From b9703449347603289cac0bd04e574ac2e777275d Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 18 Jan 2011 09:07:12 -0500 Subject: [PATCH] encrypted-keys: rename encrypted_defined files to encrypted Rename encrypted_defined.c and encrypted_defined.h files to encrypted.c and encrypted.h, respectively. Based on request from David Howells. Signed-off-by: Mimi Zohar Acked-by: David Howells Signed-off-by: James Morris --- security/keys/Makefile | 2 +- security/keys/encrypted.c | 903 +++++++++++++++++++++++++++++++++++++ security/keys/encrypted.h | 54 +++ security/keys/encrypted_defined.c | 902 ------------------------------------ security/keys/encrypted_defined.h | 54 --- 5 files changed, 958 insertions(+), 957 deletions(-) create mode 100644 security/keys/encrypted.c create mode 100644 security/keys/encrypted.h delete mode 100644 security/keys/encrypted_defined.c delete mode 100644 security/keys/encrypted_defined.h diff --git a/security/keys/Makefile b/security/keys/Makefile index ad8da87..1bf090a 100644 --- a/security/keys/Makefile +++ b/security/keys/Makefile @@ -14,7 +14,7 @@ obj-y := \ 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 diff --git a/security/keys/encrypted.c b/security/keys/encrypted.c new file mode 100644 index 0000000..9e7e4ce --- /dev/null +++ b/security/keys/encrypted.c @@ -0,0 +1,903 @@ +/* + * Copyright (C) 2010 IBM Corporation + * + * Author: + * Mimi Zohar + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 + * load + * update + * + * 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: + * + * + * 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"); diff --git a/security/keys/encrypted.h b/security/keys/encrypted.h new file mode 100644 index 0000000..cef5e2f --- /dev/null +++ b/security/keys/encrypted.h @@ -0,0 +1,54 @@ +#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 diff --git a/security/keys/encrypted_defined.c b/security/keys/encrypted_defined.c deleted file mode 100644 index 28791a6..0000000 --- a/security/keys/encrypted_defined.c +++ /dev/null @@ -1,902 +0,0 @@ -/* - * Copyright (C) 2010 IBM Corporation - * - * Author: - * Mimi Zohar - * - * 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 -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#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 - * load - * update - * - * 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: - * - * - * 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"); diff --git a/security/keys/encrypted_defined.h b/security/keys/encrypted_defined.h deleted file mode 100644 index cef5e2f..0000000 --- a/security/keys/encrypted_defined.h +++ /dev/null @@ -1,54 +0,0 @@ -#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 -- 1.7.10.4