Botan  2.13.0
Crypto and TLS for C++11
comb4p.h
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1 /*
2 * Comb4P hash combiner
3 * (C) 2010 Jack Lloyd
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7 
8 #ifndef BOTAN_COMB4P_H_
9 #define BOTAN_COMB4P_H_
10 
11 #include <botan/hash.h>
12 
14 
15 namespace Botan {
16 
17 /**
18 * Combines two hash functions using a Feistel scheme. Described in
19 * "On the Security of Hash Function Combiners", Anja Lehmann
20 */
22  {
23  public:
24  /**
25  * @param h1 the first hash
26  * @param h2 the second hash
27  */
29 
30  size_t hash_block_size() const override;
31 
32  size_t output_length() const override
33  {
34  return m_hash1->output_length() + m_hash2->output_length();
35  }
36 
37  HashFunction* clone() const override
38  {
39  return new Comb4P(m_hash1->clone(), m_hash2->clone());
40  }
41 
42  std::unique_ptr<HashFunction> copy_state() const override;
43 
44  std::string name() const override
45  {
46  return "Comb4P(" + m_hash1->name() + "," + m_hash2->name() + ")";
47  }
48 
49  void clear() override;
50  private:
51  Comb4P() = default;
52 
53  void add_data(const uint8_t input[], size_t length) override;
54  void final_result(uint8_t out[]) override;
55 
56  std::unique_ptr<HashFunction> m_hash1, m_hash2;
57  };
58 
59 }
60 
61 #endif
int(* final)(unsigned char *, CTX *)
#define BOTAN_PUBLIC_API(maj, min)
Definition: compiler.h:31
std::string name() const override
Definition: comb4p.h:44
Definition: alg_id.cpp:13
virtual void clear()=0
size_t output_length() const override
Definition: comb4p.h:32
virtual size_t hash_block_size() const
Definition: hash.h:75
HashFunction * clone() const override
Definition: comb4p.h:37
virtual std::unique_ptr< HashFunction > copy_state() const =0
#define BOTAN_FUTURE_INTERNAL_HEADER(hdr)
Definition: compiler.h:139