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| author | Roberto Sassu <roberto.sassu@huawei.com> | 2020-03-25 13:54:24 +0300 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.ibm.com> | 2020-04-20 05:03:39 +0300 |
| commit | 2592677c0486e64a08e0b930a7dfa6fbf77e6fc1 (patch) | |
| tree | c4cd48197855b2fea5f3c1e0ee86edf6a759d84c /security/integrity/ima/ima_crypto.c | |
| parent | 1ea973df6e2166d1a576cabe5d08925d3261ff9d (diff) | |
| download | linux-2592677c0486e64a08e0b930a7dfa6fbf77e6fc1.tar.xz | |
ima: Use ima_hash_algo for collision detection in the measurement list
Before calculating a digest for each PCR bank, collisions were detected
with a SHA1 digest. This patch includes ima_hash_algo among the algorithms
used to calculate the template digest and checks collisions on that digest.
The position in the measurement entry array of the template digest
calculated with the IMA default hash algorithm is stored in the
ima_hash_algo_idx global variable and is determined at IMA initialization
time.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Diffstat (limited to 'security/integrity/ima/ima_crypto.c')
| -rw-r--r-- | security/integrity/ima/ima_crypto.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index a94972d3f929..5201f5ec2ce4 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -63,6 +63,7 @@ struct ima_algo_desc { }; int ima_sha1_idx __ro_after_init; +int ima_hash_algo_idx __ro_after_init; /* * Additional number of slots reserved, as needed, for SHA1 * and IMA default algo. @@ -122,15 +123,25 @@ int __init ima_init_crypto(void) return rc; ima_sha1_idx = -1; + ima_hash_algo_idx = -1; for (i = 0; i < NR_BANKS(ima_tpm_chip); i++) { algo = ima_tpm_chip->allocated_banks[i].crypto_id; if (algo == HASH_ALGO_SHA1) ima_sha1_idx = i; + + if (algo == ima_hash_algo) + ima_hash_algo_idx = i; } - if (ima_sha1_idx < 0) + if (ima_sha1_idx < 0) { ima_sha1_idx = NR_BANKS(ima_tpm_chip) + ima_extra_slots++; + if (ima_hash_algo == HASH_ALGO_SHA1) + ima_hash_algo_idx = ima_sha1_idx; + } + + if (ima_hash_algo_idx < 0) + ima_hash_algo_idx = NR_BANKS(ima_tpm_chip) + ima_extra_slots++; ima_algo_array = kcalloc(NR_BANKS(ima_tpm_chip) + ima_extra_slots, sizeof(*ima_algo_array), GFP_KERNEL); @@ -179,6 +190,12 @@ int __init ima_init_crypto(void) ima_algo_array[ima_sha1_idx].algo = HASH_ALGO_SHA1; } + if (ima_hash_algo_idx >= NR_BANKS(ima_tpm_chip) && + ima_hash_algo_idx != ima_sha1_idx) { + ima_algo_array[ima_hash_algo_idx].tfm = ima_shash_tfm; + ima_algo_array[ima_hash_algo_idx].algo = ima_hash_algo; + } + return 0; out_array: for (i = 0; i < NR_BANKS(ima_tpm_chip) + ima_extra_slots; i++) { |