ERR_get_error_all()[1] is a openssl v3 API, so to make code
compatible with openssl v1 utilize ERR_get_err_line_data
instead.  Since openssl is already a build requirement for
the kernel (minimum requirement openssl 1.0.0), this will
allow bpftool to compile where opensslv3 is not available.
Signing-related BPF selftests pass with openssl v1.

[1] https://docs.openssl.org/3.4/man3/ERR_get_error/

Fixes: 40863f4d6ef2 ("bpftool: Add support for signing BPF programs")
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
---
 tools/bpf/bpftool/sign.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/bpf/bpftool/sign.c b/tools/bpf/bpftool/sign.c
index b34f74d210e9..f9b742f4bb10 100644
--- a/tools/bpf/bpftool/sign.c
+++ b/tools/bpf/bpftool/sign.c
@@ -28,6 +28,12 @@
 
 #define OPEN_SSL_ERR_BUF_LEN 256
 
+/* Use deprecated in 3.0 ERR_get_error_line_data for openssl < 3 */
+#if !defined(OPENSSL_VERSION_MAJOR) || (OPENSSL_VERSION_MAJOR < 3)
+#define ERR_get_error_all(file, line, func, data, flags) \
+	ERR_get_error_line_data(file, line, data, flags)
+#endif
+
 static void display_openssl_errors(int l)
 {
 	char buf[OPEN_SSL_ERR_BUF_LEN];
-- 
2.43.5

Currently selftests require xxd with the "-n <name>" option
which allows the user to specify a name not derived from
the input object path.  Instead of relying on this newer
feature, older xxd can be used if we link our desired name
("test_progs_verification_cert") to the input object.

Many distros ship xxd in vim-common package and do not have
the latest xxd with -n support.

Fixes: b720903e2b14d ("selftests/bpf: Enable signature verification for some lskel tests")
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
---
 tools/testing/selftests/bpf/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 34ea23c63bd5..8687c17c5084 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -731,7 +731,8 @@ $(VERIFICATION_CERT) $(PRIVATE_KEY): $(VERIFY_SIG_SETUP)
 	$(Q)$(VERIFY_SIG_SETUP) genkey $(BUILD_DIR)
 
 $(VERIFY_SIG_HDR): $(VERIFICATION_CERT)
-	$(Q)xxd -i -n test_progs_verification_cert $< > $@
+	$(Q)ln -fs $< test_progs_verification_cert && \
+	xxd -i test_progs_verification_cert > $@
 
 # Define test_progs test runner.
 TRUNNER_TESTS_DIR := prog_tests
-- 
2.43.5