crypto: add support for generating initialization vectors

There are a number of different algorithms that can be used
to generate initialization vectors for disk encryption. This
introduces a simple internal QCryptoBlockIV object to provide
a consistent internal API to the different algorithms. The
initially implemented algorithms are 'plain', 'plain64' and
'essiv', each matching the same named algorithm provided
by the Linux kernel dm-crypt driver.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

14 files changed, 873 insertions, 0 deletions

diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
index 7122cc8e54..f28b00e549 100644
--- a/crypto/Makefile.objs
+++ b/crypto/Makefile.objs
@@ -13,6 +13,10 @@ crypto-obj-$(if $(CONFIG_GCRYPT),n,$(CONFIG_GNUTLS_RND)) += random-gnutls.o
 crypto-obj-y += pbkdf.o
 crypto-obj-$(CONFIG_NETTLE) += pbkdf-nettle.o
 crypto-obj-$(if $(CONFIG_NETTLE),n,$(CONFIG_GCRYPT_KDF)) += pbkdf-gcrypt.o
+crypto-obj-y += ivgen.o
+crypto-obj-y += ivgen-essiv.o
+crypto-obj-y += ivgen-plain.o
+crypto-obj-y += ivgen-plain64.o
 
 # Let the userspace emulators avoid linking gnutls/etc
 crypto-aes-obj-y = aes.o
diff --git a/crypto/ivgen-essiv.c b/crypto/ivgen-essiv.c
new file mode 100644
index 0000000000..5649c01b85
--- /dev/null
+++ b/crypto/ivgen-essiv.c
@@ -0,0 +1,118 @@
+/*
+ * QEMU Crypto block IV generator - essiv
+ *
+ * Copyright (c) 2015-2016 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/ivgen-essiv.h"
+
+typedef struct QCryptoIVGenESSIV QCryptoIVGenESSIV;
+struct QCryptoIVGenESSIV {
+    QCryptoCipher *cipher;
+};
+
+static int qcrypto_ivgen_essiv_init(QCryptoIVGen *ivgen,
+                                    const uint8_t *key, size_t nkey,
+                                    Error **errp)
+{
+    uint8_t *salt;
+    size_t nhash;
+    size_t nsalt;
+    QCryptoIVGenESSIV *essiv = g_new0(QCryptoIVGenESSIV, 1);
+
+    /* Not necessarily the same as nkey */
+    nsalt = qcrypto_cipher_get_key_len(ivgen->cipher);
+
+    nhash = qcrypto_hash_digest_len(ivgen->hash);
+    /* Salt must be larger of hash size or key size */
+    salt = g_new0(uint8_t, MAX(nhash, nsalt));
+
+    if (qcrypto_hash_bytes(ivgen->hash, (const gchar *)key, nkey,
+                           &salt, &nhash,
+                           errp) < 0) {
+        g_free(essiv);
+        return -1;
+    }
+
+    /* Now potentially truncate salt to match cipher key len */
+    essiv->cipher = qcrypto_cipher_new(ivgen->cipher,
+                                       QCRYPTO_CIPHER_MODE_ECB,
+                                       salt, MIN(nhash, nsalt),
+                                       errp);
+    if (!essiv->cipher) {
+        g_free(essiv);
+        g_free(salt);
+        return -1;
+    }
+
+    g_free(salt);
+    ivgen->private = essiv;
+
+    return 0;
+}
+
+static int qcrypto_ivgen_essiv_calculate(QCryptoIVGen *ivgen,
+                                         uint64_t sector,
+                                         uint8_t *iv, size_t niv,
+                                         Error **errp)
+{
+    QCryptoIVGenESSIV *essiv = ivgen->private;
+    size_t ndata = qcrypto_cipher_get_block_len(ivgen->cipher);
+    uint8_t *data = g_new(uint8_t, ndata);
+
+    sector = cpu_to_le64(sector);
+    memcpy(data, (uint8_t *)&sector, ndata);
+    if (sizeof(sector) < ndata) {
+        memset(data + sizeof(sector), 0, ndata - sizeof(sector));
+    }
+
+    if (qcrypto_cipher_encrypt(essiv->cipher,
+                               data,
+                               data,
+                               ndata,
+                               errp) < 0) {
+        g_free(data);
+        return -1;
+    }
+
+    if (ndata > niv) {
+        ndata = niv;
+    }
+    memcpy(iv, data, ndata);
+    if (ndata < niv) {
+        memset(iv + ndata, 0, niv - ndata);
+    }
+    g_free(data);
+    return 0;
+}
+
+static void qcrypto_ivgen_essiv_cleanup(QCryptoIVGen *ivgen)
+{
+    QCryptoIVGenESSIV *essiv = ivgen->private;
+
+    qcrypto_cipher_free(essiv->cipher);
+    g_free(essiv);
+}
+
+
+struct QCryptoIVGenDriver qcrypto_ivgen_essiv = {
+    .init = qcrypto_ivgen_essiv_init,
+    .calculate = qcrypto_ivgen_essiv_calculate,
+    .cleanup = qcrypto_ivgen_essiv_cleanup,
+};
+
diff --git a/crypto/ivgen-essiv.h b/crypto/ivgen-essiv.h
new file mode 100644
index 0000000000..4a00af849a
--- /dev/null
+++ b/crypto/ivgen-essiv.h
@@ -0,0 +1,28 @@
+/*
+ * QEMU Crypto block IV generator - essiv
+ *
+ * Copyright (c) 2015-2016 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 "crypto/ivgenpriv.h"
+
+#ifndef QCRYPTO_IVGEN_ESSIV_H__
+#define QCRYPTO_IVGEN_ESSIV_H__
+
+extern struct QCryptoIVGenDriver qcrypto_ivgen_essiv;
+
+#endif /* QCRYPTO_IVGEN_ESSIV_H__ */
diff --git a/crypto/ivgen-plain.c b/crypto/ivgen-plain.c
new file mode 100644
index 0000000000..6a85256cac
--- /dev/null
+++ b/crypto/ivgen-plain.c
@@ -0,0 +1,59 @@
+/*
+ * QEMU Crypto block IV generator - plain
+ *
+ * Copyright (c) 2015-2016 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/ivgen-plain.h"
+
+static int qcrypto_ivgen_plain_init(QCryptoIVGen *ivgen,
+                                    const uint8_t *key, size_t nkey,
+                                    Error **errp)
+{
+    return 0;
+}
+
+static int qcrypto_ivgen_plain_calculate(QCryptoIVGen *ivgen,
+                                         uint64_t sector,
+                                         uint8_t *iv, size_t niv,
+                                         Error **errp)
+{
+    size_t ivprefix;
+    uint32_t shortsector = cpu_to_le32((sector & 0xffffffff));
+    ivprefix = sizeof(shortsector);
+    if (ivprefix > niv) {
+        ivprefix = niv;
+    }
+    memcpy(iv, &shortsector, ivprefix);
+    if (ivprefix < niv) {
+        memset(iv + ivprefix, 0, niv - ivprefix);
+    }
+    return 0;
+}
+
+static void qcrypto_ivgen_plain_cleanup(QCryptoIVGen *ivgen)
+{
+}
+
+
+struct QCryptoIVGenDriver qcrypto_ivgen_plain = {
+    .init = qcrypto_ivgen_plain_init,
+    .calculate = qcrypto_ivgen_plain_calculate,
+    .cleanup = qcrypto_ivgen_plain_cleanup,
+};
+
diff --git a/crypto/ivgen-plain.h b/crypto/ivgen-plain.h
new file mode 100644
index 0000000000..0fe8835c3e
--- /dev/null
+++ b/crypto/ivgen-plain.h
@@ -0,0 +1,28 @@
+/*
+ * QEMU Crypto block IV generator - plain
+ *
+ * Copyright (c) 2015-2016 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 "crypto/ivgenpriv.h"
+
+#ifndef QCRYPTO_IVGEN_PLAIN_H__
+#define QCRYPTO_IVGEN_PLAIN_H__
+
+extern struct QCryptoIVGenDriver qcrypto_ivgen_plain;
+
+#endif /* QCRYPTO_IVGEN_PLAIN_H__ */
diff --git a/crypto/ivgen-plain64.c b/crypto/ivgen-plain64.c
new file mode 100644
index 0000000000..9ca6db9df2
--- /dev/null
+++ b/crypto/ivgen-plain64.c
@@ -0,0 +1,59 @@
+/*
+ * QEMU Crypto block IV generator - plain
+ *
+ * Copyright (c) 2015-2016 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/ivgen-plain.h"
+
+static int qcrypto_ivgen_plain_init(QCryptoIVGen *ivgen,
+                                    const uint8_t *key, size_t nkey,
+                                    Error **errp)
+{
+    return 0;
+}
+
+static int qcrypto_ivgen_plain_calculate(QCryptoIVGen *ivgen,
+                                         uint64_t sector,
+                                         uint8_t *iv, size_t niv,
+                                         Error **errp)
+{
+    size_t ivprefix;
+    ivprefix = sizeof(sector);
+    sector = cpu_to_le64(sector);
+    if (ivprefix > niv) {
+        ivprefix = niv;
+    }
+    memcpy(iv, &sector, ivprefix);
+    if (ivprefix < niv) {
+        memset(iv + ivprefix, 0, niv - ivprefix);
+    }
+    return 0;
+}
+
+static void qcrypto_ivgen_plain_cleanup(QCryptoIVGen *ivgen)
+{
+}
+
+
+struct QCryptoIVGenDriver qcrypto_ivgen_plain64 = {
+    .init = qcrypto_ivgen_plain_init,
+    .calculate = qcrypto_ivgen_plain_calculate,
+    .cleanup = qcrypto_ivgen_plain_cleanup,
+};
+
diff --git a/crypto/ivgen-plain64.h b/crypto/ivgen-plain64.h
new file mode 100644
index 0000000000..c4104459b5
--- /dev/null
+++ b/crypto/ivgen-plain64.h
@@ -0,0 +1,28 @@
+/*
+ * QEMU Crypto block IV generator - plain64
+ *
+ * Copyright (c) 2015-2016 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 "crypto/ivgenpriv.h"
+
+#ifndef QCRYPTO_IVGEN_PLAIN64_H__
+#define QCRYPTO_IVGEN_PLAIN64_H__
+
+extern struct QCryptoIVGenDriver qcrypto_ivgen_plain64;
+
+#endif /* QCRYPTO_IVGEN_PLAIN64_H__ */
diff --git a/crypto/ivgen.c b/crypto/ivgen.c
new file mode 100644
index 0000000000..4ffc1eb886
--- /dev/null
+++ b/crypto/ivgen.c
@@ -0,0 +1,99 @@
+/*
+ * QEMU Crypto block IV generator
+ *
+ * Copyright (c) 2015-2016 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/ivgenpriv.h"
+#include "crypto/ivgen-plain.h"
+#include "crypto/ivgen-plain64.h"
+#include "crypto/ivgen-essiv.h"
+
+
+QCryptoIVGen *qcrypto_ivgen_new(QCryptoIVGenAlgorithm alg,
+                                QCryptoCipherAlgorithm cipheralg,
+                                QCryptoHashAlgorithm hash,
+                                const uint8_t *key, size_t nkey,
+                                Error **errp)
+{
+    QCryptoIVGen *ivgen = g_new0(QCryptoIVGen, 1);
+
+    ivgen->algorithm = alg;
+    ivgen->cipher = cipheralg;
+    ivgen->hash = hash;
+
+    switch (alg) {
+    case QCRYPTO_IVGEN_ALG_PLAIN:
+        ivgen->driver = &qcrypto_ivgen_plain;
+        break;
+    case QCRYPTO_IVGEN_ALG_PLAIN64:
+        ivgen->driver = &qcrypto_ivgen_plain64;
+        break;
+    case QCRYPTO_IVGEN_ALG_ESSIV:
+        ivgen->driver = &qcrypto_ivgen_essiv;
+        break;
+    default:
+        error_setg(errp, "Unknown block IV generator algorithm %d", alg);
+        g_free(ivgen);
+        return NULL;
+    }
+
+    if (ivgen->driver->init(ivgen, key, nkey, errp) < 0) {
+        g_free(ivgen);
+        return NULL;
+    }
+
+    return ivgen;
+}
+
+
+int qcrypto_ivgen_calculate(QCryptoIVGen *ivgen,
+                            uint64_t sector,
+                            uint8_t *iv, size_t niv,
+                            Error **errp)
+{
+    return ivgen->driver->calculate(ivgen, sector, iv, niv, errp);
+}
+
+
+QCryptoIVGenAlgorithm qcrypto_ivgen_get_algorithm(QCryptoIVGen *ivgen)
+{
+    return ivgen->algorithm;
+}
+
+
+QCryptoCipherAlgorithm qcrypto_ivgen_get_cipher(QCryptoIVGen *ivgen)
+{
+    return ivgen->cipher;
+}
+
+
+QCryptoHashAlgorithm qcrypto_ivgen_get_hash(QCryptoIVGen *ivgen)
+{
+    return ivgen->hash;
+}
+
+
+void qcrypto_ivgen_free(QCryptoIVGen *ivgen)
+{
+    if (!ivgen) {
+        return;
+    }
+    ivgen->driver->cleanup(ivgen);
+    g_free(ivgen);
+}
diff --git a/crypto/ivgenpriv.h b/crypto/ivgenpriv.h
new file mode 100644
index 0000000000..7b87e02ea7
--- /dev/null
+++ b/crypto/ivgenpriv.h
@@ -0,0 +1,49 @@
+/*
+ * QEMU Crypto block IV generator
+ *
+ * Copyright (c) 2015-2016 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_IVGEN_PRIV_H__
+#define QCRYPTO_IVGEN_PRIV_H__
+
+#include "crypto/ivgen.h"
+
+typedef struct QCryptoIVGenDriver QCryptoIVGenDriver;
+
+struct QCryptoIVGenDriver {
+    int (*init)(QCryptoIVGen *ivgen,
+                const uint8_t *key, size_t nkey,
+                Error **errp);
+    int (*calculate)(QCryptoIVGen *ivgen,
+                     uint64_t sector,
+                     uint8_t *iv, size_t niv,
+                     Error **errp);
+    void (*cleanup)(QCryptoIVGen *ivgen);
+};
+
+struct QCryptoIVGen {
+    QCryptoIVGenDriver *driver;
+    void *private;
+
+    QCryptoIVGenAlgorithm algorithm;
+    QCryptoCipherAlgorithm cipher;
+    QCryptoHashAlgorithm hash;
+};
+
+
+#endif /* QCRYPTO_IVGEN_PRIV_H__ */
diff --git a/include/crypto/ivgen.h b/include/crypto/ivgen.h
new file mode 100644
index 0000000000..09cdb6fcd9
--- /dev/null
+++ b/include/crypto/ivgen.h
@@ -0,0 +1,206 @@
+/*
+ * QEMU Crypto block IV generator
+ *
+ * Copyright (c) 2015-2016 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_IVGEN_H__
+#define QCRYPTO_IVGEN_H__
+
+#include "crypto/cipher.h"
+#include "crypto/hash.h"
+
+/**
+ * This module provides a framework for generating initialization
+ * vectors for block encryption schemes using chained cipher modes
+ * CBC. The principle is that each disk sector is assigned a unique
+ * initialization vector for use for encryption of data in that
+ * sector.
+ *
+ * <example>
+ *   <title>Encrypting block data with initialiation vectors</title>
+ *   <programlisting>
+ * uint8_t *data = ....data to encrypt...
+ * size_t ndata = XXX;
+ * uint8_t *key = ....some encryption key...
+ * size_t nkey = XXX;
+ * uint8_t *iv;
+ * size_t niv;
+ * size_t sector = 0;
+ *
+ * g_assert((ndata % 512) == 0);
+ *
+ * QCryptoIVGen *ivgen = qcrypto_ivgen_new(QCRYPTO_IVGEN_ALG_ESSIV,
+ *                                         QCRYPTO_CIPHER_ALG_AES_128,
+ *                                         QCRYPTO_HASH_ALG_SHA256,
+ *                                         key, nkey, errp);
+ * if (!ivgen) {
+ *    return -1;
+ * }
+ *
+ * QCryptoCipher *cipher = qcrypto_cipher_new(QCRYPTO_CIPHER_ALG_AES_128,
+ *                                            QCRYPTO_CIPHER_MODE_CBC,
+ *                                            key, nkey, errp);
+ * if (!cipher) {
+ *     goto error;
+ * }
+ *
+ * niv =  qcrypto_cipher_get_iv_len(QCRYPTO_CIPHER_ALG_AES_128,
+ *                                  QCRYPTO_CIPHER_MODE_CBC);
+ * iv = g_new0(uint8_t, niv);
+ *
+ *
+ * while (ndata) {
+ *     if (qcrypto_ivgen_calculate(ivgen, sector, iv, niv, errp) < 0) {
+ *         goto error;
+ *     }
+ *     if (qcrypto_cipher_setiv(cipher, iv, niv, errp) < 0) {
+ *         goto error;
+ *     }
+ *     if (qcrypto_cipher_encrypt(cipher,
+ *                                data + (sector * 512),
+ *                                data + (sector * 512),
+ *                                512, errp) < 0) {
+ *         goto error;
+ *     }
+ *     sector++;
+ *     ndata -= 512;
+ * }
+ *
+ * g_free(iv);
+ * qcrypto_ivgen_free(ivgen);
+ * qcrypto_cipher_free(cipher);
+ * return 0;
+ *
+ *error:
+ * g_free(iv);
+ * qcrypto_ivgen_free(ivgen);
+ * qcrypto_cipher_free(cipher);
+ * return -1;
+ *   </programlisting>
+ * </example>
+ */
+
+typedef struct QCryptoIVGen QCryptoIVGen;
+
+/* See also QCryptoIVGenAlgorithm enum in qapi/crypto.json */
+
+
+/**
+ * qcrypto_ivgen_new:
+ * @alg: the initialization vector generation algorithm
+ * @cipheralg: the cipher algorithm or 0
+ * @hash: the hash algorithm or 0
+ * @key: the encryption key or NULL
+ * @nkey: the size of @key in bytes
+ *
+ * Create a new initialization vector generator that uses
+ * the algorithm @alg. Whether the remaining parameters
+ * are required or not depends on the choice of @alg
+ * requested.
+ *
+ * - QCRYPTO_IVGEN_ALG_PLAIN
+ *
+ * The IVs are generated by the 32-bit truncated sector
+ * number. This should never be used for block devices
+ * that are larger than 2^32 sectors in size.
+ * All the other parameters are unused.
+ *
+ * - QCRYPTO_IVGEN_ALG_PLAIN64
+ *
+ * The IVs are generated by the 64-bit sector number.
+ * All the other parameters are unused.
+ *
+ * - QCRYPTO_IVGEN_ALG_ESSIV:
+ *
+ * The IVs are generated by encrypting the 64-bit sector
+ * number with a hash of an encryption key. The @cipheralg,
+ * @hash, @key and @nkey parameters are all required.
+ *
+ * Returns: a new IV generator, or NULL on error
+ */
+QCryptoIVGen *qcrypto_ivgen_new(QCryptoIVGenAlgorithm alg,
+                                QCryptoCipherAlgorithm cipheralg,
+                                QCryptoHashAlgorithm hash,
+                                const uint8_t *key, size_t nkey,
+                                Error **errp);
+
+/**
+ * qcrypto_ivgen_calculate:
+ * @ivgen: the IV generator object
+ * @sector: the 64-bit sector number
+ * @iv: a pre-allocated buffer to hold the generated IV
+ * @niv: the number of bytes in @iv
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Calculate a new initialiation vector for the data
+ * to be stored in sector @sector. The IV will be
+ * written into the buffer @iv of size @niv.
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int qcrypto_ivgen_calculate(QCryptoIVGen *ivgen,
+                            uint64_t sector,
+                            uint8_t *iv, size_t niv,
+                            Error **errp);
+
+
+/**
+ * qcrypto_ivgen_get_algorithm:
+ * @ivgen: the IV generator object
+ *
+ * Get the algorithm used by this IV generator
+ *
+ * Returns: the IV generator algorithm
+ */
+QCryptoIVGenAlgorithm qcrypto_ivgen_get_algorithm(QCryptoIVGen *ivgen);
+
+
+/**
+ * qcrypto_ivgen_get_cipher:
+ * @ivgen: the IV generator object
+ *
+ * Get the cipher algorithm used by this IV generator (if
+ * applicable)
+ *
+ * Returns: the cipher algorithm
+ */
+QCryptoCipherAlgorithm qcrypto_ivgen_get_cipher(QCryptoIVGen *ivgen);
+
+
+/**
+ * qcrypto_ivgen_get_hash:
+ * @ivgen: the IV generator object
+ *
+ * Get the hash algorithm used by this IV generator (if
+ * applicable)
+ *
+ * Returns: the hash algorithm
+ */
+QCryptoHashAlgorithm qcrypto_ivgen_get_hash(QCryptoIVGen *ivgen);
+
+
+/**
+ * qcrypto_ivgen_free:
+ * @ivgen: the IV generator object
+ *
+ * Release all resources associated with @ivgen, or a no-op
+ * if @ivgen is NULL
+ */
+void qcrypto_ivgen_free(QCryptoIVGen *ivgen);
+
+#endif /* QCRYPTO_IVGEN_H__ */
diff --git a/qapi/crypto.json b/qapi/crypto.json
index 4bd690fcfb..42b979a0d5 100644
--- a/qapi/crypto.json
+++ b/qapi/crypto.json
@@ -78,3 +78,22 @@
 { 'enum': 'QCryptoCipherMode',
   'prefix': 'QCRYPTO_CIPHER_MODE',
   'data': ['ecb', 'cbc']}
+
+
+##
+# QCryptoIVGenAlgorithm:
+#
+# The supported algorithms for generating initialization
+# vectors for full disk encryption. The 'plain' generator
+# should not be used for disks with sector numbers larger
+# than 2^32, except where compatibility with pre-existing
+# Linux dm-crypt volumes is required.
+#
+# @plain: 64-bit sector number truncated to 32-bits
+# @plain64: 64-bit sector number
+# @essiv: 64-bit sector number encrypted with a hash of the encryption key
+# Since: 2.6
+##
+{ 'enum': 'QCryptoIVGenAlgorithm',
+  'prefix': 'QCRYPTO_IVGEN_ALG',
+  'data': ['plain', 'plain64', 'essiv']}
diff --git a/tests/.gitignore b/tests/.gitignore
index db6b9beea8..369f848036 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -14,6 +14,7 @@ test-blockjob-txn
 test-coroutine
 test-crypto-cipher
 test-crypto-hash
+test-crypto-ivgen
 test-crypto-pbkdf
 test-crypto-secret
 test-crypto-tlscredsx509
diff --git a/tests/Makefile b/tests/Makefile
index 6e3b344e7c..5ff0e728fb 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -93,6 +93,7 @@ check-unit-y += tests/test-io-channel-command$(EXESUF)
 check-unit-y += tests/test-io-channel-buffer$(EXESUF)
 check-unit-y += tests/test-base64$(EXESUF)
 check-unit-$(if $(CONFIG_NETTLE),y,$(CONFIG_GCRYPT_KDF)) += tests/test-crypto-pbkdf$(EXESUF)
+check-unit-y += tests/test-crypto-ivgen$(EXESUF)
 
 check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
 
@@ -498,6 +499,7 @@ tests/test-io-channel-command$(EXESUF): tests/test-io-channel-command.o \
 tests/test-io-channel-buffer$(EXESUF): tests/test-io-channel-buffer.o \
         tests/io-channel-helpers.o $(test-io-obj-y)
 tests/test-crypto-pbkdf$(EXESUF): tests/test-crypto-pbkdf.o $(test-crypto-obj-y)
+tests/test-crypto-ivgen$(EXESUF): tests/test-crypto-ivgen.o $(test-crypto-obj-y)
 
 libqos-obj-y = tests/libqos/pci.o tests/libqos/fw_cfg.o tests/libqos/malloc.o
 libqos-obj-y += tests/libqos/i2c.o tests/libqos/libqos.o
diff --git a/tests/test-crypto-ivgen.c b/tests/test-crypto-ivgen.c
new file mode 100644
index 0000000000..96129da367
--- /dev/null
+++ b/tests/test-crypto-ivgen.c
@@ -0,0 +1,173 @@
+/*
+ * QEMU Crypto IV generator algorithms
+ *
+ * Copyright (c) 2015-2016 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/ivgen.h"
+
+
+struct QCryptoIVGenTestData {
+    const char *path;
+    uint64_t sector;
+    QCryptoIVGenAlgorithm ivalg;
+    QCryptoHashAlgorithm hashalg;
+    QCryptoCipherAlgorithm cipheralg;
+    const uint8_t *key;
+    size_t nkey;
+    const uint8_t *iv;
+    size_t niv;
+} test_data[] = {
+    /* Small */
+    {
+        "/crypto/ivgen/plain/1",
+        .sector = 0x1,
+        .ivalg = QCRYPTO_IVGEN_ALG_PLAIN,
+        .iv = (const uint8_t *)"\x01\x00\x00\x00\x00\x00\x00\x00"
+                               "\x00\x00\x00\x00\x00\x00\x00\x00",
+        .niv = 16,
+    },
+    /* Big ! */
+    {
+        "/crypto/ivgen/plain/1f2e3d4c",
+        .sector = 0x1f2e3d4cULL,
+        .ivalg = QCRYPTO_IVGEN_ALG_PLAIN,
+        .iv = (const uint8_t *)"\x4c\x3d\x2e\x1f\x00\x00\x00\x00"
+                               "\x00\x00\x00\x00\x00\x00\x00\x00",
+        .niv = 16,
+    },
+    /* Truncation */
+    {
+        "/crypto/ivgen/plain/1f2e3d4c5b6a7988",
+        .sector = 0x1f2e3d4c5b6a7988ULL,
+        .ivalg = QCRYPTO_IVGEN_ALG_PLAIN,
+        .iv = (const uint8_t *)"\x88\x79\x6a\x5b\x00\x00\x00\x00"
+                               "\x00\x00\x00\x00\x00\x00\x00\x00",
+        .niv = 16,
+    },
+    /* Small */
+    {
+        "/crypto/ivgen/plain64/1",
+        .sector = 0x1,
+        .ivalg = QCRYPTO_IVGEN_ALG_PLAIN64,
+        .iv = (const uint8_t *)"\x01\x00\x00\x00\x00\x00\x00\x00"
+                               "\x00\x00\x00\x00\x00\x00\x00\x00",
+        .niv = 16,
+    },
+    /* Big ! */
+    {
+        "/crypto/ivgen/plain64/1f2e3d4c",
+        .sector = 0x1f2e3d4cULL,
+        .ivalg = QCRYPTO_IVGEN_ALG_PLAIN64,
+        .iv = (const uint8_t *)"\x4c\x3d\x2e\x1f\x00\x00\x00\x00"
+                               "\x00\x00\x00\x00\x00\x00\x00\x00",
+        .niv = 16,
+    },
+    /* No Truncation */
+    {
+        "/crypto/ivgen/plain64/1f2e3d4c5b6a7988",
+        .sector = 0x1f2e3d4c5b6a7988ULL,
+        .ivalg = QCRYPTO_IVGEN_ALG_PLAIN64,
+        .iv = (const uint8_t *)"\x88\x79\x6a\x5b\x4c\x3d\x2e\x1f"
+                               "\x00\x00\x00\x00\x00\x00\x00\x00",
+        .niv = 16,
+    },
+    /* Small */
+    {
+        "/crypto/ivgen/essiv/1",
+        .sector = 0x1,
+        .ivalg = QCRYPTO_IVGEN_ALG_ESSIV,
+        .cipheralg = QCRYPTO_CIPHER_ALG_AES_128,
+        .hashalg = QCRYPTO_HASH_ALG_SHA256,
+        .key = (const uint8_t *)"\x00\x01\x02\x03\x04\x05\x06\x07"
+                                "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+        .nkey = 16,
+        .iv = (const uint8_t *)"\xd4\x83\x71\xb2\xa1\x94\x53\x88"
+                               "\x1c\x7a\x2d\06\x2d\x0b\x65\x46",
+        .niv = 16,
+    },
+    /* Big ! */
+    {
+        "/crypto/ivgen/essiv/1f2e3d4c",
+        .sector = 0x1f2e3d4cULL,
+        .ivalg = QCRYPTO_IVGEN_ALG_ESSIV,
+        .cipheralg = QCRYPTO_CIPHER_ALG_AES_128,
+        .hashalg = QCRYPTO_HASH_ALG_SHA256,
+        .key = (const uint8_t *)"\x00\x01\x02\x03\x04\x05\x06\x07"
+                                "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+        .nkey = 16,
+        .iv = (const uint8_t *)"\x5d\x36\x09\x5d\xc6\x9e\x5e\xe9"
+                               "\xe3\x02\x8d\xd8\x7a\x3d\xe7\x8f",
+        .niv = 16,
+    },
+    /* No Truncation */
+    {
+        "/crypto/ivgen/essiv/1f2e3d4c5b6a7988",
+        .sector = 0x1f2e3d4c5b6a7988ULL,
+        .ivalg = QCRYPTO_IVGEN_ALG_ESSIV,
+        .cipheralg = QCRYPTO_CIPHER_ALG_AES_128,
+        .hashalg = QCRYPTO_HASH_ALG_SHA256,
+        .key = (const uint8_t *)"\x00\x01\x02\x03\x04\x05\x06\x07"
+                                "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+        .nkey = 16,
+        .iv = (const uint8_t *)"\x58\xbb\x81\x94\x51\x83\x23\x23"
+                               "\x7a\x08\x93\xa9\xdc\xd2\xd9\xab",
+        .niv = 16,
+    },
+};
+
+
+static void test_ivgen(const void *opaque)
+{
+    const struct QCryptoIVGenTestData *data = opaque;
+    uint8_t *iv = g_new0(uint8_t, data->niv);
+    QCryptoIVGen *ivgen = qcrypto_ivgen_new(
+        data->ivalg,
+        data->cipheralg,
+        data->hashalg,
+        data->key,
+        data->nkey,
+        &error_abort);
+
+    qcrypto_ivgen_calculate(ivgen,
+                            data->sector,
+                            iv,
+                            data->niv,
+                            &error_abort);
+
+    g_assert(memcmp(iv, data->iv, data->niv) == 0);
+
+    qcrypto_ivgen_free(ivgen);
+    g_free(iv);
+}
+
+int main(int argc, char **argv)
+{
+    size_t i;
+    g_test_init(&argc, &argv, NULL);
+    for (i = 0; i < G_N_ELEMENTS(test_data); i++) {
+        if (test_data[i].ivalg == QCRYPTO_IVGEN_ALG_ESSIV &&
+            !qcrypto_hash_supports(test_data[i].hashalg)) {
+            continue;
+        }
+        g_test_add_data_func(test_data[i].path,
+                             &(test_data[i]),
+                             test_ivgen);
+    }
+    return g_test_run();
+}