lkml.org 
[lkml]   [2019]   [Jan]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 2/2] kexec, KEYS: Make use of platform keyring for signature verify
Date
This patch let kexec_file_load makes use of .platform keyring as fall
back if it failed to verify a PE signed image against secondary or
builtin key ring, make it possible to verify kernel image signed with
preboot keys as well.

This commit adds a VERIFY_USE_PLATFORM_KEYRING similar to previous
VERIFY_USE_SECONDARY_KEYRING indicating that verify_pkcs7_signature
should verify the signature using platform keyring. Also, decrease
the error message log level when verification failed with -ENOKEY,
so that if called tried multiple time with different keyring it
won't generate extra noises.

Signed-off-by: Kairui Song <kasong@redhat.com>
---
arch/x86/kernel/kexec-bzimage64.c | 13 ++++++++++---
certs/system_keyring.c | 13 ++++++++++++-
include/linux/verification.h | 1 +
3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 7d97e432cbbc..2c007abd3d40 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -534,9 +534,16 @@ static int bzImage64_cleanup(void *loader_data)
#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
{
- return verify_pefile_signature(kernel, kernel_len,
- VERIFY_USE_SECONDARY_KEYRING,
- VERIFYING_KEXEC_PE_SIGNATURE);
+ int ret;
+ ret = verify_pefile_signature(kernel, kernel_len,
+ VERIFY_USE_SECONDARY_KEYRING,
+ VERIFYING_KEXEC_PE_SIGNATURE);
+ if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) {
+ ret = verify_pefile_signature(kernel, kernel_len,
+ VERIFY_USE_PLATFORM_KEYRING,
+ VERIFYING_KEXEC_PE_SIGNATURE);
+ }
+ return ret;
}
#endif

diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 4690ef9cda8a..7085c286f4bd 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -240,11 +240,22 @@ int verify_pkcs7_signature(const void *data, size_t len,
#else
trusted_keys = builtin_trusted_keys;
#endif
+ } else if (trusted_keys == VERIFY_USE_PLATFORM_KEYRING) {
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+ trusted_keys = platform_trusted_keys;
+#else
+ trusted_keys = NULL;
+#endif
+ if (!trusted_keys) {
+ ret = -ENOKEY;
+ pr_devel("PKCS#7 platform keyring is not available\n");
+ goto error;
+ }
}
ret = pkcs7_validate_trust(pkcs7, trusted_keys);
if (ret < 0) {
if (ret == -ENOKEY)
- pr_err("PKCS#7 signature not signed with a trusted key\n");
+ pr_devel("PKCS#7 signature not signed with a trusted key\n");
goto error;
}

diff --git a/include/linux/verification.h b/include/linux/verification.h
index cfa4730d607a..018fb5f13d44 100644
--- a/include/linux/verification.h
+++ b/include/linux/verification.h
@@ -17,6 +17,7 @@
* should be used.
*/
#define VERIFY_USE_SECONDARY_KEYRING ((struct key *)1UL)
+#define VERIFY_USE_PLATFORM_KEYRING ((struct key *)2UL)

/*
* The use to which an asymmetric key is being put.
--
2.20.1
\
 
 \ /
  Last update: 2019-01-21 11:00    [W:0.048 / U:6.720 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site