> -----Original Message----- > From: owner-linux-security-module@xxxxxxxxxxxxxxx [mailto:owner-linux- > security-module@xxxxxxxxxxxxxxx] On Behalf Of Mimi Zohar > Sent: Tuesday, March 3, 2020 5:04 AM > To: Roberto Sassu <roberto.sassu@xxxxxxxxxx>; > James.Bottomley@xxxxxxxxxxxxxxxxxxxxx; > jarkko.sakkinen@xxxxxxxxxxxxxxx > Cc: linux-integrity@xxxxxxxxxxxxxxx; linux-security-module@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; Silviu Vlasceanu > <Silviu.Vlasceanu@xxxxxxxxxx> > Subject: Re: [PATCH v3 7/8] ima: Calculate and extend PCR with digests in > ima_template_entry > > On Mon, 2020-02-10 at 11:04 +0100, Roberto Sassu wrote: > > > @@ -219,6 +214,8 @@ int ima_restore_measurement_entry(struct > ima_template_entry *entry) > > > > int __init ima_init_digests(void) > > { > > + u16 digest_size; > > + u16 crypto_id; > > int i; > > > > if (!ima_tpm_chip) > > @@ -229,8 +226,17 @@ int __init ima_init_digests(void) > > if (!digests) > > return -ENOMEM; > > > > - for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) > > + for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) { > > digests[i].alg_id = ima_tpm_chip->allocated_banks[i].alg_id; > > + digest_size = ima_tpm_chip->allocated_banks[i].digest_size; > > + crypto_id = ima_tpm_chip->allocated_banks[i].crypto_id; > > + > > + /* for unmapped TPM algorithms digest is still a padded > SHA1 */ > > + if (crypto_id == HASH_ALGO__LAST) > > + digest_size = SHA1_DIGEST_SIZE; > > + > > + memset(digests[i].digest, 0xff, digest_size); > > Shouldn't the memset here be of the actual digest size even for > unmapped TPM algorithms. This is consistent with ima_calc_field_array_hash(), so that a verifier will always pad the SHA1 digest with zeros to obtain the final PCR value. I can set all bytes if you prefer. Thanks Roberto HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063 Managing Director: Li Peng, Li Jian, Shi Yanli > > + } > > > > return 0; > > }
