[mirror_qemu.git] / crypto / cipher-gnutls.c.inc

/*
 * QEMU Crypto cipher gnutls algorithms
 *
 * Copyright (c) 2021 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 2.1 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 "qemu/osdep.h"
#include "cipherpriv.h"

#include <gnutls/crypto.h>

#if GNUTLS_VERSION_NUMBER >= 0x030608
#define QEMU_GNUTLS_XTS
#endif

bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
                             QCryptoCipherMode mode)
{

    switch (mode) {
    case QCRYPTO_CIPHER_MODE_ECB:
    case QCRYPTO_CIPHER_MODE_CBC:
        switch (alg) {
        case QCRYPTO_CIPHER_ALG_AES_128:
        case QCRYPTO_CIPHER_ALG_AES_192:
        case QCRYPTO_CIPHER_ALG_AES_256:
        case QCRYPTO_CIPHER_ALG_DES:
        case QCRYPTO_CIPHER_ALG_3DES:
            return true;
        default:
            return false;
        }
#ifdef QEMU_GNUTLS_XTS
    case QCRYPTO_CIPHER_MODE_XTS:
        switch (alg) {
        case QCRYPTO_CIPHER_ALG_AES_128:
        case QCRYPTO_CIPHER_ALG_AES_256:
            return true;
        default:
            return false;
        }
#endif
    default:
        return false;
    }
}

typedef struct QCryptoCipherGnutls QCryptoCipherGnutls;
struct QCryptoCipherGnutls {
    QCryptoCipher base;
    gnutls_cipher_hd_t handle; /* XTS & CBC mode */
    gnutls_cipher_algorithm_t galg; /* ECB mode */
    guint8 *key; /* ECB mode */
    size_t nkey; /* ECB mode */
    size_t blocksize;
};


static void
qcrypto_gnutls_cipher_free(QCryptoCipher *cipher)
{
    QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);

    g_free(ctx->key);
    if (ctx->handle) {
        gnutls_cipher_deinit(ctx->handle);
    }
    g_free(ctx);
}


static int
qcrypto_gnutls_cipher_encrypt(QCryptoCipher *cipher,
                              const void *in,
                              void *out,
                              size_t len,
                              Error **errp)
{
    QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
    int err;

    if (len % ctx->blocksize) {
        error_setg(errp, "Length %zu must be a multiple of block size %zu",
                   len, ctx->blocksize);
        return -1;
    }

    if (ctx->handle) { /* CBC / XTS mode */
        err = gnutls_cipher_encrypt2(ctx->handle,
                                     in, len,
                                     out, len);
        if (err != 0) {
            error_setg(errp, "Cannot encrypt data: %s",
                       gnutls_strerror(err));
            return -1;
        }
    } else { /* ECB mode very inefficiently faked with CBC */
        g_autofree unsigned char *iv = g_new0(unsigned char, ctx->blocksize);
        while (len) {
            gnutls_cipher_hd_t handle;
            gnutls_datum_t gkey = { (unsigned char *)ctx->key, ctx->nkey };
            err = gnutls_cipher_init(&handle, ctx->galg, &gkey, NULL);
            if (err != 0) {
                error_setg(errp, "Cannot initialize cipher: %s",
                           gnutls_strerror(err));
                return -1;
            }

            gnutls_cipher_set_iv(handle, iv, ctx->blocksize);

            err = gnutls_cipher_encrypt2(handle,
                                         in, ctx->blocksize,
                                         out, ctx->blocksize);
            if (err != 0) {
                gnutls_cipher_deinit(handle);
                error_setg(errp, "Cannot encrypt data: %s",
                           gnutls_strerror(err));
                return -1;
            }
            gnutls_cipher_deinit(handle);

            len -= ctx->blocksize;
            in += ctx->blocksize;
            out += ctx->blocksize;
        }
    }

    return 0;
}


static int
qcrypto_gnutls_cipher_decrypt(QCryptoCipher *cipher,
                              const void *in,
                              void *out,
                              size_t len,
                              Error **errp)
{
    QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
    int err;

    if (len % ctx->blocksize) {
        error_setg(errp, "Length %zu must be a multiple of block size %zu",
                   len, ctx->blocksize);
        return -1;
    }

    if (ctx->handle) { /* CBC / XTS mode */
        err = gnutls_cipher_decrypt2(ctx->handle,
                                     in, len,
                                     out, len);

        if (err != 0) {
            error_setg(errp, "Cannot decrypt data: %s",
                       gnutls_strerror(err));
            return -1;
        }
    } else { /* ECB mode very inefficiently faked with CBC */
        g_autofree unsigned char *iv = g_new0(unsigned char, ctx->blocksize);
        while (len) {
            gnutls_cipher_hd_t handle;
            gnutls_datum_t gkey = { (unsigned char *)ctx->key, ctx->nkey };
            err = gnutls_cipher_init(&handle, ctx->galg, &gkey, NULL);
            if (err != 0) {
                error_setg(errp, "Cannot initialize cipher: %s",
                           gnutls_strerror(err));
                return -1;
            }

            gnutls_cipher_set_iv(handle, iv, ctx->blocksize);

            err = gnutls_cipher_decrypt2(handle,
                                         in, ctx->blocksize,
                                         out, ctx->blocksize);
            if (err != 0) {
                gnutls_cipher_deinit(handle);
                error_setg(errp, "Cannot encrypt data: %s",
                           gnutls_strerror(err));
                return -1;
            }
            gnutls_cipher_deinit(handle);

            len -= ctx->blocksize;
            in += ctx->blocksize;
            out += ctx->blocksize;
        }
    }

    return 0;
}

static int
qcrypto_gnutls_cipher_setiv(QCryptoCipher *cipher,
                            const uint8_t *iv, size_t niv,
                            Error **errp)
{
    QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);

    if (niv != ctx->blocksize) {
        error_setg(errp, "Expected IV size %zu not %zu",
                   ctx->blocksize, niv);
        return -1;
    }

    gnutls_cipher_set_iv(ctx->handle, (unsigned char *)iv, niv);

    return 0;
}


static struct QCryptoCipherDriver gnutls_driver = {
    .cipher_encrypt = qcrypto_gnutls_cipher_encrypt,
    .cipher_decrypt = qcrypto_gnutls_cipher_decrypt,
    .cipher_setiv = qcrypto_gnutls_cipher_setiv,
    .cipher_free = qcrypto_gnutls_cipher_free,
};

static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
                                             QCryptoCipherMode mode,
                                             const uint8_t *key,
                                             size_t nkey,
                                             Error **errp)
{
    QCryptoCipherGnutls *ctx;
    gnutls_datum_t gkey = { (unsigned char *)key, nkey };
    gnutls_cipher_algorithm_t galg = GNUTLS_CIPHER_UNKNOWN;
    int err;

    switch (mode) {
#ifdef QEMU_GNUTLS_XTS
    case QCRYPTO_CIPHER_MODE_XTS:
        switch (alg) {
        case QCRYPTO_CIPHER_ALG_AES_128:
            galg = GNUTLS_CIPHER_AES_128_XTS;
            break;
        case QCRYPTO_CIPHER_ALG_AES_256:
            galg = GNUTLS_CIPHER_AES_256_XTS;
            break;
        default:
            break;
        }
        break;
#endif

    case QCRYPTO_CIPHER_MODE_ECB:
    case QCRYPTO_CIPHER_MODE_CBC:
        switch (alg) {
        case QCRYPTO_CIPHER_ALG_AES_128:
            galg = GNUTLS_CIPHER_AES_128_CBC;
            break;
        case QCRYPTO_CIPHER_ALG_AES_192:
            galg = GNUTLS_CIPHER_AES_192_CBC;
            break;
        case QCRYPTO_CIPHER_ALG_AES_256:
            galg = GNUTLS_CIPHER_AES_256_CBC;
            break;
        case QCRYPTO_CIPHER_ALG_DES:
            galg = GNUTLS_CIPHER_DES_CBC;
            break;
        case QCRYPTO_CIPHER_ALG_3DES:
            galg = GNUTLS_CIPHER_3DES_CBC;
            break;
        default:
            break;
        }
        break;
    default:
        break;
    }

    if (galg == GNUTLS_CIPHER_UNKNOWN) {
        error_setg(errp, "Unsupported cipher algorithm %s with %s mode",
                   QCryptoCipherAlgorithm_str(alg),
                   QCryptoCipherMode_str(mode));
        return NULL;
    }

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

    ctx = g_new0(QCryptoCipherGnutls, 1);
    ctx->base.driver = &gnutls_driver;

    if (mode == QCRYPTO_CIPHER_MODE_ECB) {
        ctx->key = g_new0(guint8, nkey);
        memcpy(ctx->key, key, nkey);
        ctx->nkey = nkey;
        ctx->galg = galg;
    } else {
        err = gnutls_cipher_init(&ctx->handle, galg, &gkey, NULL);
        if (err != 0) {
            error_setg(errp, "Cannot initialize cipher: %s",
                       gnutls_strerror(err));
            goto error;
        }
    }

    if (alg == QCRYPTO_CIPHER_ALG_DES ||
        alg == QCRYPTO_CIPHER_ALG_3DES)
        ctx->blocksize = 8;
    else
        ctx->blocksize = 16;

    /*
     * Our API contract for requires iv to be optional
     * but nettle gets unhappy when called by gnutls
     * in this case, so we just force set a default
     * all-zeros IV, to match behaviour of other backends.
     */
    if (mode != QCRYPTO_CIPHER_MODE_ECB) {
        g_autofree unsigned char *iv = g_new0(unsigned char, ctx->blocksize);
        gnutls_cipher_set_iv(ctx->handle, iv, ctx->blocksize);
    }

    return &ctx->base;

 error:
    qcrypto_gnutls_cipher_free(&ctx->base);
    return NULL;
}
Commit	Line	Data
3d2b61ff DB	1	/*
	2	* QEMU Crypto cipher gnutls algorithms
	3	*
	4	* Copyright (c) 2021 Red Hat, Inc.
	5	*
	6	* This library is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU Lesser General Public
	8	* License as published by the Free Software Foundation; either
	9	* version 2.1 of the License, or (at your option) any later version.
	10	*
	11	* This library is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* Lesser General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU Lesser General Public
	17	* License along with this library; if not, see <http://www.gnu.org/licenses/>.
	18	*
	19	*/
	20
	21	#include "qemu/osdep.h"
	22	#include "cipherpriv.h"
	23
	24	#include <gnutls/crypto.h>
	25
	26	#if GNUTLS_VERSION_NUMBER >= 0x030608
	27	#define QEMU_GNUTLS_XTS
	28	#endif
	29
	30	bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
	31	QCryptoCipherMode mode)
	32	{
	33
	34	switch (mode) {
	35	case QCRYPTO_CIPHER_MODE_ECB:
	36	case QCRYPTO_CIPHER_MODE_CBC:
	37	switch (alg) {
	38	case QCRYPTO_CIPHER_ALG_AES_128:
	39	case QCRYPTO_CIPHER_ALG_AES_192:
	40	case QCRYPTO_CIPHER_ALG_AES_256:
	41	case QCRYPTO_CIPHER_ALG_DES:
	42	case QCRYPTO_CIPHER_ALG_3DES:
	43	return true;
	44	default:
	45	return false;
	46	}
	47	#ifdef QEMU_GNUTLS_XTS
	48	case QCRYPTO_CIPHER_MODE_XTS:
	49	switch (alg) {
	50	case QCRYPTO_CIPHER_ALG_AES_128:
	51	case QCRYPTO_CIPHER_ALG_AES_256:
	52	return true;
	53	default:
	54	return false;
	55	}
	56	#endif
	57	default:
	58	return false;
	59	}
	60	}
	61
	62	typedef struct QCryptoCipherGnutls QCryptoCipherGnutls;
	63	struct QCryptoCipherGnutls {
	64	QCryptoCipher base;
65	gnutls_cipher_hd_t handle; /* XTS & CBC mode */
66	gnutls_cipher_algorithm_t galg; /* ECB mode */
67	guint8 key; / ECB mode */
68	size_t nkey; /* ECB mode */
69	size_t blocksize;
70	};
71
72
73	static void
74	qcrypto_gnutls_cipher_free(QCryptoCipher *cipher)
75	{
76	QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
77
78	g_free(ctx->key);
79	if (ctx->handle) {
80	gnutls_cipher_deinit(ctx->handle);
81	}
82	g_free(ctx);
83	}
84
85
86	static int
87	qcrypto_gnutls_cipher_encrypt(QCryptoCipher *cipher,
88	const void *in,
89	void *out,
90	size_t len,
91	Error **errp)
92	{
93	QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
94	int err;
95
96	if (len % ctx->blocksize) {
97	error_setg(errp, "Length %zu must be a multiple of block size %zu",
98	len, ctx->blocksize);
99	return -1;
100	}
101
102	if (ctx->handle) { /* CBC / XTS mode */
103	err = gnutls_cipher_encrypt2(ctx->handle,
104	in, len,
105	out, len);
106	if (err != 0) {
107	error_setg(errp, "Cannot encrypt data: %s",
108	gnutls_strerror(err));
109	return -1;
110	}
111	} else { /* ECB mode very inefficiently faked with CBC */
112	g_autofree unsigned char *iv = g_new0(unsigned char, ctx->blocksize);
113	while (len) {
114	gnutls_cipher_hd_t handle;
115	gnutls_datum_t gkey = { (unsigned char *)ctx->key, ctx->nkey };
5f6d4f79	116	err = gnutls_cipher_init(&handle, ctx->galg, &gkey, NULL);
3d2b61ff DB	117	if (err != 0) {
	118	error_setg(errp, "Cannot initialize cipher: %s",
	119	gnutls_strerror(err));
	120	return -1;
	121	}
	122
	123	gnutls_cipher_set_iv(handle, iv, ctx->blocksize);
	124
	125	err = gnutls_cipher_encrypt2(handle,
	126	in, ctx->blocksize,
	127	out, ctx->blocksize);
	128	if (err != 0) {
	129	gnutls_cipher_deinit(handle);
	130	error_setg(errp, "Cannot encrypt data: %s",
	131	gnutls_strerror(err));
	132	return -1;
	133	}
	134	gnutls_cipher_deinit(handle);
	135
	136	len -= ctx->blocksize;
	137	in += ctx->blocksize;
	138	out += ctx->blocksize;
	139	}
	140	}
	141
	142	return 0;
	143	}
	144
	145
	146	static int
	147	qcrypto_gnutls_cipher_decrypt(QCryptoCipher *cipher,
	148	const void *in,
	149	void *out,
	150	size_t len,
	151	Error **errp)
	152	{
	153	QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
	154	int err;
	155
	156	if (len % ctx->blocksize) {
	157	error_setg(errp, "Length %zu must be a multiple of block size %zu",
	158	len, ctx->blocksize);
	159	return -1;
	160	}
	161
	162	if (ctx->handle) { /* CBC / XTS mode */
	163	err = gnutls_cipher_decrypt2(ctx->handle,
	164	in, len,
	165	out, len);
	166
	167	if (err != 0) {
	168	error_setg(errp, "Cannot decrypt data: %s",
	169	gnutls_strerror(err));
	170	return -1;
	171	}
	172	} else { /* ECB mode very inefficiently faked with CBC */
	173	g_autofree unsigned char *iv = g_new0(unsigned char, ctx->blocksize);
	174	while (len) {
	175	gnutls_cipher_hd_t handle;
	176	gnutls_datum_t gkey = { (unsigned char *)ctx->key, ctx->nkey };
5f6d4f79	177	err = gnutls_cipher_init(&handle, ctx->galg, &gkey, NULL);
3d2b61ff DB	178	if (err != 0) {
	179	error_setg(errp, "Cannot initialize cipher: %s",
	180	gnutls_strerror(err));
	181	return -1;
	182	}
	183
	184	gnutls_cipher_set_iv(handle, iv, ctx->blocksize);
	185
	186	err = gnutls_cipher_decrypt2(handle,
	187	in, ctx->blocksize,
	188	out, ctx->blocksize);
	189	if (err != 0) {
	190	gnutls_cipher_deinit(handle);
	191	error_setg(errp, "Cannot encrypt data: %s",
	192	gnutls_strerror(err));
	193	return -1;
	194	}
	195	gnutls_cipher_deinit(handle);
	196
	197	len -= ctx->blocksize;
	198	in += ctx->blocksize;
	199	out += ctx->blocksize;
	200	}
	201	}
	202
	203	return 0;
	204	}
	205
	206	static int
	207	qcrypto_gnutls_cipher_setiv(QCryptoCipher *cipher,
	208	const uint8_t *iv, size_t niv,
	209	Error **errp)
	210	{
	211	QCryptoCipherGnutls *ctx = container_of(cipher, QCryptoCipherGnutls, base);
	212
	213	if (niv != ctx->blocksize) {
	214	error_setg(errp, "Expected IV size %zu not %zu",
	215	ctx->blocksize, niv);
	216	return -1;
	217	}
	218
	219	gnutls_cipher_set_iv(ctx->handle, (unsigned char *)iv, niv);
	220
	221	return 0;
	222	}
	223
	224
	225	static struct QCryptoCipherDriver gnutls_driver = {
	226	.cipher_encrypt = qcrypto_gnutls_cipher_encrypt,
	227	.cipher_decrypt = qcrypto_gnutls_cipher_decrypt,
	228	.cipher_setiv = qcrypto_gnutls_cipher_setiv,
	229	.cipher_free = qcrypto_gnutls_cipher_free,
	230	};
	231
	232	static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
	233	QCryptoCipherMode mode,
	234	const uint8_t *key,
	235	size_t nkey,
	236	Error **errp)
	237	{
	238	QCryptoCipherGnutls *ctx;
	239	gnutls_datum_t gkey = { (unsigned char *)key, nkey };
	240	gnutls_cipher_algorithm_t galg = GNUTLS_CIPHER_UNKNOWN;
	241	int err;
242
243	switch (mode) {
244	#ifdef QEMU_GNUTLS_XTS
245	case QCRYPTO_CIPHER_MODE_XTS:
246	switch (alg) {
247	case QCRYPTO_CIPHER_ALG_AES_128:
248	galg = GNUTLS_CIPHER_AES_128_XTS;
249	break;
250	case QCRYPTO_CIPHER_ALG_AES_256:
251	galg = GNUTLS_CIPHER_AES_256_XTS;
252	break;
253	default:
254	break;
255	}
256	break;
257	#endif
258
259	case QCRYPTO_CIPHER_MODE_ECB:
260	case QCRYPTO_CIPHER_MODE_CBC:
261	switch (alg) {
262	case QCRYPTO_CIPHER_ALG_AES_128:
263	galg = GNUTLS_CIPHER_AES_128_CBC;
264	break;
265	case QCRYPTO_CIPHER_ALG_AES_192:
266	galg = GNUTLS_CIPHER_AES_192_CBC;
267	break;
268	case QCRYPTO_CIPHER_ALG_AES_256:
269	galg = GNUTLS_CIPHER_AES_256_CBC;
270	break;
271	case QCRYPTO_CIPHER_ALG_DES:
272	galg = GNUTLS_CIPHER_DES_CBC;
273	break;
274	case QCRYPTO_CIPHER_ALG_3DES:
275	galg = GNUTLS_CIPHER_3DES_CBC;
276	break;
277	default:
278	break;
279	}
280	break;
281	default:
282	break;
283	}
284
285	if (galg == GNUTLS_CIPHER_UNKNOWN) {
286	error_setg(errp, "Unsupported cipher algorithm %s with %s mode",
287	QCryptoCipherAlgorithm_str(alg),
288	QCryptoCipherMode_str(mode));
289	return NULL;
290	}
291
292	if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
293	return NULL;
294	}
295
296	ctx = g_new0(QCryptoCipherGnutls, 1);
297	ctx->base.driver = &gnutls_driver;
298
299	if (mode == QCRYPTO_CIPHER_MODE_ECB) {
300	ctx->key = g_new0(guint8, nkey);
301	memcpy(ctx->key, key, nkey);
302	ctx->nkey = nkey;
303	ctx->galg = galg;
304	} else {
305	err = gnutls_cipher_init(&ctx->handle, galg, &gkey, NULL);
306	if (err != 0) {
307	error_setg(errp, "Cannot initialize cipher: %s",
308	gnutls_strerror(err));
309	goto error;
310	}
311	}
312
313	if (alg == QCRYPTO_CIPHER_ALG_DES \|\|
314	alg == QCRYPTO_CIPHER_ALG_3DES)
315	ctx->blocksize = 8;
316	else
317	ctx->blocksize = 16;
318
319	/*
320	* Our API contract for requires iv to be optional
321	* but nettle gets unhappy when called by gnutls
322	* in this case, so we just force set a default
323	* all-zeros IV, to match behaviour of other backends.
324	*/
325	if (mode != QCRYPTO_CIPHER_MODE_ECB) {
326	g_autofree unsigned char *iv = g_new0(unsigned char, ctx->blocksize);
327	gnutls_cipher_set_iv(ctx->handle, iv, ctx->blocksize);
328	}
329
330	return &ctx->base;
331
332	error:
333	qcrypto_gnutls_cipher_free(&ctx->base);
334	return NULL;
335	}