kernel: 5.4: import wireguard backport

Rather than using the clunky, old, slower wireguard-linux-compat out of
tree module, this commit does a patch-by-patch backport of upstream's
wireguard to 5.4. This specific backport is in widespread use, being
part of SUSE's enterprise kernel, Oracle's enterprise kernel, Google's
Android kernel, Gentoo's distro kernel, and probably more I've forgotten
about. It's definately the "more proper" way of adding wireguard to a
kernel than the ugly compat.h hell of the wireguard-linux-compat repo.
And most importantly for OpenWRT, it allows using the same module
configuration code for 5.10 as for 5.4, with no need for bifurcation.

These patches are from the backport tree which is maintained in the
open here: https://git.zx2c4.com/wireguard-linux/log/?h=backport-5.4.y
I'll be sending PRs to update this as needed.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
(cherry picked from commit 3888fa78802354ab7bbd19b7d061fd80a16ce06b)
(cherry picked from commit d54072587146dd0db9bb52b513234d944edabda3)
(cherry picked from commit 196f3d586f11d96ba4ab60068cfb12420bcd20fd)
(cherry picked from commit 3500fd7938a6d0c0e320295f0aa2fa34b1ebc08d)
(cherry picked from commit 23b801d3ba57e34cc609ea40982c7fbed08164e9)
(cherry picked from commit 0c0cb97da7f5cc06919449131dd57ed805f8f78d)
(cherry picked from commit 2a27f6f90a430342cdbe84806e8b10acff446a2d)
Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>

1 files changed, 224 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.4/080-wireguard-0015-crypto-poly1305-expose-init-update-final-library-int.patch b/target/linux/generic/backport-5.4/080-wireguard-0015-crypto-poly1305-expose-init-update-final-library-int.patch
new file mode 100644
index 0000000000..bf8e90bf02
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0015-crypto-poly1305-expose-init-update-final-library-int.patch
@@ -0,0 +1,224 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ard Biesheuvel <ardb@kernel.org>
+Date: Fri, 8 Nov 2019 13:22:21 +0100
+Subject: [PATCH] crypto: poly1305 - expose init/update/final library interface
+
+commit a1d93064094cc5e24d64e35cf093e7191d0c9344 upstream.
+
+Expose the existing generic Poly1305 code via a init/update/final
+library interface so that callers are not required to go through
+the crypto API's shash abstraction to access it. At the same time,
+make some preparations so that the library implementation can be
+superseded by an accelerated arch-specific version in the future.
+
+Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
+Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ crypto/poly1305_generic.c | 22 +-----------
+ include/crypto/poly1305.h | 38 +++++++++++++++++++-
+ lib/crypto/Kconfig        | 26 ++++++++++++++
+ lib/crypto/poly1305.c     | 74 +++++++++++++++++++++++++++++++++++++++
+ 4 files changed, 138 insertions(+), 22 deletions(-)
+
+--- a/crypto/poly1305_generic.c
++++ b/crypto/poly1305_generic.c
+@@ -85,31 +85,11 @@ EXPORT_SYMBOL_GPL(crypto_poly1305_update
+ int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
+ {
+ 	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
+-	__le32 digest[4];
+-	u64 f = 0;
+ 
+ 	if (unlikely(!dctx->sset))
+ 		return -ENOKEY;
+ 
+-	if (unlikely(dctx->buflen)) {
+-		dctx->buf[dctx->buflen++] = 1;
+-		memset(dctx->buf + dctx->buflen, 0,
+-		       POLY1305_BLOCK_SIZE - dctx->buflen);
+-		poly1305_core_blocks(&dctx->h, dctx->r, dctx->buf, 1, 0);
+-	}
+-
+-	poly1305_core_emit(&dctx->h, digest);
+-
+-	/* mac = (h + s) % (2^128) */
+-	f = (f >> 32) + le32_to_cpu(digest[0]) + dctx->s[0];
+-	put_unaligned_le32(f, dst + 0);
+-	f = (f >> 32) + le32_to_cpu(digest[1]) + dctx->s[1];
+-	put_unaligned_le32(f, dst + 4);
+-	f = (f >> 32) + le32_to_cpu(digest[2]) + dctx->s[2];
+-	put_unaligned_le32(f, dst + 8);
+-	f = (f >> 32) + le32_to_cpu(digest[3]) + dctx->s[3];
+-	put_unaligned_le32(f, dst + 12);
+-
++	poly1305_final_generic(dctx, dst);
+ 	return 0;
+ }
+ EXPORT_SYMBOL_GPL(crypto_poly1305_final);
+--- a/include/crypto/poly1305.h
++++ b/include/crypto/poly1305.h
+@@ -35,7 +35,43 @@ struct poly1305_desc_ctx {
+ 	/* accumulator */
+ 	struct poly1305_state h;
+ 	/* key */
+-	struct poly1305_key r[1];
++	struct poly1305_key r[CONFIG_CRYPTO_LIB_POLY1305_RSIZE];
+ };
+ 
++void poly1305_init_arch(struct poly1305_desc_ctx *desc, const u8 *key);
++void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key);
++
++static inline void poly1305_init(struct poly1305_desc_ctx *desc, const u8 *key)
++{
++	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
++		poly1305_init_arch(desc, key);
++	else
++		poly1305_init_generic(desc, key);
++}
++
++void poly1305_update_arch(struct poly1305_desc_ctx *desc, const u8 *src,
++			  unsigned int nbytes);
++void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
++			     unsigned int nbytes);
++
++static inline void poly1305_update(struct poly1305_desc_ctx *desc,
++				   const u8 *src, unsigned int nbytes)
++{
++	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
++		poly1305_update_arch(desc, src, nbytes);
++	else
++		poly1305_update_generic(desc, src, nbytes);
++}
++
++void poly1305_final_arch(struct poly1305_desc_ctx *desc, u8 *digest);
++void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *digest);
++
++static inline void poly1305_final(struct poly1305_desc_ctx *desc, u8 *digest)
++{
++	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_POLY1305))
++		poly1305_final_arch(desc, digest);
++	else
++		poly1305_final_generic(desc, digest);
++}
++
+ #endif
+--- a/lib/crypto/Kconfig
++++ b/lib/crypto/Kconfig
+@@ -37,8 +37,34 @@ config CRYPTO_LIB_CHACHA
+ config CRYPTO_LIB_DES
+ 	tristate
+ 
++config CRYPTO_LIB_POLY1305_RSIZE
++	int
++	default 1
++
++config CRYPTO_ARCH_HAVE_LIB_POLY1305
++	tristate
++	help
++	  Declares whether the architecture provides an arch-specific
++	  accelerated implementation of the Poly1305 library interface,
++	  either builtin or as a module.
++
+ config CRYPTO_LIB_POLY1305_GENERIC
+ 	tristate
++	help
++	  This symbol can be depended upon by arch implementations of the
++	  Poly1305 library interface that require the generic code as a
++	  fallback, e.g., for SIMD implementations. If no arch specific
++	  implementation is enabled, this implementation serves the users
++	  of CRYPTO_LIB_POLY1305.
++
++config CRYPTO_LIB_POLY1305
++	tristate "Poly1305 library interface"
++	depends on CRYPTO_ARCH_HAVE_LIB_POLY1305 || !CRYPTO_ARCH_HAVE_LIB_POLY1305
++	select CRYPTO_LIB_POLY1305_GENERIC if CRYPTO_ARCH_HAVE_LIB_POLY1305=n
++	help
++	  Enable the Poly1305 library interface. This interface may be fulfilled
++	  by either the generic implementation or an arch-specific one, if one
++	  is available and enabled.
+ 
+ config CRYPTO_LIB_SHA256
+ 	tristate
+--- a/lib/crypto/poly1305.c
++++ b/lib/crypto/poly1305.c
+@@ -154,5 +154,79 @@ void poly1305_core_emit(const struct pol
+ }
+ EXPORT_SYMBOL_GPL(poly1305_core_emit);
+ 
++void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key)
++{
++	poly1305_core_setkey(desc->r, key);
++	desc->s[0] = get_unaligned_le32(key + 16);
++	desc->s[1] = get_unaligned_le32(key + 20);
++	desc->s[2] = get_unaligned_le32(key + 24);
++	desc->s[3] = get_unaligned_le32(key + 28);
++	poly1305_core_init(&desc->h);
++	desc->buflen = 0;
++	desc->sset = true;
++	desc->rset = 1;
++}
++EXPORT_SYMBOL_GPL(poly1305_init_generic);
++
++void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
++			     unsigned int nbytes)
++{
++	unsigned int bytes;
++
++	if (unlikely(desc->buflen)) {
++		bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen);
++		memcpy(desc->buf + desc->buflen, src, bytes);
++		src += bytes;
++		nbytes -= bytes;
++		desc->buflen += bytes;
++
++		if (desc->buflen == POLY1305_BLOCK_SIZE) {
++			poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 1);
++			desc->buflen = 0;
++		}
++	}
++
++	if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
++		poly1305_core_blocks(&desc->h, desc->r, src,
++				     nbytes / POLY1305_BLOCK_SIZE, 1);
++		src += nbytes - (nbytes % POLY1305_BLOCK_SIZE);
++		nbytes %= POLY1305_BLOCK_SIZE;
++	}
++
++	if (unlikely(nbytes)) {
++		desc->buflen = nbytes;
++		memcpy(desc->buf, src, nbytes);
++	}
++}
++EXPORT_SYMBOL_GPL(poly1305_update_generic);
++
++void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst)
++{
++	__le32 digest[4];
++	u64 f = 0;
++
++	if (unlikely(desc->buflen)) {
++		desc->buf[desc->buflen++] = 1;
++		memset(desc->buf + desc->buflen, 0,
++		       POLY1305_BLOCK_SIZE - desc->buflen);
++		poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 0);
++	}
++
++	poly1305_core_emit(&desc->h, digest);
++
++	/* mac = (h + s) % (2^128) */
++	f = (f >> 32) + le32_to_cpu(digest[0]) + desc->s[0];
++	put_unaligned_le32(f, dst + 0);
++	f = (f >> 32) + le32_to_cpu(digest[1]) + desc->s[1];
++	put_unaligned_le32(f, dst + 4);
++	f = (f >> 32) + le32_to_cpu(digest[2]) + desc->s[2];
++	put_unaligned_le32(f, dst + 8);
++	f = (f >> 32) + le32_to_cpu(digest[3]) + desc->s[3];
++	put_unaligned_le32(f, dst + 12);
++
++	*desc = (struct poly1305_desc_ctx){};
++}
++EXPORT_SYMBOL_GPL(poly1305_final_generic);
++
+ MODULE_LICENSE("GPL");
+ MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");