From: Mimi Zohar <zohar@linux.ibm.com>
To: Nayna Jain <nayna@linux.ibm.com>,
linuxppc-dev@ozlabs.org, linux-efi@vger.kernel.org,
linux-integrity@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Jeremy Kerr <jk@ozlabs.org>,
Matthew Garret <matthew.garret@nebula.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Claudio Carvalho <cclaudio@linux.ibm.com>,
George Wilson <gcwilson@linux.ibm.com>,
Elaine Palmer <erpalmer@us.ibm.com>,
Eric Ricther <erichte@linux.ibm.com>,
"Oliver O'Halloran" <oohall@gmail.com>,
Prakhar Srivastava <prsriva02@gmail.com>,
Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Subject: Re: [PATCH v8 7/8] ima: check against blacklisted hashes for files with modsig
Date: Sun, 20 Oct 2019 12:06:42 -0400 [thread overview]
Message-ID: <1571587602.5104.8.camel@linux.ibm.com> (raw)
In-Reply-To: <1571508377-23603-8-git-send-email-nayna@linux.ibm.com>
On Sat, 2019-10-19 at 14:06 -0400, Nayna Jain wrote:
> Asymmetric private keys are used to sign multiple files. The kernel
> currently support checking against blacklisted keys. However, if the
> public key is blacklisted, any file signed by the blacklisted key will
> automatically fail signature verification. We might not want to blacklist
> all the files signed by a particular key, but just a single file.
> Blacklisting the public key is not fine enough granularity.
>
> This patch adds support for checking against the blacklisted hash of the
> file based on the IMA policy. The blacklisted hash is the file hash
> without the appended signature. Defined is a new policy option
> "appraise_flag=check_blacklist".
Please add an example of how to blacklist a file with an appended
signature. The simplest example that works on x86 as well as Power
would be blacklisting a kernel module. The example should include
calculating the kernel module hash without the appended signature,
enabling the Kconfig option (CONFIG_SYSTEM_BLACKLIST_HASH_LIST), and
the blacklist hash format (eg. "bin:<file hash>").
thanks,
Mimi
WARNING: multiple messages have this Message-ID (diff)
From: Mimi Zohar <zohar@linux.ibm.com>
To: Nayna Jain <nayna@linux.ibm.com>,
linuxppc-dev@ozlabs.org, linux-efi@vger.kernel.org,
linux-integrity@vger.kernel.org
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Eric Ricther <erichte@linux.ibm.com>,
Prakhar Srivastava <prsriva02@gmail.com>,
linux-kernel@vger.kernel.org,
Claudio Carvalho <cclaudio@linux.ibm.com>,
Matthew Garret <matthew.garret@nebula.com>,
Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Paul Mackerras <paulus@samba.org>, Jeremy Kerr <jk@ozlabs.org>,
Elaine Palmer <erpalmer@us.ibm.com>,
Oliver O'Halloran <oohall@gmail.com>,
George Wilson <gcwilson@linux.ibm.com>
Subject: Re: [PATCH v8 7/8] ima: check against blacklisted hashes for files with modsig
Date: Sun, 20 Oct 2019 12:06:42 -0400 [thread overview]
Message-ID: <1571587602.5104.8.camel@linux.ibm.com> (raw)
In-Reply-To: <1571508377-23603-8-git-send-email-nayna@linux.ibm.com>
On Sat, 2019-10-19 at 14:06 -0400, Nayna Jain wrote:
> Asymmetric private keys are used to sign multiple files. The kernel
> currently support checking against blacklisted keys. However, if the
> public key is blacklisted, any file signed by the blacklisted key will
> automatically fail signature verification. We might not want to blacklist
> all the files signed by a particular key, but just a single file.
> Blacklisting the public key is not fine enough granularity.
>
> This patch adds support for checking against the blacklisted hash of the
> file based on the IMA policy. The blacklisted hash is the file hash
> without the appended signature. Defined is a new policy option
> "appraise_flag=check_blacklist".
Please add an example of how to blacklist a file with an appended
signature. The simplest example that works on x86 as well as Power
would be blacklisting a kernel module. The example should include
calculating the kernel module hash without the appended signature,
enabling the Kconfig option (CONFIG_SYSTEM_BLACKLIST_HASH_LIST), and
the blacklist hash format (eg. "bin:<file hash>").
thanks,
Mimi
next prev parent reply other threads:[~2019-10-20 16:07 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-19 18:06 [PATCH v8 0/8] powerpc: Enabling IMA arch specific secure boot policies Nayna Jain
2019-10-19 18:06 ` Nayna Jain
2019-10-19 18:06 ` [PATCH v8 1/8] powerpc: detect the secure boot mode of the system Nayna Jain
2019-10-19 18:06 ` Nayna Jain
2019-10-22 23:37 ` Michael Ellerman
2019-10-22 23:37 ` Michael Ellerman
2019-10-19 18:06 ` [PATCH v8 2/8] powerpc/ima: add support to initialize ima policy rules Nayna Jain
2019-10-19 18:06 ` Nayna Jain
2019-10-20 0:16 ` Mimi Zohar
2019-10-20 0:16 ` Mimi Zohar
2019-10-19 18:06 ` [PATCH v8 3/8] powerpc: detect the trusted boot state of the system Nayna Jain
2019-10-19 18:06 ` Nayna Jain
2019-10-20 12:48 ` Mimi Zohar
2019-10-20 12:48 ` Mimi Zohar
2019-10-22 23:38 ` Michael Ellerman
2019-10-22 23:38 ` Michael Ellerman
2019-10-19 18:06 ` [PATCH v8 4/8] powerpc/ima: add measurement rules to ima arch specific policy Nayna Jain
2019-10-19 18:06 ` Nayna Jain
2019-10-20 0:16 ` Mimi Zohar
2019-10-20 0:16 ` Mimi Zohar
2019-10-19 18:06 ` [PATCH v8 5/8] ima: make process_buffer_measurement() generic Nayna Jain
2019-10-19 18:06 ` Nayna Jain
2019-10-20 1:21 ` Mimi Zohar
2019-10-20 1:21 ` Mimi Zohar
2019-10-19 18:06 ` [PATCH v8 6/8] certs: add wrapper function to check blacklisted binary hash Nayna Jain
2019-10-19 18:06 ` Nayna Jain
2019-10-19 18:06 ` [PATCH v8 7/8] ima: check against blacklisted hashes for files with modsig Nayna Jain
2019-10-19 18:06 ` Nayna Jain
2019-10-20 0:58 ` Mimi Zohar
2019-10-20 0:58 ` Mimi Zohar
2019-10-20 16:06 ` Mimi Zohar [this message]
2019-10-20 16:06 ` Mimi Zohar
2019-10-20 16:09 ` Mimi Zohar
2019-10-20 16:09 ` Mimi Zohar
2019-10-19 18:06 ` [PATCH v8 8/8] powerpc/ima: update ima arch policy to check for blacklist Nayna Jain
2019-10-19 18:06 ` Nayna Jain
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