Botan 2.1.0 Crypto and TLS for C++11

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emsa.cpp
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1 /*
2 * (C) 2015 Jack Lloyd
3 *
4 * Botan is released under the Simplified BSD License (see license.txt)
5 */
6
7 #include <botan/emsa.h>
8 #include <botan/scan_name.h>
9
10 #if defined(BOTAN_HAS_EMSA1)
11 #include <botan/emsa1.h>
12 #endif
13
14 #if defined(BOTAN_HAS_EMSA_X931)
15 #include <botan/emsa_x931.h>
16 #endif
17
18 #if defined(BOTAN_HAS_EMSA_PKCS1)
19 #include <botan/emsa_pkcs1.h>
20 #endif
21
22 #if defined(BOTAN_HAS_EMSA_PSSR)
23 #include <botan/pssr.h>
24 #endif
25
26 #if defined(BOTAN_HAS_EMSA_RAW)
27 #include <botan/emsa_raw.h>
28 #endif
29
30 #if defined(BOTAN_HAS_ISO_9796)
31 #include <botan/iso9796.h>
32 #endif
33
34 namespace Botan {
35
36 EMSA* get_emsa(const std::string& algo_spec)
37 {
38 SCAN_Name req(algo_spec);
39
40 #if defined(BOTAN_HAS_EMSA1)
41 if(req.algo_name() == "EMSA1" && req.arg_count() == 1)
42 {
43 if(auto hash = HashFunction::create(req.arg(0)))
44 return new EMSA1(hash.release());
45 }
46 #endif
47
48 #if defined(BOTAN_HAS_EMSA_PKCS1)
49 if(req.algo_name() == "EMSA_PKCS1" ||
50 req.algo_name() == "EMSA-PKCS1-v1_5" ||
51 req.algo_name() == "EMSA3")
52 {
53 if(req.arg_count() == 1)
54 {
55 if(req.arg(0) == "Raw")
56 {
57 return new EMSA_PKCS1v15_Raw;
58 }
59 else
60 {
61 if(auto hash = HashFunction::create(req.arg(0)))
62 {
63 return new EMSA_PKCS1v15(hash.release());
64 }
65 }
66 }
67 }
68 #endif
69
70 #if defined(BOTAN_HAS_EMSA_PSSR)
71 if(req.algo_name() == "PSSR" ||
72 req.algo_name() == "EMSA-PSS" ||
73 req.algo_name() == "PSS-MGF1" ||
74 req.algo_name() == "EMSA4")
75 {
76 if(req.arg_count_between(1, 3))
77 {
78 if(req.arg(1, "MGF1") != "MGF1")
79 return nullptr; // not supported
80
81 if(auto h = HashFunction::create(req.arg(0)))
82 {
83 const size_t salt_size = req.arg_as_integer(2, h->output_length());
84 return new PSSR(h.release(), salt_size);
85 }
86 }
87 }
88 #endif
89
90 #if defined(BOTAN_HAS_ISO_9796)
91 if(req.algo_name() == "ISO_9796_DS2")
92 {
93 if(req.arg_count_between(1, 3))
94 {
95 if(auto h = HashFunction::create(req.arg(0)))
96 {
97 const size_t salt_size = req.arg_as_integer(2, h->output_length());
98 const bool implicit = req.arg(1, "exp") == "imp";
99 return new ISO_9796_DS2(h.release(), implicit, salt_size);
100 }
101 }
102 }
103 //ISO-9796-2 DS 3 is deterministic and DS2 without a salt
104 if(req.algo_name() == "ISO_9796_DS3")
105 {
106 if(req.arg_count_between(1, 2))
107 {
108 if(auto h = HashFunction::create(req.arg(0)))
109 {
110 const bool implicit = req.arg(1, "exp") == "imp";
111 return new ISO_9796_DS3(h.release(), implicit);
112 }
113 }
114 }
115 #endif
116
117 #if defined(BOTAN_HAS_EMSA_X931)
118 if(req.algo_name() == "EMSA_X931" ||
119 req.algo_name() == "EMSA2" ||
120 req.algo_name() == "X9.31")
121 {
122 if(req.arg_count() == 1)
123 {
124 if(auto hash = HashFunction::create(req.arg(0)))
125 {
126 return new EMSA_X931(hash.release());
127 }
128 }
129 }
130 #endif
131
132 #if defined(BOTAN_HAS_EMSA_RAW)
133 if(req.algo_name() == "Raw" && req.arg_count() == 0)
134 {
135 return new EMSA_Raw;
136 }
137 #endif
138
139 throw Algorithm_Not_Found(algo_spec);
140 }
141
142 std::string hash_for_emsa(const std::string& algo_spec)
143 {
144 SCAN_Name emsa_name(algo_spec);
145
146 if(emsa_name.arg_count() > 0)
147 {
148 const std::string pos_hash = emsa_name.arg(0);
149 return pos_hash;
150 }
151
152 return "SHA-512"; // safe default if nothing we understand
153 }
154
155 }
156
157
Botan::SCAN_Name::arg
std::string arg(size_t i) const
Definition: scan_name.cpp:122
Botan::hash_for_emsa
std::string hash_for_emsa(const std::string &algo_spec)
Definition: emsa.cpp:142
Botan::get_emsa
EMSA * get_emsa(const std::string &algo_spec)
Definition: emsa.cpp:36
Botan::SCAN_Name::arg_count
size_t arg_count() const
Definition: scan_name.h:50
salt_size
size_t salt_size
Definition: p11_mechanism.cpp:69
Botan::ISO_9796_DS3
Definition: iso9796.h:61
Botan::ISO_9796_DS2
Definition: iso9796.h:19
Botan::EMSA_X931
Definition: emsa_x931.h:21
Botan::SCAN_Name::arg_count_between
bool arg_count_between(size_t lower, size_t upper) const
Definition: scan_name.h:57
Botan::HashFunction::create
static std::unique_ptr< HashFunction > create(const std::string &algo_spec, const std::string &provider="")
Definition: hash.cpp:93
Botan::PSSR
Definition: pssr.h:19
Botan::SCAN_Name::arg_as_integer
size_t arg_as_integer(size_t i, size_t def_value) const
Definition: scan_name.cpp:137
Botan::EMSA_PKCS1v15
Definition: emsa_pkcs1.h:21
Botan::EMSA
Definition: emsa.h:21
Botan
Definition: alg_id.cpp:13
Botan::EMSA_PKCS1v15_Raw
Definition: emsa_pkcs1.h:50
Botan::SCAN_Name
Definition: scan_name.h:22
Botan::SCAN_Name::algo_name
const std::string & algo_name() const
Definition: scan_name.h:45
Botan::EMSA1
Definition: emsa1.h:20
Botan::EMSA_Raw
Definition: emsa_raw.h:19
Botan::Algorithm_Not_Found
Definition: exceptn.h:140
hash
MechanismType hash
Definition: p11_mechanism.cpp:63