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authorLinus Torvalds <torvalds@linux-foundation.org>2025-09-29 15:48:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-09-29 15:48:56 -0700
commitd8768fb12a14c30436bd0466b4fc28edeef45078 (patch)
tree49ceb107f33d3988a9f74267fb0c77f22b915904 /lib/crypto/chacha.c
parente2fffe1d958b3660bc4e07e6542d97b6cc168826 (diff)
parentb94bc4398beccd329a51052c5e7e84e4670dbcd9 (diff)
Merge tag 'libcrypto-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux
Pull crypto library updates from Eric Biggers: - Add a RISC-V optimized implementation of Poly1305. This code was written by Andy Polyakov and contributed by Zhihang Shao. - Migrate the MD5 code into lib/crypto/, and add KUnit tests for MD5. Yes, it's still the 90s, and several kernel subsystems are still using MD5 for legacy use cases. As long as that remains the case, it's helpful to clean it up in the same way as I've been doing for other algorithms. Later, I plan to convert most of these users of MD5 to use the new MD5 library API instead of the generic crypto API. - Simplify the organization of the ChaCha, Poly1305, BLAKE2s, and Curve25519 code. Consolidate these into one module per algorithm, and centralize the configuration and build process. This is the same reorganization that has already been successful for SHA-1 and SHA-2. - Remove the unused crypto_kpp API for Curve25519. - Migrate the BLAKE2s and Curve25519 self-tests to KUnit. - Always enable the architecture-optimized BLAKE2s code. * tag 'libcrypto-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: (38 commits) crypto: md5 - Implement export_core() and import_core() wireguard: kconfig: simplify crypto kconfig selections lib/crypto: tests: Enable Curve25519 test when CRYPTO_SELFTESTS lib/crypto: curve25519: Consolidate into single module lib/crypto: curve25519: Move a couple functions out-of-line lib/crypto: tests: Add Curve25519 benchmark lib/crypto: tests: Migrate Curve25519 self-test to KUnit crypto: curve25519 - Remove unused kpp support crypto: testmgr - Remove curve25519 kpp tests crypto: x86/curve25519 - Remove unused kpp support crypto: powerpc/curve25519 - Remove unused kpp support crypto: arm/curve25519 - Remove unused kpp support crypto: hisilicon/hpre - Remove unused curve25519 kpp support lib/crypto: tests: Add KUnit tests for BLAKE2s lib/crypto: blake2s: Consolidate into single C translation unit lib/crypto: blake2s: Move generic code into blake2s.c lib/crypto: blake2s: Always enable arch-optimized BLAKE2s code lib/crypto: blake2s: Remove obsolete self-test lib/crypto: x86/blake2s: Reduce size of BLAKE2S_SIGMA2 lib/crypto: chacha: Consolidate into single module ...
Diffstat (limited to 'lib/crypto/chacha.c')
-rw-r--r--lib/crypto/chacha.c142
1 files changed, 49 insertions, 93 deletions
diff --git a/lib/crypto/chacha.c b/lib/crypto/chacha.c
index 77f68de71066..e0c7cb4af318 100644
--- a/lib/crypto/chacha.c
+++ b/lib/crypto/chacha.c
@@ -1,114 +1,70 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
- * The "hash function" used as the core of the ChaCha stream cipher (RFC7539)
+ * The ChaCha stream cipher (RFC7539)
*
* Copyright (C) 2015 Martin Willi
*/
+#include <crypto/algapi.h> // for crypto_xor_cpy
#include <crypto/chacha.h>
-#include <linux/bitops.h>
-#include <linux/bug.h>
#include <linux/export.h>
#include <linux/kernel.h>
-#include <linux/string.h>
-#include <linux/unaligned.h>
+#include <linux/module.h>
-static void chacha_permute(struct chacha_state *state, int nrounds)
+static void __maybe_unused
+chacha_crypt_generic(struct chacha_state *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds)
{
- u32 *x = state->x;
- int i;
-
- /* whitelist the allowed round counts */
- WARN_ON_ONCE(nrounds != 20 && nrounds != 12);
-
- for (i = 0; i < nrounds; i += 2) {
- x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 16);
- x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 16);
- x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 16);
- x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 16);
-
- x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 12);
- x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 12);
- x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 12);
- x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 12);
-
- x[0] += x[4]; x[12] = rol32(x[12] ^ x[0], 8);
- x[1] += x[5]; x[13] = rol32(x[13] ^ x[1], 8);
- x[2] += x[6]; x[14] = rol32(x[14] ^ x[2], 8);
- x[3] += x[7]; x[15] = rol32(x[15] ^ x[3], 8);
-
- x[8] += x[12]; x[4] = rol32(x[4] ^ x[8], 7);
- x[9] += x[13]; x[5] = rol32(x[5] ^ x[9], 7);
- x[10] += x[14]; x[6] = rol32(x[6] ^ x[10], 7);
- x[11] += x[15]; x[7] = rol32(x[7] ^ x[11], 7);
-
- x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 16);
- x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 16);
- x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 16);
- x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 16);
-
- x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 12);
- x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 12);
- x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 12);
- x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 12);
-
- x[0] += x[5]; x[15] = rol32(x[15] ^ x[0], 8);
- x[1] += x[6]; x[12] = rol32(x[12] ^ x[1], 8);
- x[2] += x[7]; x[13] = rol32(x[13] ^ x[2], 8);
- x[3] += x[4]; x[14] = rol32(x[14] ^ x[3], 8);
-
- x[10] += x[15]; x[5] = rol32(x[5] ^ x[10], 7);
- x[11] += x[12]; x[6] = rol32(x[6] ^ x[11], 7);
- x[8] += x[13]; x[7] = rol32(x[7] ^ x[8], 7);
- x[9] += x[14]; x[4] = rol32(x[4] ^ x[9], 7);
+ /* aligned to potentially speed up crypto_xor() */
+ u8 stream[CHACHA_BLOCK_SIZE] __aligned(sizeof(long));
+
+ while (bytes >= CHACHA_BLOCK_SIZE) {
+ chacha_block_generic(state, stream, nrounds);
+ crypto_xor_cpy(dst, src, stream, CHACHA_BLOCK_SIZE);
+ bytes -= CHACHA_BLOCK_SIZE;
+ dst += CHACHA_BLOCK_SIZE;
+ src += CHACHA_BLOCK_SIZE;
+ }
+ if (bytes) {
+ chacha_block_generic(state, stream, nrounds);
+ crypto_xor_cpy(dst, src, stream, bytes);
}
}
-/**
- * chacha_block_generic - generate one keystream block and increment block counter
- * @state: input state matrix
- * @out: output keystream block
- * @nrounds: number of rounds (20 or 12; 20 is recommended)
- *
- * This is the ChaCha core, a function from 64-byte strings to 64-byte strings.
- * The caller has already converted the endianness of the input. This function
- * also handles incrementing the block counter in the input matrix.
- */
-void chacha_block_generic(struct chacha_state *state,
- u8 out[CHACHA_BLOCK_SIZE], int nrounds)
-{
- struct chacha_state permuted_state = *state;
- int i;
-
- chacha_permute(&permuted_state, nrounds);
-
- for (i = 0; i < ARRAY_SIZE(state->x); i++)
- put_unaligned_le32(permuted_state.x[i] + state->x[i],
- &out[i * sizeof(u32)]);
+#ifdef CONFIG_CRYPTO_LIB_CHACHA_ARCH
+#include "chacha.h" /* $(SRCARCH)/chacha.h */
+#else
+#define chacha_crypt_arch chacha_crypt_generic
+#define hchacha_block_arch hchacha_block_generic
+#endif
- state->x[12]++;
+void chacha_crypt(struct chacha_state *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds)
+{
+ chacha_crypt_arch(state, dst, src, bytes, nrounds);
}
-EXPORT_SYMBOL(chacha_block_generic);
+EXPORT_SYMBOL_GPL(chacha_crypt);
-/**
- * hchacha_block_generic - abbreviated ChaCha core, for XChaCha
- * @state: input state matrix
- * @out: the output words
- * @nrounds: number of rounds (20 or 12; 20 is recommended)
- *
- * HChaCha is the ChaCha equivalent of HSalsa and is an intermediate step
- * towards XChaCha (see https://cr.yp.to/snuffle/xsalsa-20081128.pdf). HChaCha
- * skips the final addition of the initial state, and outputs only certain words
- * of the state. It should not be used for streaming directly.
- */
-void hchacha_block_generic(const struct chacha_state *state,
- u32 out[HCHACHA_OUT_WORDS], int nrounds)
+void hchacha_block(const struct chacha_state *state,
+ u32 out[HCHACHA_OUT_WORDS], int nrounds)
{
- struct chacha_state permuted_state = *state;
+ hchacha_block_arch(state, out, nrounds);
+}
+EXPORT_SYMBOL_GPL(hchacha_block);
- chacha_permute(&permuted_state, nrounds);
+#ifdef chacha_mod_init_arch
+static int __init chacha_mod_init(void)
+{
+ chacha_mod_init_arch();
+ return 0;
+}
+subsys_initcall(chacha_mod_init);
- memcpy(&out[0], &permuted_state.x[0], 16);
- memcpy(&out[4], &permuted_state.x[12], 16);
+static void __exit chacha_mod_exit(void)
+{
}
-EXPORT_SYMBOL(hchacha_block_generic);
+module_exit(chacha_mod_exit);
+#endif
+
+MODULE_DESCRIPTION("ChaCha stream cipher (RFC7539)");
+MODULE_LICENSE("GPL");