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    Subject[RFC][PATCH 00/16] Crypto keys and module signing [ver #2]
    Date

    Here are a set of patches that create a framework for using cryptographic keys
    within the kernel. The patches can also be found at:

    http://git.kernel.org/?p=linux/kernel/git/dhowells/linux-modsign.git;a=shortlog;h=refs/heads/devel

    The basic crypto key has no requirements as to how the key is implemented; it's
    basically a jump table for the operations and an anchor for any relevant data.

    I have provided a couple of subtypes: DSA and RSA. Both types have signature
    verification facilities available within the kernel, and both can be used for
    module signature verification with any encryption algorithm known by the PGP
    parser, provided the appropriate algorithm is compiled directly into the
    kernel.

    These two subtypes store their public key data attached to the key and
    implement the algorithms within the kernel. However, it would be possible to
    merely refer to keys held in a hardware keystore (such as a TPM) and have the
    accessor methods offload the actual work to that keystore to be done in
    hardware.

    With kernel module signing enabled, and a pair of keys (one RSA, one DSA)
    compiled into the kernel, root can see these keys and the keyring that holds
    them in /proc/keys:

    195fa736 I----- 1 perm 3f010000 0 0 crypto modsign.1: dsa 5acc2142 []
    335ab517 I----- 1 perm 1f030000 0 0 keyring .module_sign: 2/4
    38d7d169 I----- 1 perm 3f010000 0 0 crypto modsign.0: rsa 57532ca5 []

    Module signing combinations that have been tested: DSA with SHA1 and RSA with
    all the SHA algorithms.

    The patches break down into a number of areas:

    (0) Dmitry Kasatkin's MPI library patches - which I have not included in this
    posting, but can be obtained from the GIT tree.

    (1) Utility: MPI function exports and make key_serial() handle a const
    pointer. Also fix a bug in the MPI library.

    (2) PGP defs and PGP packet parser; basic crypto key infrastructure.

    (3) DSA key and RSA key basic implementations.

    (4) PGP signature parser; signature verification operations.

    (5) DSA and RSA verification algorithms.

    (6) Module ELF verification and module signature verification.

    The complete crypto type documentation can be found within the GIT tree here:

    http://git.kernel.org/?p=linux/kernel/git/dhowells/linux-modsign.git;a=blob;f=Documentation/security/keys-crypto.txt;h=35e61b1bc636543bc77c0c2a33c3ef323b9f96b5;hb=6eea6dc28e465163611d26112f0ea68ec0e0a0d2

    and the module signature verification documentation can be found here:

    http://git.kernel.org/?p=linux/kernel/git/dhowells/linux-modsign.git;a=blob;f=Documentation/module-signing.txt;h=300b91a701818409f37f6065d5f14c5c73ce1b44;hb=20258f1df3a9580a26c5fc5028086bf02d28974d

    ---
    Changes made 29/11/2011:

    (*) Added RSA signature verification.

    (*) Stopped signature verification crashing on unsupported hash algorithm.

    (*) Fixed ENOMEM handling bug in MPI.

    (*) Worked around ccache problems with compilation of PGP public keyring into
    kernel (ccache hashes the preprocessor output, but the assembler includes
    the binary data, so ccache doesn't see that it changed).

    (*) Added a choice in kernel config for hash algorithm to use; forced the
    appropriate crypto module to be built directly into the kernel.

    (*) Cleaned out some debugging code.

    (*) Updated documentation.

    David
    ---
    David Howells (16):
    MODSIGN: Apply signature checking to modules on module load
    MODSIGN: Module ELF verifier
    MODSIGN: Add indications of module ELF types
    KEYS: Provide a function to load keys from a PGP keyring blob
    KEYS: Add a crypto key request function
    KEYS: RSA key signature verification
    KEYS: DSA key signature verification
    KEYS: Add signature verification facility
    PGP: Add signature parser
    KEYS: Add a RSA crypto key subtype
    KEYS: Add a DSA crypto key subtype
    KEYS: Create a key type that can be used for general cryptographic operations
    PGP: Add definitions (RFC 4880) and packet parser
    KEYS: Permit key_serial() to be called with a const key pointer
    MPILIB: Add a missing ENOMEM check
    MPILIB: Export some more symbols


    .gitignore | 15 +
    Documentation/module-signing.txt | 186 +++++++
    Documentation/security/keys-crypto.txt | 299 ++++++++++
    Makefile | 1
    arch/alpha/include/asm/module.h | 3
    arch/arm/include/asm/module.h | 5
    arch/cris/include/asm/module.h | 5
    arch/h8300/include/asm/module.h | 5
    arch/ia64/include/asm/module.h | 5
    arch/m32r/include/asm/module.h | 5
    arch/m68k/include/asm/module.h | 5
    arch/mips/include/asm/module.h | 12
    arch/parisc/include/asm/module.h | 8
    arch/powerpc/include/asm/module.h | 10
    arch/s390/include/asm/module.h | 3
    include/asm-generic/module.h | 10
    include/keys/crypto-subtype.h | 61 ++
    include/keys/crypto-type.h | 40 +
    include/linux/elfnote.h | 4
    include/linux/key.h | 2
    include/linux/modsign.h | 27 +
    include/linux/module.h | 3
    include/linux/pgp.h | 254 +++++++++
    init/Kconfig | 62 ++
    kernel/Makefile | 4
    kernel/modsign-pubkey.c | 44 ++
    kernel/module-verify-elf.c | 344 ++++++++++++
    kernel/module-verify-sig.c | 535 +++++++++++++++++++
    kernel/module-verify.c | 44 ++
    kernel/module-verify.h | 68 ++
    kernel/module.c | 25 +
    lib/mpi/mpi-cmp.c | 2
    lib/mpi/mpi-div.c | 1
    lib/mpi/mpi-inv.c | 1
    lib/mpi/mpi-mpow.c | 1
    lib/mpi/mpi-mul.c | 1
    lib/mpi/mpicoder.c | 2
    scripts/Makefile.modpost | 85 +++
    scripts/mod/.gitignore | 1
    scripts/mod/Makefile | 2
    scripts/mod/mod-extract.c | 913 ++++++++++++++++++++++++++++++++
    scripts/mod/modsign-note.sh | 16 +
    security/Kconfig | 27 +
    security/keys/Makefile | 7
    security/keys/crypto_dsa.h | 47 ++
    security/keys/crypto_dsa_subtype.c | 338 ++++++++++++
    security/keys/crypto_dsa_verify.c | 384 +++++++++++++
    security/keys/crypto_keys.h | 21 +
    security/keys/crypto_request.c | 153 +++++
    security/keys/crypto_rsa.h | 47 ++
    security/keys/crypto_rsa_subtype.c | 386 ++++++++++++++
    security/keys/crypto_rsa_verify.c | 519 ++++++++++++++++++
    security/keys/crypto_type.c | 315 +++++++++++
    security/keys/crypto_verify.c | 87 +++
    security/keys/pgp_parse.c | 528 +++++++++++++++++++
    55 files changed, 5968 insertions(+), 10 deletions(-)
    create mode 100644 Documentation/module-signing.txt
    create mode 100644 Documentation/security/keys-crypto.txt
    create mode 100644 include/keys/crypto-subtype.h
    create mode 100644 include/keys/crypto-type.h
    create mode 100644 include/linux/modsign.h
    create mode 100644 include/linux/pgp.h
    create mode 100644 kernel/modsign-pubkey.c
    create mode 100644 kernel/module-verify-elf.c
    create mode 100644 kernel/module-verify-sig.c
    create mode 100644 kernel/module-verify.c
    create mode 100644 kernel/module-verify.h
    create mode 100644 scripts/mod/mod-extract.c
    create mode 100644 scripts/mod/modsign-note.sh
    create mode 100644 security/keys/crypto_dsa.h
    create mode 100644 security/keys/crypto_dsa_subtype.c
    create mode 100644 security/keys/crypto_dsa_verify.c
    create mode 100644 security/keys/crypto_keys.h
    create mode 100644 security/keys/crypto_request.c
    create mode 100644 security/keys/crypto_rsa.h
    create mode 100644 security/keys/crypto_rsa_subtype.c
    create mode 100644 security/keys/crypto_rsa_verify.c
    create mode 100644 security/keys/crypto_type.c
    create mode 100644 security/keys/crypto_verify.c
    create mode 100644 security/keys/pgp_parse.c



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