Botan 2.1.0 Crypto and TLS for C++11

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xmss_index_registry.cpp
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1 /*
2 * XMSS Index Registry
3 * A registry for XMSS private keys, keeps track of the leaf index for
4 * independend copies of the same key.
5 * (C) 2016 Matthias Gierlings
6 *
7 * Botan is released under the Simplified BSD License (see license.txt)
8 **/
9
10 #include <botan/xmss_index_registry.h>
11
12 namespace Botan {
13
14 const std::string XMSS_Index_Registry::m_index_hash_function = "SHA-256";
15
16 uint64_t XMSS_Index_Registry::make_key_id(
17 const secure_vector<uint8_t>& private_seed,
18 const secure_vector<uint8_t>& prf) const
19 {
20 std::unique_ptr<HashFunction> hash =
21 HashFunction::create(m_index_hash_function);
22 BOTAN_ASSERT(hash != nullptr, "XMSS_Index_Registry requires SHA-256");
23 hash->update(private_seed);
24 hash->update(prf);
25 secure_vector<uint8_t> result = hash->final();
26 uint64_t key_id = 0;
27 for(size_t i = 0; i < sizeof(key_id); i++)
28 {
29 key_id = ((key_id << 8) | result[i]);
30 }
31
32 return key_id;
33 }
34
35 std::shared_ptr<Atomic<size_t>>
36 XMSS_Index_Registry::get(const secure_vector<uint8_t>& private_seed,
37 const secure_vector<uint8_t>& prf)
38 {
39 size_t pos = get(make_key_id(private_seed, prf));
40
41 if(pos < std::numeric_limits<size_t>::max())
42 {
43 return m_leaf_indices[pos];
44 }
45 else
46 {
47 return m_leaf_indices[add(make_key_id(private_seed, prf))];
48 }
49 }
50
51 size_t XMSS_Index_Registry::get(uint64_t id) const
52 {
53 for(size_t i = 0; i < m_key_ids.size(); i++)
54 {
55 if(m_key_ids[i] == id)
56 {
57 return i;
58 }
59 }
60
61 return std::numeric_limits<size_t>::max();
62 }
63
64 size_t XMSS_Index_Registry::add(uint64_t id, size_t last_unused)
65 {
66 lock_guard_type<mutex_type> lock(m_mutex);
67 size_t pos = get(id);
68 if(pos < m_key_ids.size())
69 {
70 if(last_unused > *(m_leaf_indices[pos]))
71 {
72 m_leaf_indices[pos] = std::make_shared<Atomic<size_t>>(last_unused);
73 }
74 return pos;
75 }
76
77 m_key_ids.push_back(id);
78 m_leaf_indices.push_back(std::make_shared<Atomic<size_t>>(last_unused));
79 return m_key_ids.size() - 1;
80 }
81
82 }
BOTAN_ASSERT
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:27
Botan::secure_vector
std::vector< T, secure_allocator< T >> secure_vector
Definition: secmem.h:121
Botan::HashFunction::create
static std::unique_ptr< HashFunction > create(const std::string &algo_spec, const std::string &provider="")
Definition: hash.cpp:93
Botan::XMSS_Index_Registry::get
std::shared_ptr< Atomic< size_t > > get(const secure_vector< uint8_t > &private_seed, const secure_vector< uint8_t > &prf)
Definition: xmss_index_registry.cpp:36
Botan
Definition: alg_id.cpp:13
Botan::CT::max
T max(T a, T b)
Definition: ct_utils.h:173
hash
MechanismType hash
Definition: p11_mechanism.cpp:63