Botan 2.17.3
Crypto and TLS for C&
cipher_mode.cpp
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1/*
2* Cipher Modes
3* (C) 2015 Jack Lloyd
4*
5* Botan is released under the Simplified BSD License (see license.txt)
6*/
7
8#include <botan/cipher_mode.h>
9#include <botan/stream_mode.h>
10#include <botan/scan_name.h>
11#include <botan/parsing.h>
12#include <sstream>
13
14#if defined(BOTAN_HAS_BLOCK_CIPHER)
15 #include <botan/block_cipher.h>
16#endif
17
18#if defined(BOTAN_HAS_AEAD_MODES)
19 #include <botan/aead.h>
20#endif
21
22#if defined(BOTAN_HAS_MODE_CBC)
23 #include <botan/cbc.h>
24#endif
25
26#if defined(BOTAN_HAS_MODE_CFB)
27 #include <botan/cfb.h>
28#endif
29
30#if defined(BOTAN_HAS_MODE_XTS)
31 #include <botan/xts.h>
32#endif
33
34#if defined(BOTAN_HAS_OPENSSL)
35 #include <botan/internal/openssl.h>
36#endif
37
38#if defined(BOTAN_HAS_COMMONCRYPTO)
39 #include <botan/internal/commoncrypto.h>
40#endif
41
42namespace Botan {
43
44std::unique_ptr<Cipher_Mode> Cipher_Mode::create_or_throw(const std::string& algo,
45 Cipher_Dir direction,
46 const std::string& provider)
47 {
48 if(auto mode = Cipher_Mode::create(algo, direction, provider))
49 return mode;
50
51 throw Lookup_Error("Cipher mode", algo, provider);
52 }
53
54std::unique_ptr<Cipher_Mode> Cipher_Mode::create(const std::string& algo,
55 Cipher_Dir direction,
56 const std::string& provider)
57 {
58#if defined(BOTAN_HAS_COMMONCRYPTO)
59 if(provider.empty() || provider == "commoncrypto")
60 {
61 std::unique_ptr<Cipher_Mode> commoncrypto_cipher(make_commoncrypto_cipher_mode(algo, direction));
62
63 if(commoncrypto_cipher)
64 return commoncrypto_cipher;
65
66 if(!provider.empty())
67 return std::unique_ptr<Cipher_Mode>();
68 }
69#endif
70
71#if defined(BOTAN_HAS_OPENSSL)
72 if(provider.empty() || provider == "openssl")
73 {
74 std::unique_ptr<Cipher_Mode> openssl_cipher(make_openssl_cipher_mode(algo, direction));
75
76 if(openssl_cipher)
77 return openssl_cipher;
78
79 if(!provider.empty())
80 return std::unique_ptr<Cipher_Mode>();
81 }
82#endif
83
84#if defined(BOTAN_HAS_STREAM_CIPHER)
85 if(auto sc = StreamCipher::create(algo))
86 {
87 return std::unique_ptr<Cipher_Mode>(new Stream_Cipher_Mode(sc.release()));
88 }
89#endif
90
91#if defined(BOTAN_HAS_AEAD_MODES)
92 if(auto aead = AEAD_Mode::create(algo, direction))
93 {
94 return std::unique_ptr<Cipher_Mode>(aead.release());
95 }
96#endif
97
98 if(algo.find('/') != std::string::npos)
99 {
100 const std::vector<std::string> algo_parts = split_on(algo, '/');
101 const std::string cipher_name = algo_parts[0];
102 const std::vector<std::string> mode_info = parse_algorithm_name(algo_parts[1]);
103
104 if(mode_info.empty())
105 return std::unique_ptr<Cipher_Mode>();
106
107 std::ostringstream alg_args;
108
109 alg_args << '(' << cipher_name;
110 for(size_t i = 1; i < mode_info.size(); ++i)
111 alg_args << ',' << mode_info[i];
112 for(size_t i = 2; i < algo_parts.size(); ++i)
113 alg_args << ',' << algo_parts[i];
114 alg_args << ')';
115
116 const std::string mode_name = mode_info[0] + alg_args.str();
117 return Cipher_Mode::create(mode_name, direction, provider);
118 }
119
120#if defined(BOTAN_HAS_BLOCK_CIPHER)
121
122 SCAN_Name spec(algo);
123
124 if(spec.arg_count() == 0)
125 {
126 return std::unique_ptr<Cipher_Mode>();
127 }
128
129 std::unique_ptr<BlockCipher> bc(BlockCipher::create(spec.arg(0), provider));
130
131 if(!bc)
132 {
133 return std::unique_ptr<Cipher_Mode>();
134 }
135
136#if defined(BOTAN_HAS_MODE_CBC)
137 if(spec.algo_name() == "CBC")
138 {
139 const std::string padding = spec.arg(1, "PKCS7");
140
141 if(padding == "CTS")
142 {
143 if(direction == ENCRYPTION)
144 return std::unique_ptr<Cipher_Mode>(new CTS_Encryption(bc.release()));
145 else
146 return std::unique_ptr<Cipher_Mode>(new CTS_Decryption(bc.release()));
147 }
148 else
149 {
150 std::unique_ptr<BlockCipherModePaddingMethod> pad(get_bc_pad(padding));
151
152 if(pad)
153 {
154 if(direction == ENCRYPTION)
155 return std::unique_ptr<Cipher_Mode>(new CBC_Encryption(bc.release(), pad.release()));
156 else
157 return std::unique_ptr<Cipher_Mode>(new CBC_Decryption(bc.release(), pad.release()));
158 }
159 }
160 }
161#endif
162
163#if defined(BOTAN_HAS_MODE_XTS)
164 if(spec.algo_name() == "XTS")
165 {
166 if(direction == ENCRYPTION)
167 return std::unique_ptr<Cipher_Mode>(new XTS_Encryption(bc.release()));
168 else
169 return std::unique_ptr<Cipher_Mode>(new XTS_Decryption(bc.release()));
170 }
171#endif
172
173#if defined(BOTAN_HAS_MODE_CFB)
174 if(spec.algo_name() == "CFB")
175 {
176 const size_t feedback_bits = spec.arg_as_integer(1, 8*bc->block_size());
177 if(direction == ENCRYPTION)
178 return std::unique_ptr<Cipher_Mode>(new CFB_Encryption(bc.release(), feedback_bits));
179 else
180 return std::unique_ptr<Cipher_Mode>(new CFB_Decryption(bc.release(), feedback_bits));
181 }
182#endif
183
184#endif
185
186 return std::unique_ptr<Cipher_Mode>();
187 }
188
189//static
190std::vector<std::string> Cipher_Mode::providers(const std::string& algo_spec)
191 {
192 const std::vector<std::string>& possible = { "base", "openssl", "commoncrypto" };
193 std::vector<std::string> providers;
194 for(auto&& prov : possible)
195 {
196 std::unique_ptr<Cipher_Mode> mode = Cipher_Mode::create(algo_spec, ENCRYPTION, prov);
197 if(mode)
198 {
199 providers.push_back(prov); // available
200 }
201 }
202 return providers;
203 }
204
205}
static std::unique_ptr< AEAD_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: aead.cpp:60
static std::unique_ptr< BlockCipher > create(const std::string &algo_spec, const std::string &provider="")
static std::vector< std::string > providers(const std::string &algo_spec)
virtual std::string provider() const
Definition: cipher_mode.h:180
static std::unique_ptr< Cipher_Mode > create(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: cipher_mode.cpp:54
static std::unique_ptr< Cipher_Mode > create_or_throw(const std::string &algo, Cipher_Dir direction, const std::string &provider="")
Definition: cipher_mode.cpp:44
std::string arg(size_t i) const
Definition: scan_name.cpp:127
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
Definition: scan_name.cpp:142
static std::unique_ptr< StreamCipher > create(const std::string &algo_spec, const std::string &provider="")
Definition: alg_id.cpp:13
std::vector< std::string > split_on(const std::string &str, char delim)
Definition: parsing.cpp:148
BlockCipherModePaddingMethod * get_bc_pad(const std::string &algo_spec)
Definition: mode_pad.cpp:18
Cipher_Mode * make_openssl_cipher_mode(const std::string &name, Cipher_Dir direction)
Cipher_Dir
Definition: cipher_mode.h:23
@ ENCRYPTION
Definition: cipher_mode.h:23
Cipher_Mode * make_commoncrypto_cipher_mode(const std::string &name, Cipher_Dir direction)
std::vector< std::string > parse_algorithm_name(const std::string &namex)
Definition: parsing.cpp:95