Botan 2.19.1
Crypto and TLS for C&
xmss_common_ops.cpp
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1/*
2 * XMSS Common Ops
3 * Operations shared by XMSS signature generation and verification operations.
4 * (C) 2016,2017 Matthias Gierlings
5 *
6 * Botan is released under the Simplified BSD License (see license.txt)
7 **/
8
9#include <botan/internal/xmss_common_ops.h>
10
11namespace Botan {
12
13void
15 const secure_vector<uint8_t>& left,
16 const secure_vector<uint8_t>& right,
17 XMSS_Address& adrs,
18 const secure_vector<uint8_t>& seed,
20 const XMSS_Parameters& params)
21 {
23 secure_vector<uint8_t> key { hash.prf(seed, adrs.bytes()) };
24
26 secure_vector<uint8_t> bitmask_l { hash.prf(seed, adrs.bytes()) };
27
29 secure_vector<uint8_t> bitmask_r { hash.prf(seed, adrs.bytes()) };
30
31 BOTAN_ASSERT(bitmask_l.size() == left.size() &&
32 bitmask_r.size() == right.size(),
33 "Bitmask size doesn't match node size.");
34
35 secure_vector<uint8_t> concat_xor(params.element_size() * 2);
36 for(size_t i = 0; i < left.size(); i++)
37 {
38 concat_xor[i] = left[i] ^ bitmask_l[i];
39 concat_xor[i + left.size()] = right[i] ^ bitmask_r[i];
40 }
41
42 hash.h(result, key, concat_xor);
43 }
44
45
46void
49 XMSS_Address& adrs,
50 const secure_vector<uint8_t>& seed,
52 const XMSS_Parameters& params)
53 {
54 size_t l = params.len();
55 adrs.set_tree_height(0);
56
57 while(l > 1)
58 {
59 for(size_t i = 0; i < l >> 1; i++)
60 {
61 adrs.set_tree_index(static_cast<uint32_t>(i));
62 randomize_tree_hash(pk[i], pk[2 * i], pk[2 * i + 1], adrs, seed, hash, params);
63 }
64 if(l & 0x01)
65 {
66 pk[l >> 1] = pk[l - 1];
67 }
68 l = (l >> 1) + (l & 0x01);
69 adrs.set_tree_height(adrs.get_tree_height() + 1);
70 }
71 result = pk[0];
72 }
73
74}
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:55
void set_key_mask_mode(Key_Mask value)
Definition: xmss_address.h:134
uint32_t get_tree_height() const
Definition: xmss_address.h:235
void set_tree_height(uint32_t value)
Definition: xmss_address.h:251
void set_tree_index(uint32_t value)
Definition: xmss_address.h:313
const secure_vector< uint8_t > & bytes() const
Definition: xmss_address.h:322
static void create_l_tree(secure_vector< uint8_t > &result, wots_keysig_t pk, XMSS_Address &adrs, const secure_vector< uint8_t > &seed, XMSS_Hash &hash, const XMSS_Parameters &params)
static void randomize_tree_hash(secure_vector< uint8_t > &result, const secure_vector< uint8_t > &left, const secure_vector< uint8_t > &right, XMSS_Address &adrs, const secure_vector< uint8_t > &seed, XMSS_Hash &hash, const XMSS_Parameters &params)
size_t element_size() const
Definition: alg_id.cpp:13
std::vector< secure_vector< uint8_t > > wots_keysig_t
std::vector< T, secure_allocator< T > > secure_vector
Definition: secmem.h:65
MechanismType hash