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From: Roberto Sassu <roberto.sassu@huawei.com>
To: Mimi Zohar <zohar@linux.ibm.com>, <jarkko.sakkinen@linux.intel.com>
Cc: <linux-integrity@vger.kernel.org>,
	<linux-security-module@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <silviu.vlasceanu@huawei.com>
Subject: Re: [PATCH v3 4/5] tpm: retrieve digest size of unknown algorithms with PCR read
Date: Mon, 5 Nov 2018 10:47:19 +0100	[thread overview]
Message-ID: <3034c896-788b-50f9-23cb-f4b2cd6363e6@huawei.com> (raw)
In-Reply-To: <1541088173.4035.26.camel@linux.ibm.com>

On 11/1/2018 5:02 PM, Mimi Zohar wrote:
> On Tue, 2018-10-30 at 16:47 +0100, Roberto Sassu wrote:

[...]

>> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
>> index 633e16f42107..8662e8587dce 100644
>> --- a/drivers/char/tpm/tpm.h
>> +++ b/drivers/char/tpm/tpm.h
>> @@ -237,7 +237,7 @@ struct tpm_chip {
>>   	const struct attribute_group *groups[3];
>>   	unsigned int groups_cnt;
>>   
>> -	u16 active_banks[7];
>> +	struct tpm_bank_info active_banks[7];
> 
> Commit 1db15344f874 ("tpm: implement TPM 2.0 capability to get active
> PCR banks") defined active_banks[7].  Subsequently, commit
> 4d23cc323cdb ("tpm: add securityfs support for TPM 2.0 firmware event
> log") defined TPM2_PCR_ACTIVE_BANKS as 3.  I'm not sure which is the
> correct value, but the number of active_banks should not be hard coded
> here.

Jarkko, should I change the value of TPM2_PCR_ACTIVE_BANKS, or set the
size of the active_banks array to TPM2_PCR_ACTIVE_BANKS?


>>   #ifdef CONFIG_ACPI
>>   	acpi_handle acpi_dev_handle;
>>   	char ppi_version[TPM_PPI_VERSION_LEN + 1];
>> @@ -565,7 +565,7 @@ static inline u32 tpm2_rc_value(u32 rc)
>>   }
>>   
>>   int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx,
>> -		  struct tpm_digest *digest_struct);
>> +		  struct tpm_digest *digest_struct, u16 *digest_size_ptr);
>>   int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
>>   		    struct tpm_digest *digests);
>>   int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max);
>> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
>> index 8babd826ad27..8e821e7b4674 100644
>> --- a/drivers/char/tpm/tpm2-cmd.c
>> +++ b/drivers/char/tpm/tpm2-cmd.c
>> @@ -180,11 +180,12 @@ struct tpm2_pcr_read_out {
>>    * @chip:	TPM chip to use.
>>    * @pcr_idx:	index of the PCR to read.
>>    * @digest_struct:	pcr bank and buffer current PCR value is written to.
>> + * @digest_size_ptr:	pointer to variable that stores the digest size.
>>    *
>>    * Return: Same as with tpm_transmit_cmd.
>>    */
>>   int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx,
>> -		  struct tpm_digest *digest_struct)
>> +		  struct tpm_digest *digest_struct, u16 *digest_size_ptr)
>>   {
>>   	int rc;
>>   	struct tpm_buf buf;
>> @@ -219,6 +220,9 @@ int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx,
>>   		goto out;
>>   	}
>>   
>> +	if (digest_size_ptr)
>> +		*digest_size_ptr = digest_size;
>> +
>>   	memcpy(digest_struct->digest, out->digest, digest_size);
>>   out:
>>   	tpm_buf_destroy(&buf);
>> @@ -249,7 +253,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
>>   	struct tpm2_null_auth_area auth_area;
>>   	int rc;
>>   	int i;
>> -	int j;
>>   
>>   	if (count > ARRAY_SIZE(chip->active_banks))
>>   		return -EINVAL;
>> @@ -271,14 +274,9 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
>>   	tpm_buf_append_u32(&buf, count);
>>   
>>   	for (i = 0; i < count; i++) {
>> -		for (j = 0; j < ARRAY_SIZE(tpm2_hash_map); j++) {
>> -			if (digests[i].alg_id != tpm2_hash_map[j].tpm_id)
>> -				continue;
>> -			tpm_buf_append_u16(&buf, digests[i].alg_id);
>> -			tpm_buf_append(&buf, (const unsigned char
>> -					      *)&digests[i].digest,
>> -			       hash_digest_size[tpm2_hash_map[j].crypto_id]);
>> -		}
>> +		tpm_buf_append_u16(&buf, digests[i].alg_id);
>> +		tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
>> +			       chip->active_banks[i].digest_size);
>>   	}
>>   
> 
> These tpm2_pcr_extend changes don't belong here in this patch.  Please
> move them to 1/5.

Also in this case, alg_id and digest_size are defined in patch 4/5.


>>   	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
>> @@ -855,6 +853,26 @@ int tpm2_probe(struct tpm_chip *chip)
>>   }
>>   EXPORT_SYMBOL_GPL(tpm2_probe);
>>   
>> +static int tpm2_init_bank_info(struct tpm_chip *chip,
>> +			       struct tpm_bank_info *bank)
>> +{
>> +	struct tpm_digest digest = {.alg_id = bank->alg_id};
>> +	int i;
>> +
>> +	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);
>> +}
>> +
>>   struct tpm2_pcr_selection {
>>   	__be16  hash_alg;
>>   	u8  size_of_select;
>> @@ -909,7 +927,12 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
>>   		}
>>   
>>   		memcpy(&pcr_selection, marker, sizeof(pcr_selection));
>> -		chip->active_banks[i] = be16_to_cpu(pcr_selection.hash_alg);
>> +		chip->active_banks[i].alg_id =
>> +			be16_to_cpu(pcr_selection.hash_alg);
>> +		rc =  tpm2_init_bank_info(chip, &chip->active_banks[i]);
> 
> Please fix the formatting in the above 2 lines.
> 
> There's been discussion in the past on removing scripts/Lindent from
> the coding-style documentation, but that hasn't happened quite yet. I
> do think section 3 "New drivers" in Documentation/hwmon/submitting-
> patches has a good balance.
> 
> * Running your patch or driver file(s) through checkpatch does not mean its
>    formatting is clean. If unsure about formatting in your new driver, run it
>    through Lindent. Lindent is not perfect, and you may have to do some minor
>    cleanup, but it is a good start.

Ok.

Thanks

Roberto


> thanks!
> 
> Mimi
> 
>> +		if (rc)
>> +			break;
>> +
>>   		sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
>>   			sizeof(pcr_selection.size_of_select) +
>>   			pcr_selection.size_of_select;
>> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
>> index 4f00daf44dd2..3f91124837cf 100644
>> --- a/include/linux/tpm.h
>> +++ b/include/linux/tpm.h
>> @@ -46,6 +46,12 @@ struct tpm_digest {
>>   	u8 digest[SHA512_DIGEST_SIZE];
>>   } __packed;
>>   
>> +struct tpm_bank_info {
>> +	u16 alg_id;
>> +	u16 digest_size;
>> +	u16 crypto_id;
>> +};
>> +
>>   enum TPM_OPS_FLAGS {
>>   	TPM_OPS_AUTO_STARTUP = BIT(0),
>>   };
> 

-- 
HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063
Managing Director: Bo PENG, Jian LI, Yanli SHI

  parent reply	other threads:[~2018-11-05  9:47 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-30 15:47 [PATCH v3 0/5] tpm: retrieve digest size of unknown algorithms from TPM Roberto Sassu
2018-10-30 15:47 ` [PATCH v3 1/5] tpm: change the end marker of the active_banks array to zero Roberto Sassu
2018-10-30 19:45   ` Jarkko Sakkinen
2018-10-31 14:43   ` Mimi Zohar
2018-11-01 14:42     ` Mimi Zohar
2018-11-05  8:10       ` Roberto Sassu
2018-11-05 13:02         ` Mimi Zohar
2018-11-05  8:07     ` Roberto Sassu
2018-10-30 15:47 ` [PATCH v3 2/5] tpm: rename and export tpm2_digest and tpm2_algorithms Roberto Sassu
2018-10-30 15:47 ` [PATCH v3 3/5] tpm: modify tpm_pcr_read() definition to pass a TPM hash algorithm Roberto Sassu
2018-10-30 15:47 ` [PATCH v3 4/5] tpm: retrieve digest size of unknown algorithms with PCR read Roberto Sassu
2018-11-01 16:02   ` Mimi Zohar
2018-11-01 16:23     ` Mimi Zohar
2018-11-05  9:47     ` Roberto Sassu [this message]
2018-11-05 12:01       ` Jarkko Sakkinen
2018-11-05 13:09         ` Roberto Sassu
2018-11-05 14:48           ` Mimi Zohar
2018-11-05 17:13           ` Jarkko Sakkinen
2018-11-05 17:10         ` Jarkko Sakkinen
2018-10-30 15:47 ` [PATCH v3 5/5] tpm: ensure that output of PCR read contains the correct digest size Roberto Sassu
2018-10-30 19:52   ` Jarkko Sakkinen
2018-10-31  8:16     ` Roberto Sassu
2018-11-01 14:32       ` Jarkko Sakkinen
2018-11-01 16:52   ` Mimi Zohar

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