Messages in this thread | | | Subject | Re: [PATCH v6 5/7] tpm: retrieve digest size of unknown algorithms with PCR read | From | Roberto Sassu <> | Date | Thu, 6 Dec 2018 19:00:13 +0100 |
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On 12/5/2018 12:53 AM, Jarkko Sakkinen wrote: > On Tue, Dec 04, 2018 at 09:21:36AM +0100, Roberto Sassu wrote: >> + for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) { >> + enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id; >> + >> + if (bank->alg_id != tpm2_hash_map[i].tpm_id) >> + continue; >> + >> + bank->digest_size = hash_digest_size[crypto_algo]; >> + bank->crypto_id = crypto_algo; >> + return 0; >> + } >> + >> + return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size); >> +} > > This is a part that I don't get. Coud you just always call > tpm2_pcr_read() instead of this complexity
First, we avoid operations that may increase the boot time. Second, the loop is necessary to obtain the crypto subsystem identifier from a TPM algorithm identifier.
Roberto
> /Jarkko >
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