[PATCH] crypto: chacha - constify ctx and iv arguments

[Eric Biggers]

From: Eric Biggers <ebigg...@google.com>

Constify the ctx and iv arguments to crypto_chacha_init() and the
various chacha*_stream_xor() functions.  This makes it clear that they
are not modified.

Signed-off-by: Eric Biggers <ebigg...@google.com>
---
 arch/arm/crypto/chacha-neon-glue.c   | 2 +-
 arch/arm64/crypto/chacha-neon-glue.c | 2 +-
 arch/x86/crypto/chacha_glue.c        | 2 +-
 crypto/chacha_generic.c              | 4 ++--
 include/crypto/chacha.h              | 2 +-
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm/crypto/chacha-neon-glue.c 
b/arch/arm/crypto/chacha-neon-glue.c
index 48a89537b8283..a8e9b534c8da5 100644
--- a/arch/arm/crypto/chacha-neon-glue.c
+++ b/arch/arm/crypto/chacha-neon-glue.c
@@ -63,7 +63,7 @@ static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
 }
 
 static int chacha_neon_stream_xor(struct skcipher_request *req,
-                                 struct chacha_ctx *ctx, u8 *iv)
+                                 const struct chacha_ctx *ctx, const u8 *iv)
 {
        struct skcipher_walk walk;
        u32 state[16];
diff --git a/arch/arm64/crypto/chacha-neon-glue.c 
b/arch/arm64/crypto/chacha-neon-glue.c
index 82029cda2e77a..1495d2b18518d 100644
--- a/arch/arm64/crypto/chacha-neon-glue.c
+++ b/arch/arm64/crypto/chacha-neon-glue.c
@@ -60,7 +60,7 @@ static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
 }
 
 static int chacha_neon_stream_xor(struct skcipher_request *req,
-                                 struct chacha_ctx *ctx, u8 *iv)
+                                 const struct chacha_ctx *ctx, const u8 *iv)
 {
        struct skcipher_walk walk;
        u32 state[16];
diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c
index 4967ad620775b..7276b7ef14ec4 100644
--- a/arch/x86/crypto/chacha_glue.c
+++ b/arch/x86/crypto/chacha_glue.c
@@ -128,7 +128,7 @@ static void chacha_dosimd(u32 *state, u8 *dst, const u8 
*src,
 }
 
 static int chacha_simd_stream_xor(struct skcipher_walk *walk,
-                                 struct chacha_ctx *ctx, u8 *iv)
+                                 const struct chacha_ctx *ctx, const u8 *iv)
 {
        u32 *state, state_buf[16 + 2] __aligned(8);
        int next_yield = 4096; /* bytes until next FPU yield */
diff --git a/crypto/chacha_generic.c b/crypto/chacha_generic.c
index d2ec04997832e..d283bd3bdb607 100644
--- a/crypto/chacha_generic.c
+++ b/crypto/chacha_generic.c
@@ -36,7 +36,7 @@ static void chacha_docrypt(u32 *state, u8 *dst, const u8 *src,
 }
 
 static int chacha_stream_xor(struct skcipher_request *req,
-                            struct chacha_ctx *ctx, u8 *iv)
+                            const struct chacha_ctx *ctx, const u8 *iv)
 {
        struct skcipher_walk walk;
        u32 state[16];
@@ -60,7 +60,7 @@ static int chacha_stream_xor(struct skcipher_request *req,
        return err;
 }
 
-void crypto_chacha_init(u32 *state, struct chacha_ctx *ctx, u8 *iv)
+void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv)
 {
        state[0]  = 0x61707865; /* "expa" */
        state[1]  = 0x3320646e; /* "nd 3" */
diff --git a/include/crypto/chacha.h b/include/crypto/chacha.h
index 1fc70a69d5508..d1e723c6a37dd 100644
--- a/include/crypto/chacha.h
+++ b/include/crypto/chacha.h
@@ -41,7 +41,7 @@ static inline void chacha20_block(u32 *state, u8 *stream)
 }
 void hchacha_block(const u32 *in, u32 *out, int nrounds);
 
-void crypto_chacha_init(u32 *state, struct chacha_ctx *ctx, u8 *iv);
+void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 
*iv);
 
 int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
                           unsigned int keysize);
-- 
2.21.0