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-rw-r--r--crypto/drbg.c29
1 files changed, 24 insertions, 5 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c
index 9a95b619e19a..8a4d98b4adba 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -262,6 +262,7 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
u8 *inbuf, u32 inbuflen,
u8 *outbuf, u32 outlen);
#define DRBG_CTR_NULL_LEN 128
+#define DRBG_OUTSCRATCHLEN DRBG_CTR_NULL_LEN
/* BCC function for CTR DRBG as defined in 10.4.3 */
static int drbg_ctr_bcc(struct drbg_state *drbg,
@@ -1644,6 +1645,9 @@ static int drbg_fini_sym_kernel(struct drbg_state *drbg)
kfree(drbg->ctr_null_value_buf);
drbg->ctr_null_value = NULL;
+ kfree(drbg->outscratchpadbuf);
+ drbg->outscratchpadbuf = NULL;
+
return 0;
}
@@ -1708,6 +1712,15 @@ static int drbg_init_sym_kernel(struct drbg_state *drbg)
drbg->ctr_null_value = (u8 *)PTR_ALIGN(drbg->ctr_null_value_buf,
alignmask + 1);
+ drbg->outscratchpadbuf = kmalloc(DRBG_OUTSCRATCHLEN + alignmask,
+ GFP_KERNEL);
+ if (!drbg->outscratchpadbuf) {
+ drbg_fini_sym_kernel(drbg);
+ return -ENOMEM;
+ }
+ drbg->outscratchpad = (u8 *)PTR_ALIGN(drbg->outscratchpadbuf,
+ alignmask + 1);
+
return alignmask;
}
@@ -1737,15 +1750,16 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
u8 *outbuf, u32 outlen)
{
struct scatterlist sg_in;
+ int ret;
sg_init_one(&sg_in, inbuf, inlen);
while (outlen) {
- u32 cryptlen = min_t(u32, inlen, outlen);
+ u32 cryptlen = min3(inlen, outlen, (u32)DRBG_OUTSCRATCHLEN);
struct scatterlist sg_out;
- int ret;
- sg_init_one(&sg_out, outbuf, cryptlen);
+ /* Output buffer may not be valid for SGL, use scratchpad */
+ sg_init_one(&sg_out, drbg->outscratchpad, cryptlen);
skcipher_request_set_crypt(drbg->ctr_req, &sg_in, &sg_out,
cryptlen, drbg->V);
ret = crypto_skcipher_encrypt(drbg->ctr_req);
@@ -1761,15 +1775,20 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
break;
}
default:
- return ret;
+ goto out;
}
init_completion(&drbg->ctr_completion);
+ memcpy(outbuf, drbg->outscratchpad, cryptlen);
+
outlen -= cryptlen;
outbuf += cryptlen;
}
+ ret = 0;
- return 0;
+out:
+ memzero_explicit(drbg->outscratchpad, DRBG_OUTSCRATCHLEN);
+ return ret;
}
#endif /* CONFIG_CRYPTO_DRBG_CTR */