diff options
Diffstat (limited to 'src/lib/pubkey/xmss/xmss_wots_privatekey.h')
| -rw-r--r-- | src/lib/pubkey/xmss/xmss_wots_privatekey.h | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/src/lib/pubkey/xmss/xmss_wots_privatekey.h b/src/lib/pubkey/xmss/xmss_wots_privatekey.h new file mode 100644 index 000000000..422d014f4 --- /dev/null +++ b/src/lib/pubkey/xmss/xmss_wots_privatekey.h @@ -0,0 +1,265 @@ +/** + * XMSS WOTS Private Key + * (C) 2016 Matthias Gierlings + * + * Botan is released under the Simplified BSD License (see license.txt) + **/ + +#ifndef BOTAN_XMSS_WOTS_PRIVATEKEY_H__ +#define BOTAN_XMSS_WOTS_PRIVATEKEY_H__ + +#include <cstddef> +#include <memory> +#include <botan/alg_id.h> +#include <botan/assert.h> +#include <botan/pk_keys.h> +#include <botan/types.h> +#include <botan/xmss_wots_parameters.h> +#include <botan/xmss_address.h> +#include <botan/xmss_wots_publickey.h> + +namespace Botan { + +/** A Winternitz One Time Signature private key for use with Extended Hash-Based + * Signatures. + **/ +class BOTAN_DLL XMSS_WOTS_PrivateKey : public virtual XMSS_WOTS_PublicKey, + public virtual Private_Key + { + public: + /** + * Creates a WOTS private key for the chosen XMSS WOTS signature method. + * Members need to be initialized manually. + * + * @param oid Identifier for the selected signature method. + **/ + XMSS_WOTS_PrivateKey(XMSS_WOTS_Parameters::ots_algorithm_t oid) + : XMSS_WOTS_PublicKey(oid) + {} + + /** + * Creates a WOTS private key for the chosen XMSS WOTS signature method. + * + * @param oid Identifier for the selected signature method. + * @param rng A random number generator to use for key generation. + **/ + XMSS_WOTS_PrivateKey(XMSS_WOTS_Parameters::ots_algorithm_t oid, + RandomNumberGenerator& rng) + : XMSS_WOTS_PublicKey(oid, rng), + m_private_seed(rng.random_vec(m_wots_params.element_size())) + { + set_key_data(generate(m_private_seed)); + } + + /** + * Constructs a WOTS private key. Chains will be generated on demand + * applying a hash function to a unique value generated from a secret + * seed and a counter. The secret seed of length n, will be + * automatically generated using AutoSeeded_RNG(). "n" equals + * the element size of the chosen WOTS security parameter set. + * + * @param oid Identifier for the selected signature method. + * @param public_seed A public seed used for the pseudo random generation + * of public keys derived from this private key. + * @param rng A random number generator to use for key generation. + **/ + XMSS_WOTS_PrivateKey(XMSS_WOTS_Parameters::ots_algorithm_t oid, + const secure_vector<byte>& public_seed, + RandomNumberGenerator &rng) + : XMSS_WOTS_PublicKey(oid, public_seed), + m_private_seed(rng.random_vec(m_wots_params.element_size())) + { + set_key_data(generate(m_private_seed)); + } + + /** + * Constructs a WOTS private key. Chains will be generated on demand + * applying a hash function to a unique value generated from a secret + * seed and a counter. The secret seed of length n, will be + * automatically generated using AutoSeeded_RNG(). "n" equals + * the element size of the chosen WOTS security parameter set. + * + * @param oid Identifier for the selected signature method. + * @param public_seed A public seed used for the pseudo random generation + * of public keys derived from this private key. + **/ + XMSS_WOTS_PrivateKey(XMSS_WOTS_Parameters::ots_algorithm_t oid, + const secure_vector<byte>& public_seed) + : XMSS_WOTS_PublicKey(oid, public_seed) + {} + + /** + * Constructs a WOTS private key. Chains will be generated on demand + * applying a hash function to a unique value generated from the + * secret seed and a counter. + * + * @param oid Identifier for the selected signature method. + * @param public_seed A public seed used for the pseudo random generation + * of public keys derived from this private key. + * @param private_seed A secret uniformly random n-byte value. + **/ + XMSS_WOTS_PrivateKey(XMSS_WOTS_Parameters::ots_algorithm_t oid, + const secure_vector<byte>& public_seed, + const secure_vector<byte>& private_seed) + : XMSS_WOTS_PublicKey(oid, public_seed), + m_private_seed(private_seed) + { + set_key_data(generate(private_seed)); + } + + /** + * Retrieves the i-th WOTS private key using pseudo random key + * (re-)generation. + * + * @param i Index of the key to retrieve. + * + * @return WOTS secret key. + **/ + wots_keysig_t operator[](size_t i) + { + secure_vector<byte> idx_bytes; + XMSS_Tools::get().concat(idx_bytes, i, m_wots_params.element_size()); + m_hash.h(idx_bytes, m_private_seed, idx_bytes); + return generate(idx_bytes); + } + + /** + * Retrieves the i-th WOTS private key using pseudo random key + * (re-)generation. + * + * @param adrs The address of the key to retrieve. + * + * @return WOTS secret key. + **/ + wots_keysig_t operator[](const XMSS_Address& adrs) + { + secure_vector<byte> result; + m_hash.prf(result, m_private_seed, adrs.bytes()); + return generate(result); + } + + wots_keysig_t generate_private_key(const secure_vector<byte>& priv_seed); + + /** + * Algorithm 4: "WOTS_genPK" + * Generates a Winternitz One Time Signature+ (WOTS+) Public Key from a + * given private key. + * + * @param adrs Hash function address encoding the address of the WOTS+ + * key pair within a greater structure. + * + * @return A XMSS_WOTS_PublicKey. + **/ + XMSS_WOTS_PublicKey generate_public_key( + XMSS_Address& adrs); + + /** + * Algorithm 4: "WOTS_genPK" + * Initializes a Winternitz One Time Signature+ (WOTS+) Public Key's + * key_data() member, with data derived from in_key_data using the + * WOTS chaining function. + * + * @param[out] pub_key Public key to initialize key_data() member on. + * @param in_key_data Input key material from private key used for + * public key generation. + * @param adrs Hash function address encoding the address of + * the WOTS+ key pair within a greater structure. + **/ + void generate_public_key( + XMSS_WOTS_PublicKey& pub_key, + wots_keysig_t&& in_key_data, + XMSS_Address& adrs); + + /** + * Algorithm 5: "WOTS_sign" + * Generates a signature from a private key and a message. + * + * @param msg A message to sign. + * @param adrs An OTS hash address identifying the WOTS+ key pair + * used for signing. + * + * @return signature for msg. + **/ + wots_keysig_t sign( + const secure_vector<byte>& msg, + XMSS_Address& adrs); + + /** + * Retrieves the secret seed used to generate WOTS+ chains. The seed + * should be a uniformly random n-byte value. + * + * @return secret seed. + **/ + const secure_vector<byte>& private_seed() const + { + return m_private_seed; + } + + ///** + // * Retrieves the secret seed used to generate WOTS+ chains. The seed + // * should be a uniformly random n-byte value. + // * + // * @return secret seed. + // **/ + //secure_vector<byte>& private_seed() { return m_private_seed; } + + /** + * Sets the secret seed used to generate WOTS+ chains. The seed + * should be a uniformly random n-byte value. + * + * @param private_seed Uniformly random n-byte value. + **/ + void set_private_seed(const secure_vector<byte>& private_seed) + { + m_private_seed = private_seed; + } + + /** + * Sets the secret seed used to generate WOTS+ chains. The seed + * should be a uniformly random n-byte value. + * + * @param private_seed Uniformly random n-byte value. + **/ + void set_private_seed(secure_vector<byte>&& private_seed) + { + m_private_seed = std::move(private_seed); + } + + virtual AlgorithmIdentifier + pkcs8_algorithm_identifier() const override + { + BOTAN_ASSERT(false, "No AlgorithmIdentifier available for XMSS-WOTS."); + } + + virtual std::unique_ptr<PK_Ops::Signature> + create_signature_op(RandomNumberGenerator&, + const std::string&, + const std::string& provider) const override + { + BOTAN_ASSERT(false, "XMSS_WOTS_Signature_Operation not available."); + } + + virtual secure_vector<byte> pkcs8_private_key() const override + { + BOTAN_ASSERT(false, "No PKCS8 key format defined for XMSS-WOTS."); + } + + private: + /** + * Algorithm 3: "Generating a WOTS+ Private Key". + * Generates a private key. + * + * @param private_seed Uniformly random n-byte value. + * + * @returns a vector of length key_size() of vectors of n bytes length + * containing uniformly random data. + **/ + wots_keysig_t generate(const secure_vector<byte>& private_seed); + + secure_vector<byte> m_private_seed; + }; + +} + +#endif + |