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Message-ID: <2c54d52208b1f5b3c628e6a52f5fbd0af3fff6f3.camel@linux.ibm.com>
Subject: Re: [PATCH v7 2/5] ima: define a new template field named 'd-ngv2'
 and templates
From:   Mimi Zohar <zohar@linux.ibm.com>
To:     "Guozihua (Scott)" <guozihua@huawei.com>,
        linux-integrity@vger.kernel.org
Cc:     Eric Biggers <ebiggers@kernel.org>,
        Stefan Berger <stefanb@linux.ibm.com>,
        linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Mon, 28 Mar 2022 09:50:37 -0400
In-Reply-To: <889cca45-4697-6edb-41f5-83cf6340bf32@huawei.com>
References: <20220325223824.310119-1-zohar@linux.ibm.com>
         <20220325223824.310119-3-zohar@linux.ibm.com>
         <889cca45-4697-6edb-41f5-83cf6340bf32@huawei.com>
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On Mon, 2022-03-28 at 14:14 +0800, Guozihua (Scott) wrote:
> > @@ -265,26 +285,39 @@ int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp,
> >   }
> >   
> >   static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize,
> > -                                    u8 hash_algo,
> > +                                    u8 digest_type, u8 hash_algo,
> >                                      struct ima_field_data *field_data)
> >   {
> >       /*
> >        * digest formats:
> >        *  - DATA_FMT_DIGEST: digest
> >        *  - DATA_FMT_DIGEST_WITH_ALGO: [<hash algo>] + ':' + '\0' + digest,
> > +      *  - DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO:
> > +      *      [<digest type> + ':' + <hash algo>] + ':' + '\0' + digest,
> > +      *    where <hash type> is either "ima" or "verity",
> >        *    where <hash algo> is provided if the hash algorithm is not
> >        *    SHA1 or MD5
> >        */
> > -     u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 };
> > +     u8 buffer[DIGEST_TYPE_NAME_LEN_MAX + CRYPTO_MAX_ALG_NAME + 2 +
> > +             IMA_MAX_DIGEST_SIZE] = { 0 };
> 
> Hi Mimi,
> 
> Shouldn't this contains an additional ":", Thus should +1 again?

The length of the CRYPTO_MAX_ALG_NAME includes room for the terminating
NULL.  In this case, the terminating NULL isn't needed.  It's replaced
with the ':'.

thanks,

Mimi

> 
> >       enum data_formats fmt = DATA_FMT_DIGEST;
> >       u32 offset = 0;
> >