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-rw-r--r--src/crypto/zinc/chacha20poly1305.c402
1 files changed, 402 insertions, 0 deletions
diff --git a/src/crypto/zinc/chacha20poly1305.c b/src/crypto/zinc/chacha20poly1305.c
new file mode 100644
index 0000000..571a64e
--- /dev/null
+++ b/src/crypto/zinc/chacha20poly1305.c
@@ -0,0 +1,402 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2015-2019 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 "selftest/run.h"
+
+#include <asm/unaligned.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <crypto/scatterwalk.h> // For blkcipher_walk.
+
+static const u8 pad0[CHACHA20_BLOCK_SIZE] = { 0 };
+
+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_KEY_SIZE],
+ 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);
+
+ 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_final(&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_KEY_SIZE])
+{
+ simd_context_t simd_context;
+
+ simd_get(&simd_context);
+ __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_inplace(struct scatterlist *src,
+ const size_t src_len,
+ const u8 *ad, const size_t ad_len,
+ const u64 nonce,
+ const u8 key[CHACHA20POLY1305_KEY_SIZE],
+ simd_context_t *simd_context)
+{
+ struct poly1305_ctx poly1305_state;
+ struct chacha20_ctx chacha20_state;
+ struct sg_mapping_iter miter;
+ size_t partial = 0;
+ ssize_t sl;
+ union {
+ u8 chacha20_stream[CHACHA20_BLOCK_SIZE];
+ u8 block0[POLY1305_KEY_SIZE];
+ u8 mac[POLY1305_MAC_SIZE];
+ __le64 lens[2];
+ } b __aligned(16) = { { 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);
+
+ poly1305_update(&poly1305_state, ad, ad_len, simd_context);
+ poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
+ simd_context);
+
+ sg_miter_start(&miter, src, sg_nents(src), SG_MITER_TO_SG | SG_MITER_ATOMIC);
+ for (sl = src_len; sl > 0 && sg_miter_next(&miter); sl -= miter.length) {
+ u8 *addr = miter.addr;
+ size_t length = min_t(size_t, sl, miter.length);
+
+ if (unlikely(partial)) {
+ size_t l = min(length, CHACHA20_BLOCK_SIZE - partial);
+
+ crypto_xor(addr, b.chacha20_stream + partial, l);
+ partial = (partial + l) & (CHACHA20_BLOCK_SIZE - 1);
+
+ addr += l;
+ length -= l;
+ }
+
+ if (likely(length >= CHACHA20_BLOCK_SIZE || length == sl)) {
+ size_t l = length;
+
+ if (unlikely(length < sl))
+ l &= ~(CHACHA20_BLOCK_SIZE - 1);
+ chacha20(&chacha20_state, addr, addr, l, simd_context);
+ addr += l;
+ length -= l;
+ }
+
+ if (unlikely(length > 0)) {
+ chacha20(&chacha20_state, b.chacha20_stream, pad0,
+ CHACHA20_BLOCK_SIZE, simd_context);
+ crypto_xor(addr, b.chacha20_stream, length);
+ partial = length;
+ }
+
+ poly1305_update(&poly1305_state, miter.addr,
+ min_t(size_t, sl, miter.length), simd_context);
+
+ simd_relax(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);
+
+ if (likely(sl <= -POLY1305_MAC_SIZE))
+ poly1305_final(&poly1305_state, miter.addr + miter.length + sl,
+ simd_context);
+
+ sg_miter_stop(&miter);
+
+ if (unlikely(sl > -POLY1305_MAC_SIZE)) {
+ poly1305_final(&poly1305_state, b.mac, simd_context);
+ scatterwalk_map_and_copy(b.mac, src, src_len, sizeof(b.mac), 1);
+ }
+
+ memzero_explicit(&chacha20_state, sizeof(chacha20_state));
+ memzero_explicit(&b, sizeof(b));
+ return true;
+}
+EXPORT_SYMBOL(chacha20poly1305_encrypt_sg_inplace);
+
+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_KEY_SIZE],
+ 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);
+
+ 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_final(&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_KEY_SIZE])
+{
+ simd_context_t simd_context, ret;
+
+ simd_get(&simd_context);
+ 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_inplace(struct scatterlist *src,
+ size_t src_len,
+ const u8 *ad, const size_t ad_len,
+ const u64 nonce,
+ const u8 key[CHACHA20POLY1305_KEY_SIZE],
+ simd_context_t *simd_context)
+{
+ struct poly1305_ctx poly1305_state;
+ struct chacha20_ctx chacha20_state;
+ struct sg_mapping_iter miter;
+ size_t partial = 0;
+ ssize_t sl;
+ union {
+ u8 chacha20_stream[CHACHA20_BLOCK_SIZE];
+ u8 block0[POLY1305_KEY_SIZE];
+ struct {
+ u8 read_mac[POLY1305_MAC_SIZE];
+ u8 computed_mac[POLY1305_MAC_SIZE];
+ };
+ __le64 lens[2];
+ } b __aligned(16) = { { 0 } };
+ bool ret = false;
+
+ if (unlikely(src_len < POLY1305_MAC_SIZE))
+ return ret;
+ src_len -= POLY1305_MAC_SIZE;
+
+ chacha20_init(&chacha20_state, key, nonce);
+ chacha20(&chacha20_state, b.block0, b.block0, sizeof(b.block0),
+ simd_context);
+ poly1305_init(&poly1305_state, b.block0);
+
+ poly1305_update(&poly1305_state, ad, ad_len, simd_context);
+ poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
+ simd_context);
+
+ sg_miter_start(&miter, src, sg_nents(src), SG_MITER_TO_SG | SG_MITER_ATOMIC);
+ for (sl = src_len; sl > 0 && sg_miter_next(&miter); sl -= miter.length) {
+ u8 *addr = miter.addr;
+ size_t length = min_t(size_t, sl, miter.length);
+
+ poly1305_update(&poly1305_state, addr, length, simd_context);
+
+ if (unlikely(partial)) {
+ size_t l = min(length, CHACHA20_BLOCK_SIZE - partial);
+
+ crypto_xor(addr, b.chacha20_stream + partial, l);
+ partial = (partial + l) & (CHACHA20_BLOCK_SIZE - 1);
+
+ addr += l;
+ length -= l;
+ }
+
+ if (likely(length >= CHACHA20_BLOCK_SIZE || length == sl)) {
+ size_t l = length;
+
+ if (unlikely(length < sl))
+ l &= ~(CHACHA20_BLOCK_SIZE - 1);
+ chacha20(&chacha20_state, addr, addr, l, simd_context);
+ addr += l;
+ length -= l;
+ }
+
+ if (unlikely(length > 0)) {
+ chacha20(&chacha20_state, b.chacha20_stream, pad0,
+ CHACHA20_BLOCK_SIZE, simd_context);
+ crypto_xor(addr, b.chacha20_stream, length);
+ partial = length;
+ }
+
+ simd_relax(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);
+
+ if (likely(sl <= -POLY1305_MAC_SIZE)) {
+ poly1305_final(&poly1305_state, b.computed_mac, simd_context);
+ ret = !crypto_memneq(b.computed_mac,
+ miter.addr + miter.length + sl,
+ POLY1305_MAC_SIZE);
+ }
+
+ sg_miter_stop(&miter);
+
+ if (unlikely(sl > -POLY1305_MAC_SIZE)) {
+ poly1305_final(&poly1305_state, b.computed_mac, simd_context);
+ scatterwalk_map_and_copy(b.read_mac, src, src_len,
+ sizeof(b.read_mac), 0);
+ ret = !crypto_memneq(b.read_mac, b.computed_mac,
+ POLY1305_MAC_SIZE);
+
+ }
+
+ memzero_explicit(&chacha20_state, sizeof(chacha20_state));
+ memzero_explicit(&b, sizeof(b));
+ return ret;
+}
+EXPORT_SYMBOL(chacha20poly1305_decrypt_sg_inplace);
+
+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_NONCE_SIZE],
+ const u8 key[CHACHA20POLY1305_KEY_SIZE])
+{
+ simd_context_t simd_context;
+ u32 derived_key[CHACHA20_KEY_WORDS] __aligned(16);
+
+ simd_get(&simd_context);
+ hchacha20(derived_key, nonce, key, &simd_context);
+ cpu_to_le32_array(derived_key, ARRAY_SIZE(derived_key));
+ __chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len,
+ get_unaligned_le64(nonce + 16),
+ (u8 *)derived_key, &simd_context);
+ memzero_explicit(derived_key, CHACHA20POLY1305_KEY_SIZE);
+ 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_NONCE_SIZE],
+ const u8 key[CHACHA20POLY1305_KEY_SIZE])
+{
+ bool ret;
+ simd_context_t simd_context;
+ u32 derived_key[CHACHA20_KEY_WORDS] __aligned(16);
+
+ simd_get(&simd_context);
+ hchacha20(derived_key, nonce, key, &simd_context);
+ cpu_to_le32_array(derived_key, ARRAY_SIZE(derived_key));
+ ret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,
+ get_unaligned_le64(nonce + 16),
+ (u8 *)derived_key, &simd_context);
+ memzero_explicit(derived_key, CHACHA20POLY1305_KEY_SIZE);
+ simd_put(&simd_context);
+ return ret;
+}
+EXPORT_SYMBOL(xchacha20poly1305_decrypt);
+
+#include "selftest/chacha20poly1305.c"
+
+#ifndef COMPAT_ZINC_IS_A_MODULE
+int __init chacha20poly1305_mod_init(void)
+#else
+static int __init mod_init(void)
+#endif
+{
+ if (!selftest_run("chacha20poly1305", chacha20poly1305_selftest,
+ NULL, 0))
+ return -ENOTRECOVERABLE;
+ return 0;
+}
+
+#ifdef COMPAT_ZINC_IS_A_MODULE
+static void __exit mod_exit(void)
+{
+}
+
+module_init(mod_init);
+module_exit(mod_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ChaCha20Poly1305 AEAD construction");
+MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
+#endif
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.