| Message ID | 20220825142314.8406-1-jlee@suse.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Check codeSigning extended key usage extension | expand |
On Thu, Aug 25, 2022 at 10:23:10PM +0800, Lee, Chun-Yi wrote: > NIAP PP_OS certification requests that OS need to validate the > CodeSigning extended key usage extension field for integrity > verifiction of exectable code: > > https://www.niap-ccevs.org/MMO/PP/-442-/ > FIA_X509_EXT.1.1 > > This patchset adds the logic for parsing the codeSigning EKU extension > field in X.509. And checking the CodeSigning EKU when verifying > signature of kernel module or kexec PE binary in PKCS#7. Might be cutting hairs here but you don't really explain why we want to support it. It's not a counter argument to add the feature. It's a counter argument against adding undocumented features. BR, Jarkko
Hi Jarkko, On Sun, Aug 28, 2022 at 06:30:23AM +0300, Jarkko Sakkinen wrote: > On Thu, Aug 25, 2022 at 10:23:10PM +0800, Lee, Chun-Yi wrote: > > NIAP PP_OS certification requests that OS need to validate the > > CodeSigning extended key usage extension field for integrity > > verifiction of exectable code: > > > > https://www.niap-ccevs.org/MMO/PP/-442-/ > > FIA_X509_EXT.1.1 > > > > This patchset adds the logic for parsing the codeSigning EKU extension > > field in X.509. And checking the CodeSigning EKU when verifying > > signature of kernel module or kexec PE binary in PKCS#7. > > Might be cutting hairs here but you don't really explain > why we want to support it. It's not a counter argument > to add the feature. It's a counter argument against adding > undocumented features. > In some cases, a organization may publish different certificates for difference purposes. When a certificate for a specific purpose is leaked, it will not affect other certificates. The function for using a code signing certificate to verify kernel binary or module can restrict the purpose of the certificate to avoid attacker uses other leaked non-codeSigning certificate for signing. Thanks a lot! Joey Lee
NIAP PP_OS certification requests that OS need to validate the CodeSigning extended key usage extension field for integrity verifiction of exectable code: https://www.niap-ccevs.org/MMO/PP/-442-/ FIA_X509_EXT.1.1 This patchset adds the logic for parsing the codeSigning EKU extension field in X.509. And checking the CodeSigning EKU when verifying signature of kernel module or kexec PE binary in PKCS#7. v9: - Rename the eku element in public_key structure to ext_key_usage. - Fix selftest.c v8: - Fixed the bug of is_key_on_revocation_list() when CONFIG_SYSTEM_REVOCATION_LIST is not set. v7: - Fixed the broken function call in is_key_on_revocation_list(). (be found by kernel test robot) - Use a general name check_eku_by_usage() instead of check_codesign_eku(). v6: - Add more length checking when parsing extKeyUsage and EKU's OID blob. - Add 'usage' parameter to the comment of pkcs7_validate_trust function. v5: Fixed the wording in module-signing.rst. v4: Fixed the wording in patch description. v3: - Add codeSigning EKU to x509.genkey key generation config. - Add openssl command option example for generating CodeSign EKU to module-signing.rst document. v2: Changed the help wording in the Kconfig. Lee, Chun-Yi (4): X.509: Add CodeSigning extended key usage parsing PKCS#7: Check codeSigning EKU for kernel module and kexec pe verification modsign: Add codeSigning EKU when generating X.509 key generation config Documentation/admin-guide/module-signing.rst: add openssl command option example for CodeSign EKU Documentation/admin-guide/module-signing.rst | 6 +++ certs/blacklist.c | 5 ++- certs/default_x509.genkey | 1 + certs/system_keyring.c | 4 +- crypto/asymmetric_keys/Kconfig | 9 ++++ crypto/asymmetric_keys/pkcs7_trust.c | 43 ++++++++++++++++++-- crypto/asymmetric_keys/selftest.c | 2 +- crypto/asymmetric_keys/x509_cert_parser.c | 25 ++++++++++++ include/crypto/pkcs7.h | 4 +- include/crypto/public_key.h | 1 + include/keys/system_keyring.h | 7 +++- include/linux/oid_registry.h | 5 +++ 12 files changed, 101 insertions(+), 11 deletions(-)