sign-file: Fix incorrect return values check

There are some wrong return values check in sign-file when call OpenSSL
API. The ERR() check cond is wrong because of the program only check the
return value is < 0 which ignored the return val is 0. For example:
1. CMS_final() return 1 for success or 0 for failure.
2. i2d_CMS_bio_stream() returns 1 for success or 0 for failure.
3. i2d_TYPEbio() return 1 for success and 0 for failure.
4. BIO_free() return 1 for success and 0 for failure.

Link: https://www.openssl.org/docs/manmaster/man3/
Fixes: e5a2e3c ("scripts/sign-file.c: Add support for signing with a raw signature")
Signed-off-by: Yusong Gao <[email protected]>
Reviewed-by: Juerg Haefliger <[email protected]>
Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]/ # v5
Signed-off-by: Linus Torvalds <[email protected]>

Author: Yusong Gao

scripts/sign-file.c

@@ -322,7 +322,7 @@ int main(int argc, char **argv)
 				     CMS_NOSMIMECAP | use_keyid |
 				     use_signed_attrs),
 		    "CMS_add1_signer");
-		ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) < 0,
+		ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) != 1,
 		    "CMS_final");
 
 #else
@@ -341,10 +341,10 @@ int main(int argc, char **argv)
 			b = BIO_new_file(sig_file_name, "wb");
 			ERR(!b, "%s", sig_file_name);
 #ifndef USE_PKCS7
-			ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) < 0,
+			ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) != 1,
 			    "%s", sig_file_name);
 #else
-			ERR(i2d_PKCS7_bio(b, pkcs7) < 0,
+			ERR(i2d_PKCS7_bio(b, pkcs7) != 1,
 			    "%s", sig_file_name);
 #endif
 			BIO_free(b);
@@ -374,9 +374,9 @@ int main(int argc, char **argv)
 
 	if (!raw_sig) {
 #ifndef USE_PKCS7
-		ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) < 0, "%s", dest_name);
+		ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) != 1, "%s", dest_name);
 #else
-		ERR(i2d_PKCS7_bio(bd, pkcs7) < 0, "%s", dest_name);
+		ERR(i2d_PKCS7_bio(bd, pkcs7) != 1, "%s", dest_name);
 #endif
 	} else {
 		BIO *b;
@@ -396,7 +396,7 @@ int main(int argc, char **argv)
 	ERR(BIO_write(bd, &sig_info, sizeof(sig_info)) < 0, "%s", dest_name);
 	ERR(BIO_write(bd, magic_number, sizeof(magic_number) - 1) < 0, "%s", dest_name);
 
-	ERR(BIO_free(bd) < 0, "%s", dest_name);
+	ERR(BIO_free(bd) != 1, "%s", dest_name);
 
 	/* Finally, if we're signing in place, replace the original. */
 	if (replace_orig)