- 18 7月, 2018 1 次提交
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由 Matthew Garrett 提交于
SHA1 is reasonable in HMAC constructs, but it's desirable to be able to use stronger hashes in digital signatures. Modify the EVM crypto code so the hash type is imported from the digital signature and passed down to the hash calculation code, and return the digest size to higher layers for validation. Signed-off-by: NMatthew Garrett <mjg59@google.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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- 19 5月, 2018 1 次提交
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由 Matthew Garrett 提交于
Sites may wish to provide additional metadata alongside files in order to make more fine-grained security decisions[1]. The security of this is enhanced if this metadata is protected, something that EVM makes possible. However, the kernel cannot know about the set of extended attributes that local admins may wish to protect, and hardcoding this policy in the kernel makes it difficult to change over time and less convenient for distributions to enable. This patch adds a new /sys/kernel/security/integrity/evm/evm_xattrs node, which can be read to obtain the current set of EVM-protected extended attributes or written to in order to add new entries. Extending this list will not change the validity of any existing signatures provided that the file in question does not have any of the additional extended attributes - missing xattrs are skipped when calculating the EVM hash. [1] For instance, a package manager could install information about the package uploader in an additional extended attribute. Local LSM policy could then be associated with that extended attribute in order to restrict the privileges available to packages from less trusted uploaders. Signed-off-by: NMatthew Garrett <mjg59@google.com> Reviewed-by: NJames Morris <james.morris@microsoft.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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- 15 12月, 2015 2 次提交
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由 Arnd Bergmann 提交于
The newly added EVM_LOAD_X509 code can be configured even if CONFIG_EVM is disabled, but that causes a link error: security/built-in.o: In function `integrity_load_keys': digsig_asymmetric.c:(.init.text+0x400): undefined reference to `evm_load_x509' This adds a Kconfig dependency to ensure it is only enabled when CONFIG_EVM is set as well. Signed-off-by: NArnd Bergmann <arnd@arndb.de> Fixes: 2ce523eb ("evm: load x509 certificate from the kernel") Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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由 Dmitry Kasatkin 提交于
This patch defines a configuration option and the evm_load_x509() hook to load an X509 certificate onto the EVM trusted kernel keyring. Changes in v4: * Patch description updated Changes in v3: * Removed EVM_X509_PATH definition. CONFIG_EVM_X509_PATH is used directly. Changes in v2: * default key patch changed to /etc/keys Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@huawei.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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- 07 1月, 2015 1 次提交
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由 Christoph Jaeger 提交于
Support for keyword 'boolean' will be dropped later on. No functional change. Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.comSigned-off-by: NChristoph Jaeger <cj@linux.com> Signed-off-by: NMichal Marek <mmarek@suse.cz>
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- 09 9月, 2014 1 次提交
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由 Dmitry Kasatkin 提交于
The integrity subsystem has lots of options and takes more than half of the security menu. This patch consolidates the options under "integrity", which are hidden if not enabled. This change does not affect existing configurations. Re-configuration is not needed. Changes v4: - no need to change "integrity subsystem" to menuconfig as options are hidden, when not enabled. (Mimi) - add INTEGRITY Kconfig help description Changes v3: - dependency to INTEGRITY removed when behind 'if INTEGRITY' Changes v2: - previous patch moved integrity out of the 'security' menu. This version keeps integrity as a security option (Mimi). Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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- 13 6月, 2014 2 次提交
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由 Dmitry Kasatkin 提交于
Newer versions of SMACK introduced following security xattrs: SMACK64EXEC, SMACK64TRANSMUTE and SMACK64MMAP. To protect these xattrs, this patch includes them in the HMAC calculation. However, for backwards compatibility with existing labeled filesystems, including these xattrs needs to be configurable. Changelog: - Add SMACK dependency on new option (Mimi) Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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由 Dmitry Kasatkin 提交于
Using HMAC version limits the posibility to arbitrarily add new attributes such as SMACK64EXEC to the hmac calculation. This patch replaces hmac version with attribute mask. Desired attributes can be enabled with configuration parameter. It allows to build kernels which works with previously labeled filesystems. Currently supported attribute is 'fsuuid' which is equivalent of the former version 2. Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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- 08 3月, 2014 2 次提交
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由 Dmitry Kasatkin 提交于
If keys are not enabled, EVM is not visible in the configuration menu. It may be difficult to figure out what to do unless you really know. Other subsystems as NFS, CIFS select keys automatically. This patch does the same. This patch also removes '(TRUSTED_KEYS=y || TRUSTED_KEYS=n)' dependency, which is unnecessary. EVM does not depend on trusted keys, but on encrypted keys. evm.h provides compile time dependency. Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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由 Dmitry Kasatkin 提交于
EVM does not use MD5 HMAC. Selection of CRYPTO_MD5 can be safely removed. Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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- 06 2月, 2013 1 次提交
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由 Dmitry Kasatkin 提交于
EVM uses the same key for all file systems to calculate the HMAC, making it possible to paste inodes from one file system on to another one, without EVM being able to detect it. To prevent such an attack, it is necessary to make the EVM HMAC file system specific. This patch uses the file system UUID, a file system unique identifier, to bind the EVM HMAC to the file system. The value inode->i_sb->s_uuid is used for the HMAC hash calculation, instead of using it for deriving the file system specific key. Initializing the key for every inode HMAC calculation is a bit more expensive operation than adding the uuid to the HMAC hash. Changing the HMAC calculation method or adding additional info to the calculation, requires existing EVM labeled file systems to be relabeled. This patch adds a Kconfig HMAC version option for backwards compatability. Changelog v1: - squash "hmac version setting" Changelog v0: - add missing Kconfig depends (Mimi) Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
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- 15 9月, 2011 1 次提交
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由 Mimi Zohar 提交于
All tristates selected by EVM(boolean) are forced to be builtin, except in the TCG_TPM(tristate) dependency case. Arnaud Lacombe summarizes the Kconfig bug as, "So it would seem direct dependency state influence the state of reverse dependencies.." For a detailed explanation, refer to Arnaud Lacombe's posting http://lkml.org/lkml/2011/8/23/498. With the "encrypted-keys: remove trusted-keys dependency" patch, EVM can now be built without a dependency on TCG_TPM. The trusted-keys dependency requires trusted-keys to either be builtin or not selected. This dependency will prevent the boolean/tristate mismatch from occuring. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>, Randy Dunlap <rdunlap@xenotimenet> Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
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- 18 8月, 2011 1 次提交
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由 Mimi Zohar 提交于
Although the EVM encrypted-key should be encrypted/decrypted using a trusted-key, a user-defined key could be used instead. When using a user- defined key, a TCG_TPM dependency should not be required. Unfortunately, the encrypted-key code needs to be refactored a bit in order to remove this dependency. This patch adds the TCG_TPM dependency. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>, Randy Dunlap <rdunlap@xenotimenet> Signed-off-by: NMimi Zohar <zohar@us.ibm.com> Signed-off-by: NJames Morris <jmorris@namei.org>
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- 09 8月, 2011 1 次提交
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由 James Morris 提交于
Select trusted and encrypted keys if EVM is selected, to ensure the requisite symbols are available. Otherwise, these can be selected as modules while EVM is static, leading to a kernel build failure. Signed-off-by: NJames Morris <jmorris@namei.org>
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- 19 7月, 2011 1 次提交
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由 Mimi Zohar 提交于
EVM protects a file's security extended attributes(xattrs) against integrity attacks. This patchset provides the framework and an initial method. The initial method maintains an HMAC-sha1 value across the security extended attributes, storing the HMAC value as the extended attribute 'security.evm'. Other methods of validating the integrity of a file's metadata will be posted separately (eg. EVM-digital-signatures). While this patchset does authenticate the security xattrs, and cryptographically binds them to the inode, coming extensions will bind other directory and inode metadata for more complete protection. To help simplify the review and upstreaming process, each extension will be posted separately (eg. IMA-appraisal, IMA-appraisal-directory). For a general overview of the proposed Linux integrity subsystem, refer to Dave Safford's whitepaper: http://downloads.sf.net/project/linux-ima/linux-ima/Integrity_overview.pdf. EVM depends on the Kernel Key Retention System to provide it with a trusted/encrypted key for the HMAC-sha1 operation. The key is loaded onto the root's keyring using keyctl. Until EVM receives notification that the key has been successfully loaded onto the keyring (echo 1 > <securityfs>/evm), EVM can not create or validate the 'security.evm' xattr, but returns INTEGRITY_UNKNOWN. Loading the key and signaling EVM should be done as early as possible. Normally this is done in the initramfs, which has already been measured as part of the trusted boot. For more information on creating and loading existing trusted/encrypted keys, refer to Documentation/keys-trusted-encrypted.txt. A sample dracut patch, which loads the trusted/encrypted key and enables EVM, is available from http://linux-ima.sourceforge.net/#EVM. Based on the LSMs enabled, the set of EVM protected security xattrs is defined at compile. EVM adds the following three calls to the existing security hooks: evm_inode_setxattr(), evm_inode_post_setxattr(), and evm_inode_removexattr. To initialize and update the 'security.evm' extended attribute, EVM defines three calls: evm_inode_post_init(), evm_inode_post_setattr() and evm_inode_post_removexattr() hooks. To verify the integrity of a security xattr, EVM exports evm_verifyxattr(). Changelog v7: - Fixed URL in EVM ABI documentation Changelog v6: (based on Serge Hallyn's review) - fix URL in patch description - remove evm_hmac_size definition - use SHA1_DIGEST_SIZE (removed both MAX_DIGEST_SIZE and evm_hmac_size) - moved linux include before other includes - test for crypto_hash_setkey failure - fail earlier for invalid key - clear entire encrypted key, even on failure - check xattr name length before comparing xattr names Changelog: - locking based on i_mutex, remove evm_mutex - using trusted/encrypted keys for storing the EVM key used in the HMAC-sha1 operation. - replaced crypto hash with shash (Dmitry Kasatkin) - support for additional methods of verifying the security xattrs (Dmitry Kasatkin) - iint not allocated for all regular files, but only for those appraised - Use cap_sys_admin in lieu of cap_mac_admin - Use __vfs_setxattr_noperm(), without permission checks, from EVM Signed-off-by: NMimi Zohar <zohar@us.ibm.com> Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
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