aboutsummaryrefslogtreecommitdiff
path: root/crypto/cipher-gcrypt.c
blob: 8cfc5625004370121cfb8eec04ef0098a42d0233 (plain)
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
/*
 * QEMU Crypto cipher libgcrypt 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/>.
 *
 */

#include <gcrypt.h>


bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg)
{
    switch (alg) {
    case QCRYPTO_CIPHER_ALG_DES_RFB:
    case QCRYPTO_CIPHER_ALG_AES_128:
    case QCRYPTO_CIPHER_ALG_AES_192:
    case QCRYPTO_CIPHER_ALG_AES_256:
        return true;
    default:
        return false;
    }
}


QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
                                  QCryptoCipherMode mode,
                                  const uint8_t *key, size_t nkey,
                                  Error **errp)
{
    QCryptoCipher *cipher;
    gcry_cipher_hd_t handle;
    gcry_error_t err;
    int gcryalg, gcrymode;

    switch (mode) {
    case QCRYPTO_CIPHER_MODE_ECB:
        gcrymode = GCRY_CIPHER_MODE_ECB;
        break;
    case QCRYPTO_CIPHER_MODE_CBC:
        gcrymode = GCRY_CIPHER_MODE_CBC;
        break;
    default:
        error_setg(errp, "Unsupported cipher mode %d", mode);
        return NULL;
    }

    if (!qcrypto_cipher_validate_key_length(alg, nkey, errp)) {
        return NULL;
    }

    switch (alg) {
    case QCRYPTO_CIPHER_ALG_DES_RFB:
        gcryalg = GCRY_CIPHER_DES;
        break;

    case QCRYPTO_CIPHER_ALG_AES_128:
        gcryalg = GCRY_CIPHER_AES128;
        break;

    case QCRYPTO_CIPHER_ALG_AES_192:
        gcryalg = GCRY_CIPHER_AES192;
        break;

    case QCRYPTO_CIPHER_ALG_AES_256:
        gcryalg = GCRY_CIPHER_AES256;
        break;

    default:
        error_setg(errp, "Unsupported cipher algorithm %d", alg);
        return NULL;
    }

    cipher = g_new0(QCryptoCipher, 1);
    cipher->alg = alg;
    cipher->mode = mode;

    err = gcry_cipher_open(&handle, gcryalg, gcrymode, 0);
    if (err != 0) {
        error_setg(errp, "Cannot initialize cipher: %s",
                   gcry_strerror(err));
        goto error;
    }

    if (cipher->alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
        /* We're using standard DES cipher from gcrypt, so we need
         * to munge the key so that the results are the same as the
         * bizarre RFB variant of DES :-)
         */
        uint8_t *rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
        err = gcry_cipher_setkey(handle, rfbkey, nkey);
        g_free(rfbkey);
    } else {
        err = gcry_cipher_setkey(handle, key, nkey);
    }
    if (err != 0) {
        error_setg(errp, "Cannot set key: %s",
                   gcry_strerror(err));
        goto error;
    }

    cipher->opaque = handle;
    return cipher;

 error:
    gcry_cipher_close(handle);
    g_free(cipher);
    return NULL;
}


void qcrypto_cipher_free(QCryptoCipher *cipher)
{
    gcry_cipher_hd_t handle;
    if (!cipher) {
        return;
    }
    handle = cipher->opaque;
    gcry_cipher_close(handle);
    g_free(cipher);
}


int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
                           const void *in,
                           void *out,
                           size_t len,
                           Error **errp)
{
    gcry_cipher_hd_t handle = cipher->opaque;
    gcry_error_t err;

    err = gcry_cipher_encrypt(handle,
                              out, len,
                              in, len);
    if (err != 0) {
        error_setg(errp, "Cannot encrypt data: %s",
                   gcry_strerror(err));
        return -1;
    }

    return 0;
}


int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
                           const void *in,
                           void *out,
                           size_t len,
                           Error **errp)
{
    gcry_cipher_hd_t handle = cipher->opaque;
    gcry_error_t err;

    err = gcry_cipher_decrypt(handle,
                              out, len,
                              in, len);
    if (err != 0) {
        error_setg(errp, "Cannot decrypt data: %s",
                   gcry_strerror(err));
        return -1;
    }

    return 0;
}

int qcrypto_cipher_setiv(QCryptoCipher *cipher,
                         const uint8_t *iv, size_t niv,
                         Error **errp)
{
    gcry_cipher_hd_t handle = cipher->opaque;
    gcry_error_t err;

    gcry_cipher_reset(handle);
    err = gcry_cipher_setiv(handle, iv, niv);
    if (err != 0) {
        error_setg(errp, "Cannot set IV: %s",
                   gcry_strerror(err));
        return -1;
    }

    return 0;
}