[PATCH 2/17] crypto: chacha20 - Export chacha20 functions without crypto API

Herbert Xu
2019-03-22T06:31:14Z

This patch exports the raw chacha20 functions, including the generic
as well as x86/arm accelerated versions. This allows them to be
used without going through the crypto API.

This patch also renames struct chacha20_ctx to crypto_chacha20_ctx
to avoid naming conflicts with zinc.

In order to ensure that zinc can link to the requisite functions,
this function removes the failure mode from the x86/arm accelerated
glue code so that the modules will always load, even if the hardware
is not available. In that case, the crypto API functions would not
be registered.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---

arch/arm/crypto/chacha-neon-glue.c | 28 ++++++++++++++++------------
arch/arm64/crypto/chacha-neon-glue.c | 21 +++++++++++----------
arch/x86/crypto/chacha_glue.c | 27 ++++++++++++++++-----------
crypto/chacha_generic.c | 26 ++++++++++++++------------
include/crypto/chacha.h | 10 ++++++++--
5 files changed, 65 insertions(+), 47 deletions(-)

diff --git a/arch/arm/crypto/chacha-neon-glue.c b/arch/arm/crypto/chacha-neon-glue.c
index 9d6fda81986d..6d0e880dd471 100644
--- a/arch/arm/crypto/chacha-neon-glue.c
+++ b/arch/arm/crypto/chacha-neon-glue.c
@@ -35,8 +35,8 @@ asmlinkage void chacha_4block_xor_neon(const u32 *state, u8 *dst, const u8 *src,
int nrounds);
asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds);

-static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
- unsigned int bytes, int nrounds)
+static void crypto_chacha_doneon(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds)
{
u8 buf[CHACHA_BLOCK_SIZE];

@@ -60,9 +60,10 @@ static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
memcpy(dst, buf, bytes);
}
}
+EXPORT_SYMBOL_GPL(crypto_chacha_doneon);

static int chacha_neon_stream_xor(struct skcipher_request *req,
- struct chacha_ctx *ctx, u8 *iv)
+ struct crypto_chacha_ctx *ctx, u8 *iv)
{
struct skcipher_walk walk;
u32 state[16];
@@ -79,8 +80,8 @@ static int chacha_neon_stream_xor(struct skcipher_request *req,
nbytes = round_down(nbytes, walk.stride);

kernel_neon_begin();
- chacha_doneon(state, walk.dst.virt.addr, walk.src.virt.addr,
- nbytes, ctx->nrounds);
+ crypto_chacha_doneon(state, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes, ctx->nrounds);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
@@ -91,7 +92,7 @@ static int chacha_neon_stream_xor(struct skcipher_request *req,
static int chacha_neon(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_chacha_ctx *ctx = crypto_skcipher_ctx(tfm);

if (req->cryptlen <= CHACHA_BLOCK_SIZE || !may_use_simd())
return crypto_chacha_crypt(req);
@@ -102,8 +103,8 @@ static int chacha_neon(struct skcipher_request *req)
static int xchacha_neon(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
- struct chacha_ctx subctx;
+ struct crypto_chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_chacha_ctx subctx;
u32 state[16];
u8 real_iv[16];

@@ -128,7 +129,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "chacha20-neon",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -144,7 +145,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "xchacha20-neon",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -160,7 +161,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "xchacha12-neon",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -177,13 +178,16 @@ static struct skcipher_alg algs[] = {
static int __init chacha_simd_mod_init(void)
{
if (!(elf_hwcap & HWCAP_NEON))
- return -ENODEV;
+ return 0;

return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
}

static void __exit chacha_simd_mod_fini(void)
{
+ if (!(elf_hwcap & HWCAP_NEON))
+ return;
+
crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
}

diff --git a/arch/arm64/crypto/chacha-neon-glue.c b/arch/arm64/crypto/chacha-neon-glue.c
index bece1d85bd81..405e44c02e57 100644
--- a/arch/arm64/crypto/chacha-neon-glue.c
+++ b/arch/arm64/crypto/chacha-neon-glue.c
@@ -35,7 +35,7 @@ asmlinkage void chacha_4block_xor_neon(u32 *state, u8 *dst, const u8 *src,
int nrounds, int bytes);
asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds);

-static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
+void crypto_chacha_doneon(u32 *state, u8 *dst, const u8 *src,
int bytes, int nrounds)
{
while (bytes > 0) {
@@ -57,9 +57,10 @@ static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
state[12] += 5;
}
}
+EXPORT_SYMBOL_GPL(crypto_chacha_doneon);

static int chacha_neon_stream_xor(struct skcipher_request *req,
- struct chacha_ctx *ctx, u8 *iv)
+ struct crypto_chacha_ctx *ctx, u8 *iv)
{
struct skcipher_walk walk;
u32 state[16];
@@ -76,8 +77,8 @@ static int chacha_neon_stream_xor(struct skcipher_request *req,
nbytes = rounddown(nbytes, walk.stride);

kernel_neon_begin();
- chacha_doneon(state, walk.dst.virt.addr, walk.src.virt.addr,
- nbytes, ctx->nrounds);
+ crypto_chacha_doneon(state, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes, ctx->nrounds);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
@@ -88,7 +89,7 @@ static int chacha_neon_stream_xor(struct skcipher_request *req,
static int chacha_neon(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_chacha_ctx *ctx = crypto_skcipher_ctx(tfm);

if (req->cryptlen <= CHACHA_BLOCK_SIZE || !may_use_simd())
return crypto_chacha_crypt(req);
@@ -99,8 +100,8 @@ static int chacha_neon(struct skcipher_request *req)
static int xchacha_neon(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
- struct chacha_ctx subctx;
+ struct crypto_chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_chacha_ctx subctx;
u32 state[16];
u8 real_iv[16];

@@ -125,7 +126,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "chacha20-neon",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -141,7 +142,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "xchacha20-neon",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -157,7 +158,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "xchacha12-neon",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c
index 45c1c4143176..97e278df2bc7 100644
--- a/arch/x86/crypto/chacha_glue.c
+++ b/arch/x86/crypto/chacha_glue.c
@@ -50,7 +50,7 @@ static unsigned int chacha_advance(unsigned int len, unsigned int maxblocks)
return round_up(len, CHACHA_BLOCK_SIZE) / CHACHA_BLOCK_SIZE;
}

-static void chacha_dosimd(u32 *state, u8 *dst, const u8 *src,
+void crypto_chacha_dosimd(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes, int nrounds)
{
#ifdef CONFIG_AS_AVX2
@@ -126,9 +126,10 @@ static void chacha_dosimd(u32 *state, u8 *dst, const u8 *src,
state[12]++;
}
}
+EXPORT_SYMBOL_GPL(crypto_chacha_dosimd);

static int chacha_simd_stream_xor(struct skcipher_walk *walk,
- struct chacha_ctx *ctx, u8 *iv)
+ struct crypto_chacha_ctx *ctx, u8 *iv)
{
u32 *state, state_buf[16 + 2] __aligned(8);
int next_yield = 4096; /* bytes until next FPU yield */
@@ -147,8 +148,9 @@ static int chacha_simd_stream_xor(struct skcipher_walk *walk,
next_yield -= nbytes;
}

- chacha_dosimd(state, walk->dst.virt.addr, walk->src.virt.addr,
- nbytes, ctx->nrounds);
+ crypto_chacha_dosimd(state, walk->dst.virt.addr,
+ walk->src.virt.addr, nbytes,
+ ctx->nrounds);

if (next_yield <= 0) {
/* temporarily allow preemption */
@@ -166,7 +168,7 @@ static int chacha_simd_stream_xor(struct skcipher_walk *walk,
static int chacha_simd(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err;

@@ -186,9 +188,9 @@ static int chacha_simd(struct skcipher_request *req)
static int xchacha_simd(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
- struct chacha_ctx subctx;
+ struct crypto_chacha_ctx subctx;
u32 *state, state_buf[16 + 2] __aligned(8);
u8 real_iv[16];
int err;
@@ -224,7 +226,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "chacha20-simd",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -239,7 +241,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "xchacha20-simd",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -254,7 +256,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "xchacha12-simd",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -270,7 +272,7 @@ static struct skcipher_alg algs[] = {
static int __init chacha_simd_mod_init(void)
{
if (!boot_cpu_has(X86_FEATURE_SSSE3))
- return -ENODEV;
+ return 0;

#ifdef CONFIG_AS_AVX2
chacha_use_avx2 = boot_cpu_has(X86_FEATURE_AVX) &&
@@ -287,6 +289,9 @@ static int __init chacha_simd_mod_init(void)

static void __exit chacha_simd_mod_fini(void)
{
+ if (!boot_cpu_has(X86_FEATURE_SSSE3))
+ return;
+
crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
}

diff --git a/crypto/chacha_generic.c b/crypto/chacha_generic.c
index 35b583101f4f..4a337de5c2a0 100644
--- a/crypto/chacha_generic.c
+++ b/crypto/chacha_generic.c
@@ -16,7 +16,7 @@
#include <crypto/internal/skcipher.h>
#include <linux/module.h>

-static void chacha_docrypt(u32 *state, u8 *dst, const u8 *src,
+void crypto_chacha_generic(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes, int nrounds)
{
/* aligned to potentially speed up crypto_xor() */
@@ -36,9 +36,10 @@ static void chacha_docrypt(u32 *state, u8 *dst, const u8 *src,
crypto_xor(dst, stream, bytes);
}
}
+EXPORT_SYMBOL_GPL(crypto_chacha_generic);

static int chacha_stream_xor(struct skcipher_request *req,
- struct chacha_ctx *ctx, u8 *iv)
+ struct crypto_chacha_ctx *ctx, u8 *iv)
{
struct skcipher_walk walk;
u32 state[16];
@@ -54,15 +55,16 @@ static int chacha_stream_xor(struct skcipher_request *req,
if (nbytes < walk.total)
nbytes = round_down(nbytes, walk.stride);

- chacha_docrypt(state, walk.dst.virt.addr, walk.src.virt.addr,
- nbytes, ctx->nrounds);
+ crypto_chacha_generic(state, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes,
+ ctx->nrounds);
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}

return err;
}

-void crypto_chacha_init(u32 *state, struct chacha_ctx *ctx, u8 *iv)
+void crypto_chacha_init(u32 *state, struct crypto_chacha_ctx *ctx, u8 *iv)
{
state[0] = 0x61707865; /* "expa" */
state[1] = 0x3320646e; /* "nd 3" */
@@ -86,7 +88,7 @@ EXPORT_SYMBOL_GPL(crypto_chacha_init);
static int chacha_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keysize, int nrounds)
{
- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
int i;

if (keysize != CHACHA_KEY_SIZE)
@@ -116,7 +118,7 @@ EXPORT_SYMBOL_GPL(crypto_chacha12_setkey);
int crypto_chacha_crypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_chacha_ctx *ctx = crypto_skcipher_ctx(tfm);

return chacha_stream_xor(req, ctx, req->iv);
}
@@ -125,8 +127,8 @@ EXPORT_SYMBOL_GPL(crypto_chacha_crypt);
int crypto_xchacha_crypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
- struct chacha_ctx subctx;
+ struct crypto_chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_chacha_ctx subctx;
u32 state[16];
u8 real_iv[16];

@@ -150,7 +152,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "chacha20-generic",
.base.cra_priority = 100,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -165,7 +167,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "xchacha20-generic",
.base.cra_priority = 100,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
@@ -180,7 +182,7 @@ static struct skcipher_alg algs[] = {
.base.cra_driver_name = "xchacha12-generic",
.base.cra_priority = 100,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_ctxsize = sizeof(struct crypto_chacha_ctx),
.base.cra_module = THIS_MODULE,

.min_keysize = CHACHA_KEY_SIZE,
diff --git a/include/crypto/chacha.h b/include/crypto/chacha.h
index 1fc70a69d550..24db07508701 100644
--- a/include/crypto/chacha.h
+++ b/include/crypto/chacha.h
@@ -29,7 +29,7 @@
/* 192-bit nonce, then 64-bit stream position */
#define XCHACHA_IV_SIZE 32

-struct chacha_ctx {
+struct crypto_chacha_ctx {
u32 key[8];
int nrounds;
};
@@ -41,7 +41,9 @@ 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_generic(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds);
+void crypto_chacha_init(u32 *state, struct crypto_chacha_ctx *ctx, u8 *iv);

int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keysize);
@@ -50,5 +52,9 @@ int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,

int crypto_chacha_crypt(struct skcipher_request *req);
int crypto_xchacha_crypt(struct skcipher_request *req);
+void crypto_chacha_dosimd(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds);
+void crypto_chacha_doneon(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds);

#endif /* _CRYPTO_CHACHA_H */