1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
/*
* EMSA Classes
* (C) 1999-2007 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_PUBKEY_EMSA_H_
#define BOTAN_PUBKEY_EMSA_H_
#include <botan/secmem.h>
#include <botan/asn1_obj.h>
#include <string>
namespace Botan {
class Private_Key;
class RandomNumberGenerator;
/**
* EMSA, from IEEE 1363s Encoding Method for Signatures, Appendix
*
* Any way of encoding/padding signatures
*/
class BOTAN_TEST_API EMSA
{
public:
virtual ~EMSA() = default;
/**
* Factory method for EMSA (message-encoding methods for signatures
* with appendix) objects
* @param algo_spec the name of the EMSA to create
* @return pointer to newly allocated object of that type, or nullptr
*/
static std::unique_ptr<EMSA> create(const std::string& algo_spec);
/**
* Factory method for EMSA (message-encoding methods for signatures
* with appendix) objects
* @param algo_spec the name of the EMSA to create
* @return pointer to newly allocated object of that type, or throws
*/
static std::unique_ptr<EMSA> create_or_throw(const std::string& algo_spec);
/**
* Add more data to the signature computation
* @param input some data
* @param length length of input in bytes
*/
virtual void update(const uint8_t input[], size_t length) = 0;
/**
* @return raw hash
*/
virtual secure_vector<uint8_t> raw_data() = 0;
/**
* Return true if using this EMSA correctly requires a signature scheme
* with message recovery
*/
virtual bool requires_message_recovery() const = 0;
/**
* Return the encoding of a message
* @param msg the result of raw_data()
* @param output_bits the desired output bit size
* @param rng a random number generator
* @return encoded signature
*/
virtual secure_vector<uint8_t> encoding_of(const secure_vector<uint8_t>& msg,
size_t output_bits,
RandomNumberGenerator& rng) = 0;
/**
* Verify the encoding
* @param coded the received (coded) message representative
* @param raw the computed (local, uncoded) message representative
* @param key_bits the size of the key in bits
* @return true if coded is a valid encoding of raw, otherwise false
*/
virtual bool verify(const secure_vector<uint8_t>& coded,
const secure_vector<uint8_t>& raw,
size_t key_bits) = 0;
/**
* Prepare sig_algo for use in choose_sig_format for x509 certs
*
* @param key used for checking compatibility with the encoding scheme
* @param cert_hash_name is checked to equal the hash for the encoding
* @return algorithm identifier to signatures created using this key,
* padding method and hash.
*/
virtual AlgorithmIdentifier config_for_x509(const Private_Key& key,
const std::string& cert_hash_name) const;
/**
* @return a new object representing the same encoding method as *this
*/
virtual std::unique_ptr<EMSA> new_object() = 0;
/**
* @return the SCAN name of the encoding/padding scheme
*/
virtual std::string name() const = 0;
};
/**
* Factory method for EMSA (message-encoding methods for signatures
* with appendix) objects
* @param algo_spec the name of the EMSA to create
* @return pointer to newly allocated object of that type
*/
BOTAN_TEST_API EMSA* get_emsa(const std::string& algo_spec);
/**
* Returns the hash function used in the given EMSA scheme
* If the hash function is not specified or not understood,
* returns "SHA-512"
* @param algo_spec the name of the EMSA
* @return hash function used in the given EMSA scheme
*/
BOTAN_TEST_API std::string hash_for_emsa(const std::string& algo_spec);
}
#endif
|
