From 1030e9154258b54e3c7dc07c39e7b6dcf24bc3d2 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Wed, 29 Nov 2023 15:44:17 -0800 Subject: selftests/bpf: Add test that uses fsverity and xattr to sign a file This selftests shows a proof of concept method to use BPF LSM to enforce file signature. This test is added to verify_pkcs7_sig, so that some existing logic can be reused. This file signature method uses fsverity, which provides reliable and efficient hash (known as digest) of the file. The file digest is signed with asymmetic key, and the signature is stored in xattr. At the run time, BPF LSM reads file digest and the signature, and then checks them against the public key. Note that this solution does NOT require FS_VERITY_BUILTIN_SIGNATURES. fsverity is only used to provide file digest. The signature verification and access control is all implemented in BPF LSM. Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20231129234417.856536-7-song@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c') diff --git a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c index 7748cc23de8a..f42e9f3831a1 100644 --- a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c +++ b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c @@ -10,17 +10,11 @@ #include #include #include +#include "bpf_kfuncs.h" #define MAX_DATA_SIZE (1024 * 1024) #define MAX_SIG_SIZE 1024 -extern struct bpf_key *bpf_lookup_user_key(__u32 serial, __u64 flags) __ksym; -extern struct bpf_key *bpf_lookup_system_key(__u64 id) __ksym; -extern void bpf_key_put(struct bpf_key *key) __ksym; -extern int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_ptr, - struct bpf_dynptr *sig_ptr, - struct bpf_key *trusted_keyring) __ksym; - __u32 monitored_pid; __u32 user_keyring_serial; __u64 system_keyring_id; -- cgit