Botan: src/ssl/tls_session_key.cpp Source File

Botan 1.10.17

tls_session_key.cpp
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1 /*
2 * TLS Session Key
3 * (C) 2004-2006 Jack Lloyd
4 *
5 * Released under the terms of the Botan license
6 */
7
8 #include <botan/tls_session_key.h>
9 #include <botan/prf_ssl3.h>
10 #include <botan/prf_tls.h>
11 #include <botan/lookup.h>
12
13 namespace Botan {
14
15 /**
16 * Return the client cipher key
17 */
18 SymmetricKey SessionKeys::client_cipher_key() const
19 {
20 return c_cipher;
21 }
22
23 /**
24 * Return the server cipher key
25 */
26 SymmetricKey SessionKeys::server_cipher_key() const
27 {
28 return s_cipher;
29 }
30
31 /**
32 * Return the client MAC key
33 */
34 SymmetricKey SessionKeys::client_mac_key() const
35 {
36 return c_mac;
37 }
38
39 /**
40 * Return the server MAC key
41 */
42 SymmetricKey SessionKeys::server_mac_key() const
43 {
44 return s_mac;
45 }
46
47 /**
48 * Return the client cipher IV
49 */
50 InitializationVector SessionKeys::client_iv() const
51 {
52 return c_iv;
53 }
54
55 /**
56 * Return the server cipher IV
57 */
58 InitializationVector SessionKeys::server_iv() const
59 {
60 return s_iv;
61 }
62
63 /**
64 * Return the TLS master secret
65 */
66 SecureVector<byte> SessionKeys::master_secret() const
67 {
68 return master_sec;
69 }
70
71 /**
72 * Generate SSLv3 session keys
73 */
74 SymmetricKey SessionKeys::ssl3_keygen(size_t prf_gen,
75 const MemoryRegion<byte>& pre_master,
76 const MemoryRegion<byte>& client_random,
77 const MemoryRegion<byte>& server_random)
78 {
79 SSL3_PRF prf;
80
81 SecureVector<byte> salt;
82 salt += client_random;
83 salt += server_random;
84
85 master_sec = prf.derive_key(48, pre_master, salt);
86
87 salt.clear();
88 salt += server_random;
89 salt += client_random;
90
91 return prf.derive_key(prf_gen, master_sec, salt);
92 }
93
94 /**
95 * Generate TLS 1.0 session keys
96 */
97 SymmetricKey SessionKeys::tls1_keygen(size_t prf_gen,
98 const MemoryRegion<byte>& pre_master,
99 const MemoryRegion<byte>& client_random,
100 const MemoryRegion<byte>& server_random)
101 {
102 const byte MASTER_SECRET_MAGIC[] = {
103 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x73, 0x65, 0x63, 0x72, 0x65,
104 0x74 };
105 const byte KEY_GEN_MAGIC[] = {
106 0x6B, 0x65, 0x79, 0x20, 0x65, 0x78, 0x70, 0x61, 0x6E, 0x73, 0x69, 0x6F,
107 0x6E };
108
109 TLS_PRF prf;
110
111 SecureVector<byte> salt;
112 salt += std::make_pair(MASTER_SECRET_MAGIC, sizeof(MASTER_SECRET_MAGIC));
113 salt += client_random;
114 salt += server_random;
115
116 master_sec = prf.derive_key(48, pre_master, salt);
117
118 salt.clear();
119 salt += std::make_pair(KEY_GEN_MAGIC, sizeof(KEY_GEN_MAGIC));
120 salt += server_random;
121 salt += client_random;
122
123 return prf.derive_key(prf_gen, master_sec, salt);
124 }
125
126 /**
127 * SessionKeys Constructor
128 */
129 SessionKeys::SessionKeys(const CipherSuite& suite, Version_Code version,
130 const MemoryRegion<byte>& pre_master_secret,
131 const MemoryRegion<byte>& c_random,
132 const MemoryRegion<byte>& s_random)
133 {
134 if(version != SSL_V3 && version != TLS_V10 && version != TLS_V11)
135 throw Invalid_Argument("SessionKeys: Unknown version code");
136
137 const size_t mac_keylen = output_length_of(suite.mac_algo());
138 const size_t cipher_keylen = suite.cipher_keylen();
139
140 size_t cipher_ivlen = 0;
141 if(have_block_cipher(suite.cipher_algo()))
142 cipher_ivlen = block_size_of(suite.cipher_algo());
143
144 const size_t prf_gen = 2 * (mac_keylen + cipher_keylen + cipher_ivlen);
145
146 SymmetricKey keyblock = (version == SSL_V3) ?
147 ssl3_keygen(prf_gen, pre_master_secret, c_random, s_random) :
148 tls1_keygen(prf_gen, pre_master_secret, c_random, s_random);
149
150 const byte* key_data = keyblock.begin();
151
152 c_mac = SymmetricKey(key_data, mac_keylen);
153 key_data += mac_keylen;
154
155 s_mac = SymmetricKey(key_data, mac_keylen);
156 key_data += mac_keylen;
157
158 c_cipher = SymmetricKey(key_data, cipher_keylen);
159 key_data += cipher_keylen;
160
161 s_cipher = SymmetricKey(key_data, cipher_keylen);
162 key_data += cipher_keylen;
163
164 c_iv = InitializationVector(key_data, cipher_ivlen);
165 key_data += cipher_ivlen;
166
167 s_iv = InitializationVector(key_data, cipher_ivlen);
168 }
169
170 }
Botan::SessionKeys::server_mac_key
SymmetricKey server_mac_key() const
Definition: tls_session_key.cpp:42
Botan::SessionKeys::client_mac_key
SymmetricKey client_mac_key() const
Definition: tls_session_key.cpp:34
Botan::OctetString
Definition: symkey.h:19
Botan::KDF::derive_key
SecureVector< byte > derive_key(size_t key_len, const MemoryRegion< byte > &secret, const std::string &salt="") const
Definition: kdf.cpp:15
Botan::MemoryRegion::clear
void clear()
Definition: secmem.h:158
Botan::CipherSuite::mac_algo
std::string mac_algo() const
Definition: tls_suites.h:26
Botan::Invalid_Argument
std::invalid_argument Invalid_Argument
Definition: exceptn.h:20
Botan::TLS_V10
Definition: tls_magic.h:25
Botan::SessionKeys::SessionKeys
SessionKeys()
Definition: tls_session_key.h:34
Botan::SessionKeys::client_iv
InitializationVector client_iv() const
Definition: tls_session_key.cpp:50
Botan::OctetString::begin
const byte * begin() const
Definition: symkey.h:35
Botan::SessionKeys::server_cipher_key
SymmetricKey server_cipher_key() const
Definition: tls_session_key.cpp:26
Botan::byte
unsigned char byte
Definition: types.h:22
Botan::SymmetricKey
OctetString SymmetricKey
Definition: symkey.h:147
Botan::SessionKeys::client_cipher_key
SymmetricKey client_cipher_key() const
Definition: tls_session_key.cpp:18
Botan::block_size_of
size_t block_size_of(const std::string &name)
Definition: lookup.cpp:35
Botan::Version_Code
Version_Code
Definition: tls_magic.h:22
Botan::SSL3_PRF
Definition: prf_ssl3.h:18
Botan::MemoryRegion< byte >
Botan
Definition: algo_base.h:14
Botan::SSL_V3
Definition: tls_magic.h:24
Botan::SessionKeys::server_iv
InitializationVector server_iv() const
Definition: tls_session_key.cpp:58
Botan::CipherSuite::cipher_algo
std::string cipher_algo() const
Definition: tls_suites.h:25
Botan::have_block_cipher
bool have_block_cipher(const std::string &algo_spec)
Definition: lookup.h:235
Botan::CipherSuite
Definition: tls_suites.h:20
Botan::TLS_V11
Definition: tls_magic.h:26
Botan::CipherSuite::cipher_keylen
size_t cipher_keylen() const
Definition: tls_suites.h:28
Botan::SecureVector< byte >
Botan::SessionKeys::master_secret
SecureVector< byte > master_secret() const
Definition: tls_session_key.cpp:66
Botan::output_length_of
size_t output_length_of(const std::string &name)
Definition: lookup.cpp:51
Botan::InitializationVector
OctetString InitializationVector
Definition: symkey.h:152