[qemu.git] / crypto / cipher-gcrypt.c

/*
 * 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 "qemu/osdep.h"
#include "crypto/xts.h"

#include <gcrypt.h>


bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
                             QCryptoCipherMode mode)
{
    switch (alg) {
    case QCRYPTO_CIPHER_ALG_DES_RFB:
    case QCRYPTO_CIPHER_ALG_3DES:
    case QCRYPTO_CIPHER_ALG_AES_128:
    case QCRYPTO_CIPHER_ALG_AES_192:
    case QCRYPTO_CIPHER_ALG_AES_256:
    case QCRYPTO_CIPHER_ALG_CAST5_128:
    case QCRYPTO_CIPHER_ALG_SERPENT_128:
    case QCRYPTO_CIPHER_ALG_SERPENT_192:
    case QCRYPTO_CIPHER_ALG_SERPENT_256:
    case QCRYPTO_CIPHER_ALG_TWOFISH_128:
    case QCRYPTO_CIPHER_ALG_TWOFISH_256:
        break;
    default:
        return false;
    }

    switch (mode) {
    case QCRYPTO_CIPHER_MODE_ECB:
    case QCRYPTO_CIPHER_MODE_CBC:
    case QCRYPTO_CIPHER_MODE_XTS:
    case QCRYPTO_CIPHER_MODE_CTR:
        return true;
    default:
        return false;
    }
}

typedef struct QCryptoCipherGcrypt QCryptoCipherGcrypt;
struct QCryptoCipherGcrypt {
    gcry_cipher_hd_t handle;
    gcry_cipher_hd_t tweakhandle;
    size_t blocksize;
    /* Initialization vector or Counter */
    uint8_t *iv;
};

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

    switch (mode) {
    case QCRYPTO_CIPHER_MODE_ECB:
    case QCRYPTO_CIPHER_MODE_XTS:
        gcrymode = GCRY_CIPHER_MODE_ECB;
        break;
    case QCRYPTO_CIPHER_MODE_CBC:
        gcrymode = GCRY_CIPHER_MODE_CBC;
        break;
    case QCRYPTO_CIPHER_MODE_CTR:
        gcrymode = GCRY_CIPHER_MODE_CTR;
        break;
    default:
        error_setg(errp, "Unsupported cipher mode %s",
                   QCryptoCipherMode_lookup[mode]);
        return NULL;
    }

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

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

    case QCRYPTO_CIPHER_ALG_3DES:
        gcryalg = GCRY_CIPHER_3DES;
        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;

    case QCRYPTO_CIPHER_ALG_CAST5_128:
        gcryalg = GCRY_CIPHER_CAST5;
        break;

    case QCRYPTO_CIPHER_ALG_SERPENT_128:
        gcryalg = GCRY_CIPHER_SERPENT128;
        break;

    case QCRYPTO_CIPHER_ALG_SERPENT_192:
        gcryalg = GCRY_CIPHER_SERPENT192;
        break;

    case QCRYPTO_CIPHER_ALG_SERPENT_256:
        gcryalg = GCRY_CIPHER_SERPENT256;
        break;

    case QCRYPTO_CIPHER_ALG_TWOFISH_128:
        gcryalg = GCRY_CIPHER_TWOFISH128;
        break;

    case QCRYPTO_CIPHER_ALG_TWOFISH_256:
        gcryalg = GCRY_CIPHER_TWOFISH;
        break;

    default:
        error_setg(errp, "Unsupported cipher algorithm %s",
                   QCryptoCipherAlgorithm_lookup[alg]);
        return NULL;
    }

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

    ctx = g_new0(QCryptoCipherGcrypt, 1);

    err = gcry_cipher_open(&ctx->handle, gcryalg, gcrymode, 0);
    if (err != 0) {
        error_setg(errp, "Cannot initialize cipher: %s",
                   gcry_strerror(err));
        goto error;
    }
    if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
        err = gcry_cipher_open(&ctx->tweakhandle, 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(ctx->handle, rfbkey, nkey);
        g_free(rfbkey);
        ctx->blocksize = 8;
    } else {
        if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
            nkey /= 2;
            err = gcry_cipher_setkey(ctx->handle, key, nkey);
            if (err != 0) {
                error_setg(errp, "Cannot set key: %s",
                           gcry_strerror(err));
                goto error;
            }
            err = gcry_cipher_setkey(ctx->tweakhandle, key + nkey, nkey);
        } else {
            err = gcry_cipher_setkey(ctx->handle, key, nkey);
        }
        if (err != 0) {
            error_setg(errp, "Cannot set key: %s",
                       gcry_strerror(err));
            goto error;
        }
        switch (cipher->alg) {
        case QCRYPTO_CIPHER_ALG_AES_128:
        case QCRYPTO_CIPHER_ALG_AES_192:
        case QCRYPTO_CIPHER_ALG_AES_256:
        case QCRYPTO_CIPHER_ALG_SERPENT_128:
        case QCRYPTO_CIPHER_ALG_SERPENT_192:
        case QCRYPTO_CIPHER_ALG_SERPENT_256:
        case QCRYPTO_CIPHER_ALG_TWOFISH_128:
        case QCRYPTO_CIPHER_ALG_TWOFISH_256:
            ctx->blocksize = 16;
            break;
        case QCRYPTO_CIPHER_ALG_3DES:
        case QCRYPTO_CIPHER_ALG_CAST5_128:
            ctx->blocksize = 8;
            break;
        default:
            g_assert_not_reached();
        }
    }

    if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
        if (ctx->blocksize != XTS_BLOCK_SIZE) {
            error_setg(errp,
                       "Cipher block size %zu must equal XTS block size %d",
                       ctx->blocksize, XTS_BLOCK_SIZE);
            goto error;
        }
        ctx->iv = g_new0(uint8_t, ctx->blocksize);
    }

    cipher->opaque = ctx;
    return cipher;

 error:
    gcry_cipher_close(ctx->handle);
    if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
        gcry_cipher_close(ctx->tweakhandle);
    }
    g_free(ctx);
    g_free(cipher);
    return NULL;
}


void qcrypto_cipher_free(QCryptoCipher *cipher)
{
    QCryptoCipherGcrypt *ctx;
    if (!cipher) {
        return;
    }
    ctx = cipher->opaque;
    gcry_cipher_close(ctx->handle);
    if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
        gcry_cipher_close(ctx->tweakhandle);
    }
    g_free(ctx->iv);
    g_free(ctx);
    g_free(cipher);
}


static void qcrypto_gcrypt_xts_encrypt(const void *ctx,
                                       size_t length,
                                       uint8_t *dst,
                                       const uint8_t *src)
{
    gcry_error_t err;
    err = gcry_cipher_encrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
    g_assert(err == 0);
}

static void qcrypto_gcrypt_xts_decrypt(const void *ctx,
                                       size_t length,
                                       uint8_t *dst,
                                       const uint8_t *src)
{
    gcry_error_t err;
    err = gcry_cipher_decrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
    g_assert(err == 0);
}

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

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

    if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
        xts_encrypt(ctx->handle, ctx->tweakhandle,
                    qcrypto_gcrypt_xts_encrypt,
                    qcrypto_gcrypt_xts_decrypt,
                    ctx->iv, len, out, in);
    } else {
        err = gcry_cipher_encrypt(ctx->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)
{
    QCryptoCipherGcrypt *ctx = cipher->opaque;
    gcry_error_t err;

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

    if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
        xts_decrypt(ctx->handle, ctx->tweakhandle,
                    qcrypto_gcrypt_xts_encrypt,
                    qcrypto_gcrypt_xts_decrypt,
                    ctx->iv, len, out, in);
    } else {
        err = gcry_cipher_decrypt(ctx->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)
{
    QCryptoCipherGcrypt *ctx = cipher->opaque;
    gcry_error_t err;

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

    if (ctx->iv) {
        memcpy(ctx->iv, iv, niv);
    } else {
        if (cipher->mode == QCRYPTO_CIPHER_MODE_CTR) {
            err = gcry_cipher_setctr(ctx->handle, iv, niv);
            if (err != 0) {
                error_setg(errp, "Cannot set Counter: %s",
                       gcry_strerror(err));
                return -1;
            }
        } else {
            gcry_cipher_reset(ctx->handle);
            err = gcry_cipher_setiv(ctx->handle, iv, niv);
            if (err != 0) {
                error_setg(errp, "Cannot set IV: %s",
                       gcry_strerror(err));
                return -1;
            }
        }
    }

    return 0;
}
Commit	Line	Data
62893b67 DB	1	/*
	2	* QEMU Crypto cipher libgcrypt algorithms
	3	*
	4	* Copyright (c) 2015 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 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
42f7a448	21	#include "qemu/osdep.h"
eaec903c DB	22	#include "crypto/xts.h"
eaec903c DB	23
62893b67 DB	24	#include <gcrypt.h>
	25
	26
f844836d GA	27	bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
f844836d GA	28	QCryptoCipherMode mode)
62893b67 DB	29	{
	30	switch (alg) {
	31	case QCRYPTO_CIPHER_ALG_DES_RFB:
ffb7bf45	32	case QCRYPTO_CIPHER_ALG_3DES:
62893b67 DB	33	case QCRYPTO_CIPHER_ALG_AES_128:
	34	case QCRYPTO_CIPHER_ALG_AES_192:
	35	case QCRYPTO_CIPHER_ALG_AES_256:
084a85ee	36	case QCRYPTO_CIPHER_ALG_CAST5_128:
94318522 DB	37	case QCRYPTO_CIPHER_ALG_SERPENT_128:
	38	case QCRYPTO_CIPHER_ALG_SERPENT_192:
	39	case QCRYPTO_CIPHER_ALG_SERPENT_256:
50f6753e DB	40	case QCRYPTO_CIPHER_ALG_TWOFISH_128:
50f6753e DB	41	case QCRYPTO_CIPHER_ALG_TWOFISH_256:
f844836d GA	42	break;
	43	default:
	44	return false;
	45	}
	46
	47	switch (mode) {
	48	case QCRYPTO_CIPHER_MODE_ECB:
	49	case QCRYPTO_CIPHER_MODE_CBC:
	50	case QCRYPTO_CIPHER_MODE_XTS:
	51	case QCRYPTO_CIPHER_MODE_CTR:
62893b67 DB	52	return true;
	53	default:
	54	return false;
	55	}
	56	}
	57
3a661f1e DB	58	typedef struct QCryptoCipherGcrypt QCryptoCipherGcrypt;
	59	struct QCryptoCipherGcrypt {
	60	gcry_cipher_hd_t handle;
eaec903c	61	gcry_cipher_hd_t tweakhandle;
3a661f1e	62	size_t blocksize;
3c28292f	63	/* Initialization vector or Counter */
eaec903c	64	uint8_t *iv;
3a661f1e	65	};
62893b67 DB	66
	67	QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
	68	QCryptoCipherMode mode,
	69	const uint8_t *key, size_t nkey,
	70	Error **errp)
	71	{
	72	QCryptoCipher *cipher;
3a661f1e	73	QCryptoCipherGcrypt *ctx;
62893b67 DB	74	gcry_error_t err;
	75	int gcryalg, gcrymode;
	76
	77	switch (mode) {
	78	case QCRYPTO_CIPHER_MODE_ECB:
eaec903c	79	case QCRYPTO_CIPHER_MODE_XTS:
62893b67 DB	80	gcrymode = GCRY_CIPHER_MODE_ECB;
	81	break;
	82	case QCRYPTO_CIPHER_MODE_CBC:
	83	gcrymode = GCRY_CIPHER_MODE_CBC;
	84	break;
3c28292f GA	85	case QCRYPTO_CIPHER_MODE_CTR:
	86	gcrymode = GCRY_CIPHER_MODE_CTR;
	87	break;
62893b67	88	default:
90d6f60d DB	89	error_setg(errp, "Unsupported cipher mode %s",
90d6f60d DB	90	QCryptoCipherMode_lookup[mode]);
62893b67 DB	91	return NULL;
	92	}
	93
eaec903c	94	if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
62893b67 DB	95	return NULL;
	96	}
	97
	98	switch (alg) {
	99	case QCRYPTO_CIPHER_ALG_DES_RFB:
	100	gcryalg = GCRY_CIPHER_DES;
	101	break;
	102
ffb7bf45 LM	103	case QCRYPTO_CIPHER_ALG_3DES:
	104	gcryalg = GCRY_CIPHER_3DES;
	105	break;
	106
62893b67 DB	107	case QCRYPTO_CIPHER_ALG_AES_128:
	108	gcryalg = GCRY_CIPHER_AES128;
	109	break;
	110
	111	case QCRYPTO_CIPHER_ALG_AES_192:
	112	gcryalg = GCRY_CIPHER_AES192;
	113	break;
	114
	115	case QCRYPTO_CIPHER_ALG_AES_256:
	116	gcryalg = GCRY_CIPHER_AES256;
	117	break;
	118
084a85ee DB	119	case QCRYPTO_CIPHER_ALG_CAST5_128:
	120	gcryalg = GCRY_CIPHER_CAST5;
	121	break;
	122
94318522 DB	123	case QCRYPTO_CIPHER_ALG_SERPENT_128:
	124	gcryalg = GCRY_CIPHER_SERPENT128;
	125	break;
	126
	127	case QCRYPTO_CIPHER_ALG_SERPENT_192:
	128	gcryalg = GCRY_CIPHER_SERPENT192;
	129	break;
	130
	131	case QCRYPTO_CIPHER_ALG_SERPENT_256:
	132	gcryalg = GCRY_CIPHER_SERPENT256;
	133	break;
	134
50f6753e DB	135	case QCRYPTO_CIPHER_ALG_TWOFISH_128:
	136	gcryalg = GCRY_CIPHER_TWOFISH128;
	137	break;
	138
	139	case QCRYPTO_CIPHER_ALG_TWOFISH_256:
	140	gcryalg = GCRY_CIPHER_TWOFISH;
	141	break;
	142
62893b67	143	default:
90d6f60d DB	144	error_setg(errp, "Unsupported cipher algorithm %s",
90d6f60d DB	145	QCryptoCipherAlgorithm_lookup[alg]);
62893b67 DB	146	return NULL;
	147	}
	148
	149	cipher = g_new0(QCryptoCipher, 1);
	150	cipher->alg = alg;
	151	cipher->mode = mode;
	152
3a661f1e DB	153	ctx = g_new0(QCryptoCipherGcrypt, 1);
	154
	155	err = gcry_cipher_open(&ctx->handle, gcryalg, gcrymode, 0);
62893b67 DB	156	if (err != 0) {
	157	error_setg(errp, "Cannot initialize cipher: %s",
	158	gcry_strerror(err));
	159	goto error;
	160	}
eaec903c DB	161	if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
	162	err = gcry_cipher_open(&ctx->tweakhandle, gcryalg, gcrymode, 0);
	163	if (err != 0) {
	164	error_setg(errp, "Cannot initialize cipher: %s",
	165	gcry_strerror(err));
	166	goto error;
	167	}
	168	}
62893b67 DB	169
	170	if (cipher->alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
	171	/* We're using standard DES cipher from gcrypt, so we need
	172	* to munge the key so that the results are the same as the
	173	* bizarre RFB variant of DES :-)
	174	*/
	175	uint8_t *rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
3a661f1e	176	err = gcry_cipher_setkey(ctx->handle, rfbkey, nkey);
62893b67	177	g_free(rfbkey);
3a661f1e	178	ctx->blocksize = 8;
62893b67	179	} else {
eaec903c DB	180	if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
	181	nkey /= 2;
	182	err = gcry_cipher_setkey(ctx->handle, key, nkey);
	183	if (err != 0) {
	184	error_setg(errp, "Cannot set key: %s",
	185	gcry_strerror(err));
	186	goto error;
	187	}
	188	err = gcry_cipher_setkey(ctx->tweakhandle, key + nkey, nkey);
	189	} else {
	190	err = gcry_cipher_setkey(ctx->handle, key, nkey);
	191	}
	192	if (err != 0) {
	193	error_setg(errp, "Cannot set key: %s",
	194	gcry_strerror(err));
	195	goto error;
	196	}
084a85ee DB	197	switch (cipher->alg) {
	198	case QCRYPTO_CIPHER_ALG_AES_128:
	199	case QCRYPTO_CIPHER_ALG_AES_192:
	200	case QCRYPTO_CIPHER_ALG_AES_256:
94318522 DB	201	case QCRYPTO_CIPHER_ALG_SERPENT_128:
	202	case QCRYPTO_CIPHER_ALG_SERPENT_192:
	203	case QCRYPTO_CIPHER_ALG_SERPENT_256:
50f6753e DB	204	case QCRYPTO_CIPHER_ALG_TWOFISH_128:
50f6753e DB	205	case QCRYPTO_CIPHER_ALG_TWOFISH_256:
084a85ee DB	206	ctx->blocksize = 16;
084a85ee DB	207	break;
ffb7bf45	208	case QCRYPTO_CIPHER_ALG_3DES:
084a85ee DB	209	case QCRYPTO_CIPHER_ALG_CAST5_128:
	210	ctx->blocksize = 8;
	211	break;
	212	default:
	213	g_assert_not_reached();
	214	}
62893b67	215	}
eaec903c DB	216
eaec903c DB	217	if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
a5d2f44d DB	218	if (ctx->blocksize != XTS_BLOCK_SIZE) {
	219	error_setg(errp,
	220	"Cipher block size %zu must equal XTS block size %d",
	221	ctx->blocksize, XTS_BLOCK_SIZE);
	222	goto error;
	223	}
eaec903c	224	ctx->iv = g_new0(uint8_t, ctx->blocksize);
62893b67 DB	225	}
62893b67 DB	226
3a661f1e	227	cipher->opaque = ctx;
62893b67 DB	228	return cipher;
	229
	230	error:
3a661f1e	231	gcry_cipher_close(ctx->handle);
eaec903c DB	232	if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
	233	gcry_cipher_close(ctx->tweakhandle);
	234	}
3a661f1e	235	g_free(ctx);
62893b67 DB	236	g_free(cipher);
	237	return NULL;
	238	}
	239
	240
	241	void qcrypto_cipher_free(QCryptoCipher *cipher)
	242	{
3a661f1e	243	QCryptoCipherGcrypt *ctx;
62893b67 DB	244	if (!cipher) {
	245	return;
	246	}
3a661f1e DB	247	ctx = cipher->opaque;
3a661f1e DB	248	gcry_cipher_close(ctx->handle);
eaec903c DB	249	if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
	250	gcry_cipher_close(ctx->tweakhandle);
	251	}
	252	g_free(ctx->iv);
3a661f1e	253	g_free(ctx);
62893b67 DB	254	g_free(cipher);
	255	}
	256
	257
eaec903c DB	258	static void qcrypto_gcrypt_xts_encrypt(const void *ctx,
	259	size_t length,
	260	uint8_t *dst,
	261	const uint8_t *src)
	262	{
	263	gcry_error_t err;
	264	err = gcry_cipher_encrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
	265	g_assert(err == 0);
	266	}
	267
	268	static void qcrypto_gcrypt_xts_decrypt(const void *ctx,
	269	size_t length,
	270	uint8_t *dst,
	271	const uint8_t *src)
	272	{
	273	gcry_error_t err;
	274	err = gcry_cipher_decrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
	275	g_assert(err == 0);
	276	}
	277
62893b67 DB	278	int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
	279	const void *in,
	280	void *out,
	281	size_t len,
	282	Error **errp)
	283	{
3a661f1e	284	QCryptoCipherGcrypt *ctx = cipher->opaque;
62893b67 DB	285	gcry_error_t err;
62893b67 DB	286
3a661f1e DB	287	if (len % ctx->blocksize) {
	288	error_setg(errp, "Length %zu must be a multiple of block size %zu",
	289	len, ctx->blocksize);
	290	return -1;
	291	}
	292
eaec903c DB	293	if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
	294	xts_encrypt(ctx->handle, ctx->tweakhandle,
	295	qcrypto_gcrypt_xts_encrypt,
	296	qcrypto_gcrypt_xts_decrypt,
	297	ctx->iv, len, out, in);
	298	} else {
	299	err = gcry_cipher_encrypt(ctx->handle,
	300	out, len,
	301	in, len);
	302	if (err != 0) {
	303	error_setg(errp, "Cannot encrypt data: %s",
	304	gcry_strerror(err));
	305	return -1;
	306	}
62893b67 DB	307	}
	308
	309	return 0;
	310	}
	311
	312
	313	int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
	314	const void *in,
	315	void *out,
	316	size_t len,
	317	Error **errp)
	318	{
3a661f1e	319	QCryptoCipherGcrypt *ctx = cipher->opaque;
62893b67 DB	320	gcry_error_t err;
62893b67 DB	321
3a661f1e DB	322	if (len % ctx->blocksize) {
	323	error_setg(errp, "Length %zu must be a multiple of block size %zu",
	324	len, ctx->blocksize);
	325	return -1;
	326	}
	327
eaec903c DB	328	if (cipher->mode == QCRYPTO_CIPHER_MODE_XTS) {
	329	xts_decrypt(ctx->handle, ctx->tweakhandle,
	330	qcrypto_gcrypt_xts_encrypt,
	331	qcrypto_gcrypt_xts_decrypt,
	332	ctx->iv, len, out, in);
	333	} else {
	334	err = gcry_cipher_decrypt(ctx->handle,
	335	out, len,
	336	in, len);
	337	if (err != 0) {
	338	error_setg(errp, "Cannot decrypt data: %s",
	339	gcry_strerror(err));
	340	return -1;
	341	}
62893b67 DB	342	}
	343
	344	return 0;
	345	}
	346
	347	int qcrypto_cipher_setiv(QCryptoCipher *cipher,
	348	const uint8_t *iv, size_t niv,
	349	Error **errp)
	350	{
3a661f1e	351	QCryptoCipherGcrypt *ctx = cipher->opaque;
62893b67 DB	352	gcry_error_t err;
62893b67 DB	353
3a661f1e DB	354	if (niv != ctx->blocksize) {
	355	error_setg(errp, "Expected IV size %zu not %zu",
	356	ctx->blocksize, niv);
	357	return -1;
	358	}
	359
eaec903c DB	360	if (ctx->iv) {
	361	memcpy(ctx->iv, iv, niv);
	362	} else {
3c28292f GA	363	if (cipher->mode == QCRYPTO_CIPHER_MODE_CTR) {
	364	err = gcry_cipher_setctr(ctx->handle, iv, niv);
	365	if (err != 0) {
	366	error_setg(errp, "Cannot set Counter: %s",
	367	gcry_strerror(err));
	368	return -1;
	369	}
	370	} else {
	371	gcry_cipher_reset(ctx->handle);
	372	err = gcry_cipher_setiv(ctx->handle, iv, niv);
	373	if (err != 0) {
	374	error_setg(errp, "Cannot set IV: %s",
	375	gcry_strerror(err));
	376	return -1;
	377	}
eaec903c	378	}
62893b67 DB	379	}
	380
	381	return 0;
	382	}