df71837d50
This patch series implements per packet access control via the extension of the Linux Security Modules (LSM) interface by hooks in the XFRM and pfkey subsystems that leverage IPSec security associations to label packets. Extensions to the SELinux LSM are included that leverage the patch for this purpose. This patch implements the changes necessary to the XFRM subsystem, pfkey interface, ipv4/ipv6, and xfrm_user interface to restrict a socket to use only authorized security associations (or no security association) to send/receive network packets. Patch purpose: The patch is designed to enable access control per packets based on the strongly authenticated IPSec security association. Such access controls augment the existing ones based on network interface and IP address. The former are very coarse-grained, and the latter can be spoofed. By using IPSec, the system can control access to remote hosts based on cryptographic keys generated using the IPSec mechanism. This enables access control on a per-machine basis or per-application if the remote machine is running the same mechanism and trusted to enforce the access control policy. Patch design approach: The overall approach is that policy (xfrm_policy) entries set by user-level programs (e.g., setkey for ipsec-tools) are extended with a security context that is used at policy selection time in the XFRM subsystem to restrict the sockets that can send/receive packets via security associations (xfrm_states) that are built from those policies. A presentation available at www.selinux-symposium.org/2005/presentations/session2/2-3-jaeger.pdf from the SELinux symposium describes the overall approach. Patch implementation details: On output, the policy retrieved (via xfrm_policy_lookup or xfrm_sk_policy_lookup) must be authorized for the security context of the socket and the same security context is required for resultant security association (retrieved or negotiated via racoon in ipsec-tools). This is enforced in xfrm_state_find. On input, the policy retrieved must also be authorized for the socket (at __xfrm_policy_check), and the security context of the policy must also match the security association being used. The patch has virtually no impact on packets that do not use IPSec. The existing Netfilter (outgoing) and LSM rcv_skb hooks are used as before. Also, if IPSec is used without security contexts, the impact is minimal. The LSM must allow such policies to be selected for the combination of socket and remote machine, but subsequent IPSec processing proceeds as in the original case. Testing: The pfkey interface is tested using the ipsec-tools. ipsec-tools have been modified (a separate ipsec-tools patch is available for version 0.5) that supports assignment of xfrm_policy entries and security associations with security contexts via setkey and the negotiation using the security contexts via racoon. The xfrm_user interface is tested via ad hoc programs that set security contexts. These programs are also available from me, and contain programs for setting, getting, and deleting policy for testing this interface. Testing of sa functions was done by tracing kernel behavior. Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
106 lines
3.3 KiB
Plaintext
106 lines
3.3 KiB
Plaintext
#
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# Security configuration
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#
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menu "Security options"
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config KEYS
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bool "Enable access key retention support"
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help
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This option provides support for retaining authentication tokens and
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access keys in the kernel.
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It also includes provision of methods by which such keys might be
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associated with a process so that network filesystems, encryption
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support and the like can find them.
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Furthermore, a special type of key is available that acts as keyring:
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a searchable sequence of keys. Each process is equipped with access
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to five standard keyrings: UID-specific, GID-specific, session,
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process and thread.
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If you are unsure as to whether this is required, answer N.
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config KEYS_DEBUG_PROC_KEYS
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bool "Enable the /proc/keys file by which all keys may be viewed"
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depends on KEYS
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help
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This option turns on support for the /proc/keys file through which
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all the keys on the system can be listed.
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This option is a slight security risk in that it makes it possible
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for anyone to see all the keys on the system. Normally the manager
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pretends keys that are inaccessible to a process don't exist as far
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as that process is concerned.
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config SECURITY
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bool "Enable different security models"
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depends on SYSFS
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help
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This allows you to choose different security modules to be
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configured into your kernel.
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If this option is not selected, the default Linux security
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model will be used.
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If you are unsure how to answer this question, answer N.
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config SECURITY_NETWORK
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bool "Socket and Networking Security Hooks"
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depends on SECURITY
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help
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This enables the socket and networking security hooks.
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If enabled, a security module can use these hooks to
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implement socket and networking access controls.
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If you are unsure how to answer this question, answer N.
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config SECURITY_NETWORK_XFRM
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bool "XFRM (IPSec) Networking Security Hooks"
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depends on XFRM && SECURITY_NETWORK
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help
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This enables the XFRM (IPSec) networking security hooks.
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If enabled, a security module can use these hooks to
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implement per-packet access controls based on labels
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derived from IPSec policy. Non-IPSec communications are
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designated as unlabelled, and only sockets authorized
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to communicate unlabelled data can send without using
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IPSec.
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If you are unsure how to answer this question, answer N.
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config SECURITY_CAPABILITIES
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tristate "Default Linux Capabilities"
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depends on SECURITY
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help
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This enables the "default" Linux capabilities functionality.
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If you are unsure how to answer this question, answer Y.
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config SECURITY_ROOTPLUG
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tristate "Root Plug Support"
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depends on USB && SECURITY
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help
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This is a sample LSM module that should only be used as such.
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It prevents any programs running with egid == 0 if a specific
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USB device is not present in the system.
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See <http://www.linuxjournal.com/article.php?sid=6279> for
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more information about this module.
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If you are unsure how to answer this question, answer N.
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config SECURITY_SECLVL
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tristate "BSD Secure Levels"
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depends on SECURITY
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select CRYPTO
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select CRYPTO_SHA1
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help
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Implements BSD Secure Levels as an LSM. See
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<file:Documentation/seclvl.txt> for instructions on how to use this
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module.
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If you are unsure how to answer this question, answer N.
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source security/selinux/Kconfig
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endmenu
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