[PATCH 4/4] crypto: lib/chacha - add array bounds to function prototypes
From: Eric Biggers <ebiggers@kernel.org>
Date: 2025-05-05 18:19:24
Also in:
linux-arm-kernel, linux-bcachefs, linux-crypto, linux-mips, linux-riscv, linux-s390, lkml
Subsystem:
arm port, arm64 port (aarch64 architecture), crypto api, crypto library, library code, linux for powerpc (32-bit and 64-bit), mips, risc-v architecture, s390 architecture, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Russell King, Catalin Marinas, Will Deacon, Herbert Xu, "David S. Miller", Eric Biggers, Jason A. Donenfeld, Ard Biesheuvel, Andrew Morton, Madhavan Srinivasan, Michael Ellerman, Thomas Bogendoerfer, Paul Walmsley, Palmer Dabbelt, Albert Ou, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Eric Biggers <redacted> Add explicit array bounds to the function prototypes for the parameters that didn't already get handled by the conversion to use chacha_state: - chacha_block_*(): Change 'u8 *out' or 'u8 *stream' to u8 out[CHACHA_BLOCK_SIZE]. - hchacha_block_*(): Change 'u32 *out' or 'u32 *stream' to u32 out[HCHACHA_OUT_WORDS]. - chacha_init(): Change 'const u32 *key' to 'const u32 key[CHACHA_KEY_WORDS]'. Change 'const u8 *iv' to 'const u8 iv[CHACHA_IV_SIZE]'. No functional changes. This just makes it clear when fixed-size arrays are expected. Signed-off-by: Eric Biggers <redacted> --- arch/arm/lib/crypto/chacha-glue.c | 12 ++++----- arch/arm/lib/crypto/chacha-scalar-core.S | 2 +- arch/arm64/lib/crypto/chacha-neon-glue.c | 10 ++++---- arch/mips/lib/crypto/chacha-glue.c | 2 +- arch/powerpc/lib/crypto/chacha-p10-glue.c | 4 +-- arch/riscv/lib/crypto/chacha-riscv64-glue.c | 3 ++- arch/s390/lib/crypto/chacha-glue.c | 4 +-- arch/x86/lib/crypto/chacha_glue.c | 8 +++--- crypto/chacha.c | 4 +-- include/crypto/chacha.h | 27 ++++++++++++--------- lib/crypto/chacha.c | 15 ++++++------ lib/crypto/chacha20poly1305.c | 2 -- 12 files changed, 49 insertions(+), 44 deletions(-)
diff --git a/arch/arm/lib/crypto/chacha-glue.c b/arch/arm/lib/crypto/chacha-glue.c
index 0c2b4c62d484..88ec96415283 100644
--- a/arch/arm/lib/crypto/chacha-glue.c
+++ b/arch/arm/lib/crypto/chacha-glue.c@@ -21,13 +21,13 @@ asmlinkage void chacha_block_xor_neon(const struct chacha_state *state, u8 *dst, const u8 *src, int nrounds); asmlinkage void chacha_4block_xor_neon(const struct chacha_state *state, u8 *dst, const u8 *src, int nrounds, unsigned int nbytes); asmlinkage void hchacha_block_arm(const struct chacha_state *state, - u32 *out, int nrounds); + u32 out[HCHACHA_OUT_WORDS], int nrounds); asmlinkage void hchacha_block_neon(const struct chacha_state *state, - u32 *out, int nrounds); + u32 out[HCHACHA_OUT_WORDS], int nrounds); asmlinkage void chacha_doarm(u8 *dst, const u8 *src, unsigned int bytes, const struct chacha_state *state, int nrounds); static __ro_after_init DEFINE_STATIC_KEY_FALSE(use_neon);
@@ -62,18 +62,18 @@ static void chacha_doneon(struct chacha_state *state, u8 *dst, const u8 *src, memcpy(dst, buf, bytes); state->x[12]++; } } -void hchacha_block_arch(const struct chacha_state *state, u32 *stream, - int nrounds) +void hchacha_block_arch(const struct chacha_state *state, + u32 out[HCHACHA_OUT_WORDS], int nrounds) { if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon_usable()) { - hchacha_block_arm(state, stream, nrounds); + hchacha_block_arm(state, out, nrounds); } else { kernel_neon_begin(); - hchacha_block_neon(state, stream, nrounds); + hchacha_block_neon(state, out, nrounds); kernel_neon_end(); } } EXPORT_SYMBOL(hchacha_block_arch);
diff --git a/arch/arm/lib/crypto/chacha-scalar-core.S b/arch/arm/lib/crypto/chacha-scalar-core.S
index d20b5de755cc..4951df05c158 100644
--- a/arch/arm/lib/crypto/chacha-scalar-core.S
+++ b/arch/arm/lib/crypto/chacha-scalar-core.S@@ -406,11 +406,11 @@ ENTRY(chacha_doarm) b 0b ENDPROC(chacha_doarm) /* * void hchacha_block_arm(const struct chacha_state *state, - * u32 out[8], int nrounds); + * u32 out[HCHACHA_OUT_WORDS], int nrounds); */ ENTRY(hchacha_block_arm) push {r1,r4-r11,lr} cmp r2, #12 // ChaCha12 ?
diff --git a/arch/arm64/lib/crypto/chacha-neon-glue.c b/arch/arm64/lib/crypto/chacha-neon-glue.c
index 7b451b3c7240..d0188f974ca5 100644
--- a/arch/arm64/lib/crypto/chacha-neon-glue.c
+++ b/arch/arm64/lib/crypto/chacha-neon-glue.c@@ -32,11 +32,11 @@ asmlinkage void chacha_block_xor_neon(const struct chacha_state *state, u8 *dst, const u8 *src, int nrounds); asmlinkage void chacha_4block_xor_neon(const struct chacha_state *state, u8 *dst, const u8 *src, int nrounds, int bytes); asmlinkage void hchacha_block_neon(const struct chacha_state *state, - u32 *out, int nrounds); + u32 out[HCHACHA_OUT_WORDS], int nrounds); static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon); static void chacha_doneon(struct chacha_state *state, u8 *dst, const u8 *src, int bytes, int nrounds)
@@ -59,18 +59,18 @@ static void chacha_doneon(struct chacha_state *state, u8 *dst, const u8 *src, dst += l; state->x[12] += DIV_ROUND_UP(l, CHACHA_BLOCK_SIZE); } } -void hchacha_block_arch(const struct chacha_state *state, u32 *stream, - int nrounds) +void hchacha_block_arch(const struct chacha_state *state, + u32 out[HCHACHA_OUT_WORDS], int nrounds) { if (!static_branch_likely(&have_neon) || !crypto_simd_usable()) { - hchacha_block_generic(state, stream, nrounds); + hchacha_block_generic(state, out, nrounds); } else { kernel_neon_begin(); - hchacha_block_neon(state, stream, nrounds); + hchacha_block_neon(state, out, nrounds); kernel_neon_end(); } } EXPORT_SYMBOL(hchacha_block_arch);
diff --git a/arch/mips/lib/crypto/chacha-glue.c b/arch/mips/lib/crypto/chacha-glue.c
index 75df4040cded..88c097594eb0 100644
--- a/arch/mips/lib/crypto/chacha-glue.c
+++ b/arch/mips/lib/crypto/chacha-glue.c@@ -13,11 +13,11 @@ asmlinkage void chacha_crypt_arch(struct chacha_state *state, u8 *dst, const u8 *src, unsigned int bytes, int nrounds); EXPORT_SYMBOL(chacha_crypt_arch); asmlinkage void hchacha_block_arch(const struct chacha_state *state, - u32 *stream, int nrounds); + u32 out[HCHACHA_OUT_WORDS], int nrounds); EXPORT_SYMBOL(hchacha_block_arch); bool chacha_is_arch_optimized(void) { return true;
diff --git a/arch/powerpc/lib/crypto/chacha-p10-glue.c b/arch/powerpc/lib/crypto/chacha-p10-glue.c
index a6e6a8da1b8b..fcd23c6f1590 100644
--- a/arch/powerpc/lib/crypto/chacha-p10-glue.c
+++ b/arch/powerpc/lib/crypto/chacha-p10-glue.c@@ -47,13 +47,13 @@ static void chacha_p10_do_8x(struct chacha_state *state, u8 *dst, const u8 *src, if (bytes > 0) chacha_crypt_generic(state, dst, src, bytes, nrounds); } void hchacha_block_arch(const struct chacha_state *state, - u32 *stream, int nrounds) + u32 out[HCHACHA_OUT_WORDS], int nrounds) { - hchacha_block_generic(state, stream, nrounds); + hchacha_block_generic(state, out, nrounds); } EXPORT_SYMBOL(hchacha_block_arch); void chacha_crypt_arch(struct chacha_state *state, u8 *dst, const u8 *src, unsigned int bytes, int nrounds)
diff --git a/arch/riscv/lib/crypto/chacha-riscv64-glue.c b/arch/riscv/lib/crypto/chacha-riscv64-glue.c
index 57541621981e..8c3f11d79be3 100644
--- a/arch/riscv/lib/crypto/chacha-riscv64-glue.c
+++ b/arch/riscv/lib/crypto/chacha-riscv64-glue.c@@ -16,11 +16,12 @@ static __ro_after_init DEFINE_STATIC_KEY_FALSE(use_zvkb); asmlinkage void chacha_zvkb(struct chacha_state *state, const u8 *in, u8 *out, size_t nblocks, int nrounds); -void hchacha_block_arch(const struct chacha_state *state, u32 *out, int nrounds) +void hchacha_block_arch(const struct chacha_state *state, + u32 out[HCHACHA_OUT_WORDS], int nrounds) { hchacha_block_generic(state, out, nrounds); } EXPORT_SYMBOL(hchacha_block_arch);
diff --git a/arch/s390/lib/crypto/chacha-glue.c b/arch/s390/lib/crypto/chacha-glue.c
index 0a9fd50c1bd8..f95ba3483bbc 100644
--- a/arch/s390/lib/crypto/chacha-glue.c
+++ b/arch/s390/lib/crypto/chacha-glue.c@@ -15,14 +15,14 @@ #include <linux/sizes.h> #include <asm/fpu.h> #include "chacha-s390.h" void hchacha_block_arch(const struct chacha_state *state, - u32 *stream, int nrounds) + u32 out[HCHACHA_OUT_WORDS], int nrounds) { /* TODO: implement hchacha_block_arch() in assembly */ - hchacha_block_generic(state, stream, nrounds); + hchacha_block_generic(state, out, nrounds); } EXPORT_SYMBOL(hchacha_block_arch); void chacha_crypt_arch(struct chacha_state *state, u8 *dst, const u8 *src, unsigned int bytes, int nrounds)
diff --git a/arch/x86/lib/crypto/chacha_glue.c b/arch/x86/lib/crypto/chacha_glue.c
index 6f00a56e3e9a..10b2c945f541 100644
--- a/arch/x86/lib/crypto/chacha_glue.c
+++ b/arch/x86/lib/crypto/chacha_glue.c@@ -17,11 +17,11 @@ asmlinkage void chacha_block_xor_ssse3(const struct chacha_state *state, unsigned int len, int nrounds); asmlinkage void chacha_4block_xor_ssse3(const struct chacha_state *state, u8 *dst, const u8 *src, unsigned int len, int nrounds); asmlinkage void hchacha_block_ssse3(const struct chacha_state *state, - u32 *out, int nrounds); + u32 out[HCHACHA_OUT_WORDS], int nrounds); asmlinkage void chacha_2block_xor_avx2(const struct chacha_state *state, u8 *dst, const u8 *src, unsigned int len, int nrounds); asmlinkage void chacha_4block_xor_avx2(const struct chacha_state *state,
@@ -125,17 +125,17 @@ static void chacha_dosimd(struct chacha_state *state, u8 *dst, const u8 *src, state->x[12]++; } } void hchacha_block_arch(const struct chacha_state *state, - u32 *stream, int nrounds) + u32 out[HCHACHA_OUT_WORDS], int nrounds) { if (!static_branch_likely(&chacha_use_simd)) { - hchacha_block_generic(state, stream, nrounds); + hchacha_block_generic(state, out, nrounds); } else { kernel_fpu_begin(); - hchacha_block_ssse3(state, stream, nrounds); + hchacha_block_ssse3(state, out, nrounds); kernel_fpu_end(); } } EXPORT_SYMBOL(hchacha_block_arch);
diff --git a/crypto/chacha.c b/crypto/chacha.c
index 73ce62a9ac22..c3a11f4e2d13 100644
--- a/crypto/chacha.c
+++ b/crypto/chacha.c@@ -44,12 +44,12 @@ static int chacha12_setkey(struct crypto_skcipher *tfm, { return chacha_setkey(tfm, key, keysize, 12); } static int chacha_stream_xor(struct skcipher_request *req, - const struct chacha_ctx *ctx, const u8 *iv, - bool arch) + const struct chacha_ctx *ctx, + const u8 iv[CHACHA_IV_SIZE], bool arch) { struct skcipher_walk walk; struct chacha_state state; int err;
diff --git a/include/crypto/chacha.h b/include/crypto/chacha.h
index 7c2e6c68919b..91f6b4cf561c 100644
--- a/include/crypto/chacha.h
+++ b/include/crypto/chacha.h@@ -24,32 +24,36 @@ #define CHACHA_KEY_SIZE 32 #define CHACHA_BLOCK_SIZE 64 #define CHACHAPOLY_IV_SIZE 12 -#define CHACHA_STATE_WORDS (CHACHA_BLOCK_SIZE / sizeof(u32)) +#define CHACHA_KEY_WORDS 8 +#define CHACHA_STATE_WORDS 16 +#define HCHACHA_OUT_WORDS 8 /* 192-bit nonce, then 64-bit stream position */ #define XCHACHA_IV_SIZE 32 struct chacha_state { u32 x[CHACHA_STATE_WORDS]; }; -void chacha_block_generic(struct chacha_state *state, u8 *stream, int nrounds); -static inline void chacha20_block(struct chacha_state *state, u8 *stream) +void chacha_block_generic(struct chacha_state *state, + u8 out[CHACHA_BLOCK_SIZE], int nrounds); +static inline void chacha20_block(struct chacha_state *state, + u8 out[CHACHA_BLOCK_SIZE]) { - chacha_block_generic(state, stream, 20); + chacha_block_generic(state, out, 20); } -void hchacha_block_arch(const struct chacha_state *state, u32 *out, - int nrounds); -void hchacha_block_generic(const struct chacha_state *state, u32 *out, - int nrounds); +void hchacha_block_arch(const struct chacha_state *state, + u32 out[HCHACHA_OUT_WORDS], int nrounds); +void hchacha_block_generic(const struct chacha_state *state, + u32 out[HCHACHA_OUT_WORDS], int nrounds); -static inline void hchacha_block(const struct chacha_state *state, u32 *out, - int nrounds) +static inline void hchacha_block(const struct chacha_state *state, + u32 out[HCHACHA_OUT_WORDS], int nrounds) { if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CHACHA)) hchacha_block_arch(state, out, nrounds); else hchacha_block_generic(state, out, nrounds);
@@ -69,11 +73,12 @@ static inline void chacha_init_consts(struct chacha_state *state) state->x[2] = CHACHA_CONSTANT_2_BY; state->x[3] = CHACHA_CONSTANT_TE_K; } static inline void chacha_init(struct chacha_state *state, - const u32 *key, const u8 *iv) + const u32 key[CHACHA_KEY_WORDS], + const u8 iv[CHACHA_IV_SIZE]) { chacha_init_consts(state); state->x[4] = key[0]; state->x[5] = key[1]; state->x[6] = key[2];
diff --git a/lib/crypto/chacha.c b/lib/crypto/chacha.c
index ae50e441f9fb..ced87dd31a97 100644
--- a/lib/crypto/chacha.c
+++ b/lib/crypto/chacha.c@@ -65,49 +65,50 @@ static void chacha_permute(struct chacha_state *state, int nrounds) } /** * chacha_block_generic - generate one keystream block and increment block counter * @state: input state matrix - * @stream: output keystream block (64 bytes) + * @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 *stream, int nrounds) +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], - &stream[i * sizeof(u32)]); + &out[i * sizeof(u32)]); state->x[12]++; } EXPORT_SYMBOL(chacha_block_generic); /** * hchacha_block_generic - abbreviated ChaCha core, for XChaCha * @state: input state matrix - * @stream: output (8 32-bit words) + * @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 *stream, int nrounds) + u32 out[HCHACHA_OUT_WORDS], int nrounds) { struct chacha_state permuted_state = *state; chacha_permute(&permuted_state, nrounds); - memcpy(&stream[0], &permuted_state.x[0], 16); - memcpy(&stream[4], &permuted_state.x[12], 16); + memcpy(&out[0], &permuted_state.x[0], 16); + memcpy(&out[4], &permuted_state.x[12], 16); } EXPORT_SYMBOL(hchacha_block_generic);
diff --git a/lib/crypto/chacha20poly1305.c b/lib/crypto/chacha20poly1305.c
index 2e7bbc1a67ea..fbd3690e2531 100644
--- a/lib/crypto/chacha20poly1305.c
+++ b/lib/crypto/chacha20poly1305.c@@ -16,12 +16,10 @@ #include <linux/kernel.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/module.h> -#define CHACHA_KEY_WORDS (CHACHA_KEY_SIZE / sizeof(u32)) - static void chacha_load_key(u32 *k, const u8 *in) { k[0] = get_unaligned_le32(in); k[1] = get_unaligned_le32(in + 4); k[2] = get_unaligned_le32(in + 8);
--
2.49.0