user_defined.o
obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
-obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted_defined.o
+obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted.o
obj-$(CONFIG_KEYS_COMPAT) += compat.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_SYSCTL) += sysctl.o
--- /dev/null
+/*
+ * Copyright (C) 2010 IBM Corporation
+ *
+ * Author:
+ * Mimi Zohar <zohar@us.ibm.com>
+ *
+ * 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/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 <crypto/hash.h>
+#include <crypto/sha.h>
+#include <crypto/aes.h>
+
+#include "encrypted.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 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 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
+};
+
+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_master_desc - verify the 'key-type:desc' of a new/updated master-key
+ *
+ * key-type:= "trusted:" | "encrypted:"
+ * 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 <master-key name> <decrypted data length>
+ * load <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, char **master_desc,
+ char **decrypted_datalen, char **hex_encoded_iv)
+{
+ substring_t args[MAX_OPT_ARGS];
+ int ret = -EINVAL;
+ int key_cmd;
+ char *p;
+
+ p = strsep(&datablob, " \t");
+ if (!p)
+ return ret;
+ key_cmd = match_token(p, key_tokens, args);
+
+ *master_desc = strsep(&datablob, " \t");
+ if (!*master_desc)
+ goto out;
+
+ if (valid_master_desc(*master_desc, NULL) < 0)
+ goto out;
+
+ if (decrypted_datalen) {
+ *decrypted_datalen = strsep(&datablob, " \t");
+ if (!*decrypted_datalen)
+ goto out;
+ }
+
+ switch (key_cmd) {
+ case Opt_new:
+ if (!decrypted_datalen)
+ break;
+ ret = 0;
+ break;
+ case Opt_load:
+ if (!decrypted_datalen)
+ break;
+ *hex_encoded_iv = strsep(&datablob, " \t");
+ if (!*hex_encoded_iv)
+ break;
+ ret = 0;
+ break;
+ case Opt_update:
+ if (decrypted_datalen)
+ break;
+ ret = 0;
+ break;
+ case Opt_err:
+ 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 ", 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);
+ if (mkey)
+ 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->master_desc + epayload->datablob_len;
+ ret = calc_hmac(digest, derived_key, sizeof derived_key,
+ epayload->master_desc, 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 *master_key, size_t master_keylen)
+{
+ u8 derived_key[HASH_SIZE];
+ u8 digest[HASH_SIZE];
+ int ret;
+
+ ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen);
+ if (ret < 0)
+ goto out;
+
+ ret = calc_hmac(digest, derived_key, sizeof derived_key,
+ epayload->master_desc, epayload->datablob_len);
+ if (ret < 0)
+ goto out;
+ ret = memcmp(digest, epayload->master_desc + epayload->datablob_len,
+ sizeof digest);
+ if (ret) {
+ ret = -EINVAL;
+ dump_hmac("datablob",
+ epayload->master_desc + 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 *master_desc,
+ const char *datalen)
+{
+ struct encrypted_key_payload *epayload = NULL;
+ unsigned short datablob_len;
+ unsigned short decrypted_datalen;
+ unsigned int encrypted_datalen;
+ 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);
+
+ decrypted_datalen = dlen;
+ encrypted_datalen = roundup(decrypted_datalen, blksize);
+
+ datablob_len = strlen(master_desc) + 1 + strlen(datalen) + 1
+ + ivsize + 1 + encrypted_datalen;
+
+ ret = key_payload_reserve(key, decrypted_datalen + datablob_len
+ + HASH_SIZE + 1);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ epayload = kzalloc(sizeof(*epayload) + decrypted_datalen +
+ datablob_len + HASH_SIZE + 1, GFP_KERNEL);
+ if (!epayload)
+ return ERR_PTR(-ENOMEM);
+
+ epayload->decrypted_datalen = decrypted_datalen;
+ epayload->datablob_len = datablob_len;
+ return epayload;
+}
+
+static int encrypted_key_decrypt(struct encrypted_key_payload *epayload,
+ 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->master_desc + 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, 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 *master_desc, const char *datalen)
+{
+ epayload->master_desc = epayload->decrypted_data
+ + epayload->decrypted_datalen;
+ epayload->datalen = epayload->master_desc + strlen(master_desc) + 1;
+ epayload->iv = epayload->datalen + strlen(datalen) + 1;
+ epayload->encrypted_data = epayload->iv + ivsize + 1;
+
+ 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 *master_desc, const char *datalen,
+ const char *hex_encoded_iv)
+{
+ int ret = 0;
+
+ __ekey_init(epayload, 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, 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;
+ 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, &master_desc, &decrypted_datalen,
+ &hex_encoded_iv);
+ if (ret < 0)
+ goto out;
+
+ epayload = encrypted_key_alloc(key, master_desc, decrypted_datalen);
+ if (IS_ERR(epayload)) {
+ ret = PTR_ERR(epayload);
+ goto out;
+ }
+ ret = encrypted_init(epayload, 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;
+ 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, &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, new_master_desc,
+ epayload->datalen);
+ if (IS_ERR(new_epayload)) {
+ ret = PTR_ERR(new_epayload);
+ goto out;
+ }
+
+ __ekey_init(new_epayload, new_master_desc, epayload->datalen);
+
+ memcpy(new_epayload->iv, epayload->iv, ivsize);
+ memcpy(new_epayload->decrypted_data, epayload->decrypted_data,
+ epayload->decrypted_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_protected(key->payload.data,
+ rwsem_is_locked(&((struct key *)key)->sem));
+
+ /* 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");
--- /dev/null
+#ifndef __ENCRYPTED_KEY_H
+#define __ENCRYPTED_KEY_H
+
+#define ENCRYPTED_DEBUG 0
+
+#if ENCRYPTED_DEBUG
+static inline void dump_master_key(const u8 *master_key, size_t master_keylen)
+{
+ print_hex_dump(KERN_ERR, "master key: ", DUMP_PREFIX_NONE, 32, 1,
+ master_key, master_keylen, 0);
+}
+
+static inline void dump_decrypted_data(struct encrypted_key_payload *epayload)
+{
+ print_hex_dump(KERN_ERR, "decrypted data: ", DUMP_PREFIX_NONE, 32, 1,
+ epayload->decrypted_data,
+ epayload->decrypted_datalen, 0);
+}
+
+static inline void dump_encrypted_data(struct encrypted_key_payload *epayload,
+ unsigned int encrypted_datalen)
+{
+ print_hex_dump(KERN_ERR, "encrypted data: ", DUMP_PREFIX_NONE, 32, 1,
+ epayload->encrypted_data, encrypted_datalen, 0);
+}
+
+static inline void dump_hmac(const char *str, const u8 *digest,
+ unsigned int hmac_size)
+{
+ if (str)
+ pr_info("encrypted_key: %s", str);
+ print_hex_dump(KERN_ERR, "hmac: ", DUMP_PREFIX_NONE, 32, 1, digest,
+ hmac_size, 0);
+}
+#else
+static inline void dump_master_key(const u8 *master_key, size_t master_keylen)
+{
+}
+
+static inline void dump_decrypted_data(struct encrypted_key_payload *epayload)
+{
+}
+
+static inline void dump_encrypted_data(struct encrypted_key_payload *epayload,
+ unsigned int encrypted_datalen)
+{
+}
+
+static inline void dump_hmac(const char *str, const u8 *digest,
+ unsigned int hmac_size)
+{
+}
+#endif
+#endif
+++ /dev/null
-/*
- * Copyright (C) 2010 IBM Corporation
- *
- * Author:
- * Mimi Zohar <zohar@us.ibm.com>
- *
- * 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/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 <crypto/hash.h>
-#include <crypto/sha.h>
-#include <crypto/aes.h>
-
-#include "encrypted_defined.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 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 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
-};
-
-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_master_desc - verify the 'key-type:desc' of a new/updated master-key
- *
- * key-type:= "trusted:" | "encrypted:"
- * 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 <master-key name> <decrypted data length>
- * load <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, char **master_desc,
- char **decrypted_datalen, char **hex_encoded_iv)
-{
- substring_t args[MAX_OPT_ARGS];
- int ret = -EINVAL;
- int key_cmd;
- char *p;
-
- p = strsep(&datablob, " \t");
- if (!p)
- return ret;
- key_cmd = match_token(p, key_tokens, args);
-
- *master_desc = strsep(&datablob, " \t");
- if (!*master_desc)
- goto out;
-
- if (valid_master_desc(*master_desc, NULL) < 0)
- goto out;
-
- if (decrypted_datalen) {
- *decrypted_datalen = strsep(&datablob, " \t");
- if (!*decrypted_datalen)
- goto out;
- }
-
- switch (key_cmd) {
- case Opt_new:
- if (!decrypted_datalen)
- break;
- ret = 0;
- break;
- case Opt_load:
- if (!decrypted_datalen)
- break;
- *hex_encoded_iv = strsep(&datablob, " \t");
- if (!*hex_encoded_iv)
- break;
- ret = 0;
- break;
- case Opt_update:
- if (decrypted_datalen)
- break;
- ret = 0;
- break;
- case Opt_err:
- 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 ", 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);
- if (mkey)
- 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->master_desc + epayload->datablob_len;
- ret = calc_hmac(digest, derived_key, sizeof derived_key,
- epayload->master_desc, 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 *master_key, size_t master_keylen)
-{
- u8 derived_key[HASH_SIZE];
- u8 digest[HASH_SIZE];
- int ret;
-
- ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen);
- if (ret < 0)
- goto out;
-
- ret = calc_hmac(digest, derived_key, sizeof derived_key,
- epayload->master_desc, epayload->datablob_len);
- if (ret < 0)
- goto out;
- ret = memcmp(digest, epayload->master_desc + epayload->datablob_len,
- sizeof digest);
- if (ret) {
- ret = -EINVAL;
- dump_hmac("datablob",
- epayload->master_desc + 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 *master_desc,
- const char *datalen)
-{
- struct encrypted_key_payload *epayload = NULL;
- unsigned short datablob_len;
- unsigned short decrypted_datalen;
- unsigned int encrypted_datalen;
- 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);
-
- decrypted_datalen = dlen;
- encrypted_datalen = roundup(decrypted_datalen, blksize);
-
- datablob_len = strlen(master_desc) + 1 + strlen(datalen) + 1
- + ivsize + 1 + encrypted_datalen;
-
- ret = key_payload_reserve(key, decrypted_datalen + datablob_len
- + HASH_SIZE + 1);
- if (ret < 0)
- return ERR_PTR(ret);
-
- epayload = kzalloc(sizeof(*epayload) + decrypted_datalen +
- datablob_len + HASH_SIZE + 1, GFP_KERNEL);
- if (!epayload)
- return ERR_PTR(-ENOMEM);
-
- epayload->decrypted_datalen = decrypted_datalen;
- epayload->datablob_len = datablob_len;
- return epayload;
-}
-
-static int encrypted_key_decrypt(struct encrypted_key_payload *epayload,
- 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->master_desc + 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, 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 *master_desc, const char *datalen)
-{
- epayload->master_desc = epayload->decrypted_data
- + epayload->decrypted_datalen;
- epayload->datalen = epayload->master_desc + strlen(master_desc) + 1;
- epayload->iv = epayload->datalen + strlen(datalen) + 1;
- epayload->encrypted_data = epayload->iv + ivsize + 1;
-
- 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 *master_desc, const char *datalen,
- const char *hex_encoded_iv)
-{
- int ret = 0;
-
- __ekey_init(epayload, 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, 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;
- 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, &master_desc, &decrypted_datalen,
- &hex_encoded_iv);
- if (ret < 0)
- goto out;
-
- epayload = encrypted_key_alloc(key, master_desc, decrypted_datalen);
- if (IS_ERR(epayload)) {
- ret = PTR_ERR(epayload);
- goto out;
- }
- ret = encrypted_init(epayload, 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;
- 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, &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, new_master_desc,
- epayload->datalen);
- if (IS_ERR(new_epayload)) {
- ret = PTR_ERR(new_epayload);
- goto out;
- }
-
- __ekey_init(new_epayload, new_master_desc, epayload->datalen);
-
- memcpy(new_epayload->iv, epayload->iv, ivsize);
- memcpy(new_epayload->decrypted_data, epayload->decrypted_data,
- epayload->decrypted_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_protected(key->payload.data,
- rwsem_is_locked(&((struct key *)key)->sem));
-
- /* 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");
+++ /dev/null
-#ifndef __ENCRYPTED_KEY_H
-#define __ENCRYPTED_KEY_H
-
-#define ENCRYPTED_DEBUG 0
-
-#if ENCRYPTED_DEBUG
-static inline void dump_master_key(const u8 *master_key, size_t master_keylen)
-{
- print_hex_dump(KERN_ERR, "master key: ", DUMP_PREFIX_NONE, 32, 1,
- master_key, master_keylen, 0);
-}
-
-static inline void dump_decrypted_data(struct encrypted_key_payload *epayload)
-{
- print_hex_dump(KERN_ERR, "decrypted data: ", DUMP_PREFIX_NONE, 32, 1,
- epayload->decrypted_data,
- epayload->decrypted_datalen, 0);
-}
-
-static inline void dump_encrypted_data(struct encrypted_key_payload *epayload,
- unsigned int encrypted_datalen)
-{
- print_hex_dump(KERN_ERR, "encrypted data: ", DUMP_PREFIX_NONE, 32, 1,
- epayload->encrypted_data, encrypted_datalen, 0);
-}
-
-static inline void dump_hmac(const char *str, const u8 *digest,
- unsigned int hmac_size)
-{
- if (str)
- pr_info("encrypted_key: %s", str);
- print_hex_dump(KERN_ERR, "hmac: ", DUMP_PREFIX_NONE, 32, 1, digest,
- hmac_size, 0);
-}
-#else
-static inline void dump_master_key(const u8 *master_key, size_t master_keylen)
-{
-}
-
-static inline void dump_decrypted_data(struct encrypted_key_payload *epayload)
-{
-}
-
-static inline void dump_encrypted_data(struct encrypted_key_payload *epayload,
- unsigned int encrypted_datalen)
-{
-}
-
-static inline void dump_hmac(const char *str, const u8 *digest,
- unsigned int hmac_size)
-{
-}
-#endif
-#endif
projects / mirror_ubuntu-eoan-kernel.git / commitdiff