sign-file,extract-cert: move common SSL helper functions to a header

commit 300e6d4116f956b035281ec94297dc4dc8d4e1d3 upstream.

Couple error handling helpers are repeated in both tools, so
move them to a common header.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: R Nageswara Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts/ssl-common.h

@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+/*
+ * SSL helper functions shared by sign-file and extract-cert.
+ */
+
+static void display_openssl_errors(int l)
+{
+	const char *file;
+	char buf[120];
+	int e, line;
+
+	if (ERR_peek_error() == 0)
+		return;
+	fprintf(stderr, "At main.c:%d:\n", l);
+
+	while ((e = ERR_get_error_line(&file, &line))) {
+		ERR_error_string(e, buf);
+		fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
+	}
+}
+
+static void drain_openssl_errors(void)
+{
+	const char *file;
+	int line;
+
+	if (ERR_peek_error() == 0)
+		return;
+	while (ERR_get_error_line(&file, &line)) {}
+}
+
+#define ERR(cond, fmt, ...)				\
+	do {						\
+		bool __cond = (cond);			\
+		display_openssl_errors(__LINE__);	\
+		if (__cond) {				\
+			errx(1, fmt, ## __VA_ARGS__);	\
+		}					\
+	} while (0)