Messages in this thread | | | Date | Fri, 21 Nov 2014 14:59:46 +0200 | From | Dmitry Kasatkin <> | Subject | Re: [PATCH 0/5] MODSIGN: Use PKCS#7 for module signatures |
| |
Hi David,
Before I go into reviewing the patches just want to let you know that Integrity stuff seems to work fine with these changes.
Thanks, Dmitry
On 20/11/14 18:53, David Howells wrote: > Here's a set of patches that does the following: > > (1) Extracts both parts of an X.509 AuthorityKeyIdentifier (AKID) extension. > We already extract the bit that can match the subjectKeyIdentifier (SKID) > of the parent X.509 cert, but we currently ignore the bits that can match > the issuer and serialNumber. > > Looks up an X.509 cert by issuer and serialNumber if those are provided in > the AKID. If the keyIdentifier is also provided, checks that the > subjectKeyIdentifier of the cert found matches that also. > > If no issuer and serialNumber are provided in the AKID, looks up an X.509 > cert by SKID using the AKID keyIdentifier. > > This allows module signing to be done with certificates that don't have an > SKID by which they can be looked up. > > (2) Makes use of the PKCS#7 facility to provide module signatures. > > sign-file is replaced with a program that generates a PKCS#7 message that > has no X.509 certs embedded and that has detached data (the module > content) and adds it onto the message with magic string and descriptor. > > (3) The PKCS#7 message (and matching X.509 cert) supply all the information > that is needed to select the X.509 cert to be used to verify the signature > by standard means (including selection of digest algorithm and public key > algorithm). No kernel-specific magic values are required. > > Note that the revised sign-file program no longer supports the "-s <signature>" > option as I'm not sure what the best way to deal with this is. Do we generate > a PKCS#7 cert from the signature given, or do we get given a PKCS#7 cert? I > lean towards the latter. > > They can be found here also: > > http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=modsign-pkcs7 > > These patches are based on the security tree's next branch. > > David > --- > David Howells (5): > X.509: Extract both parts of the AuthorityKeyIdentifier > X.509: Support X.509 lookup by Issuer+Serial form AuthorityKeyIdentifier > PKCS#7: Allow detached data to be supplied for signature checking purposes > MODSIGN: Provide a utility to append a PKCS#7 signature to a module > MODSIGN: Use PKCS#7 messages as module signatures > > > crypto/asymmetric_keys/Makefile | 8 - > crypto/asymmetric_keys/pkcs7_trust.c | 10 - > crypto/asymmetric_keys/pkcs7_verify.c | 81 ++++-- > crypto/asymmetric_keys/x509_akid.asn1 | 35 ++ > crypto/asymmetric_keys/x509_cert_parser.c | 142 ++++++---- > crypto/asymmetric_keys/x509_parser.h | 3 > crypto/asymmetric_keys/x509_public_key.c | 85 ++++-- > include/crypto/pkcs7.h | 3 > include/crypto/public_key.h | 4 > init/Kconfig | 1 > kernel/module_signing.c | 220 +++------------ > scripts/Makefile | 2 > scripts/sign-file | 421 ----------------------------- > scripts/sign-file.c | 189 +++++++++++++ > 14 files changed, 505 insertions(+), 699 deletions(-) > create mode 100644 crypto/asymmetric_keys/x509_akid.asn1 > delete mode 100755 scripts/sign-file > create mode 100755 scripts/sign-file.c > >
| |