From: Nayna Jain <nayna@linux.ibm.com>
To: James Morris <jmorris@namei.org>
Cc: linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org,
linux-kernel@vger.kernel.org, zohar@linux.ibm.com,
dhowells@redhat.com, jforbes@redhat.com,
seth.forshee@canonical.com, kexec@lists.infradead.org,
keyrings@vger.kernel.org, vgoyal@redhat.com,
ebiederm@xmission.com, mpe@ellerman.id.au,
Josh Boyer <jwboyer@fedoraproject.org>
Subject: Re: [PATCH v2 5/7] efi: Import certificates from UEFI Secure Boot
Date: Wed, 12 Dec 2018 23:01:15 +0530 [thread overview]
Message-ID: <d36bfd7c-7564-778b-1e75-5b835d40b6f1@linux.ibm.com> (raw)
In-Reply-To: <alpine.LRH.2.21.1812120547110.11653@namei.org>
On 12/12/2018 12:17 AM, James Morris wrote:
> On Sun, 9 Dec 2018, Nayna Jain wrote:
>
>> +/*
>> + * Blacklist an X509 TBS hash.
>> + */
>> +static __init void uefi_blacklist_x509_tbs(const char *source,
>> + const void *data, size_t len)
>> +{
>> + char *hash, *p;
>> +
>> + hash = kmalloc(4 + len * 2 + 1, GFP_KERNEL);
>> + if (!hash)
>> + return;
>> + p = memcpy(hash, "tbs:", 4);
>> + p += 4;
>> + bin2hex(p, data, len);
>> + p += len * 2;
>> + *p = 0;
>> +
>> + mark_hash_blacklisted(hash);
>> + kfree(hash);
>> +}
>> +
>> +/*
>> + * Blacklist the hash of an executable.
>> + */
>> +static __init void uefi_blacklist_binary(const char *source,
>> + const void *data, size_t len)
>> +{
>> + char *hash, *p;
>> +
>> + hash = kmalloc(4 + len * 2 + 1, GFP_KERNEL);
>> + if (!hash)
>> + return;
>> + p = memcpy(hash, "bin:", 4);
>> + p += 4;
>> + bin2hex(p, data, len);
>> + p += len * 2;
>> + *p = 0;
>> +
>> + mark_hash_blacklisted(hash);
>> + kfree(hash);
>> +}
>>
> These could be refactored into one function.
>
>
Thanks James for reviewing.
Yes, the code should be refactored. However, I think making it a single
function would require adding a new field to the function callback
definitions as well. Probably, a simpler approach would be to define a
common function uefi_blacklist_hash(...) which can then be used by the
two functions uefi_blacklist_x509_tbs(...) and
uefi_blacklist_binary(...). These two functions now act as wrapper
functions. Below is the example code:
+/*
+ * Blacklist a hash.
+ */
+static __init void uefi_blacklist_hash(const char *source, const void
*data,
+ size_t len, char *type, size_t type_len)
+{
+ char *hash, *p;
+
+ hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL);
+ if (!hash)
+ return;
+ p = memcpy(hash, type, type_len);
+ p += type_len;
+ bin2hex(p, data, len);
+ p += len * 2;
+ *p = 0;
+
+ mark_hash_blacklisted(hash);
+ kfree(hash);
+}
+
+/*
+ * Blacklist an X509 TBS hash.
+ */
+static __init void uefi_blacklist_x509_tbs(const char *source,
+ const void *data, size_t len)
+{
+ uefi_blacklist_hash(source, data, len, "tbs:" , 4);
+}
+
+/*
+ * Blacklist the hash of an executable.
+ */
+static __init void uefi_blacklist_binary(const char *source,
+ const void *data, size_t len)
+{
+ uefi_blacklist_hash(source, data, len, "bin:" , 4);
+}
Thanks & Regards,
- Nayna
next prev parent reply other threads:[~2018-12-12 17:34 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-08 20:26 [PATCH v2 0/7] add platform/firmware keys support for kernel verification by IMA Nayna Jain
2018-12-08 20:26 ` [PATCH v2 1/7] integrity: Define a trusted platform keyring Nayna Jain
2018-12-09 4:48 ` Nayna Jain
2018-12-13 0:15 ` Thiago Jung Bauermann
2018-12-11 18:27 ` James Morris
2018-12-08 20:27 ` [PATCH v2 2/7] integrity: Load certs to the " Nayna Jain
2018-12-11 18:30 ` James Morris
2018-12-13 0:17 ` Thiago Jung Bauermann
2018-12-08 20:27 ` [PATCH v2 3/7] efi: Add EFI signature data types Nayna Jain
2018-12-11 18:30 ` James Morris
2018-12-08 20:27 ` [PATCH v2 4/7] efi: Add an EFI signature blob parser Nayna Jain
2018-12-08 20:27 ` [PATCH v2 5/7] efi: Import certificates from UEFI Secure Boot Nayna Jain
2018-12-11 18:47 ` James Morris
2018-12-12 17:31 ` Nayna Jain [this message]
2018-12-12 21:32 ` [PATCH v2a " Nayna Jain
2018-12-08 20:27 ` [PATCH v2 6/7] efi: Allow the "db" UEFI variable to be suppressed Nayna Jain
2018-12-11 18:49 ` James Morris
2018-12-08 20:27 ` [PATCH v2 7/7] ima: Support platform keyring for kernel appraisal Nayna Jain
2018-12-11 18:53 ` James Morris
2018-12-12 18:14 ` Thiago Jung Bauermann
2018-12-13 0:18 ` Mimi Zohar
2018-12-13 0:19 ` Thiago Jung Bauermann
2018-12-09 18:39 ` [PATCH v2 0/7] add platform/firmware keys support for kernel verification by IMA Mimi Zohar
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