- 18 Nov, 2014 1 commit
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Dmitry Kasatkin authored
This patch defines a new function called integrity_read_file() to read file from the kernel into a buffer. Subsequent patches will read a file containing the public keys and load them onto the IMA keyring. This patch moves and renames ima_kernel_read(), the non-security checking version of kernel_read(), to integrity_kernel_read(). Changes in v3: * Patch descriptions improved (Mimi) * Add missing cast (kbuild test robot) Changes in v2: * configuration option removed * function declared as '__init' Signed-off-by:
Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by:
Mimi Zohar <zohar@linux.vnet.ibm.com>
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- 13 Oct, 2014 5 commits
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Roberto Sassu authored
This patch allows users to provide a custom template format through the new kernel command line parameter 'ima_template_fmt'. If the supplied format is not valid, IMA uses the default template descriptor. Changelog: - v3: - added check for 'fields' and 'num_fields' in template_desc_init_fields() (suggested by Mimi Zohar) - v2: - using template_desc_init_fields() to validate a format string (Roberto Sassu) - updated documentation by stating that only the chosen template descriptor is initialized (Roberto Sassu) - v1: - simplified code of ima_template_fmt_setup() (Roberto Sassu, suggested by Mimi Zohar) Signed-off-by:Roberto Sassu <roberto.sassu@polito.it> Signed-off-by:
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Roberto Sassu authored
The allocation of a field pointers array is moved at the end of template_desc_init_fields() and done only if the value of the 'fields' and 'num_fields' parameters is not NULL. For just validating a template format string, retrieved template field pointers are placed in a temporary array. Changelog: - v3: - do not check in this patch if 'fields' and 'num_fields' are NULL (suggested by Mimi Zohar) Signed-off-by: -
Roberto Sassu authored
This patch removes the allocation of a copy of 'template_fmt', needed for iterating over all fields in the passed template format string. The removal was possible by replacing strcspn(), which modifies the passed string, with strchrnul(). The currently processed template field is copied in a temporary variable. The purpose of this change is use template_desc_init_fields() in two ways: for just validating a template format string (the function should work if called by a setup function, when memory cannot be allocated), and for actually initializing a template descriptor. The implementation of this feature will be complete with the next patch. Changelog: - v3: - added 'goto out' in template_desc_init_fields() to free allocated memory if a template field length is not valid (suggested by Mimi Zohar) Signed-off-by: -
Roberto Sassu authored
With the introduction of the 'ima_template_fmt' kernel cmdline parameter, a user can define a new template descriptor with custom format. However, in this case, userspace tools will be unable to parse the measurements list because the new template is unknown. For this reason, this patch modifies the current IMA behavior to display in the list the template format instead of the name (only if the length of the latter is zero) so that a tool can extract needed information if it can handle listed fields. This patch also correctly displays the error log message in ima_init_template() if the selected template cannot be initialized. Changelog: - v3: - check the first byte of 'e->template_desc->name' instead of using strlen() in ima_fs.c (suggested by Mimi Zohar) - v2: - print the template format in ima_init_template(), if the selected template is custom (Roberto Sassu) - v1: - fixed patch description (Roberto Sassu, suggested by Mimi Zohar) - set 'template_name' variable in ima_fs.c only once (Roberto Sassu, suggested by Mimi Zohar) Signed-off-by: -
Roberto Sassu authored
This patch adds some error messages to inform users about the following events: template descriptor not found, invalid template descriptor, template field not found and template initialization failed. Changelog: - v2: - display an error message if the format string contains too many fields (Roberto Sassu) Signed-off-by:
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- 12 Oct, 2014 4 commits
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Dmitry Kasatkin authored
The current implementation uses an atomic counter to provide exclusive access to the sysfs 'policy' entry to update the IMA policy. While it is highly unlikely, the usage of a counter might potentially allow another process to overflow the counter, open the interface and insert additional rules into the policy being loaded. This patch replaces using an atomic counter with atomic bit operations which is more reliable and a widely used method to provide exclusive access. As bit operation keep the interface locked after successful update, it makes it unnecessary to verify if the default policy was set or not during parsing and interface closing. This patch also removes that code. Changes in v3: * move audit log message to ima_relead_policy() to report successful and unsuccessful result * unnecessary comment removed Changes in v2: * keep interface locked after successful policy load as in original design * remove sysfs entry as in original design Signed-off-by:
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Dmitry Kasatkin authored
Empty policy lines cause parsing failures which is, especially for new users, hard to spot. This patch prevents it. Changes in v2: * strip leading blanks and tabs in rules to prevent parsing failures Signed-off-by:
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Dmitry Kasatkin authored
If a rule is a comment, there is no need to allocate an entry. Move the checking for comments before allocating the entry. Signed-off-by:
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Dmitry Kasatkin authored
Audit messages are rate limited, often causing the policy update info to not be visible. Report policy loading status also using pr_info. Changes in v2: * reporting moved to ima_release_policy to notice parsing errors * reporting both completed and failed status Signed-off-by:
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- 07 Oct, 2014 4 commits
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Dmitry Kasatkin authored
__getname() uses slab allocation which is faster than kmalloc. Make use of it. Signed-off-by:
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Dmitry Kasatkin authored
If filesystem is mounted read-only or file is immutable, updating xattr will fail. This is a usual case during early boot until filesystem is remount read-write. This patch verifies conditions to skip unnecessary attempt to calculate HMAC and set xattr. Changes in v2: * indention changed according to Lindent (requested by Mimi) Signed-off-by:
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Dmitry Kasatkin authored
integrity_init_keyring() is used only from kernel '__init' functions. Add it there as well. Signed-off-by:
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Dmitry Kasatkin authored
This patch completes the switching to the 'ima_policy_flag' variable in the checks at the beginning of IMA functions, starting with the commit a756024e. Checking 'iint_initialized' is completely unnecessary, because S_IMA flag is unset if iint was not allocated. At the same time the integrity cache is allocated with SLAB_PANIC and the kernel will panic if the allocation fails during kernel initialization. So on a running system iint_initialized is always true and can be removed. Changes in v3: * not limiting test to IMA_APPRAISE (spotted by Roberto Sassu) Changes in v2: * 'iint_initialized' removal patch merged to this patch (requested by Mimi) Signed-off-by:
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- 06 Oct, 2014 5 commits
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Dmitry Kasatkin authored
Latest KEYS code return error if hexadecimal string length id odd. Fix it. Signed-off-by:
David Howells <dhowells@redhat.com>
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Dmitry Kasatkin authored
Previous version of KEYS used to output last 4 bytes of fingerprint. Now it outputs 8 last bytes of raw subject, which does not make any visual meaning at all. This patch restores old behavior. Signed-off-by:
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Dmitry Kasatkin authored
The 'id:' prefix must be stripped for asymmetric_key_hex_to_key_id() to be able to process ca_keyid. Signed-off-by:
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Dmitry Kasatkin authored
Earlier KEYS code used pure subject key identifiers (fingerprint) for searching keys. Latest merged code removed that and broke compatibility with integrity subsytem signatures and original format of module signatures. This patch returns back partial matching on SKID. Reported-by:
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Dmitry Kasatkin authored
Bring back the functionality whereby an asymmetric key can be matched with a partial match on one of its IDs. Whilst we're at it, allow for the possibility of having an increased number of IDs. Reported-by:
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- 03 Oct, 2014 2 commits
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David Howells authored
Module signing matches keys by comparing against the key description exactly. However, the way the key description gets constructed got changed to be composed of the subject name plus the certificate serial number instead of the subject name and the subjectKeyId. I changed this to avoid problems with certificates that don't *have* a subjectKeyId. Instead, if available, use the raw subjectKeyId to form the key description and only use the serial number if the subjectKeyId doesn't exist. Reported-by:
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Dmitry Kasatkin authored
If hexlen is odd then function returns an error. Use IS_ERR to check for error, otherwise invalid pointer is used and kernel gives oops: [ 132.816522] BUG: unable to handle kernel paging request at ffffffffffffffea [ 132.819902] IP: [<ffffffff812bfc20>] asymmetric_key_id_same+0x14/0x36 [ 132.820302] PGD 1a12067 PUD 1a14067 PMD 0 [ 132.820302] Oops: 0000 [#1] SMP [ 132.820302] Modules linked in: bridge(E) stp(E) llc(E) evdev(E) serio_raw(E) i2c_piix4(E) button(E) fuse(E) [ 132.820302] CPU: 0 PID: 2993 Comm: cat Tainted: G E 3.16.0-kds+ #2847 [ 132.820302] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 132.820302] task: ffff88004249a430 ti: ffff880056640000 task.ti: ffff880056640000 [ 132.820302] RIP: 0010:[<ffffffff812bfc20>] [<ffffffff812bfc20>] asymmetric_key_id_same+0x14/0x36 [ 132.820302] RSP: 0018:ffff880056643930 EFLAGS: 00010246 [ 132.820302] RAX: 0000000000000000 RBX: ffffffffffffffea RCX: ffff880056643ae0 [ 132.820302] RDX: 000000000000005e RSI: ffffffffffffffea RDI: ffff88005bac9300 [ 132.820302] RBP: ffff880056643948 R08: 0000000000000003 R09: 00000007504aa01a [ 132.820302] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88005d68ca40 [ 132.820302] R13: 0000000000000101 R14: 0000000000000000 R15: ffff88005bac5280 [ 132.820302] FS: 00007f67a153c740(0000) GS:ffff88005da00000(0000) knlGS:0000000000000000 [ 132.820302] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 132.820302] CR2: ffffffffffffffea CR3: 000000002e663000 CR4: 00000000000006f0 [ 132.820302] Stack: [ 132.820302] ffffffff812bfc66 ffff880056643ae0 ffff88005bac5280 ffff880056643958 [ 132.820302] ffffffff812bfc9d ffff880056643980 ffffffff812971d9 ffff88005ce930c1 [ 132.820302] ffff88005ce930c0 0000000000000000 ffff8800566439c8 ffffffff812fb753 [ 132.820302] Call Trace: [ 132.820302] [<ffffffff812bfc66>] ? asymmetric_match_key_ids+0x24/0x42 [ 132.820302] [<ffffffff812bfc9d>] asymmetric_key_cmp+0x19/0x1b [ 132.820302] [<ffffffff812971d9>] keyring_search_iterator+0x74/0xd7 [ 132.820302] [<ffffffff812fb753>] assoc_array_subtree_iterate+0x67/0xd2 [ 132.820302] [<ffffffff81297165>] ? key_default_cmp+0x20/0x20 [ 132.820302] [<ffffffff812fbaa1>] assoc_array_iterate+0x19/0x1e [ 132.820302] [<ffffffff81297332>] search_nested_keyrings+0xf6/0x2b6 [ 132.820302] [<ffffffff810728da>] ? sched_clock_cpu+0x91/0xa2 [ 132.820302] [<ffffffff810860d2>] ? mark_held_locks+0x58/0x6e [ 132.820302] [<ffffffff810a137d>] ? current_kernel_time+0x77/0xb8 [ 132.820302] [<ffffffff81297871>] keyring_search_aux+0xe1/0x14c [ 132.820302] [<ffffffff812977fc>] ? keyring_search_aux+0x6c/0x14c [ 132.820302] [<ffffffff8129796b>] keyring_search+0x8f/0xb6 [ 132.820302] [<ffffffff812bfc84>] ? asymmetric_match_key_ids+0x42/0x42 [ 132.820302] [<ffffffff81297165>] ? key_default_cmp+0x20/0x20 [ 132.820302] [<ffffffff812ab9e3>] asymmetric_verify+0xa4/0x214 [ 132.820302] [<ffffffff812ab90e>] integrity_digsig_verify+0xb1/0xe2 [ 132.820302] [<ffffffff812abe41>] ? evm_verifyxattr+0x6a/0x7a [ 132.820302] [<ffffffff812b0390>] ima_appraise_measurement+0x160/0x370 [ 132.820302] [<ffffffff81161db2>] ? d_absolute_path+0x5b/0x7a [ 132.820302] [<ffffffff812ada30>] process_measurement+0x322/0x404 Reported-by:
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- 02 Oct, 2014 1 commit
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James Morris authored
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next
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- 30 Sep, 2014 2 commits
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James Morris authored
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- 22 Sep, 2014 3 commits
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Richard Guy Briggs authored
Restructure to keyword=value pairs without spaces. Drop superfluous words in text. Make invalid_context a keyword. Change result= keyword to seresult=. Signed-off-by:
Richard Guy Briggs <rgb@redhat.com> [Minor rewrite to the patch subject line] Signed-off-by:
Paul Moore <pmoore@redhat.com>
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Richard Guy Briggs authored
Convert audit_log() call to WARN_ONCE(). Rename "type=" to nlmsg_type=" to avoid confusion with the audit record type. Added "protocol=" to help track down which protocol (NETLINK_AUDIT?) was used within the netlink protocol family. Signed-off-by:
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James Morris authored
Merge tag 'keys-next-20140922' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next
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- 21 Sep, 2014 1 commit
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David Howells authored
As it stands, the code to generate an asymmetric key ID prechecks the hex string it is given whilst determining the length, before it allocates the buffer for hex2bin() to translate into - which mean that checking the result of hex2bin() is redundant. Unfortunately, hex2bin() is marked as __must_check, which means that the following warning may be generated if the return value isn't checked: crypto/asymmetric_keys/asymmetric_type.c: In function asymmetric_key_hex_to_key_id: crypto/asymmetric_keys/asymmetric_type.c:110: warning: ignoring return value of hex2bin, declared with attribute warn_unused_result The warning can't be avoided by casting the result to void. Instead, use strlen() to check the length of the string and ignore the fact that the string might not be entirely valid hex until after the allocation has been done - in which case we can use the result of hex2bin() for this. Signed-off-by:
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- 18 Sep, 2014 3 commits
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Roberto Sassu authored
This patch fixes the detection of the 'open_writers' violation for mmaped files. before) an 'open_writers' violation is detected if the policy contains a rule with the criteria: func=FILE_CHECK mask=MAY_READ after) an 'open_writers' violation is detected if the current event matches one of the policy rules. With the old behaviour, the 'open_writers' violation is not detected in the following case: policy: measure func=FILE_MMAP mask=MAY_EXEC steps: 1) open a shared library for writing 2) execute a binary that links that shared library 3) during the binary execution, modify the shared library and save the change result: the 'open_writers' violation measurement is not present in the IMA list. Only binaries executed are protected from writes. For libraries mapped in memory there is the flag MAP_DENYWRITE for this purpose, but according to the output of 'man mmap', the mmap flag is ignored. Since ima_rdwr_violation_check() is now called by process_measurement() the information about if the inode must be measured is already provided by ima_get_action(). Thus the unnecessary function ima_must_measure() has been removed. Changes in v3 (Dmitry Kasatkin): - Violation for MMAP_CHECK function are verified since this patch - Changed patch description a bit Signed-off-by: -
Roberto Sassu authored
This patch fixes a race condition between two functions that try to access the same inode. Since the i_mutex lock is held and released separately in the two functions, there may be the possibility that a violation is not correctly detected. Suppose there are two processes, A (reader) and B (writer), if the following sequence happens: A: ima_rdwr_violation_check() B: ima_rdwr_violation_check() B: process_measurement() B: starts writing the inode A: process_measurement() the ToMToU violation (a reader may be accessing a content different from that measured, due to a concurrent modification by a writer) will not be detected. To avoid this issue, the violation check and the measurement must be done atomically. This patch fixes the problem by moving the violation check inside process_measurement() when the i_mutex lock is held. Differently from the old code, the violation check is executed also for the MMAP_CHECK hook (other than for FILE_CHECK). This allows to detect ToMToU violations that are possible because shared libraries can be opened for writing while they are in use (according to the output of 'man mmap', the mmap() flag MAP_DENYWRITE is ignored). Changes in v5 (Roberto Sassu): * get iint if action is not zero * exit process_measurement() after the violation check if action is zero * reverse order process_measurement() exit cleanup (Mimi) Changes in v4 (Dmitry Kasatkin): * iint allocation is done before calling ima_rdrw_violation_check() (Suggested-by Mimi) * do not check for violations if the policy does not contain 'measure' rules (done by Roberto Sassu) Changes in v3 (Dmitry Kasatkin): * no violation checking for MMAP_CHECK function in this patch * remove use of filename from violation * removes checking if ima is enabled from ima_rdrw_violation_check * slight style change Suggested-by:
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- 17 Sep, 2014 4 commits
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Roberto Sassu authored
This patch introduces the new variable 'ima_policy_flag', whose bits are set depending on the action of the current policy rules. Only the flags IMA_MEASURE, IMA_APPRAISE and IMA_AUDIT are set. The new variable will be used to improve performance by skipping the unnecessary execution of IMA code if the policy does not contain rules with the above actions. Changes in v6 (Roberto Sassu) * do not check 'ima_initialized' before calling ima_update_policy_flag() in ima_update_policy() (suggested by Dmitry) * calling ima_update_policy_flag() moved to init_ima to co-locate with ima_initialized (Dmitry) * add/revise comments (Mimi) Changes in v5 (Roberto Sassu) * reset IMA_APPRAISE flag in 'ima_policy_flag' if 'ima_appraise' is set to zero (reported by Dmitry) * update 'ima_policy_flag' only if IMA initialization is successful (suggested by Mimi and Dmitry) * check 'ima_policy_flag' instead of 'ima_initialized' (suggested by Mimi and Dmitry) Signed-off-by:
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Roberto Sassu authored
This patch modifies ima_add_boot_aggregate() to return an error code. This way we can determine if all the initialization procedures have been executed successfully. Signed-off-by:
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Dmitry Kasatkin authored
The kernel boot parameter "ima_appraise" currently defines 'off', 'enforce' and 'fix' modes. When designing a policy and labeling the system, access to files are either blocked in the default 'enforce' mode or automatically fixed in the 'fix' mode. It is beneficial to be able to run the system in a logging only mode, without fixing it, in order to properly analyze the system. This patch adds a 'log' mode to run the system in a permissive mode and log the appraisal results. Signed-off-by:
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Dmitry Kasatkin authored
ima_init() is used as a single place for all initializations. Experimental keyring patches used the 'late_initcall' which was co-located with the late_initcall(init_ima). When the late_initcall for the keyring initialization was abandoned, initialization moved to init_ima, though it would be more logical to move it to ima_init, where the rest of the initialization is done. This patch moves the keyring initialization to ima_init() as a preparatory step for loading the keys which will be added to ima_init() in following patches. Signed-off-by:
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- 16 Sep, 2014 5 commits
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David Howells authored
Changes for next to improve the matching of asymmetric keys and to improve the handling of PKCS#7 certificates: (1) Provide a method to preparse the data supplied for matching a key. This permits they key type to extract out the bits it needs for matching once only. Further, the type of search (direct lookup or iterative) can be set and the function used to actually check the match can be set by preparse rather than being hard coded for the type. (2) Improves asymmetric keys identification. Keys derived from X.509 certs now get labelled with IDs derived from their issuer and certificate number (required to match PKCS#7) and from their SKID and subject (required to match X.509). IDs are now binary and match criterion preparsing is provided so that criteria can be turned into binary blobs to make matching faster. (3) Improves PKCS#7 message handling to permit PKCS#7 messages without X.509 cert lists to be matched to trusted keys, thereby allowing minimally sized PKCS#7 certs to be used. (4) Improves PKCS#7 message handling to better handle certificate chains that are broken due to unsupported crypto that can otherwise by used to intersect a trust keyring. These must go on top of the PKCS#7 parser cleanup fixes. Signed-off-by: -
David Howells authored
The X.509 certificate list in a PKCS#7 message is optional. To save space, we can omit the inclusion of any X.509 certificates if we are sure that we can look the relevant public key up by the serial number and issuer given in a signed info block. This also supports use of a signed info block for which we can't find a matching X.509 cert in the certificate list, though it be populated. Signed-off-by:
Vivek Goyal <vgoyal@redhat.com>
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David Howells authored
Provide better handling of unsupported crypto when verifying a PKCS#7 message. If we can't bridge the gap between a pair of X.509 certs or between a signed info block and an X.509 cert because it involves some crypto we don't support, that's not necessarily the end of the world as there may be other ways points at which we can intersect with a ring of trusted keys. Instead, only produce ENOPKG immediately if all the signed info blocks in a PKCS#7 message require unsupported crypto to bridge to the first X.509 cert. Otherwise, we defer the generation of ENOPKG until we get ENOKEY during trust validation. Signed-off-by:
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David Howells authored
Make use of the new match string preparsing to overhaul key identification when searching for asymmetric keys. The following changes are made: (1) Use the previously created asymmetric_key_id struct to hold the following key IDs derived from the X.509 certificate or PKCS#7 message: id: serial number + issuer skid: subjKeyId + subject authority: authKeyId + issuer (2) Replace the hex fingerprint attached to key->type_data[1] with an asymmetric_key_ids struct containing the id and the skid (if present). (3) Make the asymmetric_type match data preparse select one of two searches: (a) An iterative search for the key ID given if prefixed with "id:". The prefix is expected to be followed by a hex string giving the ID to search for. The criterion key ID is checked against all key IDs recorded on the key. (b) A direct search if the key ID is not prefixed with "id:". This will look for an exact match on the key description. (4) Make x509_request_asymmetric_key() take a key ID. This is then converted into "id:<hex>" and passed into keyring_search() where match preparsing will turn it back into a binary ID. (5) X.509 certificate verification then takes the authority key ID and looks up a key that matches it to find the public key for the certificate signature. (6) PKCS#7 certificate verification then takes the id key ID and looks up a key that matches it to find the public key for the signed information block signature. Additional changes: (1) Multiple subjKeyId and authKeyId values on an X.509 certificate cause the cert to be rejected with -EBADMSG. (2) The 'fingerprint' ID is gone. This was primarily intended to convey PGP public key fingerprints. If PGP is supported in future, this should generate a key ID that carries the fingerprint. (3) Th ca_keyid= kernel command line option is now converted to a key ID and used to match the authority key ID. Possibly this should only match the actual authKeyId part and not the issuer as well. Signed-off-by: -
David Howells authored
Implement the first step in using binary key IDs for asymmetric keys rather than hex string keys. The previously added match data preparsing will be able to convert hex criterion strings into binary which can then be compared more rapidly. Further, we actually want more then one ID string per public key. The problem is that X.509 certs refer to other X.509 certs by matching Issuer + AuthKeyId to Subject + SubjKeyId, but PKCS#7 messages match against X.509 Issuer + SerialNumber. This patch just provides facilities for a later patch to make use of. Signed-off-by:
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