Botan 2.19.3
Crypto and TLS for C&
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/hash.h>
9#include <botan/scan_name.h>
10#include <botan/exceptn.h>
11
12#if defined(BOTAN_HAS_EMSA1)
13 #include <botan/emsa1.h>
14#endif
15
16#if defined(BOTAN_HAS_EMSA_X931)
17 #include <botan/emsa_x931.h>
18#endif
19
20#if defined(BOTAN_HAS_EMSA_PKCS1)
21 #include <botan/emsa_pkcs1.h>
22#endif
23
24#if defined(BOTAN_HAS_EMSA_PSSR)
25 #include <botan/pssr.h>
26#endif
27
28#if defined(BOTAN_HAS_EMSA_RAW)
29 #include <botan/emsa_raw.h>
30#endif
31
32#if defined(BOTAN_HAS_ISO_9796)
33 #include <botan/iso9796.h>
34#endif
35
36namespace Botan {
37
39 const std::string&) const
40 {
41 throw Not_Implemented("Encoding " + name() + " not supported for signing X509 objects");
42 }
43
44EMSA* get_emsa(const std::string& algo_spec)
45 {
46 SCAN_Name req(algo_spec);
47
48#if defined(BOTAN_HAS_EMSA1)
49 if(req.algo_name() == "EMSA1" && req.arg_count() == 1)
50 {
51 if(auto hash = HashFunction::create(req.arg(0)))
52 return new EMSA1(hash.release());
53 }
54#endif
55
56#if defined(BOTAN_HAS_EMSA_PKCS1)
57 if(req.algo_name() == "EMSA_PKCS1" ||
58 req.algo_name() == "PKCS1v15" ||
59 req.algo_name() == "EMSA-PKCS1-v1_5" ||
60 req.algo_name() == "EMSA3")
61 {
62 if(req.arg_count() == 2 && req.arg(0) == "Raw")
63 {
64 return new EMSA_PKCS1v15_Raw(req.arg(1));
65 }
66 else if(req.arg_count() == 1)
67 {
68 if(req.arg(0) == "Raw")
69 {
70 return new EMSA_PKCS1v15_Raw;
71 }
72 else
73 {
74 if(auto hash = HashFunction::create(req.arg(0)))
75 {
76 return new EMSA_PKCS1v15(hash.release());
77 }
78 }
79 }
80 }
81#endif
82
83#if defined(BOTAN_HAS_EMSA_PSSR)
84 if(req.algo_name() == "PSS_Raw" ||
85 req.algo_name() == "PSSR_Raw")
86 {
87 if(req.arg_count_between(1, 3) && req.arg(1, "MGF1") == "MGF1")
88 {
89 if(auto h = HashFunction::create(req.arg(0)))
90 {
91 if(req.arg_count() == 3)
92 {
93 const size_t salt_size = req.arg_as_integer(2, 0);
94 return new PSSR_Raw(h.release(), salt_size);
95 }
96 else
97 {
98 return new PSSR_Raw(h.release());
99 }
100 }
101 }
102 }
103
104 if(req.algo_name() == "PSS" ||
105 req.algo_name() == "PSSR" ||
106 req.algo_name() == "EMSA-PSS" ||
107 req.algo_name() == "PSS-MGF1" ||
108 req.algo_name() == "EMSA4")
109 {
110 if(req.arg_count_between(1, 3) && req.arg(1, "MGF1") == "MGF1")
111 {
112 if(auto h = HashFunction::create(req.arg(0)))
113 {
114 if(req.arg_count() == 3)
115 {
116 const size_t salt_size = req.arg_as_integer(2, 0);
117 return new PSSR(h.release(), salt_size);
118 }
119 else
120 {
121 return new PSSR(h.release());
122 }
123 }
124 }
125 }
126#endif
127
128#if defined(BOTAN_HAS_ISO_9796)
129 if(req.algo_name() == "ISO_9796_DS2")
130 {
131 if(req.arg_count_between(1, 3))
132 {
133 if(auto h = HashFunction::create(req.arg(0)))
134 {
135 const size_t salt_size = req.arg_as_integer(2, h->output_length());
136 const bool implicit = req.arg(1, "exp") == "imp";
137 return new ISO_9796_DS2(h.release(), implicit, salt_size);
138 }
139 }
140 }
141 //ISO-9796-2 DS 3 is deterministic and DS2 without a salt
142 if(req.algo_name() == "ISO_9796_DS3")
143 {
144 if(req.arg_count_between(1, 2))
145 {
146 if(auto h = HashFunction::create(req.arg(0)))
147 {
148 const bool implicit = req.arg(1, "exp") == "imp";
149 return new ISO_9796_DS3(h.release(), implicit);
150 }
151 }
152 }
153#endif
154
155#if defined(BOTAN_HAS_EMSA_X931)
156 if(req.algo_name() == "EMSA_X931" ||
157 req.algo_name() == "EMSA2" ||
158 req.algo_name() == "X9.31")
159 {
160 if(req.arg_count() == 1)
161 {
162 if(auto hash = HashFunction::create(req.arg(0)))
163 {
164 return new EMSA_X931(hash.release());
165 }
166 }
167 }
168#endif
169
170#if defined(BOTAN_HAS_EMSA_RAW)
171 if(req.algo_name() == "Raw")
172 {
173 if(req.arg_count() == 0)
174 {
175 return new EMSA_Raw;
176 }
177 else
178 {
179 auto hash = HashFunction::create(req.arg(0));
180 if(hash)
181 return new EMSA_Raw(hash->output_length());
182 }
183 }
184#endif
185
186 throw Algorithm_Not_Found(algo_spec);
187 }
188
189std::string hash_for_emsa(const std::string& algo_spec)
190 {
191 SCAN_Name emsa_name(algo_spec);
192
193 if(emsa_name.arg_count() > 0)
194 {
195 const std::string pos_hash = emsa_name.arg(0);
196 return pos_hash;
197 }
198
199 // If we don't understand what this is return a safe default
200#if defined(BOTAN_HAS_SHA2_64)
201 return "SHA-512";
202#else
203 return "SHA-256";
204#endif
205 }
206
207}
virtual std::string name() const =0
virtual AlgorithmIdentifier config_for_x509(const Private_Key &key, const std::string &cert_hash_name) const
Definition emsa.cpp:38
static std::unique_ptr< HashFunction > create(const std::string &algo_spec, const std::string &provider="")
Definition hash.cpp:102
std::string arg(size_t i) const
size_t arg_count() const
Definition scan_name.h:56
const std::string & algo_name() const
Definition scan_name.h:51
size_t arg_as_integer(size_t i, size_t def_value) const
bool arg_count_between(size_t lower, size_t upper) const
Definition scan_name.h:63
std::string hash_for_emsa(const std::string &algo_spec)
Definition emsa.cpp:189
EMSA * get_emsa(const std::string &algo_spec)
Definition emsa.cpp:44
MechanismType hash
size_t salt_size