From: David Howells Date: Wed, 26 Sep 2012 09:11:03 +0000 (+0100) Subject: MODSIGN: Implement module signature checking X-Git-Tag: v3.7-rc1~2^2~9 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48ba2462ace6072741fd8d0058207d630ce93bf1;p=pandora-kernel.git MODSIGN: Implement module signature checking Check the signature on the module against the keys compiled into the kernel or available in a hardware key store. Currently, only RSA keys are supported - though that's easy enough to change, and the signature is expected to contain raw components (so not a PGP or PKCS#7 formatted blob). The signature blob is expected to consist of the following pieces in order: (1) The binary identifier for the key. This is expected to match the SubjectKeyIdentifier from an X.509 certificate. Only X.509 type identifiers are currently supported. (2) The signature data, consisting of a series of MPIs in which each is in the format of a 2-byte BE word sizes followed by the content data. (3) A 12 byte information block of the form: struct module_signature { enum pkey_algo algo : 8; enum pkey_hash_algo hash : 8; enum pkey_id_type id_type : 8; u8 __pad; __be32 id_length; __be32 sig_length; }; The three enums are defined in crypto/public_key.h. 'algo' contains the public-key algorithm identifier (0->DSA, 1->RSA). 'hash' contains the digest algorithm identifier (0->MD4, 1->MD5, 2->SHA1, etc.). 'id_type' contains the public-key identifier type (0->PGP, 1->X.509). '__pad' should be 0. 'id_length' should contain in the binary identifier length in BE form. 'sig_length' should contain in the signature data length in BE form. The lengths are in BE order rather than CPU order to make dealing with cross-compilation easier. Signed-off-by: David Howells Signed-off-by: Rusty Russell (minor Kconfig fix) --- Reading git-diff-tree failed