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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/*
* QEMU Crypto cipher algorithms
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef QCRYPTO_CIPHER_H__
#define QCRYPTO_CIPHER_H__
#include "qemu-common.h"
#include "qapi/error.h"
typedef struct QCryptoCipher QCryptoCipher;
typedef enum {
QCRYPTO_CIPHER_ALG_AES_128,
QCRYPTO_CIPHER_ALG_AES_192,
QCRYPTO_CIPHER_ALG_AES_256,
QCRYPTO_CIPHER_ALG_DES_RFB, /* A stupid variant on DES for VNC */
QCRYPTO_CIPHER_ALG_LAST
} QCryptoCipherAlgorithm;
typedef enum {
QCRYPTO_CIPHER_MODE_ECB,
QCRYPTO_CIPHER_MODE_CBC,
QCRYPTO_CIPHER_MODE_LAST
} QCryptoCipherMode;
/**
* QCryptoCipher:
*
* The QCryptoCipher object provides a way to perform encryption
* and decryption of data, with a standard API, regardless of the
* algorithm used. It further isolates the calling code from the
* details of the specific underlying implementation, whether
* built-in, libgcrypt or nettle.
*
* Each QCryptoCipher object is capable of performing both
* encryption and decryption, and can operate in a number
* or modes including ECB, CBC.
*
* <example>
* <title>Encrypting data with AES-128 in CBC mode</title>
* <programlisting>
* QCryptoCipher *cipher;
* uint8_t key = ....;
* size_t keylen = 16;
* uint8_t iv = ....;
*
* if (!qcrypto_cipher_supports(QCRYPTO_CIPHER_ALG_AES_128)) {
* error_report(errp, "Feature <blah> requires AES cipher support");
* return -1;
* }
*
* cipher = qcrypto_cipher_new(QCRYPTO_CIPHER_ALG_AES_128,
* QCRYPTO_CIPHER_MODE_CBC,
* key, keylen,
* errp);
* if (!cipher) {
* return -1;
* }
*
* if (qcrypto_cipher_set_iv(cipher, iv, keylen, errp) < 0) {
* return -1;
* }
*
* if (qcrypto_cipher_encrypt(cipher, rawdata, encdata, datalen, errp) < 0) {
* return -1;
* }
*
* qcrypto_cipher_free(cipher);
* </programlisting>
* </example>
*
*/
struct QCryptoCipher {
QCryptoCipherAlgorithm alg;
QCryptoCipherMode mode;
void *opaque;
};
/**
* qcrypto_cipher_supports:
* @alg: the cipher algorithm
*
* Determine if @alg cipher algorithm is supported by the
* current configured build
*
* Returns: true if the algorithm is supported, false otherwise
*/
bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg);
/**
* qcrypto_cipher_new:
* @alg: the cipher algorithm
* @mode: the cipher usage mode
* @key: the private key bytes
* @nkey: the length of @key
* @errp: pointer to an uninitialized error object
*
* Creates a new cipher object for encrypting/decrypting
* data with the algorithm @alg in the usage mode @mode.
*
* The @key parameter provides the bytes representing
* the encryption/decryption key to use. The @nkey parameter
* specifies the length of @key in bytes. Each algorithm has
* one or more valid key lengths, and it is an error to provide
* a key of the incorrect length.
*
* The returned cipher object must be released with
* qcrypto_cipher_free() when no longer required
*
* Returns: a new cipher object, or NULL on error
*/
QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
QCryptoCipherMode mode,
const uint8_t *key, size_t nkey,
Error **errp);
/**
* qcrypto_cipher_free:
* @cipher: the cipher object
*
* Release the memory associated with @cipher that
* was previously allocated by qcrypto_cipher_new()
*/
void qcrypto_cipher_free(QCryptoCipher *cipher);
/**
* qcrypto_cipher_encrypt:
* @cipher: the cipher object
* @in: buffer holding the plain text input data
* @out: buffer to fill with the cipher text output data
* @len: the length of @in and @out buffers
* @errp: pointer to an uninitialized error object
*
* Encrypts the plain text stored in @in, filling
* @out with the resulting ciphered text. Both the
* @in and @out buffers must have the same size,
* given by @len.
*
* Returns: 0 on success, or -1 on error
*/
int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp);
/**
* qcrypto_cipher_decrypt:
* @cipher: the cipher object
* @in: buffer holding the cipher text input data
* @out: buffer to fill with the plain text output data
* @len: the length of @in and @out buffers
* @errp: pointer to an uninitialized error object
*
* Decrypts the cipher text stored in @in, filling
* @out with the resulting plain text. Both the
* @in and @out buffers must have the same size,
* given by @len.
*
* Returns: 0 on success, or -1 on error
*/
int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
const void *in,
void *out,
size_t len,
Error **errp);
/**
* qcrypto_cipher_setiv:
* @cipher: the cipher object
* @iv: the initialization vector bytes
* @niv: the length of @iv
* @errpr: pointer to an uninitialized error object
*
* If the @cipher object is setup to use a mode that requires
* initialization vectors, this sets the initialization vector
* bytes. The @iv data should have the same length as the
* cipher key used when originally constructing the cipher
* object. It is an error to set an initialization vector
* if the cipher mode does not require one.
*
* Returns: 0 on success, -1 on error
*/
int qcrypto_cipher_setiv(QCryptoCipher *cipher,
const uint8_t *iv, size_t niv,
Error **errp);
#endif /* QCRYPTO_CIPHER_H__ */
|
