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Subject: Re: [PATCH 2/2] SELinux: Measure state and hash of policy using IMA
To:     Stephen Smalley <stephen.smalley.work@gmail.com>,
        zohar@linux.ibm.com, casey@schaufler-ca.com
Cc:     tyhicks@linux.microsoft.com, tusharsu@linux.microsoft.com,
        sashal@kernel.org, jmorris@namei.org,
        linux-integrity@vger.kernel.org, selinux@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, paul Moore <paul@paul-moore.com>
References: <20200813170707.2659-1-nramas@linux.microsoft.com>
 <20200813170707.2659-3-nramas@linux.microsoft.com>
 <5f738fd8-fe28-5358-b3d8-b671b45caa7f@gmail.com>
From:   Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Message-ID: <7315b7e8-2c53-2555-bc2e-aae42e16aaa2@linux.microsoft.com>
Date:   Thu, 13 Aug 2020 10:52:02 -0700
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On 8/13/20 10:42 AM, Stephen Smalley wrote:

>> diff --git a/security/selinux/measure.c b/security/selinux/measure.c
>> new file mode 100644
>> index 000000000000..f21b7de4e2ae
>> --- /dev/null
>> +++ b/security/selinux/measure.c
>> @@ -0,0 +1,204 @@
>> +static int selinux_hash_buffer(void *buf, size_t buf_len,
>> +                   void **buf_hash, int *buf_hash_len)
>> +{
>> +    struct crypto_shash *tfm;
>> +    struct shash_desc *desc = NULL;
>> +    void *digest = NULL;
>> +    int desc_size;
>> +    int digest_size;
>> +    int ret = 0;
>> +
>> +    tfm = crypto_alloc_shash("sha256", 0, 0);
>> +    if (IS_ERR(tfm))
>> +        return PTR_ERR(tfm);
> Can we make the algorithm selectable via kernel parameter and/or writing 
> to a new selinuxfs node?

I can add a kernel parameter to select this hash algorithm.

  -lakshmi