From 71f68cc45a269b206fc996309ef026f39d5af3df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niels=20M=C3=B6ller?= <nisse@lysator.liu.se>
Date: Thu, 9 Aug 2018 20:54:18 +0200
Subject: [PATCH] Avoid cast between incompatible function types.
---
ChangeLog | 5 +++++
nettle-internal.c | 36 ++++++++++++++++++++++++++----------
2 files changed, 31 insertions(+), 10 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index a205a6ff..c37eff0c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
2018-08-09 Niels Möller <nisse@lysator.liu.se>
+ * nettle-internal.c (des_set_key_wrapper, des3_set_key_wrapper)
+ (blowfish128_set_key_wrapper): Wrapper functions, to avoid cast
+ between incompatible function types (which gcc-8 warns about).
+ Wrappers are expected to compile to a single jmp instruction.
+
* des-compat.c (des_compat_des3_encrypt)
(des_compat_des3_decrypt): Change length argument type to size_t.
diff --git a/nettle-internal.c b/nettle-internal.c
index 45f6f98e..2a809472 100644
--- a/nettle-internal.c
+++ b/nettle-internal.c
@@ -46,14 +46,32 @@
#include "chacha.h"
#include "salsa20.h"
-/* NOTE: A bit ugly. Ignores weak keys, and pretends the set_key
- functions have no return value. */
+/* Wrapper functions discarding the return value. Needed for the
+ ciphers with weak keys. */
+static void
+des_set_key_wrapper (void *ctx, const uint8_t *key)
+{
+ des_set_key (ctx, key);
+}
+
+static void
+des3_set_key_wrapper (void *ctx, const uint8_t *key)
+{
+ des3_set_key (ctx, key);
+}
+
+static void
+blowfish128_set_key_wrapper (void *ctx, const uint8_t *key)
+{
+ blowfish128_set_key (ctx, key);
+}
+
const struct nettle_cipher
nettle_des = {
"des", sizeof(struct des_ctx),
DES_BLOCK_SIZE, DES_KEY_SIZE,
- (nettle_set_key_func *) des_set_key,
- (nettle_set_key_func *) des_set_key,
+ des_set_key_wrapper,
+ des_set_key_wrapper,
(nettle_cipher_func *) des_encrypt,
(nettle_cipher_func *) des_decrypt
};
@@ -62,20 +80,18 @@ const struct nettle_cipher
nettle_des3 = {
"des3", sizeof(struct des3_ctx),
DES3_BLOCK_SIZE, DES3_KEY_SIZE,
- (nettle_set_key_func *) des3_set_key,
- (nettle_set_key_func *) des3_set_key,
+ des3_set_key_wrapper,
+ des3_set_key_wrapper,
(nettle_cipher_func *) des3_encrypt,
(nettle_cipher_func *) des3_decrypt
};
-/* NOTE: This is not as nice as one might think, as we pretend
- blowfish_set_key has no return value. */
const struct nettle_cipher
nettle_blowfish128 =
{ "blowfish128", sizeof(struct blowfish_ctx),
BLOWFISH_BLOCK_SIZE, BLOWFISH128_KEY_SIZE,
- (nettle_set_key_func *) blowfish128_set_key,
- (nettle_set_key_func *) blowfish128_set_key,
+ blowfish128_set_key_wrapper,
+ blowfish128_set_key_wrapper,
(nettle_cipher_func *) blowfish_encrypt,
(nettle_cipher_func *) blowfish_decrypt
};
--
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