2009-05-31 06:02:13

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] Use kzfree in crypto API context initialization and key/iv handling

From: "Larry H." <[email protected]>
Date: Sat, 30 May 2009 19:57:20 -0700

> [PATCH] Use kzfree in crypto API context initialization and key/iv handling

Thanks for not CC:ing the crypto list, and also not CC:'ing the
crypto maintainer.

Your submissions leave a lot to be desired, on every level.

> This patch replaces the kfree() calls within the crypto API (algorithms,
> key setup and handling, etc) with kzfree(), to enforce sanitization of
> the allocated memory.
>
> This prevents such information from persisting on memory and eventually
> leak to other kernel users or during coldboot attacks.
>
> This patch replaces kfree() for context (algorithm meta-data) structures
> too. Those are initialized or released once, and remain in use during the
> lifetime of the cipher/algorithm instance, therefore no performance impact
> exists for those specific changes.
>
> This patch doesn't affect fastpaths.
>
> Signed-off-by: Larry Highsmith <[email protected]>
>
> ---
> crypto/ablkcipher.c | 3 +--
> crypto/aead.c | 7 +++----
> crypto/ahash.c | 3 +--
> crypto/algapi.c | 4 ++--
> crypto/algboss.c | 8 ++++----
> crypto/api.c | 13 +++++--------
> crypto/authenc.c | 4 ++--
> crypto/blkcipher.c | 13 +++++++------
> crypto/cbc.c | 2 +-
> crypto/ccm.c | 8 ++++----
> crypto/cipher.c | 3 +--
> crypto/cryptd.c | 4 ++--
> crypto/ctr.c | 2 +-
> crypto/cts.c | 2 +-
> crypto/deflate.c | 4 ++--
> crypto/ecb.c | 2 +-
> crypto/gcm.c | 10 +++++-----
> crypto/gf128mul.c | 4 ++--
> crypto/hash.c | 3 +--
> crypto/hmac.c | 2 +-
> crypto/lrw.c | 2 +-
> crypto/pcbc.c | 2 +-
> crypto/rng.c | 2 +-
> crypto/seqiv.c | 4 ++--
> crypto/shash.c | 3 +--
> crypto/xcbc.c | 2 +-
> crypto/xts.c | 2 +-
> 27 files changed, 55 insertions(+), 63 deletions(-)
>
> Index: linux-2.6/crypto/ablkcipher.c
> ===================================================================
> --- linux-2.6.orig/crypto/ablkcipher.c
> +++ linux-2.6/crypto/ablkcipher.c
> @@ -42,8 +42,7 @@ static int setkey_unaligned(struct crypt
> alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
> memcpy(alignbuffer, key, keylen);
> ret = cipher->setkey(tfm, alignbuffer, keylen);
> - memset(alignbuffer, 0, keylen);
> - kfree(buffer);
> + kzfree(buffer);
> return ret;
> }
>
> Index: linux-2.6/crypto/aead.c
> ===================================================================
> --- linux-2.6.orig/crypto/aead.c
> +++ linux-2.6/crypto/aead.c
> @@ -40,8 +40,7 @@ static int setkey_unaligned(struct crypt
> alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
> memcpy(alignbuffer, key, keylen);
> ret = aead->setkey(tfm, alignbuffer, keylen);
> - memset(alignbuffer, 0, keylen);
> - kfree(buffer);
> + kzfree(buffer);
> return ret;
> }
>
> @@ -298,7 +297,7 @@ out:
> err_drop_alg:
> crypto_drop_aead(spawn);
> err_free_inst:
> - kfree(inst);
> + kzfree(inst);
> inst = ERR_PTR(err);
> goto out;
> }
> @@ -307,7 +306,7 @@ EXPORT_SYMBOL_GPL(aead_geniv_alloc);
> void aead_geniv_free(struct crypto_instance *inst)
> {
> crypto_drop_aead(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
> EXPORT_SYMBOL_GPL(aead_geniv_free);
>
> Index: linux-2.6/crypto/ahash.c
> ===================================================================
> --- linux-2.6.orig/crypto/ahash.c
> +++ linux-2.6/crypto/ahash.c
> @@ -145,8 +145,7 @@ static int ahash_setkey_unaligned(struct
> alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
> memcpy(alignbuffer, key, keylen);
> ret = ahash->setkey(tfm, alignbuffer, keylen);
> - memset(alignbuffer, 0, keylen);
> - kfree(buffer);
> + kzfree(buffer);
> return ret;
> }
>
> Index: linux-2.6/crypto/algapi.c
> ===================================================================
> --- linux-2.6.orig/crypto/algapi.c
> +++ linux-2.6/crypto/algapi.c
> @@ -185,7 +185,7 @@ out:
> return larval;
>
> free_larval:
> - kfree(larval);
> + kzfree(larval);
> err:
> larval = ERR_PTR(ret);
> goto out;
> @@ -657,7 +657,7 @@ struct crypto_instance *crypto_alloc_ins
> return inst;
>
> err_free_inst:
> - kfree(inst);
> + kzfree(inst);
> return ERR_PTR(err);
> }
> EXPORT_SYMBOL_GPL(crypto_alloc_instance);
> Index: linux-2.6/crypto/algboss.c
> ===================================================================
> --- linux-2.6.orig/crypto/algboss.c
> +++ linux-2.6/crypto/algboss.c
> @@ -81,7 +81,7 @@ static int cryptomgr_probe(void *data)
> goto err;
>
> out:
> - kfree(param);
> + kzfree(param);
> module_put_and_exit(0);
>
> err:
> @@ -193,7 +193,7 @@ static int cryptomgr_schedule_probe(stru
> return NOTIFY_STOP;
>
> err_free_param:
> - kfree(param);
> + kzfree(param);
> err_put_module:
> module_put(THIS_MODULE);
> err:
> @@ -215,7 +215,7 @@ static int cryptomgr_test(void *data)
> skiptest:
> crypto_alg_tested(param->driver, err);
>
> - kfree(param);
> + kzfree(param);
> module_put_and_exit(0);
> }
>
> @@ -242,7 +242,7 @@ static int cryptomgr_schedule_test(struc
> return NOTIFY_STOP;
>
> err_free_param:
> - kfree(param);
> + kzfree(param);
> err_put_module:
> module_put(THIS_MODULE);
> err:
> Index: linux-2.6/crypto/api.c
> ===================================================================
> --- linux-2.6.orig/crypto/api.c
> +++ linux-2.6/crypto/api.c
> @@ -107,7 +107,7 @@ static void crypto_larval_destroy(struct
> BUG_ON(!crypto_is_larval(alg));
> if (larval->adult)
> crypto_mod_put(larval->adult);
> - kfree(larval);
> + kzfree(larval);
> }
>
> struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
> @@ -151,7 +151,7 @@ static struct crypto_alg *crypto_larval_
> up_write(&crypto_alg_sem);
>
> if (alg != &larval->alg)
> - kfree(larval);
> + kzfree(larval);
>
> return alg;
> }
> @@ -400,7 +400,7 @@ cra_init_failed:
> out_free_tfm:
> if (err == -EAGAIN)
> crypto_shoot_alg(alg);
> - kfree(tfm);
> + kzfree(tfm);
> out_err:
> tfm = ERR_PTR(err);
> out:
> @@ -497,7 +497,7 @@ cra_init_failed:
> out_free_tfm:
> if (err == -EAGAIN)
> crypto_shoot_alg(alg);
> - kfree(mem);
> + kzfree(mem);
> out_err:
> tfm = ERR_PTR(err);
> out:
> @@ -580,20 +580,17 @@ EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
> void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
> {
> struct crypto_alg *alg;
> - int size;
>
> if (unlikely(!mem))
> return;
>
> alg = tfm->__crt_alg;
> - size = ksize(mem);
>
> if (!tfm->exit && alg->cra_exit)
> alg->cra_exit(tfm);
> crypto_exit_ops(tfm);
> crypto_mod_put(alg);
> - memset(mem, 0, size);
> - kfree(mem);
> + kzfree(mem);
> }
> EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
>
> Index: linux-2.6/crypto/authenc.c
> ===================================================================
> --- linux-2.6.orig/crypto/authenc.c
> +++ linux-2.6/crypto/authenc.c
> @@ -461,7 +461,7 @@ err_drop_enc:
> err_drop_auth:
> crypto_drop_spawn(&ctx->auth);
> err_free_inst:
> - kfree(inst);
> + kzfree(inst);
> out_put_auth:
> inst = ERR_PTR(err);
> goto out;
> @@ -473,7 +473,7 @@ static void crypto_authenc_free(struct c
>
> crypto_drop_skcipher(&ctx->enc);
> crypto_drop_spawn(&ctx->auth);
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_authenc_tmpl = {
> Index: linux-2.6/crypto/blkcipher.c
> ===================================================================
> --- linux-2.6.orig/crypto/blkcipher.c
> +++ linux-2.6/crypto/blkcipher.c
> @@ -136,9 +136,11 @@ err:
> if (walk->iv != desc->info)
> memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
> if (walk->buffer != walk->page)
> - kfree(walk->buffer);
> - if (walk->page)
> + kzfree(walk->buffer);
> + if (walk->page) {
> + memset(walk->page, 0, PAGE_SIZE);
> free_page((unsigned long)walk->page);
> + }
>
> return err;
> }
> @@ -373,8 +375,7 @@ static int setkey_unaligned(struct crypt
> alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
> memcpy(alignbuffer, key, keylen);
> ret = cipher->setkey(tfm, alignbuffer, keylen);
> - memset(alignbuffer, 0, keylen);
> - kfree(buffer);
> + kzfree(buffer);
> return ret;
> }
>
> @@ -661,7 +662,7 @@ out:
> err_drop_alg:
> crypto_drop_skcipher(spawn);
> err_free_inst:
> - kfree(inst);
> + kzfree(inst);
> inst = ERR_PTR(err);
> goto out;
> }
> @@ -670,7 +671,7 @@ EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
> void skcipher_geniv_free(struct crypto_instance *inst)
> {
> crypto_drop_skcipher(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
> EXPORT_SYMBOL_GPL(skcipher_geniv_free);
>
> Index: linux-2.6/crypto/cbc.c
> ===================================================================
> --- linux-2.6.orig/crypto/cbc.c
> +++ linux-2.6/crypto/cbc.c
> @@ -264,7 +264,7 @@ out_put_alg:
> static void crypto_cbc_free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_cbc_tmpl = {
> Index: linux-2.6/crypto/ccm.c
> ===================================================================
> --- linux-2.6.orig/crypto/ccm.c
> +++ linux-2.6/crypto/ccm.c
> @@ -565,7 +565,7 @@ err_drop_ctr:
> err_drop_cipher:
> crypto_drop_spawn(&ictx->cipher);
> err_free_inst:
> - kfree(inst);
> + kzfree(inst);
> out_put_cipher:
> inst = ERR_PTR(err);
> goto out;
> @@ -600,7 +600,7 @@ static void crypto_ccm_free(struct crypt
>
> crypto_drop_spawn(&ctx->cipher);
> crypto_drop_skcipher(&ctx->ctr);
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_ccm_tmpl = {
> @@ -831,7 +831,7 @@ out:
> out_drop_alg:
> crypto_drop_aead(spawn);
> out_free_inst:
> - kfree(inst);
> + kzfree(inst);
> inst = ERR_PTR(err);
> goto out;
> }
> @@ -839,7 +839,7 @@ out_free_inst:
> static void crypto_rfc4309_free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_rfc4309_tmpl = {
> Index: linux-2.6/crypto/cipher.c
> ===================================================================
> --- linux-2.6.orig/crypto/cipher.c
> +++ linux-2.6/crypto/cipher.c
> @@ -37,8 +37,7 @@ static int setkey_unaligned(struct crypt
> alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
> memcpy(alignbuffer, key, keylen);
> ret = cia->cia_setkey(tfm, alignbuffer, keylen);
> - memset(alignbuffer, 0, keylen);
> - kfree(buffer);
> + kzfree(buffer);
> return ret;
>
> }
> Index: linux-2.6/crypto/cryptd.c
> ===================================================================
> --- linux-2.6.orig/crypto/cryptd.c
> +++ linux-2.6/crypto/cryptd.c
> @@ -225,7 +225,7 @@ out:
> return inst;
>
> out_free_inst:
> - kfree(inst);
> + kzfree(inst);
> inst = ERR_PTR(err);
> goto out;
> }
> @@ -527,7 +527,7 @@ static void cryptd_free(struct crypto_in
> struct cryptd_instance_ctx *ctx = crypto_instance_ctx(inst);
>
> crypto_drop_spawn(&ctx->spawn);
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template cryptd_tmpl = {
> Index: linux-2.6/crypto/ctr.c
> ===================================================================
> --- linux-2.6.orig/crypto/ctr.c
> +++ linux-2.6/crypto/ctr.c
> @@ -231,7 +231,7 @@ out_put_alg:
> static void crypto_ctr_free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_ctr_tmpl = {
> Index: linux-2.6/crypto/cts.c
> ===================================================================
> --- linux-2.6.orig/crypto/cts.c
> +++ linux-2.6/crypto/cts.c
> @@ -326,7 +326,7 @@ out_put_alg:
> static void crypto_cts_free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_cts_tmpl = {
> Index: linux-2.6/crypto/deflate.c
> ===================================================================
> --- linux-2.6.orig/crypto/deflate.c
> +++ linux-2.6/crypto/deflate.c
> @@ -86,7 +86,7 @@ static int deflate_decomp_init(struct de
> out:
> return ret;
> out_free:
> - kfree(stream->workspace);
> + kzfree(stream->workspace);
> goto out;
> }
>
> @@ -99,7 +99,7 @@ static void deflate_comp_exit(struct def
> static void deflate_decomp_exit(struct deflate_ctx *ctx)
> {
> zlib_inflateEnd(&ctx->decomp_stream);
> - kfree(ctx->decomp_stream.workspace);
> + kzfree(ctx->decomp_stream.workspace);
> }
>
> static int deflate_init(struct crypto_tfm *tfm)
> Index: linux-2.6/crypto/ecb.c
> ===================================================================
> --- linux-2.6.orig/crypto/ecb.c
> +++ linux-2.6/crypto/ecb.c
> @@ -160,7 +160,7 @@ out_put_alg:
> static void crypto_ecb_free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_ecb_tmpl = {
> Index: linux-2.6/crypto/gcm.c
> ===================================================================
> --- linux-2.6.orig/crypto/gcm.c
> +++ linux-2.6/crypto/gcm.c
> @@ -242,7 +242,7 @@ static int crypto_gcm_setkey(struct cryp
> err = -ENOMEM;
>
> out:
> - kfree(data);
> + kzfree(data);
> return err;
> }
>
> @@ -507,7 +507,7 @@ out:
> out_put_ctr:
> crypto_drop_skcipher(&ctx->ctr);
> err_free_inst:
> - kfree(inst);
> + kzfree(inst);
> inst = ERR_PTR(err);
> goto out;
> }
> @@ -540,7 +540,7 @@ static void crypto_gcm_free(struct crypt
> struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst);
>
> crypto_drop_skcipher(&ctx->ctr);
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_gcm_tmpl = {
> @@ -762,7 +762,7 @@ out:
> out_drop_alg:
> crypto_drop_aead(spawn);
> out_free_inst:
> - kfree(inst);
> + kzfree(inst);
> inst = ERR_PTR(err);
> goto out;
> }
> @@ -770,7 +770,7 @@ out_free_inst:
> static void crypto_rfc4106_free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_rfc4106_tmpl = {
> Index: linux-2.6/crypto/gf128mul.c
> ===================================================================
> --- linux-2.6.orig/crypto/gf128mul.c
> +++ linux-2.6/crypto/gf128mul.c
> @@ -352,8 +352,8 @@ void gf128mul_free_64k(struct gf128mul_6
> int i;
>
> for (i = 0; i < 16; i++)
> - kfree(t->t[i]);
> - kfree(t);
> + kzfree(t->t[i]);
> + kzfree(t);
> }
> EXPORT_SYMBOL(gf128mul_free_64k);
>
> Index: linux-2.6/crypto/hash.c
> ===================================================================
> --- linux-2.6.orig/crypto/hash.c
> +++ linux-2.6/crypto/hash.c
> @@ -42,8 +42,7 @@ static int hash_setkey_unaligned(struct
> alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
> memcpy(alignbuffer, key, keylen);
> ret = alg->setkey(crt, alignbuffer, keylen);
> - memset(alignbuffer, 0, keylen);
> - kfree(buffer);
> + kzfree(buffer);
> return ret;
> }
>
> Index: linux-2.6/crypto/hmac.c
> ===================================================================
> --- linux-2.6.orig/crypto/hmac.c
> +++ linux-2.6/crypto/hmac.c
> @@ -218,7 +218,7 @@ static void hmac_exit_tfm(struct crypto_
> static void hmac_free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_instance *hmac_alloc(struct rtattr **tb)
> Index: linux-2.6/crypto/lrw.c
> ===================================================================
> --- linux-2.6.orig/crypto/lrw.c
> +++ linux-2.6/crypto/lrw.c
> @@ -287,7 +287,7 @@ out_put_alg:
> static void free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_tmpl = {
> Index: linux-2.6/crypto/pcbc.c
> ===================================================================
> --- linux-2.6.orig/crypto/pcbc.c
> +++ linux-2.6/crypto/pcbc.c
> @@ -270,7 +270,7 @@ out_put_alg:
> static void crypto_pcbc_free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_pcbc_tmpl = {
> Index: linux-2.6/crypto/rng.c
> ===================================================================
> --- linux-2.6.orig/crypto/rng.c
> +++ linux-2.6/crypto/rng.c
> @@ -42,7 +42,7 @@ static int rngapi_reset(struct crypto_rn
>
> err = crypto_rng_alg(tfm)->rng_reset(tfm, seed, slen);
>
> - kfree(buf);
> + kzfree(buf);
> return err;
> }
>
> Index: linux-2.6/crypto/seqiv.c
> ===================================================================
> --- linux-2.6.orig/crypto/seqiv.c
> +++ linux-2.6/crypto/seqiv.c
> @@ -43,7 +43,7 @@ static void seqiv_complete2(struct skcip
> memcpy(req->creq.info, subreq->info, crypto_ablkcipher_ivsize(geniv));
>
> out:
> - kfree(subreq->info);
> + kzfree(subreq->info);
> }
>
> static void seqiv_complete(struct crypto_async_request *base, int err)
> @@ -69,7 +69,7 @@ static void seqiv_aead_complete2(struct
> memcpy(req->areq.iv, subreq->iv, crypto_aead_ivsize(geniv));
>
> out:
> - kfree(subreq->iv);
> + kzfree(subreq->iv);
> }
>
> static void seqiv_aead_complete(struct crypto_async_request *base, int err)
> Index: linux-2.6/crypto/shash.c
> ===================================================================
> --- linux-2.6.orig/crypto/shash.c
> +++ linux-2.6/crypto/shash.c
> @@ -44,8 +44,7 @@ static int shash_setkey_unaligned(struct
> alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
> memcpy(alignbuffer, key, keylen);
> err = shash->setkey(tfm, alignbuffer, keylen);
> - memset(alignbuffer, 0, keylen);
> - kfree(buffer);
> + kzfree(buffer);
> return err;
> }
>
> Index: linux-2.6/crypto/xcbc.c
> ===================================================================
> --- linux-2.6.orig/crypto/xcbc.c
> +++ linux-2.6/crypto/xcbc.c
> @@ -346,7 +346,7 @@ out_put_alg:
> static void xcbc_free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_xcbc_tmpl = {
> Index: linux-2.6/crypto/xts.c
> ===================================================================
> --- linux-2.6.orig/crypto/xts.c
> +++ linux-2.6/crypto/xts.c
> @@ -264,7 +264,7 @@ out_put_alg:
> static void free(struct crypto_instance *inst)
> {
> crypto_drop_spawn(crypto_instance_ctx(inst));
> - kfree(inst);
> + kzfree(inst);
> }
>
> static struct crypto_template crypto_tmpl = {
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/


2009-05-31 14:38:52

by Rik van Riel

[permalink] [raw]
Subject: Re: [PATCH] Use kzfree in crypto API context initialization and key/iv handling

David Miller wrote:
> From: "Larry H." <[email protected]>
> Date: Sat, 30 May 2009 19:57:20 -0700
>
>> [PATCH] Use kzfree in crypto API context initialization and key/iv handling
>
> Thanks for not CC:ing the crypto list, and also not CC:'ing the
> crypto maintainer.
>
> Your submissions leave a lot to be desired, on every level.

That's a pretty roundabout way of saying "I have no
technical objections" :)

--
All rights reversed.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to [email protected]. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"[email protected]"> [email protected] </a>

2009-06-01 04:46:23

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] Use kzfree in crypto API context initialization and key/iv handling

From: Rik van Riel <[email protected]>
Date: Sun, 31 May 2009 10:38:52 -0400

> David Miller wrote:
>> From: "Larry H." <[email protected]>
>> Date: Sat, 30 May 2009 19:57:20 -0700
>>
>>> [PATCH] Use kzfree in crypto API context initialization and key/iv
>>> handling
>> Thanks for not CC:ing the crypto list, and also not CC:'ing the
>> crypto maintainer.
>> Your submissions leave a lot to be desired, on every level.
>
> That's a pretty roundabout way of saying "I have no
> technical objections" :)

One of those "levels" was technical.

I don't even want to think about what this does to IPSEC rule creation
rates, that that matters heavily for cell phone networks where
hundreds of thousands of nodes come in and out of the server and each
such entry requires creating 4 IPSEC rules.

2009-06-01 04:48:37

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH] Use kzfree in crypto API context initialization and key/iv handling

On Sun, May 31, 2009 at 09:46:23PM -0700, David Miller wrote:
>
> I don't even want to think about what this does to IPSEC rule creation
> rates, that that matters heavily for cell phone networks where
> hundreds of thousands of nodes come in and out of the server and each
> such entry requires creating 4 IPSEC rules.

I completely agree. The zeroing of metadata is gratuitous.

Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to [email protected]. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"[email protected]"> [email protected] </a>

2009-06-01 07:58:14

by Alan

[permalink] [raw]
Subject: Re: [PATCH] Use kzfree in crypto API context initialization and key/iv handling

On Mon, 1 Jun 2009 14:48:37 +1000
Herbert Xu <[email protected]> wrote:

> On Sun, May 31, 2009 at 09:46:23PM -0700, David Miller wrote:
> >
> > I don't even want to think about what this does to IPSEC rule creation
> > rates, that that matters heavily for cell phone networks where
> > hundreds of thousands of nodes come in and out of the server and each
> > such entry requires creating 4 IPSEC rules.
>
> I completely agree. The zeroing of metadata is gratuitous.

Zeroing long term keys makes sense but for the short lifepsan keys used on
the wire its a bit pointless irrespective of speed (I suspect done
properly the performance impact would be close to nil anyway)

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to [email protected]. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"[email protected]"> [email protected] </a>

2009-06-01 12:34:03

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH] Use kzfree in crypto API context initialization and key/iv handling

Alan Cox <[email protected]> wrote:
>
> Zeroing long term keys makes sense but for the short lifepsan keys used on
> the wire its a bit pointless irrespective of speed (I suspect done
> properly the performance impact would be close to nil anyway)

Sure, though we're not actually arguing whether keys should be
zeroed here, but the metadata, i.e., pointers to keys, buffers,
etc.

Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt