diff options
Diffstat (limited to 'security/keys/encrypted.c')
| -rw-r--r-- | security/keys/encrypted.c | 75 |
1 files changed, 68 insertions, 7 deletions
diff --git a/security/keys/encrypted.c b/security/keys/encrypted.c index 89981c987ba7..e7eca9ec4c65 100644 --- a/security/keys/encrypted.c +++ b/security/keys/encrypted.c @@ -29,11 +29,13 @@ #include <linux/rcupdate.h> #include <linux/scatterlist.h> #include <linux/crypto.h> +#include <linux/ctype.h> #include <crypto/hash.h> #include <crypto/sha.h> #include <crypto/aes.h> #include "encrypted.h" +#include "ecryptfs_format.h" static const char KEY_TRUSTED_PREFIX[] = "trusted:"; static const char KEY_USER_PREFIX[] = "user:"; @@ -41,11 +43,13 @@ static const char hash_alg[] = "sha256"; static const char hmac_alg[] = "hmac(sha256)"; static const char blkcipher_alg[] = "cbc(aes)"; static const char key_format_default[] = "default"; +static const char key_format_ecryptfs[] = "ecryptfs"; static unsigned int ivsize; static int blksize; #define KEY_TRUSTED_PREFIX_LEN (sizeof (KEY_TRUSTED_PREFIX) - 1) #define KEY_USER_PREFIX_LEN (sizeof (KEY_USER_PREFIX) - 1) +#define KEY_ECRYPTFS_DESC_LEN 16 #define HASH_SIZE SHA256_DIGEST_SIZE #define MAX_DATA_SIZE 4096 #define MIN_DATA_SIZE 20 @@ -63,11 +67,12 @@ enum { }; enum { - Opt_error = -1, Opt_default + Opt_error = -1, Opt_default, Opt_ecryptfs }; static const match_table_t key_format_tokens = { {Opt_default, "default"}, + {Opt_ecryptfs, "ecryptfs"}, {Opt_error, NULL} }; @@ -95,6 +100,34 @@ static int aes_get_sizes(void) } /* + * valid_ecryptfs_desc - verify the description of a new/loaded encrypted key + * + * The description of a encrypted key with format 'ecryptfs' must contain + * exactly 16 hexadecimal characters. + * + */ +static int valid_ecryptfs_desc(const char *ecryptfs_desc) +{ + int i; + + if (strlen(ecryptfs_desc) != KEY_ECRYPTFS_DESC_LEN) { + pr_err("encrypted_key: key description must be %d hexadecimal " + "characters long\n", KEY_ECRYPTFS_DESC_LEN); + return -EINVAL; + } + + for (i = 0; i < KEY_ECRYPTFS_DESC_LEN; i++) { + if (!isxdigit(ecryptfs_desc[i])) { + pr_err("encrypted_key: key description must contain " + "only hexadecimal characters\n"); + return -EINVAL; + } + } + + return 0; +} + +/* * valid_master_desc - verify the 'key-type:desc' of a new/updated master-key * * key-type:= "trusted:" | "user:" @@ -158,7 +191,7 @@ static int datablob_parse(char *datablob, const char **format, } key_cmd = match_token(keyword, key_tokens, args); - /* Get optional format: default */ + /* Get optional format: default | ecryptfs */ p = strsep(&datablob, " \t"); if (!p) { pr_err("encrypted_key: insufficient parameters specified\n"); @@ -167,6 +200,7 @@ static int datablob_parse(char *datablob, const char **format, key_format = match_token(p, key_format_tokens, args); switch (key_format) { + case Opt_ecryptfs: case Opt_default: *format = p; *master_desc = strsep(&datablob, " \t"); @@ -601,6 +635,17 @@ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key, format_len = (!format) ? strlen(key_format_default) : strlen(format); decrypted_datalen = dlen; payload_datalen = decrypted_datalen; + if (format && !strcmp(format, key_format_ecryptfs)) { + if (dlen != ECRYPTFS_MAX_KEY_BYTES) { + pr_err("encrypted_key: keylen for the ecryptfs format " + "must be equal to %d bytes\n", + ECRYPTFS_MAX_KEY_BYTES); + return ERR_PTR(-EINVAL); + } + decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES; + payload_datalen = sizeof(struct ecryptfs_auth_tok); + } + encrypted_datalen = roundup(decrypted_datalen, blksize); datablob_len = format_len + 1 + strlen(master_desc) + 1 @@ -686,8 +731,14 @@ static void __ekey_init(struct encrypted_key_payload *epayload, if (!format) memcpy(epayload->format, key_format_default, format_len); - else + else { + if (!strcmp(format, key_format_ecryptfs)) + epayload->decrypted_data = + ecryptfs_get_auth_tok_key((struct ecryptfs_auth_tok *)epayload->payload_data); + memcpy(epayload->format, format, format_len); + } + memcpy(epayload->master_desc, master_desc, strlen(master_desc)); memcpy(epayload->datalen, datalen, strlen(datalen)); } @@ -699,11 +750,21 @@ 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 *format, const char *master_desc, - const char *datalen, const char *hex_encoded_iv) + const char *key_desc, const char *format, + const char *master_desc, const char *datalen, + const char *hex_encoded_iv) { int ret = 0; + if (format && !strcmp(format, key_format_ecryptfs)) { + ret = valid_ecryptfs_desc(key_desc); + if (ret < 0) + return ret; + + ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data, + key_desc); + } + __ekey_init(epayload, format, master_desc, datalen); if (!hex_encoded_iv) { get_random_bytes(epayload->iv, ivsize); @@ -753,8 +814,8 @@ static int encrypted_instantiate(struct key *key, const void *data, ret = PTR_ERR(epayload); goto out; } - ret = encrypted_init(epayload, format, master_desc, decrypted_datalen, - hex_encoded_iv); + ret = encrypted_init(epayload, key->description, format, master_desc, + decrypted_datalen, hex_encoded_iv); if (ret < 0) { kfree(epayload); goto out; |