1. 17 2月, 2014 1 次提交
  2. 20 6月, 2013 1 次提交
    • M
      integrity: move integrity_audit_msg() · d726d8d7
      Mimi Zohar 提交于
      This patch moves the integrity_audit_msg() function and defintion to
      security/integrity/, the parent directory, renames the 'ima_audit'
      boot command line option to 'integrity_audit', and fixes the Kconfig
      help text to reflect the actual code.
      
      Changelog:
      - Fixed ifdef inclusion of integrity_audit_msg() (Fengguang Wu)
      Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
      d726d8d7
  3. 07 2月, 2013 1 次提交
    • D
      ima: digital signature verification using asymmetric keys · e0751257
      Dmitry Kasatkin 提交于
      Asymmetric keys were introduced in linux-3.7 to verify the signature on
      signed kernel modules. The asymmetric keys infrastructure abstracts the
      signature verification from the crypto details. This patch adds IMA/EVM
      signature verification using asymmetric keys. Support for additional
      signature verification methods can now be delegated to the asymmetric
      key infrastructure.
      
      Although the module signature header and the IMA/EVM signature header
      could use the same format, to minimize the signature length and save
      space in the extended attribute, this patch defines a new IMA/EVM
      header format.  The main difference is that the key identifier is a
      sha1[12 - 19] hash of the key modulus and exponent, similar to the
      current implementation.  The only purpose of the key identifier is to
      identify the corresponding key in the kernel keyring.  ima-evm-utils
      was updated to support the new signature format.
      
      While asymmetric signature verification functionality supports many
      different hash algorithms, the hash used in this patch is calculated
      during the IMA collection phase, based on the configured algorithm.
      The default algorithm is sha1, but for backwards compatibility md5
      is supported.  Due to this current limitation, signatures should be
      generated using a sha1 hash algorithm.
      
      Changes in this patch:
      - Functionality has been moved to separate source file in order to get rid of
        in source #ifdefs.
      - keyid is derived according to the RFC 3280. It does not require to assign
        IMA/EVM specific "description" when loading X509 certificate. Kernel
        asymmetric key subsystem automatically generate the description. Also
        loading a certificate does not require using of ima-evm-utils and can be
        done using keyctl only.
      - keyid size is reduced to 32 bits to save xattr space.  Key search is done
        using partial match functionality of asymmetric_key_match().
      - Kconfig option title was changed
      Signed-off-by: NDmitry Kasatkin <dmitry.kasatkin@intel.com>
      Acked-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
      e0751257
  4. 18 1月, 2012 1 次提交
  5. 09 11月, 2011 1 次提交
  6. 19 7月, 2011 2 次提交
    • M
      evm: re-release · 66dbc325
      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>
      66dbc325
    • M
      integrity: move ima inode integrity data management · f381c272
      Mimi Zohar 提交于
      Move the inode integrity data(iint) management up to the integrity directory
      in order to share the iint among the different integrity models.
      
      Changelog:
      - don't define MAX_DIGEST_SIZE
      - rename several globally visible 'ima_' prefixed functions, structs,
        locks, etc to 'integrity_'
      - replace '20' with SHA1_DIGEST_SIZE
      - reflect location change in appropriate Kconfig and Makefiles
      - remove unnecessary initialization of iint_initialized to 0
      - rebased on current ima_iint.c
      - define integrity_iint_store/lock as static
      
      There should be no other functional changes.
      Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
      Acked-by: NSerge Hallyn <serge.hallyn@ubuntu.com>
      f381c272