X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=secnet.git;a=blobdiff_plain;f=transform-common.h;fp=transform-common.h;h=b3c70a8d30e3bcc49818547b495276330892521d;hp=0000000000000000000000000000000000000000;hb=92a7d254975db245c3320855515bffc1aebda9e4;hpb=9018e07aec9e5a32e85b03d997a272c40ff2d915

diff --git a/transform-common.h b/transform-common.h
new file mode 100644
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--- /dev/null
+++ b/transform-common.h
@@ -0,0 +1,56 @@
+
+#ifndef TRANSFORM_COMMON_H
+#define TRANSFORM_COMMON_H
+
+#define KEYED_CHECK do{				\
+	if (!ti->keyed) {			\
+	    *errmsg="transform unkeyed";	\
+	    return 1;				\
+	}					\
+    }while(0)
+
+#define SEQNUM_CHECK(seqnum, max_skew) do{	\
+	uint32_t skew=seqnum-ti->lastrecvseq;	\
+	if (skew<0x8fffffff) {			\
+	    /* Ok */				\
+	    ti->lastrecvseq=seqnum;		\
+	} else if ((0-skew)<max_skew) {	\
+	    /* Ok */				\
+	} else {				\
+	    /* Too much skew */			\
+	    *errmsg="seqnum: too much skew";	\
+	    return 2;				\
+	}					\
+    }while(0)
+
+#define TRANSFORM_VALID				\
+    static bool_t transform_valid(void *sst)	\
+    {						\
+	struct transform_inst *ti=sst;		\
+						\
+	return ti->keyed;			\
+    }
+
+#define TRANSFORM_DESTROY				\
+    static void transform_destroy(void *sst)		\
+    {							\
+	struct transform_inst *st=sst;			\
+							\
+	FILLZERO(*st); /* Destroy key material */	\
+	free(st);					\
+    }
+
+#define TRANSFORM_CREATE_CORE				\
+	struct transform_inst *ti;			\
+	ti=safe_malloc(sizeof(*ti),"transform_create");	\
+	/* mlock XXX */					\
+	ti->ops.st=ti;					\
+	ti->ops.setkey=transform_setkey;		\
+	ti->ops.valid=transform_valid;			\
+	ti->ops.delkey=transform_delkey;		\
+	ti->ops.forwards=transform_forward;		\
+	ti->ops.reverse=transform_reverse;		\
+	ti->ops.destroy=transform_destroy;		\
+	ti->keyed=False;
+
+#endif /*TRANSFORM_COMMON_H*/