[PATCH v2] sign-file: Convert API usage to support OpenSSL v3

[Kees Cook]

OpenSSL's ENGINE API is deprecated in OpenSSL v3.0, along with some
other functions. Remove the ENGINE use and a macro work-around for
ERR_get_error_line().

Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Eric Biggers <ebiggers@xxxxxxxxxx>
Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Cc: Salvatore Bonaccorso <carnil@xxxxxxxxxx>
Cc: keyrings@xxxxxxxxxxxxxxx
Suggested-by: Adam Langley <agl@xxxxxxxxxx>
Co-developed-by: Lee Jones <lee.jones@xxxxxxxxxx>
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
v1: https://lore.kernel.org/lkml/20211005161833.1522737-1-lee.jones@xxxxxxxxxx/
v2: https://lore.kernel.org/lkml/Yicwb+Ceiu8JjVIS@xxxxxxxxxx/
v3:
 - Eliminate all the build warnings with OpenSSL 3
 - Fully remove ENGINE usage, if it can be optional, just drop it.
---
 scripts/sign-file.c | 49 ++++++++++-----------------------------------
 1 file changed, 11 insertions(+), 38 deletions(-)

diff --git a/scripts/sign-file.c b/scripts/sign-file.c
index fbd34b8e8f57..2d633c5f57c3 100644
--- a/scripts/sign-file.c
+++ b/scripts/sign-file.c
@@ -52,6 +52,10 @@
 #include <openssl/pkcs7.h>
 #endif
 
+#if OPENSSL_VERSION_MAJOR >= 3
+#define ERR_get_error_line(f, l)	ERR_get_error_all(f, l, NULL, NULL, NULL)
+#endif
+
 struct module_signature {
 	uint8_t		algo;		/* Public-key crypto algorithm [0] */
 	uint8_t		hash;		/* Digest algorithm [0] */
@@ -92,16 +96,6 @@ static void display_openssl_errors(int l)
 	}
 }
 
-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);			\
@@ -135,35 +129,14 @@ static int pem_pw_cb(char *buf, int len, int w, void *v)
 static EVP_PKEY *read_private_key(const char *private_key_name)
 {
 	EVP_PKEY *private_key;
+	BIO *b;
 
-	if (!strncmp(private_key_name, "pkcs11:", 7)) {
-		ENGINE *e;
-
-		ENGINE_load_builtin_engines();
-		drain_openssl_errors();
-		e = ENGINE_by_id("pkcs11");
-		ERR(!e, "Load PKCS#11 ENGINE");
-		if (ENGINE_init(e))
-			drain_openssl_errors();
-		else
-			ERR(1, "ENGINE_init");
-		if (key_pass)
-			ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0),
-			    "Set PKCS#11 PIN");
-		private_key = ENGINE_load_private_key(e, private_key_name,
-						      NULL, NULL);
-		ERR(!private_key, "%s", private_key_name);
-	} else {
-		BIO *b;
-
-		b = BIO_new_file(private_key_name, "rb");
-		ERR(!b, "%s", private_key_name);
-		private_key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb,
-						      NULL);
-		ERR(!private_key, "%s", private_key_name);
-		BIO_free(b);
-	}
-
+	b = BIO_new_file(private_key_name, "rb");
+	ERR(!b, "%s", private_key_name);
+	private_key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb,
+					      NULL);
+	ERR(!private_key, "%s", private_key_name);
+	BIO_free(b);
 	return private_key;
 }
 
-- 
2.32.0