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-rw-r--r--security/keys/encrypted.c141
1 files changed, 101 insertions, 40 deletions
diff --git a/security/keys/encrypted.c b/security/keys/encrypted.c
index f36a105de791..89981c987ba7 100644
--- a/security/keys/encrypted.c
+++ b/security/keys/encrypted.c
@@ -1,8 +1,11 @@
/*
* Copyright (C) 2010 IBM Corporation
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ * TORSEC group -- http://security.polito.it
*
- * Author:
+ * Authors:
* Mimi Zohar <zohar@us.ibm.com>
+ * Roberto Sassu <roberto.sassu@polito.it>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -37,6 +40,7 @@ static const char KEY_USER_PREFIX[] = "user:";
static const char hash_alg[] = "sha256";
static const char hmac_alg[] = "hmac(sha256)";
static const char blkcipher_alg[] = "cbc(aes)";
+static const char key_format_default[] = "default";
static unsigned int ivsize;
static int blksize;
@@ -58,6 +62,15 @@ enum {
Opt_err = -1, Opt_new, Opt_load, Opt_update
};
+enum {
+ Opt_error = -1, Opt_default
+};
+
+static const match_table_t key_format_tokens = {
+ {Opt_default, "default"},
+ {Opt_error, NULL}
+};
+
static const match_table_t key_tokens = {
{Opt_new, "new"},
{Opt_load, "load"},
@@ -118,8 +131,9 @@ out:
* 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>
+ * new [<format>] <master-key name> <decrypted data length>
+ * load [<format>] <master-key name> <decrypted data length>
+ * <encrypted iv + data>
* update <new-master-key name>
*
* Tokenizes a copy of the keyctl data, returning a pointer to each token,
@@ -127,13 +141,15 @@ out:
*
* On success returns 0, otherwise -EINVAL.
*/
-static int datablob_parse(char *datablob, char **master_desc,
- char **decrypted_datalen, char **hex_encoded_iv)
+static int datablob_parse(char *datablob, const char **format,
+ char **master_desc, char **decrypted_datalen,
+ char **hex_encoded_iv)
{
substring_t args[MAX_OPT_ARGS];
int ret = -EINVAL;
int key_cmd;
- char *keyword;
+ int key_format;
+ char *p, *keyword;
keyword = strsep(&datablob, " \t");
if (!keyword) {
@@ -142,7 +158,24 @@ static int datablob_parse(char *datablob, char **master_desc,
}
key_cmd = match_token(keyword, key_tokens, args);
- *master_desc = strsep(&datablob, " \t");
+ /* Get optional format: default */
+ p = strsep(&datablob, " \t");
+ if (!p) {
+ pr_err("encrypted_key: insufficient parameters specified\n");
+ return ret;
+ }
+
+ key_format = match_token(p, key_format_tokens, args);
+ switch (key_format) {
+ case Opt_default:
+ *format = p;
+ *master_desc = strsep(&datablob, " \t");
+ break;
+ case Opt_error:
+ *master_desc = p;
+ break;
+ }
+
if (!*master_desc) {
pr_info("encrypted_key: master key parameter is missing\n");
goto out;
@@ -220,8 +253,8 @@ static char *datablob_format(struct encrypted_key_payload *epayload,
ascii_buf[asciiblob_len] = '\0';
/* copy datablob master_desc and datalen strings */
- len = sprintf(ascii_buf, "%s %s ", epayload->master_desc,
- epayload->datalen);
+ len = sprintf(ascii_buf, "%s %s %s ", epayload->format,
+ epayload->master_desc, epayload->datalen);
/* convert the hex encoded iv, encrypted-data and HMAC to ascii */
bufp = &ascii_buf[len];
@@ -464,9 +497,9 @@ static int datablob_hmac_append(struct encrypted_key_payload *epayload,
if (ret < 0)
goto out;
- digest = epayload->master_desc + epayload->datablob_len;
+ digest = epayload->format + epayload->datablob_len;
ret = calc_hmac(digest, derived_key, sizeof derived_key,
- epayload->master_desc, epayload->datablob_len);
+ epayload->format, epayload->datablob_len);
if (!ret)
dump_hmac(NULL, digest, HASH_SIZE);
out:
@@ -475,26 +508,35 @@ out:
/* verify HMAC before decrypting encrypted key */
static int datablob_hmac_verify(struct encrypted_key_payload *epayload,
- const u8 *master_key, size_t master_keylen)
+ const u8 *format, const u8 *master_key,
+ size_t master_keylen)
{
u8 derived_key[HASH_SIZE];
u8 digest[HASH_SIZE];
int ret;
+ char *p;
+ unsigned short len;
ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen);
if (ret < 0)
goto out;
- ret = calc_hmac(digest, derived_key, sizeof derived_key,
- epayload->master_desc, epayload->datablob_len);
+ len = epayload->datablob_len;
+ if (!format) {
+ p = epayload->master_desc;
+ len -= strlen(epayload->format) + 1;
+ } else
+ p = epayload->format;
+
+ ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len);
if (ret < 0)
goto out;
- ret = memcmp(digest, epayload->master_desc + epayload->datablob_len,
+ ret = memcmp(digest, epayload->format + epayload->datablob_len,
sizeof digest);
if (ret) {
ret = -EINVAL;
dump_hmac("datablob",
- epayload->master_desc + epayload->datablob_len,
+ epayload->format + epayload->datablob_len,
HASH_SIZE);
dump_hmac("calc", digest, HASH_SIZE);
}
@@ -539,13 +581,16 @@ out:
/* Allocate memory for decrypted key and datablob. */
static struct encrypted_key_payload *encrypted_key_alloc(struct key *key,
+ const char *format,
const char *master_desc,
const char *datalen)
{
struct encrypted_key_payload *epayload = NULL;
unsigned short datablob_len;
unsigned short decrypted_datalen;
+ unsigned short payload_datalen;
unsigned int encrypted_datalen;
+ unsigned int format_len;
long dlen;
int ret;
@@ -553,29 +598,32 @@ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key,
if (ret < 0 || dlen < MIN_DATA_SIZE || dlen > MAX_DATA_SIZE)
return ERR_PTR(-EINVAL);
+ format_len = (!format) ? strlen(key_format_default) : strlen(format);
decrypted_datalen = dlen;
+ payload_datalen = decrypted_datalen;
encrypted_datalen = roundup(decrypted_datalen, blksize);
- datablob_len = strlen(master_desc) + 1 + strlen(datalen) + 1
- + ivsize + 1 + encrypted_datalen;
+ datablob_len = format_len + 1 + strlen(master_desc) + 1
+ + strlen(datalen) + 1 + ivsize + 1 + encrypted_datalen;
- ret = key_payload_reserve(key, decrypted_datalen + datablob_len
+ ret = key_payload_reserve(key, payload_datalen + datablob_len
+ HASH_SIZE + 1);
if (ret < 0)
return ERR_PTR(ret);
- epayload = kzalloc(sizeof(*epayload) + decrypted_datalen +
+ epayload = kzalloc(sizeof(*epayload) + payload_datalen +
datablob_len + HASH_SIZE + 1, GFP_KERNEL);
if (!epayload)
return ERR_PTR(-ENOMEM);
+ epayload->payload_datalen = payload_datalen;
epayload->decrypted_datalen = decrypted_datalen;
epayload->datablob_len = datablob_len;
return epayload;
}
static int encrypted_key_decrypt(struct encrypted_key_payload *epayload,
- const char *hex_encoded_iv)
+ const char *format, const char *hex_encoded_iv)
{
struct key *mkey;
u8 derived_key[HASH_SIZE];
@@ -596,14 +644,14 @@ static int encrypted_key_decrypt(struct encrypted_key_payload *epayload,
hex2bin(epayload->iv, hex_encoded_iv, ivsize);
hex2bin(epayload->encrypted_data, hex_encoded_data, encrypted_datalen);
- hmac = epayload->master_desc + epayload->datablob_len;
+ hmac = epayload->format + epayload->datablob_len;
hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), HASH_SIZE);
mkey = request_master_key(epayload, &master_key, &master_keylen);
if (IS_ERR(mkey))
return PTR_ERR(mkey);
- ret = datablob_hmac_verify(epayload, master_key, master_keylen);
+ ret = datablob_hmac_verify(epayload, format, master_key, master_keylen);
if (ret < 0) {
pr_err("encrypted_key: bad hmac (%d)\n", ret);
goto out;
@@ -623,14 +671,23 @@ out:
}
static void __ekey_init(struct encrypted_key_payload *epayload,
- const char *master_desc, const char *datalen)
+ const char *format, const char *master_desc,
+ const char *datalen)
{
- epayload->master_desc = epayload->decrypted_data
- + epayload->decrypted_datalen;
+ unsigned int format_len;
+
+ format_len = (!format) ? strlen(key_format_default) : strlen(format);
+ epayload->format = epayload->payload_data + epayload->payload_datalen;
+ epayload->master_desc = epayload->format + format_len + 1;
epayload->datalen = epayload->master_desc + strlen(master_desc) + 1;
epayload->iv = epayload->datalen + strlen(datalen) + 1;
epayload->encrypted_data = epayload->iv + ivsize + 1;
+ epayload->decrypted_data = epayload->payload_data;
+ if (!format)
+ memcpy(epayload->format, key_format_default, format_len);
+ else
+ memcpy(epayload->format, format, format_len);
memcpy(epayload->master_desc, master_desc, strlen(master_desc));
memcpy(epayload->datalen, datalen, strlen(datalen));
}
@@ -642,19 +699,19 @@ static void __ekey_init(struct encrypted_key_payload *epayload,
* 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)
+ const char *format, const char *master_desc,
+ const char *datalen, const char *hex_encoded_iv)
{
int ret = 0;
- __ekey_init(epayload, master_desc, datalen);
+ __ekey_init(epayload, format, master_desc, datalen);
if (!hex_encoded_iv) {
get_random_bytes(epayload->iv, ivsize);
get_random_bytes(epayload->decrypted_data,
epayload->decrypted_datalen);
} else
- ret = encrypted_key_decrypt(epayload, hex_encoded_iv);
+ ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv);
return ret;
}
@@ -671,6 +728,7 @@ static int encrypted_instantiate(struct key *key, const void *data,
{
struct encrypted_key_payload *epayload = NULL;
char *datablob = NULL;
+ const char *format = NULL;
char *master_desc = NULL;
char *decrypted_datalen = NULL;
char *hex_encoded_iv = NULL;
@@ -684,17 +742,18 @@ static int encrypted_instantiate(struct key *key, const void *data,
return -ENOMEM;
datablob[datalen] = 0;
memcpy(datablob, data, datalen);
- ret = datablob_parse(datablob, &master_desc, &decrypted_datalen,
- &hex_encoded_iv);
+ ret = datablob_parse(datablob, &format, &master_desc,
+ &decrypted_datalen, &hex_encoded_iv);
if (ret < 0)
goto out;
- epayload = encrypted_key_alloc(key, master_desc, decrypted_datalen);
+ epayload = encrypted_key_alloc(key, format, master_desc,
+ decrypted_datalen);
if (IS_ERR(epayload)) {
ret = PTR_ERR(epayload);
goto out;
}
- ret = encrypted_init(epayload, master_desc, decrypted_datalen,
+ ret = encrypted_init(epayload, format, master_desc, decrypted_datalen,
hex_encoded_iv);
if (ret < 0) {
kfree(epayload);
@@ -731,6 +790,7 @@ static int encrypted_update(struct key *key, const void *data, size_t datalen)
struct encrypted_key_payload *new_epayload;
char *buf;
char *new_master_desc = NULL;
+ const char *format = NULL;
int ret = 0;
if (datalen <= 0 || datalen > 32767 || !data)
@@ -742,7 +802,7 @@ static int encrypted_update(struct key *key, const void *data, size_t datalen)
buf[datalen] = 0;
memcpy(buf, data, datalen);
- ret = datablob_parse(buf, &new_master_desc, NULL, NULL);
+ ret = datablob_parse(buf, &format, &new_master_desc, NULL, NULL);
if (ret < 0)
goto out;
@@ -750,18 +810,19 @@ static int encrypted_update(struct key *key, const void *data, size_t datalen)
if (ret < 0)
goto out;
- new_epayload = encrypted_key_alloc(key, new_master_desc,
- epayload->datalen);
+ new_epayload = encrypted_key_alloc(key, epayload->format,
+ new_master_desc, epayload->datalen);
if (IS_ERR(new_epayload)) {
ret = PTR_ERR(new_epayload);
goto out;
}
- __ekey_init(new_epayload, new_master_desc, epayload->datalen);
+ __ekey_init(new_epayload, epayload->format, new_master_desc,
+ epayload->datalen);
memcpy(new_epayload->iv, epayload->iv, ivsize);
- memcpy(new_epayload->decrypted_data, epayload->decrypted_data,
- epayload->decrypted_datalen);
+ memcpy(new_epayload->payload_data, epayload->payload_data,
+ epayload->payload_datalen);
rcu_assign_pointer(key->payload.data, new_epayload);
call_rcu(&epayload->rcu, encrypted_rcu_free);

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