bpftool: Allow bpftool to build with openssl < 3

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: 40863f4 ("bpftool: Add support for signing BPF programs")
Signed-off-by: Alan Maguire <[email protected]>
Acked-by: Song Liu <[email protected]>
Acked-by: Quentin Monnet <[email protected]>

Author: alan-maguire

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];