crypto: af_alg - User-space interface for Crypto API

This patch creates the backbone of the user-space interface for
the Crypto API, through a new socket family AF_ALG.

Each session corresponds to one or more connections obtained from
that socket.  The number depends on the number of inputs/outputs
of that particular type of operation.  For most types there will
be a s ingle connection/file descriptor that is used for both input
and output.  AEAD is one of the few that require two inputs.

Each algorithm type will provide its own implementation that plugs
into af_alg.  They're keyed using a string such as "skcipher" or
"hash".

IOW this patch only contains the boring bits that is required
to hold everything together.

Thakns to Miloslav Trmac for reviewing this and contributing
fixes and improvements.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Martin Willi <martin@strongswan.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/include/linux/if_alg.h b/include/linux/if_alg.h
new file mode 100644
index 0000000..0f9acce
--- /dev/null
+++ b/include/linux/if_alg.h
@@ -0,0 +1,40 @@
+/*
+ * if_alg: User-space algorithm interface
+ *
+ * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#ifndef _LINUX_IF_ALG_H
+#define _LINUX_IF_ALG_H
+
+#include <linux/types.h>
+
+struct sockaddr_alg {
+	__u16	salg_family;
+	__u8	salg_type[14];
+	__u32	salg_feat;
+	__u32	salg_mask;
+	__u8	salg_name[64];
+};
+
+struct af_alg_iv {
+	__u32	ivlen;
+	__u8	iv[0];
+};
+
+/* Socket options */
+#define ALG_SET_KEY			1
+#define ALG_SET_IV			2
+#define ALG_SET_OP			3
+
+/* Operations */
+#define ALG_OP_DECRYPT			0
+#define ALG_OP_ENCRYPT			1
+
+#endif	/* _LINUX_IF_ALG_H */