Botan 3.0.0-alpha0
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#include <botan/xmss_hash.h>
11
12namespace Botan {
13
14void
16 const secure_vector<uint8_t>& left,
17 const secure_vector<uint8_t>& right,
18 XMSS_Address& adrs,
19 const secure_vector<uint8_t>& seed,
21 const XMSS_Parameters& params)
22 {
24 secure_vector<uint8_t> key { hash.prf(seed, adrs.bytes()) };
25
27 secure_vector<uint8_t> bitmask_l { hash.prf(seed, adrs.bytes()) };
28
30 secure_vector<uint8_t> bitmask_r { hash.prf(seed, adrs.bytes()) };
31
32 BOTAN_ASSERT(bitmask_l.size() == left.size() &&
33 bitmask_r.size() == right.size(),
34 "Bitmask size doesn't match node size.");
35
36 secure_vector<uint8_t> concat_xor(params.element_size() * 2);
37 for(size_t i = 0; i < left.size(); i++)
38 {
39 concat_xor[i] = left[i] ^ bitmask_l[i];
40 concat_xor[i + left.size()] = right[i] ^ bitmask_r[i];
41 }
42
43 hash.h(result, key, concat_xor);
44 }
45
46
47void
50 XMSS_Address& adrs,
51 const secure_vector<uint8_t>& seed,
53 const XMSS_Parameters& params)
54 {
55 size_t l = params.len();
56 adrs.set_tree_height(0);
57
58 while(l > 1)
59 {
60 for(size_t i = 0; i < l >> 1; i++)
61 {
62 adrs.set_tree_index(static_cast<uint32_t>(i));
63 randomize_tree_hash(pk[i], pk[2 * i], pk[2 * i + 1], adrs, seed, hash, params);
64 }
65 if(l & 0x01)
66 {
67 pk[l >> 1] = pk[l - 1];
68 }
69 l = (l >> 1) + (l & 0x01);
70 adrs.set_tree_height(adrs.get_tree_height() + 1);
71 }
72 result = pk[0];
73 }
74
75}
#define BOTAN_ASSERT(expr, assertion_made)
Definition: assert.h:54
void set_key_mask_mode(Key_Mask value)
Definition: xmss_address.h:135
uint32_t get_tree_height() const
Definition: xmss_address.h:236
void set_tree_height(uint32_t value)
Definition: xmss_address.h:252
void set_tree_index(uint32_t value)
Definition: xmss_address.h:314
const secure_vector< uint8_t > & bytes() const
Definition: xmss_address.h:323
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