crypto: import zinc

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 333 insertions, 0 deletions

diff --git a/src/crypto/zinc/chacha20poly1305.c b/src/crypto/zinc/chacha20poly1305.c
new file mode 100644
index 0000000..3991482
--- /dev/null
+++ b/src/crypto/zinc/chacha20poly1305.c
@@ -0,0 +1,333 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * This is an implementation of the ChaCha20Poly1305 AEAD construction.
+ *
+ * Information: https://tools.ietf.org/html/rfc8439
+ */
+
+#include <zinc/chacha20poly1305.h>
+#include <zinc/chacha20.h>
+#include <zinc/poly1305.h>
+#include <asm/unaligned.h>
+#include <linux/kernel.h>
+#include <crypto/scatterwalk.h>
+
+static const u8 pad0[16] = { 0 };
+
+static struct crypto_alg chacha20_alg = {
+	.cra_blocksize = 1,
+	.cra_alignmask = sizeof(u32) - 1
+};
+static struct crypto_blkcipher chacha20_cipher = {
+	.base = {
+		.__crt_alg = &chacha20_alg
+	}
+};
+static struct blkcipher_desc chacha20_desc = {
+	.tfm = &chacha20_cipher
+};
+
+static inline void
+__chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,
+			   const u8 *ad, const size_t ad_len, const u64 nonce,
+			   const u8 key[CHACHA20POLY1305_KEYLEN],
+			   simd_context_t simd_context)
+{
+	struct poly1305_ctx poly1305_state;
+	struct chacha20_ctx chacha20_state;
+	union {
+		u8 block0[POLY1305_KEY_SIZE];
+		__le64 lens[2];
+	} b = { { 0 } };
+
+	chacha20_init(&chacha20_state, key, nonce);
+	chacha20(&chacha20_state, b.block0, b.block0, sizeof(b.block0),
+		 simd_context);
+	poly1305_init(&poly1305_state, b.block0, simd_context);
+
+	poly1305_update(&poly1305_state, ad, ad_len, simd_context);
+	poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
+			simd_context);
+
+	chacha20(&chacha20_state, dst, src, src_len, simd_context);
+
+	poly1305_update(&poly1305_state, dst, src_len, simd_context);
+	poly1305_update(&poly1305_state, pad0, (0x10 - src_len) & 0xf,
+			simd_context);
+
+	b.lens[0] = cpu_to_le64(ad_len);
+	b.lens[1] = cpu_to_le64(src_len);
+	poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens),
+			simd_context);
+
+	poly1305_finish(&poly1305_state, dst + src_len, simd_context);
+
+	memzero_explicit(&chacha20_state, sizeof(chacha20_state));
+	memzero_explicit(&b, sizeof(b));
+}
+
+void chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,
+			      const u8 *ad, const size_t ad_len,
+			      const u64 nonce,
+			      const u8 key[CHACHA20POLY1305_KEYLEN])
+{
+	simd_context_t simd_context;
+
+	simd_context = simd_get();
+	__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len, nonce, key,
+				   simd_context);
+	simd_put(simd_context);
+}
+EXPORT_SYMBOL(chacha20poly1305_encrypt);
+
+bool chacha20poly1305_encrypt_sg(struct scatterlist *dst,
+				 struct scatterlist *src, const size_t src_len,
+				 const u8 *ad, const size_t ad_len,
+				 const u64 nonce,
+				 const u8 key[CHACHA20POLY1305_KEYLEN],
+				 simd_context_t simd_context)
+{
+	struct poly1305_ctx poly1305_state;
+	struct chacha20_ctx chacha20_state;
+	int ret = 0;
+	struct blkcipher_walk walk;
+	union {
+		u8 block0[POLY1305_KEY_SIZE];
+		u8 mac[POLY1305_MAC_SIZE];
+		__le64 lens[2];
+	} b = { { 0 } };
+
+	chacha20_init(&chacha20_state, key, nonce);
+	chacha20(&chacha20_state, b.block0, b.block0, sizeof(b.block0),
+		 simd_context);
+	poly1305_init(&poly1305_state, b.block0, simd_context);
+
+	poly1305_update(&poly1305_state, ad, ad_len, simd_context);
+	poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
+			simd_context);
+
+	if (likely(src_len)) {
+		blkcipher_walk_init(&walk, dst, src, src_len);
+		ret = blkcipher_walk_virt_block(&chacha20_desc, &walk,
+						CHACHA20_BLOCK_SIZE);
+		while (walk.nbytes >= CHACHA20_BLOCK_SIZE) {
+			size_t chunk_len =
+				rounddown(walk.nbytes, CHACHA20_BLOCK_SIZE);
+
+			chacha20(&chacha20_state, walk.dst.virt.addr,
+				 walk.src.virt.addr, chunk_len, simd_context);
+			poly1305_update(&poly1305_state, walk.dst.virt.addr,
+					chunk_len, simd_context);
+			ret = blkcipher_walk_done(&chacha20_desc, &walk,
+					walk.nbytes % CHACHA20_BLOCK_SIZE);
+		}
+		if (walk.nbytes) {
+			chacha20(&chacha20_state, walk.dst.virt.addr,
+				 walk.src.virt.addr, walk.nbytes, simd_context);
+			poly1305_update(&poly1305_state, walk.dst.virt.addr,
+					walk.nbytes, simd_context);
+			ret = blkcipher_walk_done(&chacha20_desc, &walk, 0);
+		}
+	}
+	if (unlikely(ret))
+		goto err;
+
+	poly1305_update(&poly1305_state, pad0, (0x10 - src_len) & 0xf,
+			simd_context);
+
+	b.lens[0] = cpu_to_le64(ad_len);
+	b.lens[1] = cpu_to_le64(src_len);
+	poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens),
+			simd_context);
+
+	poly1305_finish(&poly1305_state, b.mac, simd_context);
+	scatterwalk_map_and_copy(b.mac, dst, src_len, sizeof(b.mac), 1);
+err:
+	memzero_explicit(&chacha20_state, sizeof(chacha20_state));
+	memzero_explicit(&b, sizeof(b));
+	return !ret;
+}
+EXPORT_SYMBOL(chacha20poly1305_encrypt_sg);
+
+static inline bool
+__chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
+			   const u8 *ad, const size_t ad_len, const u64 nonce,
+			   const u8 key[CHACHA20POLY1305_KEYLEN],
+			   simd_context_t simd_context)
+{
+	struct poly1305_ctx poly1305_state;
+	struct chacha20_ctx chacha20_state;
+	int ret;
+	size_t dst_len;
+	union {
+		u8 block0[POLY1305_KEY_SIZE];
+		u8 mac[POLY1305_MAC_SIZE];
+		__le64 lens[2];
+	} b = { { 0 } };
+
+	if (unlikely(src_len < POLY1305_MAC_SIZE))
+		return false;
+
+	chacha20_init(&chacha20_state, key, nonce);
+	chacha20(&chacha20_state, b.block0, b.block0, sizeof(b.block0),
+		 simd_context);
+	poly1305_init(&poly1305_state, b.block0, simd_context);
+
+	poly1305_update(&poly1305_state, ad, ad_len, simd_context);
+	poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
+			simd_context);
+
+	dst_len = src_len - POLY1305_MAC_SIZE;
+	poly1305_update(&poly1305_state, src, dst_len, simd_context);
+	poly1305_update(&poly1305_state, pad0, (0x10 - dst_len) & 0xf,
+			simd_context);
+
+	b.lens[0] = cpu_to_le64(ad_len);
+	b.lens[1] = cpu_to_le64(dst_len);
+	poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens),
+			simd_context);
+
+	poly1305_finish(&poly1305_state, b.mac, simd_context);
+
+	ret = crypto_memneq(b.mac, src + dst_len, POLY1305_MAC_SIZE);
+	if (likely(!ret))
+		chacha20(&chacha20_state, dst, src, dst_len, simd_context);
+
+	memzero_explicit(&chacha20_state, sizeof(chacha20_state));
+	memzero_explicit(&b, sizeof(b));
+
+	return !ret;
+}
+
+bool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
+			      const u8 *ad, const size_t ad_len,
+			      const u64 nonce,
+			      const u8 key[CHACHA20POLY1305_KEYLEN])
+{
+	simd_context_t simd_context, ret;
+
+	simd_context = simd_get();
+	ret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len, nonce,
+					 key, simd_context);
+	simd_put(simd_context);
+	return ret;
+}
+EXPORT_SYMBOL(chacha20poly1305_decrypt);
+
+bool chacha20poly1305_decrypt_sg(struct scatterlist *dst,
+				 struct scatterlist *src, const size_t src_len,
+				 const u8 *ad, const size_t ad_len,
+				 const u64 nonce,
+				 const u8 key[CHACHA20POLY1305_KEYLEN],
+				 simd_context_t simd_context)
+{
+	struct poly1305_ctx poly1305_state;
+	struct chacha20_ctx chacha20_state;
+	struct blkcipher_walk walk;
+	int ret = 0;
+	size_t dst_len;
+	union {
+		u8 block0[POLY1305_KEY_SIZE];
+		struct {
+			u8 read_mac[POLY1305_MAC_SIZE];
+			u8 computed_mac[POLY1305_MAC_SIZE];
+		};
+		__le64 lens[2];
+	} b = { { 0 } };
+
+	if (unlikely(src_len < POLY1305_MAC_SIZE))
+		return false;
+
+	chacha20_init(&chacha20_state, key, nonce);
+	chacha20(&chacha20_state, b.block0, b.block0, sizeof(b.block0),
+		 simd_context);
+	poly1305_init(&poly1305_state, b.block0, simd_context);
+
+	poly1305_update(&poly1305_state, ad, ad_len, simd_context);
+	poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
+			simd_context);
+
+	dst_len = src_len - POLY1305_MAC_SIZE;
+	if (likely(dst_len)) {
+		blkcipher_walk_init(&walk, dst, src, dst_len);
+		ret = blkcipher_walk_virt_block(&chacha20_desc, &walk,
+						CHACHA20_BLOCK_SIZE);
+		while (walk.nbytes >= CHACHA20_BLOCK_SIZE) {
+			size_t chunk_len =
+				rounddown(walk.nbytes, CHACHA20_BLOCK_SIZE);
+
+			poly1305_update(&poly1305_state, walk.src.virt.addr,
+					chunk_len, simd_context);
+			chacha20(&chacha20_state, walk.dst.virt.addr,
+				 walk.src.virt.addr, chunk_len, simd_context);
+			ret = blkcipher_walk_done(&chacha20_desc, &walk,
+					walk.nbytes % CHACHA20_BLOCK_SIZE);
+		}
+		if (walk.nbytes) {
+			poly1305_update(&poly1305_state, walk.src.virt.addr,
+					walk.nbytes, simd_context);
+			chacha20(&chacha20_state, walk.dst.virt.addr,
+				 walk.src.virt.addr, walk.nbytes, simd_context);
+			ret = blkcipher_walk_done(&chacha20_desc, &walk, 0);
+		}
+	}
+	if (unlikely(ret))
+		goto err;
+
+	poly1305_update(&poly1305_state, pad0, (0x10 - dst_len) & 0xf,
+			simd_context);
+
+	b.lens[0] = cpu_to_le64(ad_len);
+	b.lens[1] = cpu_to_le64(dst_len);
+	poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens),
+			simd_context);
+
+	poly1305_finish(&poly1305_state, b.computed_mac, simd_context);
+
+	scatterwalk_map_and_copy(b.read_mac, src, dst_len, POLY1305_MAC_SIZE, 0);
+	ret = crypto_memneq(b.read_mac, b.computed_mac, POLY1305_MAC_SIZE);
+err:
+	memzero_explicit(&chacha20_state, sizeof(chacha20_state));
+	memzero_explicit(&b, sizeof(b));
+	return !ret;
+}
+EXPORT_SYMBOL(chacha20poly1305_decrypt_sg);
+
+void xchacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,
+			       const u8 *ad, const size_t ad_len,
+			       const u8 nonce[XCHACHA20POLY1305_NONCELEN],
+			       const u8 key[CHACHA20POLY1305_KEYLEN])
+{
+	simd_context_t simd_context = simd_get();
+	u8 derived_key[CHACHA20POLY1305_KEYLEN] __aligned(16);
+
+	hchacha20(derived_key, nonce, key, simd_context);
+	__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len,
+				   get_unaligned_le64(nonce + 16),
+				   derived_key, simd_context);
+	memzero_explicit(derived_key, CHACHA20POLY1305_KEYLEN);
+	simd_put(simd_context);
+}
+EXPORT_SYMBOL(xchacha20poly1305_encrypt);
+
+bool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
+			       const u8 *ad, const size_t ad_len,
+			       const u8 nonce[XCHACHA20POLY1305_NONCELEN],
+			       const u8 key[CHACHA20POLY1305_KEYLEN])
+{
+	bool ret, simd_context = simd_get();
+	u8 derived_key[CHACHA20POLY1305_KEYLEN] __aligned(16);
+
+	hchacha20(derived_key, nonce, key, simd_context);
+	ret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,
+					 get_unaligned_le64(nonce + 16),
+					 derived_key, simd_context);
+	memzero_explicit(derived_key, CHACHA20POLY1305_KEYLEN);
+	simd_put(simd_context);
+	return ret;
+}
+EXPORT_SYMBOL(xchacha20poly1305_decrypt);
+
+#include "selftest/chacha20poly1305.h"