nettle/cipher: document that ctx_ptr is 16-byte aligned, and use void* to avoid compi...

Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>

diff --git a/lib/nettle/cipher.c b/lib/nettle/cipher.c
index 269001ae0cfa7ffa48e8695c3c8f988b67b632d1..61e4a6cb6288facb707bfef56cb8015adaef21b5 100644 (file)
--- a/lib/nettle/cipher.c
+++ b/lib/nettle/cipher.c
@@ -92,7 +92,7 @@ struct nettle_cipher_st {
 
 struct nettle_cipher_ctx {
        const struct nettle_cipher_st *cipher;
-       uint8_t *ctx_ptr;
+       void *ctx_ptr; /* always 16-aligned */
        uint8_t iv[MAX_CIPHER_BLOCK_SIZE];
        unsigned iv_size;
 
@@ -517,6 +517,7 @@ wrap_nettle_cipher_init(gnutls_cipher_algorithm_t algo, void **_ctx,
        ptrdiff_t cur_alignment;
        int idx = -1;
        unsigned i;
+       uint8_t *ctx_ptr;
 
        for (i=0;i<sizeof(builtin_ciphers)/sizeof(builtin_ciphers[0]);i++) {
                if (algo == builtin_ciphers[i].algo) {
@@ -538,12 +539,13 @@ wrap_nettle_cipher_init(gnutls_cipher_algorithm_t algo, void **_ctx,
        }
 
        ctx->enc = enc;
-       ctx->ctx_ptr = ((uint8_t*)ctx) + sizeof(*ctx);
+       ctx_ptr = ((uint8_t*)ctx) + sizeof(*ctx);
 
-       cur_alignment = ((ptrdiff_t)ctx->ctx_ptr) % 16;
+       cur_alignment = ((ptrdiff_t)ctx_ptr) % 16;
        if (cur_alignment > 0)
-               ctx->ctx_ptr += 16 - cur_alignment;
+               ctx_ptr += 16 - cur_alignment;
 
+       ctx->ctx_ptr = ctx_ptr;
        ctx->cipher = &builtin_ciphers[idx];
 
        *_ctx = ctx;