_Operation::verify(const byte msg[], size_t msg_len,
+ const byte sig[], size_t sig_len)
+ {
+ if(sig_len != m_order.bytes()*2)
+ return false;
+
+ BigInt e(msg, msg_len);
+
+ BigInt r(sig, sig_len / 2);
+ BigInt s(sig + sig_len / 2, sig_len / 2);
+
+ if(r <= 0 || r >= m_order || s <= 0 || s >= m_order)
+ return false;
+
+ BigInt w = inverse_mod(r, m_order);
+
+ const BigInt u1 = m_mod_order.reduce(e * w);
+ const BigInt u2 = m_mod_order.reduce(s * w);
+ const PointGFp R = multi_exponentiate(m_base_point, u1, m_public_point, u2);
+
+ if(R.is_zero())
+ return false;
+
+ const BigInt v = m_mod_order.reduce(R.get_affine_x());
+ return (v == r);
+ }
+
+BOTAN_REGISTER_PK_SIGNATURE_OP("ECGDSA", ECGDSA_Signature_Operation);
+BOTAN_REGISTER_PK_VERIFY_OP("ECGDSA", ECGDSA_Verification_Operation);
+
+}
+
+}
diff --git a/src/lib/pubkey/ecgdsa/ecgdsa.h b/src/lib/pubkey/ecgdsa/ecgdsa.h
new file mode 100644
index 000000000..518adeeab
--- /dev/null
+++ b/src/lib/pubkey/ecgdsa/ecgdsa.h
@@ -0,0 +1,91 @@
+/*
+* ECGDSA (BSI-TR-03111, version 2.0)
+* (C) 2016 René Korthaus
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_ECGDSA_KEY_H__
+#define BOTAN_ECGDSA_KEY_H__
+
+#include <botan/ecc_key.h>
+
+namespace Botan {
+
+/**
+* This class represents ECGDSA public keys.
+*/
+class BOTAN_DLL ECGDSA_PublicKey : public virtual EC_PublicKey
+ {
+ public:
+
+ /**
+ * Construct a public key from a given public point.
+ * @param dom_par the domain parameters associated with this key
+ * @param public_point the public point defining this key
+ */
+ ECGDSA_PublicKey(const EC_Group& dom_par,
+ const PointGFp& public_point) :
+ EC_PublicKey(dom_par, public_point) {}
+
+ ECGDSA_PublicKey(const AlgorithmIdentifier& alg_id,
+ const secure_vector<byte>& key_bits) :
+ EC_PublicKey(alg_id, key_bits) {}
+
+ /**
+ * Get this keys algorithm name.
+ * @result this keys algorithm name ("ECGDSA")
+ */
+ std::string algo_name() const override { return "ECGDSA"; }
+
+ /**
+ * Get the maximum number of bits allowed to be fed to this key.
+ * This is the bitlength of the order of the base point.
+ * @result the maximum number of input bits
+ */
+ size_t max_input_bits() const override
+ { return domain().get_order().bits(); }
+
+ size_t message_parts() const override { return 2; }
+
+ size_t message_part_size() const override
+ { return domain().get_order().bytes(); }
+
+ protected:
+ ECGDSA_PublicKey() {}
+ };
+
+/**
+* This class represents ECGDSA private keys.
+*/
+class BOTAN_DLL ECGDSA_PrivateKey : public ECGDSA_PublicKey,
+ public EC_PrivateKey
+ {
+ public:
+
+ /**
+ * Load a private key
+ * @param alg_id the X.509 algorithm identifier
+ * @param key_bits PKCS #8 structure
+ */
+ ECGDSA_PrivateKey(const AlgorithmIdentifier& alg_id,
+ const secure_vector<byte>& key_bits) :
+ EC_PrivateKey(alg_id, key_bits, true) {}
+
+ /**
+ * Generate a new private key
+ * @param rng a random number generator
+ * @param domain parameters to used for this key
+ * @param x the private key (if zero, generate a new random key)
+ */
+ ECGDSA_PrivateKey(RandomNumberGenerator& rng,
+ const EC_Group& domain,
+ const BigInt& x = 0) :
+ EC_PrivateKey(rng, domain, x, true) {}
+
+ bool check_key(RandomNumberGenerator& rng, bool) const override;
+ };
+
+}
+
+#endif
diff --git a/src/lib/pubkey/ecgdsa/info.txt b/src/lib/pubkey/ecgdsa/info.txt
new file mode 100644
index 000000000..9583c47d4
--- /dev/null
+++ b/src/lib/pubkey/ecgdsa/info.txt
@@ -0,0 +1,13 @@
+define ECGDSA 20160301
+
+load_on request
+
+<requires>
+asn1
+bigint
+ec_group
+ecc_key
+keypair
+numbertheory
+rng
+</requires>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 12:11:33 +0000