SUNRPC: Use a static buffer for the checksum initialization vector

Allocating and zeroing a buffer during every call to
krb5_etm_checksum() is inefficient. Instead, set aside a static
buffer that is the maximum crypto block size, and use a portion
(or all) of that.

Reported-by: Markus Elfring <Markus.Elfring@web.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Chuck Lever 2024-01-01 11:37:45 -05:00
parent 3cfcfc102a
commit 561141dd49

View File

@ -921,6 +921,8 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
* Caller provides the truncation length of the output token (h) in
* cksumout.len.
*
* Note that for RPCSEC, the "initial cipher state" is always all zeroes.
*
* Return values:
* %GSS_S_COMPLETE: Digest computed, @cksumout filled in
* %GSS_S_FAILURE: Call failed
@ -931,22 +933,19 @@ u32 krb5_etm_checksum(struct crypto_sync_skcipher *cipher,
int body_offset, struct xdr_netobj *cksumout)
{
unsigned int ivsize = crypto_sync_skcipher_ivsize(cipher);
static const u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
struct ahash_request *req;
struct scatterlist sg[1];
u8 *iv, *checksumdata;
int err = -ENOMEM;
u8 *checksumdata;
checksumdata = kmalloc(crypto_ahash_digestsize(tfm), GFP_KERNEL);
if (!checksumdata)
return GSS_S_FAILURE;
/* For RPCSEC, the "initial cipher state" is always all zeroes. */
iv = kzalloc(ivsize, GFP_KERNEL);
if (!iv)
goto out_free_mem;
req = ahash_request_alloc(tfm, GFP_KERNEL);
if (!req)
goto out_free_mem;
goto out_free_cksumdata;
ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
err = crypto_ahash_init(req);
if (err)
@ -970,8 +969,7 @@ u32 krb5_etm_checksum(struct crypto_sync_skcipher *cipher,
out_free_ahash:
ahash_request_free(req);
out_free_mem:
kfree(iv);
out_free_cksumdata:
kfree_sensitive(checksumdata);
return err ? GSS_S_FAILURE : GSS_S_COMPLETE;
}