[RFC][PATCH 5/6] selftests/bpf: Prepare a test for UMD-parsed signatures

25 Apr 2023

From: Roberto Sassu roberto.sassu@huawei.com
Reuse the existing test for PKCS#7 signatures, to test also UMD-parsed
signatures.
Don't enable the test just yet, as the test would fail without a UMD parser
for PGP keys and signatures.
Signed-off-by: Roberto Sassu roberto.sassu@huawei.com
---
 ...ify_pkcs7_sig.c => verify_pkcs7_umd_sig.c} | 109 ++++++++++++++----
 ...kcs7_sig.c => test_verify_pkcs7_umd_sig.c} |  18 ++-
 .../testing/selftests/bpf/verify_sig_setup.sh |  82 +++++++++++--
 3 files changed, 176 insertions(+), 33 deletions(-)
 rename tools/testing/selftests/bpf/prog_tests/{verify_pkcs7_sig.c => verify_pkcs7_umd_sig.c} (75%)
 rename tools/testing/selftests/bpf/progs/{test_verify_pkcs7_sig.c => test_verify_pkcs7_umd_sig.c} (82%)

diff --git a/tools/testing/selftests/bpf/prog_tests/verify_pkcs7_sig.c b/tools/testing/selftests/bpf/prog_tests/verify_pkcs7_umd_sig.c
similarity index 75%
rename from tools/testing/selftests/bpf/prog_tests/verify_pkcs7_sig.c
rename to tools/testing/selftests/bpf/prog_tests/verify_pkcs7_umd_sig.c
index dd7f2bc7004..94d78146989 100644
--- a/tools/testing/selftests/bpf/prog_tests/verify_pkcs7_sig.c
+++ b/tools/testing/selftests/bpf/prog_tests/verify_pkcs7_umd_sig.c
@@ -18,7 +18,7 @@
 #include <linux/keyctl.h>
 #include <test_progs.h>
-#include "test_verify_pkcs7_sig.skel.h"
+#include "test_verify_pkcs7_umd_sig.skel.h"
#define MAX_DATA_SIZE (1024 * 1024)
 #define MAX_SIG_SIZE 1024
@@ -29,6 +29,24 @@
 /* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
 #define MODULE_SIG_STRING "~Module signature appended~\n"
+#define PKEY_ID_PGP 0
+#define PKEY_ID_X509 1
+#define PKEY_ID_PKCS7 2
+
+static char *key_types_str[PKEY_ID_PKCS7 + 1] = {
+	[PKEY_ID_PGP] = "pgp",
+	[PKEY_ID_X509] = "x509",
+	[PKEY_ID_PKCS7] = "pkcs7",
+};
+
+enum algos { ALGO_RSA, ALGO_ECDSA_P256, ALGO_ECDSA_P384, ALGO__LAST };
+
+static char *algos_str[ALGO_ECDSA_P384 + 1] = {
+	[ALGO_RSA] = "rsa",
+	[ALGO_ECDSA_P256] = "ecdsa_p256",
+	[ALGO_ECDSA_P384] = "ecdsa_p384",
+};
+
 /*
  * Module signature information block.
  *
@@ -74,13 +92,15 @@ static int libbpf_print_cb(enum libbpf_print_level level, const char *fmt,
    return 0;
 }
-static int _run_setup_process(const char *setup_dir, const char *cmd)
+static int _run_setup_process(const char *setup_dir, const char *cmd,
+			      __u8 key_type, __u8 pkey_algo)
 {
    int child_pid, child_status;
child_pid = fork();
    if (child_pid == 0) {
-		execlp("./verify_sig_setup.sh", "./verify_sig_setup.sh", cmd,
+		execlp("./verify_sig_setup.sh", "./verify_sig_setup.sh",
+		       cmd, key_types_str[key_type], algos_str[pkey_algo] ?: "",
    	       setup_dir, NULL);
    	exit(errno);
@@ -92,7 +112,8 @@ static int _run_setup_process(const char *setup_dir, const char *cmd)
    return -EINVAL;
 }
-static int populate_data_item_str(const char *tmp_dir, struct data *data_item)
+static int populate_data_item_str(const char *tmp_dir, __u8 key_type,
+				  struct data *data_item)
 {
    struct stat st;
    char data_template[] = "/tmp/dataXXXXXX";
@@ -123,10 +144,26 @@ static int populate_data_item_str(const char *tmp_dir, struct data *data_item)
    }
if (child_pid == 0) {
-		snprintf(path, sizeof(path), "%s/signing_key.pem", tmp_dir);
-
-		return execlp("./sign-file", "./sign-file", "-d", "sha256",
-			      path, path, data_template, NULL);
+		if (key_type == PKEY_ID_PKCS7) {
+			snprintf(path, sizeof(path), "%s/signing_key.pem",
+				 tmp_dir);
+
+			return execlp("./sign-file", "./sign-file", "-d",
+				      "sha256", path, path, data_template,
+				      NULL);
+		} else {
+			snprintf(path, sizeof(path), "%s.gpg", data_template);
+
+			return execlp("gpg", "gpg", "--no-options",
+				      "--no-auto-check-trustdb",
+				      "--no-permission-warning",
+				      "--default-key", "eBPF_UMD_Test",
+				      "--sign", "-o", path, "--batch", "--yes",
+				      "--compress-algo=none", "-b",
+				      "--passphrase", "abc",
+				      "--pinentry-mode", "loopback", "-q",
+				      data_template, NULL);
+		}
    }
waitpid(child_pid, &child_status, 0);
@@ -135,7 +172,10 @@ static int populate_data_item_str(const char *tmp_dir, struct data *data_item)
    if (ret)
    	goto out;
-	snprintf(path, sizeof(path), "%s.p7s", data_template);
+	if (key_type == PKEY_ID_PKCS7)
+		snprintf(path, sizeof(path), "%s.p7s", data_template);
+	else
+		snprintf(path, sizeof(path), "%s.gpg", data_template);
ret = stat(path, &st);
    if (ret == -1) {
@@ -254,12 +294,12 @@ static int populate_data_item_mod(struct data *data_item)
    return ret;
 }
-void test_verify_pkcs7_sig(void)
+static void test_verify_pkcs7_umd_sig(__u8 key_type, __u8 pkey_algo)
 {
    libbpf_print_fn_t old_print_cb;
    char tmp_dir_template[] = "/tmp/verify_sigXXXXXX";
    char *tmp_dir;
-	struct test_verify_pkcs7_sig *skel = NULL;
+	struct test_verify_pkcs7_umd_sig *skel = NULL;
    struct bpf_map *map;
    struct data data;
    int ret, zero = 0;
@@ -272,37 +312,38 @@ void test_verify_pkcs7_sig(void)
    if (!ASSERT_OK_PTR(tmp_dir, "mkdtemp"))
    	return;
-	ret = _run_setup_process(tmp_dir, "setup");
+	ret = _run_setup_process(tmp_dir, "setup", key_type, pkey_algo);
    if (!ASSERT_OK(ret, "_run_setup_process"))
    	goto close_prog;
-	skel = test_verify_pkcs7_sig__open();
-	if (!ASSERT_OK_PTR(skel, "test_verify_pkcs7_sig__open"))
+	skel = test_verify_pkcs7_umd_sig__open();
+	if (!ASSERT_OK_PTR(skel, "test_verify_pkcs7_umd_sig__open"))
    	goto close_prog;
old_print_cb = libbpf_set_print(libbpf_print_cb);
-	ret = test_verify_pkcs7_sig__load(skel);
+	ret = test_verify_pkcs7_umd_sig__load(skel);
    libbpf_set_print(old_print_cb);
if (ret < 0 && kfunc_not_supported) {
    	printf(
-		  "%s:SKIP:bpf_verify_pkcs7_signature() kfunc not supported\n",
+		  "%s:SKIP:bpf_verify_*_signature() kfunc not supported\n",
    	  __func__);
    	test__skip();
    	goto close_prog;
    }
-	if (!ASSERT_OK(ret, "test_verify_pkcs7_sig__load"))
+	if (!ASSERT_OK(ret, "test_verify_pkcs7_umd_sig__load"))
    	goto close_prog;
-	ret = test_verify_pkcs7_sig__attach(skel);
-	if (!ASSERT_OK(ret, "test_verify_pkcs7_sig__attach"))
+	ret = test_verify_pkcs7_umd_sig__attach(skel);
+	if (!ASSERT_OK(ret, "test_verify_pkcs7_umd_sig__attach"))
    	goto close_prog;
map = bpf_object__find_map_by_name(skel->obj, "data_input");
    if (!ASSERT_OK_PTR(map, "data_input not found"))
    	goto close_prog;
+	skel->bss->key_type = key_type;
    skel->bss->monitored_pid = getpid();
/* Test without data and signature. */
@@ -313,7 +354,7 @@ void test_verify_pkcs7_sig(void)
    	goto close_prog;
/* Test successful signature verification with session keyring. */
-	ret = populate_data_item_str(tmp_dir, &data);
+	ret = populate_data_item_str(tmp_dir, key_type, &data);
    if (!ASSERT_OK(ret, "populate_data_item_str"))
    	goto close_prog;
@@ -363,9 +404,13 @@ void test_verify_pkcs7_sig(void)
    if (!ASSERT_LT(ret, 0, "bpf_map_update_elem data_input"))
    	goto close_prog;
-	ret = populate_data_item_mod(&data);
-	if (!ASSERT_OK(ret, "populate_data_item_mod"))
-		goto close_prog;
+	data.data_len = 0;
+
+	if (key_type == PKEY_ID_PKCS7) {
+		ret = populate_data_item_mod(&data);
+		if (!ASSERT_OK(ret, "populate_data_item_mod"))
+			goto close_prog;
+	}
/* Test signature verification with system keyrings. */
    if (data.data_len) {
@@ -392,11 +437,25 @@ void test_verify_pkcs7_sig(void)
    }
close_prog:
-	_run_setup_process(tmp_dir, "cleanup");
+	_run_setup_process(tmp_dir, "cleanup", key_type, pkey_algo);
if (!skel)
    	return;
skel->bss->monitored_pid = 0;
-	test_verify_pkcs7_sig__destroy(skel);
+	test_verify_pkcs7_umd_sig__destroy(skel);
+}
+
+void test_verify_pkcs7_sig(void)
+{
+	return test_verify_pkcs7_umd_sig(PKEY_ID_PKCS7, ALGO__LAST);
+}
+
+void test_verify_umd_sig(void)
+{
+	int i;
+
+	/* Change the limit to ALGO__LAST when UMD supports PGP. */
+	for (i = 0; i < 0; i++)
+		test_verify_pkcs7_umd_sig(PKEY_ID_PGP, i);
 }
diff --git a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_umd_sig.c
similarity index 82%
rename from tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
rename to tools/testing/selftests/bpf/progs/test_verify_pkcs7_umd_sig.c
index 7748cc23de8..e22b013a4e4 100644
--- a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
+++ b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_umd_sig.c
@@ -20,10 +20,14 @@ 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;
+extern int bpf_verify_umd_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;
+__u8 key_type;
struct data {
    __u8 data[MAX_DATA_SIZE];
@@ -86,7 +90,19 @@ int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size)
    if (!trusted_keyring)
    	return -ENOENT;
-	ret = bpf_verify_pkcs7_signature(&data_ptr, &sig_ptr, trusted_keyring);
+	switch (key_type) {
+	case PKEY_ID_PKCS7:
+		ret = bpf_verify_pkcs7_signature(&data_ptr, &sig_ptr,
+						 trusted_keyring);
+		break;
+	case PKEY_ID_PGP:
+		ret = bpf_verify_umd_signature(&data_ptr, &sig_ptr,
+					       trusted_keyring);
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
bpf_key_put(trusted_keyring);
diff --git a/tools/testing/selftests/bpf/verify_sig_setup.sh b/tools/testing/selftests/bpf/verify_sig_setup.sh
index ba08922b4a2..5f6e612aae9 100755
--- a/tools/testing/selftests/bpf/verify_sig_setup.sh
+++ b/tools/testing/selftests/bpf/verify_sig_setup.sh
@@ -26,13 +26,39 @@ subjectKeyIdentifier=hash
 authorityKeyIdentifier=keyid
 "
+gpg_genkey_content_common="\
+     Name-Real: eBPF_UMD_Test
+     Name-Comment: eBPF_UMD_Test
+     Name-Email: ebpf_umd_test@localhost
+     Expire-Date: 0
+     Passphrase: abc
+     %commit
+"
+gpg_genkey_content_rsa="\
+     Key-Type: RSA
+     Key-Length: 4096
+     $gpg_genkey_content_common
+"
+
+gpg_genkey_content_ecdsa_p256="\
+     Key-Type: ECDSA
+     Key-Curve: NIST P-256
+     $gpg_genkey_content_common
+"
+
+gpg_genkey_content_ecdsa_p384="\
+     Key-Type: ECDSA
+     Key-Curve: NIST P-384
+     $gpg_genkey_content_common
+"
+
 usage()
 {
-	echo "Usage: $0 <setup|cleanup <existing_tmp_dir>"
+	echo "Usage: $0 <setup|cleanup> <key type> <existing_tmp_dir>"
    exit 1
 }
-setup()
+setup_pkcs7()
 {
    local tmp_dir="$1"
@@ -52,11 +78,37 @@ setup()
    keyctl link $key_id $keyring_id
 }
-cleanup() {
+setup_pgp()
+{
+	local tmp_dir="$1"
+	local varname="gpg_genkey_content_$2"
+
+	modprobe ecdsa_generic
+
+	echo "${!varname}" > ${tmp_dir}/gpg.genkey
+	gpg --batch --generate-key ${tmp_dir}/gpg.genkey
+
+	key_id=$(gpg --export eBPF_UMD_Test | keyctl padd asymmetric ebpf_testing_key @s)
+	keyring_id=$(keyctl newring ebpf_testing_keyring @s)
+	keyctl link $key_id $keyring_id
+}
+
+cleanup_pkcs7() {
+	local tmp_dir="$1"
+
+	keyctl unlink $(keyctl search @s asymmetric ebpf_testing_key) @s
+	keyctl unlink $(keyctl search @s keyring ebpf_testing_keyring) @s
+	rm -rf ${tmp_dir}
+}
+
+cleanup_pgp() {
    local tmp_dir="$1"
keyctl unlink $(keyctl search @s asymmetric ebpf_testing_key) @s
    keyctl unlink $(keyctl search @s keyring ebpf_testing_keyring) @s
+	key_fingerprint=$(gpg --fingerprint --with-colons eBPF_UMD_Test | awk -F ":" '$1 == "fpr" {print $(NF-1)}')
+	gpg --delete-secret-key --batch --yes $key_fingerprint
+	gpg --delete-key --batch --yes $key_fingerprint
    rm -rf ${tmp_dir}
 }
@@ -75,17 +127,33 @@ catch()
main()
 {
-	[[ $# -ne 2 ]] && usage
+	[[ $# -ne 4 ]] && usage
local action="$1"
-	local tmp_dir="$2"
+	local key_type="$2"
+	local key_algo="$3"
+	local tmp_dir="$4"
[[ ! -d "${tmp_dir}" ]] && echo "Directory ${tmp_dir} doesn't exist" && exit 1
if [[ "${action}" == "setup" ]]; then
-		setup "${tmp_dir}"
+		if [[ "${key_type}" == "pkcs7" ]]; then
+			setup_pkcs7 "${tmp_dir}"
+		elif [[ "${key_type}" == "pgp" ]]; then
+			setup_pgp "${tmp_dir}" "${key_algo}"
+		else
+			echo "Unknown key type: ${key_type}"
+			exit 1
+		fi
    elif [[ "${action}" == "cleanup" ]]; then
-		cleanup "${tmp_dir}"
+		if [[ "${key_type}" == "pkcs7" ]]; then
+			cleanup_pkcs7 "${tmp_dir}"
+		elif [[ "${key_type}" == "pgp" ]]; then
+			cleanup_pgp "${tmp_dir}"
+		else
+			echo "Unknown key type: ${key_type}"
+			exit 1
+		fi
    else
    	echo "Unknown action: ${action}"
    	exit 1
-- 
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[RFC][PATCH 5/6] selftests/bpf: Prepare a test for UMD-parsed signatures