diff options
Diffstat (limited to 'src/lib/pubkey/xmss/xmss.h')
| -rw-r--r-- | src/lib/pubkey/xmss/xmss.h | 462 |
1 files changed, 448 insertions, 14 deletions
diff --git a/src/lib/pubkey/xmss/xmss.h b/src/lib/pubkey/xmss/xmss.h index 42b825f8f..529bbe3bc 100644 --- a/src/lib/pubkey/xmss/xmss.h +++ b/src/lib/pubkey/xmss/xmss.h @@ -1,26 +1,460 @@ +/* + * XMSS Keys + * (C) 2016,2017 Matthias Gierlings + * (C) 2019 René Korthaus, Rohde & Schwarz Cybersecurity + * + * Botan is released under the Simplified BSD License (see license.txt) + **/ + +#ifndef BOTAN_XMSS_H_ +#define BOTAN_XMSS_H_ + +#include <botan/pk_keys.h> +#include <botan/exceptn.h> +#include <botan/xmss_parameters.h> +#include <botan/xmss_wots_parameters.h> +#include <botan/xmss_wots_privatekey.h> + +namespace Botan { + +class RandomNumberGenerator; +class XMSS_Verification_Operation; + /** - * @file xmss.h - * Includes headers required for Extended Hash-Based Signatures (XMSS) - * as described in [1]. @see Botan::XMSS_PublicKey and @see - * Botan::XMSS_PrivateKey for further - * details. + * An XMSS: Extended Hash-Based Signature public key. * - * <pre> * [1] XMSS: Extended Hash-Based Signatures, * Request for Comments: 8391 * Release: May 2018. * https://datatracker.ietf.org/doc/rfc8391/ - * </pre> - * - * (C) 2016,2017,2018 Matthias Gierlings + **/ +class BOTAN_PUBLIC_API(2,0) XMSS_PublicKey : public virtual Public_Key + { + public: + /** + * Creates a new XMSS public key for the chosen XMSS signature method. + * New public and prf seeds are generated using rng. The appropriate WOTS + * signature method will be automatically set based on the chosen XMSS + * signature method. + * + * @param xmss_oid Identifier for the selected XMSS signature method. + * @param rng A random number generator to use for key generation. + **/ + XMSS_PublicKey(XMSS_Parameters::xmss_algorithm_t xmss_oid, + RandomNumberGenerator& rng); + + /** + * Loads a public key. + * + * Public key must be encoded as in RFC + * draft-vangeest-x509-hash-sigs-03. + * + * @param key_bits DER encoded public key bits + */ + XMSS_PublicKey(const std::vector<uint8_t>& key_bits); + + /** + * Creates a new XMSS public key for a chosen XMSS signature method as + * well as pre-computed root node and public_seed values. + * + * @param xmss_oid Identifier for the selected XMSS signature method. + * @param root Root node value. + * @param public_seed Public seed value. + **/ + XMSS_PublicKey(XMSS_Parameters::xmss_algorithm_t xmss_oid, + const secure_vector<uint8_t>& root, + const secure_vector<uint8_t>& public_seed) + : m_xmss_params(xmss_oid), m_wots_params(m_xmss_params.ots_oid()), + m_root(root), m_public_seed(public_seed) {} + + /** + * Creates a new XMSS public key for a chosen XMSS signature method as + * well as pre-computed root node and public_seed values. + * + * @param xmss_oid Identifier for the selected XMSS signature method. + * @param root Root node value. + * @param public_seed Public seed value. + **/ + XMSS_PublicKey(XMSS_Parameters::xmss_algorithm_t xmss_oid, + secure_vector<uint8_t>&& root, + secure_vector<uint8_t>&& public_seed) + : m_xmss_params(xmss_oid), m_wots_params(m_xmss_params.ots_oid()), + m_root(std::move(root)), m_public_seed(std::move(public_seed)) {} + + /** + * Retrieves the chosen XMSS signature method. + * + * @return XMSS signature method identifier. + **/ + XMSS_Parameters::xmss_algorithm_t xmss_oid() const + { + return m_xmss_params.oid(); + } + + /** + * Sets the chosen XMSS signature method + **/ + void set_xmss_oid(XMSS_Parameters::xmss_algorithm_t xmss_oid) + { + m_xmss_params = XMSS_Parameters(xmss_oid); + m_wots_params = XMSS_WOTS_Parameters(m_xmss_params.ots_oid()); + } + + /** + * Retrieves the XMSS parameters determined by the chosen XMSS Signature + * method. + * + * @return XMSS parameters. + **/ + const XMSS_Parameters& xmss_parameters() const + { + return m_xmss_params; + } + + /** + * Retrieves the XMSS parameters determined by the chosen XMSS Signature + * method. + * + * @return XMSS parameters. + **/ + std::string xmss_hash_function() const + { + return m_xmss_params.hash_function_name(); + } + + /** + * Retrieves the Winternitz One Time Signature (WOTS) method, + * corresponding to the chosen XMSS signature method. + * + * @return XMSS WOTS signature method identifier. + **/ + XMSS_WOTS_Parameters::ots_algorithm_t wots_oid() const + { + return m_wots_params.oid(); + } + + /** + * Retrieves the Winternitz One Time Signature (WOTS) parameters + * corresponding to the chosen XMSS signature method. + * + * @return XMSS WOTS signature method parameters. + **/ + const XMSS_WOTS_Parameters& wots_parameters() const + { + return m_wots_params; + } + + secure_vector<uint8_t>& root() + { + return m_root; + } + + void set_root(const secure_vector<uint8_t>& root) + { + m_root = root; + } + + void set_root(secure_vector<uint8_t>&& root) + { + m_root = std::move(root); + } + + const secure_vector<uint8_t>& root() const + { + return m_root; + } + + virtual secure_vector<uint8_t>& public_seed() + { + return m_public_seed; + } + + virtual void set_public_seed(const secure_vector<uint8_t>& public_seed) + { + m_public_seed = public_seed; + } + + virtual void set_public_seed(secure_vector<uint8_t>&& public_seed) + { + m_public_seed = std::move(public_seed); + } + + virtual const secure_vector<uint8_t>& public_seed() const + { + return m_public_seed; + } + + std::string algo_name() const override + { + return "XMSS"; + } + + AlgorithmIdentifier algorithm_identifier() const override + { + return AlgorithmIdentifier(get_oid(), AlgorithmIdentifier::USE_EMPTY_PARAM); + } + + bool check_key(RandomNumberGenerator&, bool) const override + { + return true; + } + + std::unique_ptr<PK_Ops::Verification> + create_verification_op(const std::string&, + const std::string& provider) const override; + + size_t estimated_strength() const override + { + return m_xmss_params.estimated_strength(); + } + + size_t key_length() const override + { + return m_xmss_params.estimated_strength(); + } + + /** + * Returns the encoded public key as defined in RFC + * draft-vangeest-x509-hash-sigs-03. + * + * @return encoded public key bits + **/ + std::vector<uint8_t> public_key_bits() const override; + + /** + * Size in bytes of the serialized XMSS public key produced by + * raw_public_key(). + * + * @return size in bytes of serialized Public Key. + **/ + virtual size_t size() const + { + return sizeof(uint32_t) + 2 * m_xmss_params.element_size(); + } + + /** + * Generates a byte sequence representing the XMSS + * public key, as defined in [1] (p. 23, "XMSS Public Key") + * + * @return 4-byte OID, followed by n-byte root node, followed by + * public seed. + **/ + virtual std::vector<uint8_t> raw_public_key() const; + + protected: + std::vector<uint8_t> m_raw_key; + XMSS_Parameters m_xmss_params; + XMSS_WOTS_Parameters m_wots_params; + secure_vector<uint8_t> m_root; + secure_vector<uint8_t> m_public_seed; + + private: + XMSS_Parameters::xmss_algorithm_t deserialize_xmss_oid( + const std::vector<uint8_t>& raw_key); + }; + +template<typename> class Atomic; + +class XMSS_Index_Registry; + +/** + * An XMSS: Extended Hash-Based Signature private key. + * The XMSS private key does not support the X509 and PKCS7 standard. Instead + * the raw format described in [1] is used. * - * Botan is released under the Simplified BSD License (see license.txt) + * [1] XMSS: Extended Hash-Based Signatures, + * Request for Comments: 8391 + * Release: May 2018. + * https://datatracker.ietf.org/doc/rfc8391/ **/ +class BOTAN_PUBLIC_API(2,0) XMSS_PrivateKey final : public virtual XMSS_PublicKey, + public virtual Private_Key + { + public: + /** + * Creates a new XMSS private key for the chosen XMSS signature method. + * New seeds for public/private key and pseudo random function input are + * generated using the provided RNG. The appropriate WOTS signature method + * will be automatically set based on the chosen XMSS signature method. + * + * @param xmss_algo_id Identifier for the selected XMSS signature method. + * @param rng A random number generator to use for key generation. + **/ + XMSS_PrivateKey(XMSS_Parameters::xmss_algorithm_t xmss_algo_id, + RandomNumberGenerator& rng); -#ifndef BOTAN_XMSS_H_ -#define BOTAN_XMSS_H_ + /** + * Creates an XMSS_PrivateKey from a byte sequence produced by + * raw_private_key(). + * + * @param raw_key An XMSS private key serialized using raw_private_key(). + **/ + XMSS_PrivateKey(const secure_vector<uint8_t>& raw_key); + + /** + * Creates a new XMSS private key for the chosen XMSS signature method + * using precomputed seeds for public/private keys and pseudo random + * function input. The appropriate WOTS signature method will be + * automatically set, based on the chosen XMSS signature method. + * + * @param xmss_algo_id Identifier for the selected XMSS signature method. + * @param idx_leaf Index of the next unused leaf. + * @param wots_priv_seed A seed to generate a Winternitz-One-Time- + * Signature private key from. + * @param prf a secret n-byte key sourced from a secure source + * of uniformly random data. + * @param root Root node of the binary hash tree. + * @param public_seed The public seed. + **/ + XMSS_PrivateKey(XMSS_Parameters::xmss_algorithm_t xmss_algo_id, + size_t idx_leaf, + const secure_vector<uint8_t>& wots_priv_seed, + const secure_vector<uint8_t>& prf, + const secure_vector<uint8_t>& root, + const secure_vector<uint8_t>& public_seed); + + bool stateful_operation() const override { return true; } + + /** + * Retrieves the last unused leaf index of the private key. Reusing a leaf + * by utilizing leaf indices lower than the last unused leaf index will + * compromise security. + * + * @return Index of the last unused leaf. + **/ + size_t unused_leaf_index() const; + + /** + * Sets the last unused leaf index of the private key. The leaf index + * will be updated automatically during every signing operation, and + * should not be set manually. + * + * @param idx Index of the last unused leaf. + **/ + void set_unused_leaf_index(size_t idx); + + size_t reserve_unused_leaf_index(); + + /** + * Winternitz One Time Signature Scheme key utilized for signing + * operations. + * + * @return WOTS+ private key. + **/ + const XMSS_WOTS_PrivateKey& wots_private_key() const + { + return m_wots_priv_key; + } + + /** + * Winternitz One Time Signature Scheme key utilized for signing + * operations. + * + * @return WOTS+ private key. + **/ + XMSS_WOTS_PrivateKey& wots_private_key() + { + return m_wots_priv_key; + } + + const secure_vector<uint8_t>& prf() const + { + return m_prf; + } + + secure_vector<uint8_t>& prf() + { + return m_prf; + } + + void set_public_seed( + const secure_vector<uint8_t>& public_seed) override + { + m_public_seed = public_seed; + m_wots_priv_key.set_public_seed(public_seed); + } + + void set_public_seed(secure_vector<uint8_t>&& public_seed) override + { + m_public_seed = std::move(public_seed); + m_wots_priv_key.set_public_seed(m_public_seed); + } + + const secure_vector<uint8_t>& public_seed() const override + { + return m_public_seed; + } + + std::unique_ptr<PK_Ops::Signature> + create_signature_op(RandomNumberGenerator&, + const std::string&, + const std::string& provider) const override; + + secure_vector<uint8_t> private_key_bits() const override; + + size_t size() const override + { + return XMSS_PublicKey::size() + + sizeof(uint32_t) + + 2 * XMSS_PublicKey::m_xmss_params.element_size(); + } + + /** + * Generates a non standartized byte sequence representing the XMSS + * private key. + * + * @return byte sequence consisting of the following elements in order: + * 4-byte OID, n-byte root node, n-byte public seed, + * 8-byte unused leaf index, n-byte prf seed, n-byte private seed. + **/ + secure_vector<uint8_t> raw_private_key() const; + /** + * Algorithm 9: "treeHash" + * Computes the internal n-byte nodes of a Merkle tree. + * + * @param start_idx The start index. + * @param target_node_height Height of the target node. + * @param adrs Address of the tree containing the target node. + * + * @return The root node of a tree of height target_node height with the + * leftmost leaf being the hash of the WOTS+ pk with index + * start_idx. + **/ + secure_vector<uint8_t> tree_hash( + size_t start_idx, + size_t target_node_height, + XMSS_Address& adrs); + + private: + /** + * Fetches shared unused leaf index from the index registry + **/ + std::shared_ptr<Atomic<size_t>> recover_global_leaf_index() const; + + inline void tree_hash_subtree(secure_vector<uint8_t>& result, + size_t start_idx, + size_t target_node_height, + XMSS_Address& adrs) + { + return tree_hash_subtree(result, start_idx, target_node_height, adrs, m_hash); + } + + + /** + * Helper for multithreaded tree hashing. + */ + void tree_hash_subtree(secure_vector<uint8_t>& result, + size_t start_idx, + size_t target_node_height, + XMSS_Address& adrs, + XMSS_Hash& hash); + + XMSS_WOTS_PrivateKey m_wots_priv_key; + XMSS_Hash m_hash; + secure_vector<uint8_t> m_prf; + XMSS_Index_Registry& m_index_reg; + }; -#include <botan/xmss_publickey.h> -#include <botan/xmss_privatekey.h> +} #endif |