crypto: drbg - use full CTR AES for update
The CTR DRBG update function performs a full CTR AES operation including the XOR with "plaintext" data. Hence, remove the XOR from the code and use the CTR mode to do the XOR. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
parent
3cfc3b9721
commit
a07203fbfc
|
@ -258,7 +258,10 @@ static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval,
|
|||
const struct drbg_string *in);
|
||||
static int drbg_init_sym_kernel(struct drbg_state *drbg);
|
||||
static int drbg_fini_sym_kernel(struct drbg_state *drbg);
|
||||
static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, u8 *outbuf, u32 outlen);
|
||||
static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
|
||||
u8 *inbuf, u32 inbuflen,
|
||||
u8 *outbuf, u32 outlen);
|
||||
#define DRBG_CTR_NULL_LEN 128
|
||||
|
||||
/* BCC function for CTR DRBG as defined in 10.4.3 */
|
||||
static int drbg_ctr_bcc(struct drbg_state *drbg,
|
||||
|
@ -481,8 +484,6 @@ static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed,
|
|||
unsigned char *temp = drbg->scratchpad;
|
||||
unsigned char *df_data = drbg->scratchpad + drbg_statelen(drbg) +
|
||||
drbg_blocklen(drbg);
|
||||
unsigned char *temp_p, *df_data_p; /* pointer to iterate over buffers */
|
||||
unsigned int len = 0;
|
||||
|
||||
if (3 > reseed)
|
||||
memset(df_data, 0, drbg_statelen(drbg));
|
||||
|
@ -510,18 +511,11 @@ static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed,
|
|||
goto out;
|
||||
}
|
||||
|
||||
ret = drbg_kcapi_sym_ctr(drbg, temp, drbg_statelen(drbg));
|
||||
ret = drbg_kcapi_sym_ctr(drbg, df_data, drbg_statelen(drbg),
|
||||
temp, drbg_statelen(drbg));
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
/* 10.2.1.2 step 4 */
|
||||
temp_p = temp;
|
||||
df_data_p = df_data;
|
||||
for (len = 0; len < drbg_statelen(drbg); len++) {
|
||||
*temp_p ^= *df_data_p;
|
||||
df_data_p++; temp_p++;
|
||||
}
|
||||
|
||||
/* 10.2.1.2 step 5 */
|
||||
memcpy(drbg->C, temp, drbg_keylen(drbg));
|
||||
ret = crypto_skcipher_setkey(drbg->ctr_handle, drbg->C,
|
||||
|
@ -561,7 +555,8 @@ static int drbg_ctr_generate(struct drbg_state *drbg,
|
|||
}
|
||||
|
||||
/* 10.2.1.5.2 step 4.1 */
|
||||
ret = drbg_kcapi_sym_ctr(drbg, buf, len);
|
||||
ret = drbg_kcapi_sym_ctr(drbg, drbg->ctr_null_value, DRBG_CTR_NULL_LEN,
|
||||
buf, len);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
|
@ -1657,7 +1652,6 @@ static void drbg_skcipher_cb(struct crypto_async_request *req, int error)
|
|||
complete(&drbg->ctr_completion);
|
||||
}
|
||||
|
||||
#define DRBG_CTR_NULL_LEN 128
|
||||
static int drbg_init_sym_kernel(struct drbg_state *drbg)
|
||||
{
|
||||
struct crypto_cipher *tfm;
|
||||
|
@ -1733,14 +1727,16 @@ static int drbg_kcapi_sym(struct drbg_state *drbg, unsigned char *outval,
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, u8 *outbuf, u32 outlen)
|
||||
static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
|
||||
u8 *inbuf, u32 inlen,
|
||||
u8 *outbuf, u32 outlen)
|
||||
{
|
||||
struct scatterlist sg_in;
|
||||
|
||||
sg_init_one(&sg_in, drbg->ctr_null_value, DRBG_CTR_NULL_LEN);
|
||||
sg_init_one(&sg_in, inbuf, inlen);
|
||||
|
||||
while (outlen) {
|
||||
u32 cryptlen = min_t(u32, outlen, DRBG_CTR_NULL_LEN);
|
||||
u32 cryptlen = min_t(u32, inlen, outlen);
|
||||
struct scatterlist sg_out;
|
||||
int ret;
|
||||
|
||||
|
|
Loading…
Reference in a new issue