encrypted-keys: create encrypted-keys directory

Move all files associated with encrypted keys to keys/encrypted-keys.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>

1 files changed, 0 insertions, 1049 deletions

diff --git a/security/keys/encrypted.c b/security/keys/encrypted.c
deleted file mode 100644
index e7eca9ec4c65..000000000000
--- a/security/keys/encrypted.c
+++ /dev/null
@@ -1,1049 +0,0 @@
-/*
- * Copyright (C) 2010 IBM Corporation
- * Copyright (C) 2010 Politecnico di Torino, Italy
- *                    TORSEC group -- http://security.polito.it
- *
- * Authors:
- * Mimi Zohar <zohar@us.ibm.com>
- * Roberto Sassu <roberto.sassu@polito.it>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, version 2 of the License.
- *
- * See Documentation/security/keys-trusted-encrypted.txt
- */
-
-#include <linux/uaccess.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/parser.h>
-#include <linux/string.h>
-#include <linux/err.h>
-#include <keys/user-type.h>
-#include <keys/trusted-type.h>
-#include <keys/encrypted-type.h>
-#include <linux/key-type.h>
-#include <linux/random.h>
-#include <linux/rcupdate.h>
-#include <linux/scatterlist.h>
-#include <linux/crypto.h>
-#include <linux/ctype.h>
-#include <crypto/hash.h>
-#include <crypto/sha.h>
-#include <crypto/aes.h>
-
-#include "encrypted.h"
-#include "ecryptfs_format.h"
-
-static const char KEY_TRUSTED_PREFIX[] = "trusted:";
-static const char KEY_USER_PREFIX[] = "user:";
-static const char hash_alg[] = "sha256";
-static const char hmac_alg[] = "hmac(sha256)";
-static const char blkcipher_alg[] = "cbc(aes)";
-static const char key_format_default[] = "default";
-static const char key_format_ecryptfs[] = "ecryptfs";
-static unsigned int ivsize;
-static int blksize;
-
-#define KEY_TRUSTED_PREFIX_LEN (sizeof (KEY_TRUSTED_PREFIX) - 1)
-#define KEY_USER_PREFIX_LEN (sizeof (KEY_USER_PREFIX) - 1)
-#define KEY_ECRYPTFS_DESC_LEN 16
-#define HASH_SIZE SHA256_DIGEST_SIZE
-#define MAX_DATA_SIZE 4096
-#define MIN_DATA_SIZE  20
-
-struct sdesc {
-        struct shash_desc shash;
-        char ctx[];
-};
-
-static struct crypto_shash *hashalg;
-static struct crypto_shash *hmacalg;
-
-enum {
-        Opt_err = -1, Opt_new, Opt_load, Opt_update
-};
-
-enum {
-        Opt_error = -1, Opt_default, Opt_ecryptfs
-};
-
-static const match_table_t key_format_tokens = {
-        {Opt_default, "default"},
-        {Opt_ecryptfs, "ecryptfs"},
-        {Opt_error, NULL}
-};
-
-static const match_table_t key_tokens = {
-        {Opt_new, "new"},
-        {Opt_load, "load"},
-        {Opt_update, "update"},
-        {Opt_err, NULL}
-};
-
-static int aes_get_sizes(void)
-{
-        struct crypto_blkcipher *tfm;
-
-        tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC);
-        if (IS_ERR(tfm)) {
-                pr_err("encrypted_key: failed to alloc_cipher (%ld)\n",
-                       PTR_ERR(tfm));
-                return PTR_ERR(tfm);
-        }
-        ivsize = crypto_blkcipher_ivsize(tfm);
-        blksize = crypto_blkcipher_blocksize(tfm);
-        crypto_free_blkcipher(tfm);
-        return 0;
-}
-
-/*
- * valid_ecryptfs_desc - verify the description of a new/loaded encrypted key
- *
- * The description of a encrypted key with format 'ecryptfs' must contain
- * exactly 16 hexadecimal characters.
- *
- */
-static int valid_ecryptfs_desc(const char *ecryptfs_desc)
-{
-        int i;
-
-        if (strlen(ecryptfs_desc) != KEY_ECRYPTFS_DESC_LEN) {
-                pr_err("encrypted_key: key description must be %d hexadecimal "
-                       "characters long\n", KEY_ECRYPTFS_DESC_LEN);
-                return -EINVAL;
-        }
-
-        for (i = 0; i < KEY_ECRYPTFS_DESC_LEN; i++) {
-                if (!isxdigit(ecryptfs_desc[i])) {
-                        pr_err("encrypted_key: key description must contain "
-                               "only hexadecimal characters\n");
-                        return -EINVAL;
-                }
-        }
-
-        return 0;
-}
-
-/*
- * valid_master_desc - verify the 'key-type:desc' of a new/updated master-key
- *
- * key-type:= "trusted:" | "user:"
- * desc:= master-key description
- *
- * Verify that 'key-type' is valid and that 'desc' exists. On key update,
- * only the master key description is permitted to change, not the key-type.
- * The key-type remains constant.
- *
- * On success returns 0, otherwise -EINVAL.
- */
-static int valid_master_desc(const char *new_desc, const char *orig_desc)
-{
-        if (!memcmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) {
-                if (strlen(new_desc) == KEY_TRUSTED_PREFIX_LEN)
-                        goto out;
-                if (orig_desc)
-                        if (memcmp(new_desc, orig_desc, KEY_TRUSTED_PREFIX_LEN))
-                                goto out;
-        } else if (!memcmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) {
-                if (strlen(new_desc) == KEY_USER_PREFIX_LEN)
-                        goto out;
-                if (orig_desc)
-                        if (memcmp(new_desc, orig_desc, KEY_USER_PREFIX_LEN))
-                                goto out;
-        } else
-                goto out;
-        return 0;
-out:
-        return -EINVAL;
-}
-
-/*
- * datablob_parse - parse the keyctl data
- *
- * datablob format:
- * new [<format>] <master-key name> <decrypted data length>
- * load [<format>] <master-key name> <decrypted data length>
- *     <encrypted iv + data>
- * update <new-master-key name>
- *
- * Tokenizes a copy of the keyctl data, returning a pointer to each token,
- * which is null terminated.
- *
- * On success returns 0, otherwise -EINVAL.
- */
-static int datablob_parse(char *datablob, const char **format,
-                          char **master_desc, char **decrypted_datalen,
-                          char **hex_encoded_iv)
-{
-        substring_t args[MAX_OPT_ARGS];
-        int ret = -EINVAL;
-        int key_cmd;
-        int key_format;
-        char *p, *keyword;
-
-        keyword = strsep(&datablob, " \t");
-        if (!keyword) {
-                pr_info("encrypted_key: insufficient parameters specified\n");
-                return ret;
-        }
-        key_cmd = match_token(keyword, key_tokens, args);
-
-        /* Get optional format: default | ecryptfs */
-        p = strsep(&datablob, " \t");
-        if (!p) {
-                pr_err("encrypted_key: insufficient parameters specified\n");
-                return ret;
-        }
-
-        key_format = match_token(p, key_format_tokens, args);
-        switch (key_format) {
-        case Opt_ecryptfs:
-        case Opt_default:
-                *format = p;
-                *master_desc = strsep(&datablob, " \t");
-                break;
-        case Opt_error:
-                *master_desc = p;
-                break;
-        }
-
-        if (!*master_desc) {
-                pr_info("encrypted_key: master key parameter is missing\n");
-                goto out;
-        }
-
-        if (valid_master_desc(*master_desc, NULL) < 0) {
-                pr_info("encrypted_key: master key parameter \'%s\' "
-                        "is invalid\n", *master_desc);
-                goto out;
-        }
-
-        if (decrypted_datalen) {
-                *decrypted_datalen = strsep(&datablob, " \t");
-                if (!*decrypted_datalen) {
-                        pr_info("encrypted_key: keylen parameter is missing\n");
-                        goto out;
-                }
-        }
-
-        switch (key_cmd) {
-        case Opt_new:
-                if (!decrypted_datalen) {
-                        pr_info("encrypted_key: keyword \'%s\' not allowed "
-                                "when called from .update method\n", keyword);
-                        break;
-                }
-                ret = 0;
-                break;
-        case Opt_load:
-                if (!decrypted_datalen) {
-                        pr_info("encrypted_key: keyword \'%s\' not allowed "
-                                "when called from .update method\n", keyword);
-                        break;
-                }
-                *hex_encoded_iv = strsep(&datablob, " \t");
-                if (!*hex_encoded_iv) {
-                        pr_info("encrypted_key: hex blob is missing\n");
-                        break;
-                }
-                ret = 0;
-                break;
-        case Opt_update:
-                if (decrypted_datalen) {
-                        pr_info("encrypted_key: keyword \'%s\' not allowed "
-                                "when called from .instantiate method\n",
-                                keyword);
-                        break;
-                }
-                ret = 0;
-                break;
-        case Opt_err:
-                pr_info("encrypted_key: keyword \'%s\' not recognized\n",
-                        keyword);
-                break;
-        }
-out:
-        return ret;
-}
-
-/*
- * datablob_format - format as an ascii string, before copying to userspace
- */
-static char *datablob_format(struct encrypted_key_payload *epayload,
-                             size_t asciiblob_len)
-{
-        char *ascii_buf, *bufp;
-        u8 *iv = epayload->iv;
-        int len;
-        int i;
-
-        ascii_buf = kmalloc(asciiblob_len + 1, GFP_KERNEL);
-        if (!ascii_buf)
-                goto out;
-
-        ascii_buf[asciiblob_len] = '\0';
-
-        /* copy datablob master_desc and datalen strings */
-        len = sprintf(ascii_buf, "%s %s %s ", epayload->format,
-                      epayload->master_desc, epayload->datalen);
-
-        /* convert the hex encoded iv, encrypted-data and HMAC to ascii */
-        bufp = &ascii_buf[len];
-        for (i = 0; i < (asciiblob_len - len) / 2; i++)
-                bufp = pack_hex_byte(bufp, iv[i]);
-out:
-        return ascii_buf;
-}
-
-/*
- * request_trusted_key - request the trusted key
- *
- * Trusted keys are sealed to PCRs and other metadata. Although userspace
- * manages both trusted/encrypted key-types, like the encrypted key type
- * data, trusted key type data is not visible decrypted from userspace.
- */
-static struct key *request_trusted_key(const char *trusted_desc,
-                                       u8 **master_key, size_t *master_keylen)
-{
-        struct trusted_key_payload *tpayload;
-        struct key *tkey;
-
-        tkey = request_key(&key_type_trusted, trusted_desc, NULL);
-        if (IS_ERR(tkey))
-                goto error;
-
-        down_read(&tkey->sem);
-        tpayload = rcu_dereference(tkey->payload.data);
-        *master_key = tpayload->key;
-        *master_keylen = tpayload->key_len;
-error:
-        return tkey;
-}
-
-/*
- * request_user_key - request the user key
- *
- * Use a user provided key to encrypt/decrypt an encrypted-key.
- */
-static struct key *request_user_key(const char *master_desc, u8 **master_key,
-                                    size_t *master_keylen)
-{
-        struct user_key_payload *upayload;
-        struct key *ukey;
-
-        ukey = request_key(&key_type_user, master_desc, NULL);
-        if (IS_ERR(ukey))
-                goto error;
-
-        down_read(&ukey->sem);
-        upayload = rcu_dereference(ukey->payload.data);
-        *master_key = upayload->data;
-        *master_keylen = upayload->datalen;
-error:
-        return ukey;
-}
-
-static struct sdesc *alloc_sdesc(struct crypto_shash *alg)
-{
-        struct sdesc *sdesc;
-        int size;
-
-        size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
-        sdesc = kmalloc(size, GFP_KERNEL);
-        if (!sdesc)
-                return ERR_PTR(-ENOMEM);
-        sdesc->shash.tfm = alg;
-        sdesc->shash.flags = 0x0;
-        return sdesc;
-}
-
-static int calc_hmac(u8 *digest, const u8 *key, unsigned int keylen,
-                     const u8 *buf, unsigned int buflen)
-{
-        struct sdesc *sdesc;
-        int ret;
-
-        sdesc = alloc_sdesc(hmacalg);
-        if (IS_ERR(sdesc)) {
-                pr_info("encrypted_key: can't alloc %s\n", hmac_alg);
-                return PTR_ERR(sdesc);
-        }
-
-        ret = crypto_shash_setkey(hmacalg, key, keylen);
-        if (!ret)
-                ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest);
-        kfree(sdesc);
-        return ret;
-}
-
-static int calc_hash(u8 *digest, const u8 *buf, unsigned int buflen)
-{
-        struct sdesc *sdesc;
-        int ret;
-
-        sdesc = alloc_sdesc(hashalg);
-        if (IS_ERR(sdesc)) {
-                pr_info("encrypted_key: can't alloc %s\n", hash_alg);
-                return PTR_ERR(sdesc);
-        }
-
-        ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest);
-        kfree(sdesc);
-        return ret;
-}
-
-enum derived_key_type { ENC_KEY, AUTH_KEY };
-
-/* Derive authentication/encryption key from trusted key */
-static int get_derived_key(u8 *derived_key, enum derived_key_type key_type,
-                           const u8 *master_key, size_t master_keylen)
-{
-        u8 *derived_buf;
-        unsigned int derived_buf_len;
-        int ret;
-
-        derived_buf_len = strlen("AUTH_KEY") + 1 + master_keylen;
-        if (derived_buf_len < HASH_SIZE)
-                derived_buf_len = HASH_SIZE;
-
-        derived_buf = kzalloc(derived_buf_len, GFP_KERNEL);
-        if (!derived_buf) {
-                pr_err("encrypted_key: out of memory\n");
-                return -ENOMEM;
-        }
-        if (key_type)
-                strcpy(derived_buf, "AUTH_KEY");
-        else
-                strcpy(derived_buf, "ENC_KEY");
-
-        memcpy(derived_buf + strlen(derived_buf) + 1, master_key,
-               master_keylen);
-        ret = calc_hash(derived_key, derived_buf, derived_buf_len);
-        kfree(derived_buf);
-        return ret;
-}
-
-static int init_blkcipher_desc(struct blkcipher_desc *desc, const u8 *key,
-                               unsigned int key_len, const u8 *iv,
-                               unsigned int ivsize)
-{
-        int ret;
-
-        desc->tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC);
-        if (IS_ERR(desc->tfm)) {
-                pr_err("encrypted_key: failed to load %s transform (%ld)\n",
-                       blkcipher_alg, PTR_ERR(desc->tfm));
-                return PTR_ERR(desc->tfm);
-        }
-        desc->flags = 0;
-
-        ret = crypto_blkcipher_setkey(desc->tfm, key, key_len);
-        if (ret < 0) {
-                pr_err("encrypted_key: failed to setkey (%d)\n", ret);
-                crypto_free_blkcipher(desc->tfm);
-                return ret;
-        }
-        crypto_blkcipher_set_iv(desc->tfm, iv, ivsize);
-        return 0;
-}
-
-static struct key *request_master_key(struct encrypted_key_payload *epayload,
-                                      u8 **master_key, size_t *master_keylen)
-{
-        struct key *mkey = NULL;
-
-        if (!strncmp(epayload->master_desc, KEY_TRUSTED_PREFIX,
-                     KEY_TRUSTED_PREFIX_LEN)) {
-                mkey = request_trusted_key(epayload->master_desc +
-                                           KEY_TRUSTED_PREFIX_LEN,
-                                           master_key, master_keylen);
-        } else if (!strncmp(epayload->master_desc, KEY_USER_PREFIX,
-                            KEY_USER_PREFIX_LEN)) {
-                mkey = request_user_key(epayload->master_desc +
-                                        KEY_USER_PREFIX_LEN,
-                                        master_key, master_keylen);
-        } else
-                goto out;
-
-        if (IS_ERR(mkey)) {
-                pr_info("encrypted_key: key %s not found",
-                        epayload->master_desc);
-                goto out;
-        }
-
-        dump_master_key(*master_key, *master_keylen);
-out:
-        return mkey;
-}
-
-/* Before returning data to userspace, encrypt decrypted data. */
-static int derived_key_encrypt(struct encrypted_key_payload *epayload,
-                               const u8 *derived_key,
-                               unsigned int derived_keylen)
-{
-        struct scatterlist sg_in[2];
-        struct scatterlist sg_out[1];
-        struct blkcipher_desc desc;
-        unsigned int encrypted_datalen;
-        unsigned int padlen;
-        char pad[16];
-        int ret;
-
-        encrypted_datalen = roundup(epayload->decrypted_datalen, blksize);
-        padlen = encrypted_datalen - epayload->decrypted_datalen;
-
-        ret = init_blkcipher_desc(&desc, derived_key, derived_keylen,
-                                  epayload->iv, ivsize);
-        if (ret < 0)
-                goto out;
-        dump_decrypted_data(epayload);
-
-        memset(pad, 0, sizeof pad);
-        sg_init_table(sg_in, 2);
-        sg_set_buf(&sg_in[0], epayload->decrypted_data,
-                   epayload->decrypted_datalen);
-        sg_set_buf(&sg_in[1], pad, padlen);
-
-        sg_init_table(sg_out, 1);
-        sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen);
-
-        ret = crypto_blkcipher_encrypt(&desc, sg_out, sg_in, encrypted_datalen);
-        crypto_free_blkcipher(desc.tfm);
-        if (ret < 0)
-                pr_err("encrypted_key: failed to encrypt (%d)\n", ret);
-        else
-                dump_encrypted_data(epayload, encrypted_datalen);
-out:
-        return ret;
-}
-
-static int datablob_hmac_append(struct encrypted_key_payload *epayload,
-                                const u8 *master_key, size_t master_keylen)
-{
-        u8 derived_key[HASH_SIZE];
-        u8 *digest;
-        int ret;
-
-        ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen);
-        if (ret < 0)
-                goto out;
-
-        digest = epayload->format + epayload->datablob_len;
-        ret = calc_hmac(digest, derived_key, sizeof derived_key,
-                        epayload->format, epayload->datablob_len);
-        if (!ret)
-                dump_hmac(NULL, digest, HASH_SIZE);
-out:
-        return ret;
-}
-
-/* verify HMAC before decrypting encrypted key */
-static int datablob_hmac_verify(struct encrypted_key_payload *epayload,
-                                const u8 *format, const u8 *master_key,
-                                size_t master_keylen)
-{
-        u8 derived_key[HASH_SIZE];
-        u8 digest[HASH_SIZE];
-        int ret;
-        char *p;
-        unsigned short len;
-
-        ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen);
-        if (ret < 0)
-                goto out;
-
-        len = epayload->datablob_len;
-        if (!format) {
-                p = epayload->master_desc;
-                len -= strlen(epayload->format) + 1;
-        } else
-                p = epayload->format;
-
-        ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len);
-        if (ret < 0)
-                goto out;
-        ret = memcmp(digest, epayload->format + epayload->datablob_len,
-                     sizeof digest);
-        if (ret) {
-                ret = -EINVAL;
-                dump_hmac("datablob",
-                          epayload->format + epayload->datablob_len,
-                          HASH_SIZE);
-                dump_hmac("calc", digest, HASH_SIZE);
-        }
-out:
-        return ret;
-}
-
-static int derived_key_decrypt(struct encrypted_key_payload *epayload,
-                               const u8 *derived_key,
-                               unsigned int derived_keylen)
-{
-        struct scatterlist sg_in[1];
-        struct scatterlist sg_out[2];
-        struct blkcipher_desc desc;
-        unsigned int encrypted_datalen;
-        char pad[16];
-        int ret;
-
-        encrypted_datalen = roundup(epayload->decrypted_datalen, blksize);
-        ret = init_blkcipher_desc(&desc, derived_key, derived_keylen,
-                                  epayload->iv, ivsize);
-        if (ret < 0)
-                goto out;
-        dump_encrypted_data(epayload, encrypted_datalen);
-
-        memset(pad, 0, sizeof pad);
-        sg_init_table(sg_in, 1);
-        sg_init_table(sg_out, 2);
-        sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen);
-        sg_set_buf(&sg_out[0], epayload->decrypted_data,
-                   epayload->decrypted_datalen);
-        sg_set_buf(&sg_out[1], pad, sizeof pad);
-
-        ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in, encrypted_datalen);
-        crypto_free_blkcipher(desc.tfm);
-        if (ret < 0)
-                goto out;
-        dump_decrypted_data(epayload);
-out:
-        return ret;
-}
-
-/* Allocate memory for decrypted key and datablob. */
-static struct encrypted_key_payload *encrypted_key_alloc(struct key *key,
-                                                         const char *format,
-                                                         const char *master_desc,
-                                                         const char *datalen)
-{
-        struct encrypted_key_payload *epayload = NULL;
-        unsigned short datablob_len;
-        unsigned short decrypted_datalen;
-        unsigned short payload_datalen;
-        unsigned int encrypted_datalen;
-        unsigned int format_len;
-        long dlen;
-        int ret;
-
-        ret = strict_strtol(datalen, 10, &dlen);
-        if (ret < 0 || dlen < MIN_DATA_SIZE || dlen > MAX_DATA_SIZE)
-                return ERR_PTR(-EINVAL);
-
-        format_len = (!format) ? strlen(key_format_default) : strlen(format);
-        decrypted_datalen = dlen;
-        payload_datalen = decrypted_datalen;
-        if (format && !strcmp(format, key_format_ecryptfs)) {
-                if (dlen != ECRYPTFS_MAX_KEY_BYTES) {
-                        pr_err("encrypted_key: keylen for the ecryptfs format "
-                               "must be equal to %d bytes\n",
-                               ECRYPTFS_MAX_KEY_BYTES);
-                        return ERR_PTR(-EINVAL);
-                }
-                decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES;
-                payload_datalen = sizeof(struct ecryptfs_auth_tok);
-        }
-
-        encrypted_datalen = roundup(decrypted_datalen, blksize);
-
-        datablob_len = format_len + 1 + strlen(master_desc) + 1
-            + strlen(datalen) + 1 + ivsize + 1 + encrypted_datalen;
-
-        ret = key_payload_reserve(key, payload_datalen + datablob_len
-                                  + HASH_SIZE + 1);
-        if (ret < 0)
-                return ERR_PTR(ret);
-
-        epayload = kzalloc(sizeof(*epayload) + payload_datalen +
-                           datablob_len + HASH_SIZE + 1, GFP_KERNEL);
-        if (!epayload)
-                return ERR_PTR(-ENOMEM);
-
-        epayload->payload_datalen = payload_datalen;
-        epayload->decrypted_datalen = decrypted_datalen;
-        epayload->datablob_len = datablob_len;
-        return epayload;
-}
-
-static int encrypted_key_decrypt(struct encrypted_key_payload *epayload,
-                                 const char *format, const char *hex_encoded_iv)
-{
-        struct key *mkey;
-        u8 derived_key[HASH_SIZE];
-        u8 *master_key;
-        u8 *hmac;
-        const char *hex_encoded_data;
-        unsigned int encrypted_datalen;
-        size_t master_keylen;
-        size_t asciilen;
-        int ret;
-
-        encrypted_datalen = roundup(epayload->decrypted_datalen, blksize);
-        asciilen = (ivsize + 1 + encrypted_datalen + HASH_SIZE) * 2;
-        if (strlen(hex_encoded_iv) != asciilen)
-                return -EINVAL;
-
-        hex_encoded_data = hex_encoded_iv + (2 * ivsize) + 2;
-        hex2bin(epayload->iv, hex_encoded_iv, ivsize);
-        hex2bin(epayload->encrypted_data, hex_encoded_data, encrypted_datalen);
-
-        hmac = epayload->format + epayload->datablob_len;
-        hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), HASH_SIZE);
-
-        mkey = request_master_key(epayload, &master_key, &master_keylen);
-        if (IS_ERR(mkey))
-                return PTR_ERR(mkey);
-
-        ret = datablob_hmac_verify(epayload, format, master_key, master_keylen);
-        if (ret < 0) {
-                pr_err("encrypted_key: bad hmac (%d)\n", ret);
-                goto out;
-        }
-
-        ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen);
-        if (ret < 0)
-                goto out;
-
-        ret = derived_key_decrypt(epayload, derived_key, sizeof derived_key);
-        if (ret < 0)
-                pr_err("encrypted_key: failed to decrypt key (%d)\n", ret);
-out:
-        up_read(&mkey->sem);
-        key_put(mkey);
-        return ret;
-}
-
-static void __ekey_init(struct encrypted_key_payload *epayload,
-                        const char *format, const char *master_desc,
-                        const char *datalen)
-{
-        unsigned int format_len;
-
-        format_len = (!format) ? strlen(key_format_default) : strlen(format);
-        epayload->format = epayload->payload_data + epayload->payload_datalen;
-        epayload->master_desc = epayload->format + format_len + 1;
-        epayload->datalen = epayload->master_desc + strlen(master_desc) + 1;
-        epayload->iv = epayload->datalen + strlen(datalen) + 1;
-        epayload->encrypted_data = epayload->iv + ivsize + 1;
-        epayload->decrypted_data = epayload->payload_data;
-
-        if (!format)
-                memcpy(epayload->format, key_format_default, format_len);
-        else {
-                if (!strcmp(format, key_format_ecryptfs))
-                        epayload->decrypted_data =
-                                ecryptfs_get_auth_tok_key((struct ecryptfs_auth_tok *)epayload->payload_data);
-
-                memcpy(epayload->format, format, format_len);
-        }
-
-        memcpy(epayload->master_desc, master_desc, strlen(master_desc));
-        memcpy(epayload->datalen, datalen, strlen(datalen));
-}
-
-/*
- * encrypted_init - initialize an encrypted key
- *
- * For a new key, use a random number for both the iv and data
- * itself.  For an old key, decrypt the hex encoded data.
- */
-static int encrypted_init(struct encrypted_key_payload *epayload,
-                          const char *key_desc, const char *format,
-                          const char *master_desc, const char *datalen,
-                          const char *hex_encoded_iv)
-{
-        int ret = 0;
-
-        if (format && !strcmp(format, key_format_ecryptfs)) {
-                ret = valid_ecryptfs_desc(key_desc);
-                if (ret < 0)
-                        return ret;
-
-                ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data,
-                                       key_desc);
-        }
-
-        __ekey_init(epayload, format, master_desc, datalen);
-        if (!hex_encoded_iv) {
-                get_random_bytes(epayload->iv, ivsize);
-
-                get_random_bytes(epayload->decrypted_data,
-                                 epayload->decrypted_datalen);
-        } else
-                ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv);
-        return ret;
-}
-
-/*
- * encrypted_instantiate - instantiate an encrypted key
- *
- * Decrypt an existing encrypted datablob or create a new encrypted key
- * based on a kernel random number.
- *
- * On success, return 0. Otherwise return errno.
- */
-static int encrypted_instantiate(struct key *key, const void *data,
-                                 size_t datalen)
-{
-        struct encrypted_key_payload *epayload = NULL;
-        char *datablob = NULL;
-        const char *format = NULL;
-        char *master_desc = NULL;
-        char *decrypted_datalen = NULL;
-        char *hex_encoded_iv = NULL;
-        int ret;
-
-        if (datalen <= 0 || datalen > 32767 || !data)
-                return -EINVAL;
-
-        datablob = kmalloc(datalen + 1, GFP_KERNEL);
-        if (!datablob)
-                return -ENOMEM;
-        datablob[datalen] = 0;
-        memcpy(datablob, data, datalen);
-        ret = datablob_parse(datablob, &format, &master_desc,
-                             &decrypted_datalen, &hex_encoded_iv);
-        if (ret < 0)
-                goto out;
-
-        epayload = encrypted_key_alloc(key, format, master_desc,
-                                       decrypted_datalen);
-        if (IS_ERR(epayload)) {
-                ret = PTR_ERR(epayload);
-                goto out;
-        }
-        ret = encrypted_init(epayload, key->description, format, master_desc,
-                             decrypted_datalen, hex_encoded_iv);
-        if (ret < 0) {
-                kfree(epayload);
-                goto out;
-        }
-
-        rcu_assign_pointer(key->payload.data, epayload);
-out:
-        kfree(datablob);
-        return ret;
-}
-
-static void encrypted_rcu_free(struct rcu_head *rcu)
-{
-        struct encrypted_key_payload *epayload;
-
-        epayload = container_of(rcu, struct encrypted_key_payload, rcu);
-        memset(epayload->decrypted_data, 0, epayload->decrypted_datalen);
-        kfree(epayload);
-}
-
-/*
- * encrypted_update - update the master key description
- *
- * Change the master key description for an existing encrypted key.
- * The next read will return an encrypted datablob using the new
- * master key description.
- *
- * On success, return 0. Otherwise return errno.
- */
-static int encrypted_update(struct key *key, const void *data, size_t datalen)
-{
-        struct encrypted_key_payload *epayload = key->payload.data;
-        struct encrypted_key_payload *new_epayload;
-        char *buf;
-        char *new_master_desc = NULL;
-        const char *format = NULL;
-        int ret = 0;
-
-        if (datalen <= 0 || datalen > 32767 || !data)
-                return -EINVAL;
-
-        buf = kmalloc(datalen + 1, GFP_KERNEL);
-        if (!buf)
-                return -ENOMEM;
-
-        buf[datalen] = 0;
-        memcpy(buf, data, datalen);
-        ret = datablob_parse(buf, &format, &new_master_desc, NULL, NULL);
-        if (ret < 0)
-                goto out;
-
-        ret = valid_master_desc(new_master_desc, epayload->master_desc);
-        if (ret < 0)
-                goto out;
-
-        new_epayload = encrypted_key_alloc(key, epayload->format,
-                                           new_master_desc, epayload->datalen);
-        if (IS_ERR(new_epayload)) {
-                ret = PTR_ERR(new_epayload);
-                goto out;
-        }
-
-        __ekey_init(new_epayload, epayload->format, new_master_desc,
-                    epayload->datalen);
-
-        memcpy(new_epayload->iv, epayload->iv, ivsize);
-        memcpy(new_epayload->payload_data, epayload->payload_data,
-               epayload->payload_datalen);
-
-        rcu_assign_pointer(key->payload.data, new_epayload);
-        call_rcu(&epayload->rcu, encrypted_rcu_free);
-out:
-        kfree(buf);
-        return ret;
-}
-
-/*
- * encrypted_read - format and copy the encrypted data to userspace
- *
- * The resulting datablob format is:
- * <master-key name> <decrypted data length> <encrypted iv> <encrypted data>
- *
- * On success, return to userspace the encrypted key datablob size.
- */
-static long encrypted_read(const struct key *key, char __user *buffer,
-                           size_t buflen)
-{
-        struct encrypted_key_payload *epayload;
-        struct key *mkey;
-        u8 *master_key;
-        size_t master_keylen;
-        char derived_key[HASH_SIZE];
-        char *ascii_buf;
-        size_t asciiblob_len;
-        int ret;
-
-        epayload = rcu_dereference_key(key);
-
-        /* returns the hex encoded iv, encrypted-data, and hmac as ascii */
-        asciiblob_len = epayload->datablob_len + ivsize + 1
-            + roundup(epayload->decrypted_datalen, blksize)
-            + (HASH_SIZE * 2);
-
-        if (!buffer || buflen < asciiblob_len)
-                return asciiblob_len;
-
-        mkey = request_master_key(epayload, &master_key, &master_keylen);
-        if (IS_ERR(mkey))
-                return PTR_ERR(mkey);
-
-        ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen);
-        if (ret < 0)
-                goto out;
-
-        ret = derived_key_encrypt(epayload, derived_key, sizeof derived_key);
-        if (ret < 0)
-                goto out;
-
-        ret = datablob_hmac_append(epayload, master_key, master_keylen);
-        if (ret < 0)
-                goto out;
-
-        ascii_buf = datablob_format(epayload, asciiblob_len);
-        if (!ascii_buf) {
-                ret = -ENOMEM;
-                goto out;
-        }
-
-        up_read(&mkey->sem);
-        key_put(mkey);
-
-        if (copy_to_user(buffer, ascii_buf, asciiblob_len) != 0)
-                ret = -EFAULT;
-        kfree(ascii_buf);
-
-        return asciiblob_len;
-out:
-        up_read(&mkey->sem);
-        key_put(mkey);
-        return ret;
-}
-
-/*
- * encrypted_destroy - before freeing the key, clear the decrypted data
- *
- * Before freeing the key, clear the memory containing the decrypted
- * key data.
- */
-static void encrypted_destroy(struct key *key)
-{
-        struct encrypted_key_payload *epayload = key->payload.data;
-
-        if (!epayload)
-                return;
-
-        memset(epayload->decrypted_data, 0, epayload->decrypted_datalen);
-        kfree(key->payload.data);
-}
-
-struct key_type key_type_encrypted = {
-        .name = "encrypted",
-        .instantiate = encrypted_instantiate,
-        .update = encrypted_update,
-        .match = user_match,
-        .destroy = encrypted_destroy,
-        .describe = user_describe,
-        .read = encrypted_read,
-};
-EXPORT_SYMBOL_GPL(key_type_encrypted);
-
-static void encrypted_shash_release(void)
-{
-        if (hashalg)
-                crypto_free_shash(hashalg);
-        if (hmacalg)
-                crypto_free_shash(hmacalg);
-}
-
-static int __init encrypted_shash_alloc(void)
-{
-        int ret;
-
-        hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
-        if (IS_ERR(hmacalg)) {
-                pr_info("encrypted_key: could not allocate crypto %s\n",
-                        hmac_alg);
-                return PTR_ERR(hmacalg);
-        }
-
-        hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
-        if (IS_ERR(hashalg)) {
-                pr_info("encrypted_key: could not allocate crypto %s\n",
-                        hash_alg);
-                ret = PTR_ERR(hashalg);
-                goto hashalg_fail;
-        }
-
-        return 0;
-
-hashalg_fail:
-        crypto_free_shash(hmacalg);
-        return ret;
-}
-
-static int __init init_encrypted(void)
-{
-        int ret;
-
-        ret = encrypted_shash_alloc();
-        if (ret < 0)
-                return ret;
-        ret = register_key_type(&key_type_encrypted);
-        if (ret < 0)
-                goto out;
-        return aes_get_sizes();
-out:
-        encrypted_shash_release();
-        return ret;
-
-}
-
-static void __exit cleanup_encrypted(void)
-{
-        encrypted_shash_release();
-        unregister_key_type(&key_type_encrypted);
-}
-
-late_initcall(init_encrypted);
-module_exit(cleanup_encrypted);
-
-MODULE_LICENSE("GPL");