diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c new file mode 100644 index 0000000000..7748cc23de --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu <roberto.sassu@huawei.com> + */ + +#include "vmlinux.h" +#include <errno.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.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; + +struct data { + __u8 data[MAX_DATA_SIZE]; + __u32 data_len; + __u8 sig[MAX_SIG_SIZE]; + __u32 sig_len; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, struct data); +} data_input SEC(".maps"); + +char _license[] SEC("license") = "GPL"; + +SEC("lsm.s/bpf") +int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size) +{ + struct bpf_dynptr data_ptr, sig_ptr; + struct data *data_val; + struct bpf_key *trusted_keyring; + __u32 pid; + __u64 value; + int ret, zero = 0; + + pid = bpf_get_current_pid_tgid() >> 32; + if (pid != monitored_pid) + return 0; + + data_val = bpf_map_lookup_elem(&data_input, &zero); + if (!data_val) + return 0; + + ret = bpf_probe_read_kernel(&value, sizeof(value), &attr->value); + if (ret) + return ret; + + ret = bpf_copy_from_user(data_val, sizeof(struct data), + (void *)(unsigned long)value); + if (ret) + return ret; + + if (data_val->data_len > sizeof(data_val->data)) + return -EINVAL; + + bpf_dynptr_from_mem(data_val->data, data_val->data_len, 0, &data_ptr); + + if (data_val->sig_len > sizeof(data_val->sig)) + return -EINVAL; + + bpf_dynptr_from_mem(data_val->sig, data_val->sig_len, 0, &sig_ptr); + + if (user_keyring_serial) + trusted_keyring = bpf_lookup_user_key(user_keyring_serial, 0); + else + trusted_keyring = bpf_lookup_system_key(system_keyring_id); + + if (!trusted_keyring) + return -ENOENT; + + ret = bpf_verify_pkcs7_signature(&data_ptr, &sig_ptr, trusted_keyring); + + bpf_key_put(trusted_keyring); + + return ret; +} |