1. 09 Sep, 2018 1 commit
  2. 11 Apr, 2016 5 commits
    • David Howells's avatar
      certs: Add a secondary system keyring that can be added to dynamically · d3bfe841
      David Howells authored
      Add a secondary system keyring that can be added to by root whilst the
      system is running - provided the key being added is vouched for by a key
      built into the kernel or already added to the secondary keyring.
      
      Rename .system_keyring to .builtin_trusted_keys to distinguish it more
      obviously from the new keyring (called .secondary_trusted_keys).
      
      The new keyring needs to be enabled with CONFIG_SECONDARY_TRUSTED_KEYRING.
      
      If the secondary keyring is enabled, a link is created from that to
      .builtin_trusted_keys so that the the latter will automatically be searched
      too if the secondary keyring is searched.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      d3bfe841
    • David Howells's avatar
      KEYS: Remove KEY_FLAG_TRUSTED and KEY_ALLOC_TRUSTED · 77f68bac
      David Howells authored
      Remove KEY_FLAG_TRUSTED and KEY_ALLOC_TRUSTED as they're no longer
      meaningful.  Also we can drop the trusted flag from the preparse structure.
      
      Given this, we no longer need to pass the key flags through to
      restrict_link().
      
      Further, we can now get rid of keyring_restrict_trusted_only() also.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      77f68bac
    • David Howells's avatar
      KEYS: Move the point of trust determination to __key_link() · a511e1af
      David Howells authored
      Move the point at which a key is determined to be trustworthy to
      __key_link() so that we use the contents of the keyring being linked in to
      to determine whether the key being linked in is trusted or not.
      
      What is 'trusted' then becomes a matter of what's in the keyring.
      
      Currently, the test is done when the key is parsed, but given that at that
      point we can only sensibly refer to the contents of the system trusted
      keyring, we can only use that as the basis for working out the
      trustworthiness of a new key.
      
      With this change, a trusted keyring is a set of keys that once the
      trusted-only flag is set cannot be added to except by verification through
      one of the contained keys.
      
      Further, adding a key into a trusted keyring, whilst it might grant
      trustworthiness in the context of that keyring, does not automatically
      grant trustworthiness in the context of a second keyring to which it could
      be secondarily linked.
      
      To accomplish this, the authentication data associated with the key source
      must now be retained.  For an X.509 cert, this means the contents of the
      AuthorityKeyIdentifier and the signature data.
      
      
      If system keyrings are disabled then restrict_link_by_builtin_trusted()
      resolves to restrict_link_reject().  The integrity digital signature code
      still works correctly with this as it was previously using
      KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there
      is no system keyring against which trust can be determined.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      a511e1af
    • David Howells's avatar
      KEYS: Make the system trusted keyring depend on the asymmetric key type · 99716b7c
      David Howells authored
      Make the system trusted keyring depend on the asymmetric key type as
      there's not a lot of point having it if you can't then load asymmetric keys
      onto it.
      
      This requires the ASYMMETRIC_KEY_TYPE to be made a bool, not a tristate, as
      the Kconfig language doesn't then correctly force ASYMMETRIC_KEY_TYPE to
      'y' rather than 'm' if SYSTEM_TRUSTED_KEYRING is 'y'.
      
      Making SYSTEM_TRUSTED_KEYRING *select* ASYMMETRIC_KEY_TYPE instead doesn't
      work as the Kconfig interpreter then wrongly complains about dependency
      loops.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      99716b7c
    • David Howells's avatar
      KEYS: Add a facility to restrict new links into a keyring · 5ac7eace
      David Howells authored
      Add a facility whereby proposed new links to be added to a keyring can be
      vetted, permitting them to be rejected if necessary.  This can be used to
      block public keys from which the signature cannot be verified or for which
      the signature verification fails.  It could also be used to provide
      blacklisting.
      
      This affects operations like add_key(), KEYCTL_LINK and KEYCTL_INSTANTIATE.
      
      To this end:
      
       (1) A function pointer is added to the key struct that, if set, points to
           the vetting function.  This is called as:
      
      	int (*restrict_link)(struct key *keyring,
      			     const struct key_type *key_type,
      			     unsigned long key_flags,
      			     const union key_payload *key_payload),
      
           where 'keyring' will be the keyring being added to, key_type and
           key_payload will describe the key being added and key_flags[*] can be
           AND'ed with KEY_FLAG_TRUSTED.
      
           [*] This parameter will be removed in a later patch when
           	 KEY_FLAG_TRUSTED is removed.
      
           The function should return 0 to allow the link to take place or an
           error (typically -ENOKEY, -ENOPKG or -EKEYREJECTED) to reject the
           link.
      
           The pointer should not be set directly, but rather should be set
           through keyring_alloc().
      
           Note that if called during add_key(), preparse is called before this
           method, but a key isn't actually allocated until after this function
           is called.
      
       (2) KEY_ALLOC_BYPASS_RESTRICTION is added.  This can be passed to
           key_create_or_update() or key_instantiate_and_link() to bypass the
           restriction check.
      
       (3) KEY_FLAG_TRUSTED_ONLY is removed.  The entire contents of a keyring
           with this restriction emplaced can be considered 'trustworthy' by
           virtue of being in the keyring when that keyring is consulted.
      
       (4) key_alloc() and keyring_alloc() take an extra argument that will be
           used to set restrict_link in the new key.  This ensures that the
           pointer is set before the key is published, thus preventing a window
           of unrestrictedness.  Normally this argument will be NULL.
      
       (5) As a temporary affair, keyring_restrict_trusted_only() is added.  It
           should be passed to keyring_alloc() as the extra argument instead of
           setting KEY_FLAG_TRUSTED_ONLY on a keyring.  This will be replaced in
           a later patch with functions that look in the appropriate places for
           authoritative keys.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      Reviewed-by: 's avatarMimi Zohar <zohar@linux.vnet.ibm.com>
      5ac7eace
  3. 06 Apr, 2016 2 commits
    • David Howells's avatar
      PKCS#7: Make trust determination dependent on contents of trust keyring · bda850cd
      David Howells authored
      Make the determination of the trustworthiness of a key dependent on whether
      a key that can verify it is present in the supplied ring of trusted keys
      rather than whether or not the verifying key has KEY_FLAG_TRUSTED set.
      
      verify_pkcs7_signature() will return -ENOKEY if the PKCS#7 message trust
      chain cannot be verified.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      bda850cd
    • David Howells's avatar
      KEYS: Generalise system_verify_data() to provide access to internal content · e68503bd
      David Howells authored
      Generalise system_verify_data() to provide access to internal content
      through a callback.  This allows all the PKCS#7 stuff to be hidden inside
      this function and removed from the PE file parser and the PKCS#7 test key.
      
      If external content is not required, NULL should be passed as data to the
      function.  If the callback is not required, that can be set to NULL.
      
      The function is now called verify_pkcs7_signature() to contrast with
      verify_pefile_signature() and the definitions of both have been moved into
      linux/verification.h along with the key_being_used_for enum.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      e68503bd
  4. 29 Feb, 2016 1 commit
  5. 26 Feb, 2016 2 commits
    • Mehmet Kayaalp's avatar
      KEYS: Reserve an extra certificate symbol for inserting without recompiling · c4c36105
      Mehmet Kayaalp authored
      Place a system_extra_cert buffer of configurable size, right after the
      system_certificate_list, so that inserted keys can be readily processed by
      the existing mechanism. Added script takes a key file and a kernel image
      and inserts its contents to the reserved area. The
      system_certificate_list_size is also adjusted accordingly.
      
      Call the script as:
      
          scripts/insert-sys-cert -b <vmlinux> -c <certfile>
      
      If vmlinux has no symbol table, supply System.map file with -s flag.
      Subsequent runs replace the previously inserted key, instead of appending
      the new one.
      Signed-off-by: 's avatarMehmet Kayaalp <mkayaalp@linux.vnet.ibm.com>
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      Acked-by: 's avatarMimi Zohar <zohar@linux.vnet.ibm.com>
      c4c36105
    • Arnd Bergmann's avatar
      modsign: hide openssl output in silent builds · 5d06ee20
      Arnd Bergmann authored
      When a user calls 'make -s', we can assume they don't want to
      see any output except for warnings and errors, but instead
      they see this for a warning free build:
      
       ###
       ### Now generating an X.509 key pair to be used for signing modules.
       ###
       ### If this takes a long time, you might wish to run rngd in the
       ### background to keep the supply of entropy topped up.  It
       ### needs to be run as root, and uses a hardware random
       ### number generator if one is available.
       ###
       Generating a 4096 bit RSA private key
       .................................................................................................................................................................................................................................++
       ..............................................................................................................................++
       writing new private key to 'certs/signing_key.pem'
       -----
       ###
       ### Key pair generated.
       ###
      
      The output can confuse simple build testing scripts that just check
      for an empty build log.
      
      This patch silences all the output:
       - "echo" is changed to "@$(kecho)", which is dropped when "-s" gets
         passed
       - the openssl command itself is only printed with V=1, using the
         $(Q) macro
       - The output of openssl gets redirected to /dev/null on "-s" builds.
      Signed-off-by: 's avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      5d06ee20
  6. 09 Feb, 2016 1 commit
  7. 21 Oct, 2015 1 commit
  8. 14 Aug, 2015 3 commits
    • David Woodhouse's avatar
      modsign: Handle signing key in source tree · 3ee550f1
      David Woodhouse authored
      Since commit 1329e8cc ("modsign: Extract signing cert from
      CONFIG_MODULE_SIG_KEY if needed"), the build system has carefully coped
      with the signing key being specified as a relative path in either the
      source or or the build trees.
      
      However, the actual signing of modules has not worked if the filename
      is relative to the source tree.
      
      Fix that by moving the config_filename helper into scripts/Kbuild.include
      so that it can be used from elsewhere, and then using it in the top-level
      Makefile to find the signing key file.
      
      Kill the intermediate $(MODPUBKEY) and $(MODSECKEY) variables too, while
      we're at it. There's no need for them.
      Signed-off-by: 's avatarDavid Woodhouse <David.Woodhouse@intel.com>
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      3ee550f1
    • David Woodhouse's avatar
      modsign: Use if_changed rule for extracting cert from module signing key · 62172c81
      David Woodhouse authored
      We couldn't use if_changed for this before, because it didn't live in
      the kernel/ directory so we couldn't add it to $(targets). It was easier
      just to leave it as it was.
      
      Now it's in the certs/ directory we can use if_changed, the same as we
      do for the trusted certificate list.
      
      Aside from making things consistent, this means we don't need to depend
      explicitly on the include/config/module/sig/key.h file. And we also get
      to automatically do the right thing and re-extract the cert if the user
      does odd things like using a relative filename and then playing silly
      buggers with adding/removing that file in both the source and object
      trees. We always favour the one in the object tree if it exists, and
      now we'll correctly re-extract the cert when it changes. Previously we'd
      *only* re-extract the cert if the config option changed, even if the
      actual file we're using did change.
      Signed-off-by: 's avatarDavid Woodhouse <David.Woodhouse@intel.com>
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      62172c81
    • David Howells's avatar
      Move certificate handling to its own directory · cfc411e7
      David Howells authored
      Move certificate handling out of the kernel/ directory and into a certs/
      directory to get all the weird stuff in one place and move the generated
      signing keys into this directory.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      Reviewed-by: 's avatarDavid Woodhouse <David.Woodhouse@intel.com>
      cfc411e7