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authorEric Biggers <ebiggers@google.com>2018-11-16 17:26:21 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2018-11-20 14:26:55 +0800
commit1ca1b917940c24ca3d1f490118c5474168622953 (patch)
tree26cde5a85d0792a8dd709a6f5316f76af8801a35 /drivers/char/random.c
parentde61d7ae5d3789dcba3749a418f76613fbee8414 (diff)
crypto: chacha20-generic - refactor to allow varying number of rounds
In preparation for adding XChaCha12 support, rename/refactor chacha20-generic to support different numbers of rounds. The justification for needing XChaCha12 support is explained in more detail in the patch "crypto: chacha - add XChaCha12 support". The only difference between ChaCha{8,12,20} are the number of rounds itself; all other parts of the algorithm are the same. Therefore, remove the "20" from all definitions, structures, functions, files, etc. that will be shared by all ChaCha versions. Also make ->setkey() store the round count in the chacha_ctx (previously chacha20_ctx). The generic code then passes the round count through to chacha_block(). There will be a ->setkey() function for each explicitly allowed round count; the encrypt/decrypt functions will be the same. I decided not to do it the opposite way (same ->setkey() function for all round counts, with different encrypt/decrypt functions) because that would have required more boilerplate code in architecture-specific implementations of ChaCha and XChaCha. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Martin Willi <martin@strongswan.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char/random.c')
-rw-r--r--drivers/char/random.c51
1 files changed, 25 insertions, 26 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 2eb70e76ed35..38c6d1af6d1c 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -265,7 +265,7 @@
#include <linux/syscalls.h>
#include <linux/completion.h>
#include <linux/uuid.h>
-#include <crypto/chacha20.h>
+#include <crypto/chacha.h>
#include <asm/processor.h>
#include <linux/uaccess.h>
@@ -431,11 +431,10 @@ static int crng_init = 0;
#define crng_ready() (likely(crng_init > 1))
static int crng_init_cnt = 0;
static unsigned long crng_global_init_time = 0;
-#define CRNG_INIT_CNT_THRESH (2*CHACHA20_KEY_SIZE)
-static void _extract_crng(struct crng_state *crng,
- __u8 out[CHACHA20_BLOCK_SIZE]);
+#define CRNG_INIT_CNT_THRESH (2*CHACHA_KEY_SIZE)
+static void _extract_crng(struct crng_state *crng, __u8 out[CHACHA_BLOCK_SIZE]);
static void _crng_backtrack_protect(struct crng_state *crng,
- __u8 tmp[CHACHA20_BLOCK_SIZE], int used);
+ __u8 tmp[CHACHA_BLOCK_SIZE], int used);
static void process_random_ready_list(void);
static void _get_random_bytes(void *buf, int nbytes);
@@ -863,7 +862,7 @@ static int crng_fast_load(const char *cp, size_t len)
}
p = (unsigned char *) &primary_crng.state[4];
while (len > 0 && crng_init_cnt < CRNG_INIT_CNT_THRESH) {
- p[crng_init_cnt % CHACHA20_KEY_SIZE] ^= *cp;
+ p[crng_init_cnt % CHACHA_KEY_SIZE] ^= *cp;
cp++; crng_init_cnt++; len--;
}
spin_unlock_irqrestore(&primary_crng.lock, flags);
@@ -895,7 +894,7 @@ static int crng_slow_load(const char *cp, size_t len)
unsigned long flags;
static unsigned char lfsr = 1;
unsigned char tmp;
- unsigned i, max = CHACHA20_KEY_SIZE;
+ unsigned i, max = CHACHA_KEY_SIZE;
const char * src_buf = cp;
char * dest_buf = (char *) &primary_crng.state[4];
@@ -913,8 +912,8 @@ static int crng_slow_load(const char *cp, size_t len)
lfsr >>= 1;
if (tmp & 1)
lfsr ^= 0xE1;
- tmp = dest_buf[i % CHACHA20_KEY_SIZE];
- dest_buf[i % CHACHA20_KEY_SIZE] ^= src_buf[i % len] ^ lfsr;
+ tmp = dest_buf[i % CHACHA_KEY_SIZE];
+ dest_buf[i % CHACHA_KEY_SIZE] ^= src_buf[i % len] ^ lfsr;
lfsr += (tmp << 3) | (tmp >> 5);
}
spin_unlock_irqrestore(&primary_crng.lock, flags);
@@ -926,7 +925,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r)
unsigned long flags;
int i, num;
union {
- __u8 block[CHACHA20_BLOCK_SIZE];
+ __u8 block[CHACHA_BLOCK_SIZE];
__u32 key[8];
} buf;
@@ -937,7 +936,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r)
} else {
_extract_crng(&primary_crng, buf.block);
_crng_backtrack_protect(&primary_crng, buf.block,
- CHACHA20_KEY_SIZE);
+ CHACHA_KEY_SIZE);
}
spin_lock_irqsave(&crng->lock, flags);
for (i = 0; i < 8; i++) {
@@ -973,7 +972,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r)
}
static void _extract_crng(struct crng_state *crng,
- __u8 out[CHACHA20_BLOCK_SIZE])
+ __u8 out[CHACHA_BLOCK_SIZE])
{
unsigned long v, flags;
@@ -990,7 +989,7 @@ static void _extract_crng(struct crng_state *crng,
spin_unlock_irqrestore(&crng->lock, flags);
}
-static void extract_crng(__u8 out[CHACHA20_BLOCK_SIZE])
+static void extract_crng(__u8 out[CHACHA_BLOCK_SIZE])
{
struct crng_state *crng = NULL;
@@ -1008,14 +1007,14 @@ static void extract_crng(__u8 out[CHACHA20_BLOCK_SIZE])
* enough) to mutate the CRNG key to provide backtracking protection.
*/
static void _crng_backtrack_protect(struct crng_state *crng,
- __u8 tmp[CHACHA20_BLOCK_SIZE], int used)
+ __u8 tmp[CHACHA_BLOCK_SIZE], int used)
{
unsigned long flags;
__u32 *s, *d;
int i;
used = round_up(used, sizeof(__u32));
- if (used + CHACHA20_KEY_SIZE > CHACHA20_BLOCK_SIZE) {
+ if (used + CHACHA_KEY_SIZE > CHACHA_BLOCK_SIZE) {
extract_crng(tmp);
used = 0;
}
@@ -1027,7 +1026,7 @@ static void _crng_backtrack_protect(struct crng_state *crng,
spin_unlock_irqrestore(&crng->lock, flags);
}
-static void crng_backtrack_protect(__u8 tmp[CHACHA20_BLOCK_SIZE], int used)
+static void crng_backtrack_protect(__u8 tmp[CHACHA_BLOCK_SIZE], int used)
{
struct crng_state *crng = NULL;
@@ -1042,8 +1041,8 @@ static void crng_backtrack_protect(__u8 tmp[CHACHA20_BLOCK_SIZE], int used)
static ssize_t extract_crng_user(void __user *buf, size_t nbytes)
{
- ssize_t ret = 0, i = CHACHA20_BLOCK_SIZE;
- __u8 tmp[CHACHA20_BLOCK_SIZE] __aligned(4);
+ ssize_t ret = 0, i = CHACHA_BLOCK_SIZE;
+ __u8 tmp[CHACHA_BLOCK_SIZE] __aligned(4);
int large_request = (nbytes > 256);
while (nbytes) {
@@ -1057,7 +1056,7 @@ static ssize_t extract_crng_user(void __user *buf, size_t nbytes)
}
extract_crng(tmp);
- i = min_t(int, nbytes, CHACHA20_BLOCK_SIZE);
+ i = min_t(int, nbytes, CHACHA_BLOCK_SIZE);
if (copy_to_user(buf, tmp, i)) {
ret = -EFAULT;
break;
@@ -1622,14 +1621,14 @@ static void _warn_unseeded_randomness(const char *func_name, void *caller,
*/
static void _get_random_bytes(void *buf, int nbytes)
{
- __u8 tmp[CHACHA20_BLOCK_SIZE] __aligned(4);
+ __u8 tmp[CHACHA_BLOCK_SIZE] __aligned(4);
trace_get_random_bytes(nbytes, _RET_IP_);
- while (nbytes >= CHACHA20_BLOCK_SIZE) {
+ while (nbytes >= CHACHA_BLOCK_SIZE) {
extract_crng(buf);
- buf += CHACHA20_BLOCK_SIZE;
- nbytes -= CHACHA20_BLOCK_SIZE;
+ buf += CHACHA_BLOCK_SIZE;
+ nbytes -= CHACHA_BLOCK_SIZE;
}
if (nbytes > 0) {
@@ -1637,7 +1636,7 @@ static void _get_random_bytes(void *buf, int nbytes)
memcpy(buf, tmp, nbytes);
crng_backtrack_protect(tmp, nbytes);
} else
- crng_backtrack_protect(tmp, CHACHA20_BLOCK_SIZE);
+ crng_backtrack_protect(tmp, CHACHA_BLOCK_SIZE);
memzero_explicit(tmp, sizeof(tmp));
}
@@ -2208,8 +2207,8 @@ struct ctl_table random_table[] = {
struct batched_entropy {
union {
- u64 entropy_u64[CHACHA20_BLOCK_SIZE / sizeof(u64)];
- u32 entropy_u32[CHACHA20_BLOCK_SIZE / sizeof(u32)];
+ u64 entropy_u64[CHACHA_BLOCK_SIZE / sizeof(u64)];
+ u32 entropy_u32[CHACHA_BLOCK_SIZE / sizeof(u32)];
};
unsigned int position;
};