make the SHA256_CTX local to the inline digest function

src/vmod_blobsha256.c

@@ -86,9 +86,10 @@ errmsg(VRT_CTX, const char *fmt, ...)
 }
 
 static inline void
-digest(SHA256_CTX *restrict const ctx, VCL_BLOB restrict const b,
-       uint8_t *restrict digest)
+digest(VCL_BLOB restrict const b, uint8_t *restrict digest)
 {
+	SHA256_CTX ctx[1];
+
 	SHA256_Init(ctx);
 	SHA256_Update(ctx, b->priv, b->len);
 	SHA256_Final(digest, ctx);
@@ -114,10 +115,9 @@ vmod_hmac__init(VRT_CTX, struct vmod_blobsha256_hmac **hmacp,
 
 	if (key->len <= SHA256_BLOCKSZ)
 		memcpy(k, key->priv, key->len);
-	else {
-		SHA256_CTX hctx[1];
-		digest(hctx, key, k);
-	}
+	else
+		digest(key, k);
+
 	for (int i = 0; i < SHA256_BLOCKSZ; i++) {
 		innerk[i] = k[i] ^ 0x36;
 		outerk[i] = k[i] ^ 0x5c;
@@ -185,7 +185,6 @@ vmod_blob__init(VRT_CTX, struct vmod_blobsha256_blob **blobp,
 		const char *vcl_name, VCL_BLOB b)
 {
 	struct vmod_blobsha256_blob *blob;
-	SHA256_CTX hctx[1];
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	AN(blobp);
@@ -203,7 +202,7 @@ vmod_blob__init(VRT_CTX, struct vmod_blobsha256_blob **blobp,
 
 	blob->hash.len = SHA256_LEN;
 	blob->hash.free = NULL;
-	digest(hctx, b, blob->hash.priv);
+	digest(b, blob->hash.priv);
 }
 
 VCL_BLOB
@@ -233,7 +232,6 @@ vmod_hash(VRT_CTX, VCL_BLOB msg)
 {
 	struct vmod_priv *b;
 	char *snap;
-	SHA256_CTX hctx[1];
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	if (INIT_FINI(ctx)) {
@@ -256,7 +254,7 @@ vmod_hash(VRT_CTX, VCL_BLOB msg)
 	}
 	b->len = SHA256_LEN;
 	b->free = NULL;
-	digest(hctx, msg, b->priv);
+	digest(msg, b->priv);
 	return b;
 }