aboutsummaryrefslogtreecommitdiff
path: root/crypto/chainiv.c
diff options
context:
space:
mode:
authorHerbert Xu <herbert@gondor.apana.org.au>2015-06-21 19:11:46 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2015-06-22 15:49:28 +0800
commit341476d6cf224f1dea5c439cd70181053629ce15 (patch)
tree23976bbcaf26202ea1082567bd4d402e7ba1c3eb /crypto/chainiv.c
parent9aa867e46565d61491f884c793e4988678fbffa3 (diff)
downloadlinux-341476d6cf224f1dea5c439cd70181053629ce15.tar.gz
crypto: chainiv - Offer normal cipher functionality without RNG
The RNG may not be available during early boot, e.g., the relevant modules may not be included in the initramfs. As the RNG Is only needed for IPsec, we should not let this prevent use of ciphers without IV generators, e.g., for disk encryption. This patch postpones the RNG allocation to the init function so that one failure during early boot does not make the RNG unavailable for all subsequent users of the same cipher. More importantly, it lets the cipher live even if RNG allocation fails. Of course we no longer offer IV generation and which will fail with an error if invoked. But all other cipher capabilities will function as usual. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/chainiv.c')
-rw-r--r--crypto/chainiv.c55
1 files changed, 29 insertions, 26 deletions
diff --git a/crypto/chainiv.c b/crypto/chainiv.c
index be0bd521c46f..b4340018c8d4 100644
--- a/crypto/chainiv.c
+++ b/crypto/chainiv.c
@@ -83,21 +83,34 @@ unlock:
static int chainiv_init_common(struct crypto_tfm *tfm, char iv[])
{
struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
+ int err = 0;
tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request);
- return crypto_rng_get_bytes(crypto_default_rng, iv,
- crypto_ablkcipher_ivsize(geniv)) ?:
- skcipher_geniv_init(tfm);
+ if (iv) {
+ err = crypto_rng_get_bytes(crypto_default_rng, iv,
+ crypto_ablkcipher_ivsize(geniv));
+ crypto_put_default_rng();
+ }
+
+ return err ?: skcipher_geniv_init(tfm);
}
static int chainiv_init(struct crypto_tfm *tfm)
{
+ struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
struct chainiv_ctx *ctx = crypto_tfm_ctx(tfm);
+ char *iv;
spin_lock_init(&ctx->lock);
- return chainiv_init_common(tfm, ctx->iv);
+ iv = NULL;
+ if (!crypto_get_default_rng()) {
+ crypto_ablkcipher_crt(geniv)->givencrypt = chainiv_givencrypt;
+ iv = ctx->iv;
+ }
+
+ return chainiv_init_common(tfm, iv);
}
static int async_chainiv_schedule_work(struct async_chainiv_ctx *ctx)
@@ -216,14 +229,23 @@ static void async_chainiv_do_postponed(struct work_struct *work)
static int async_chainiv_init(struct crypto_tfm *tfm)
{
+ struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
struct async_chainiv_ctx *ctx = crypto_tfm_ctx(tfm);
+ char *iv;
spin_lock_init(&ctx->lock);
crypto_init_queue(&ctx->queue, 100);
INIT_WORK(&ctx->postponed, async_chainiv_do_postponed);
- return chainiv_init_common(tfm, ctx->iv);
+ iv = NULL;
+ if (!crypto_get_default_rng()) {
+ crypto_ablkcipher_crt(geniv)->givencrypt =
+ async_chainiv_givencrypt;
+ iv = ctx->iv;
+ }
+
+ return chainiv_init_common(tfm, iv);
}
static void async_chainiv_exit(struct crypto_tfm *tfm)
@@ -241,21 +263,14 @@ static struct crypto_instance *chainiv_alloc(struct rtattr **tb)
{
struct crypto_attr_type *algt;
struct crypto_instance *inst;
- int err;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return ERR_CAST(algt);
- err = crypto_get_default_rng();
- if (err)
- return ERR_PTR(err);
-
inst = skcipher_geniv_alloc(&chainiv_tmpl, tb, 0, 0);
if (IS_ERR(inst))
- goto put_rng;
-
- inst->alg.cra_ablkcipher.givencrypt = chainiv_givencrypt;
+ goto out;
inst->alg.cra_init = chainiv_init;
inst->alg.cra_exit = skcipher_geniv_exit;
@@ -265,8 +280,6 @@ static struct crypto_instance *chainiv_alloc(struct rtattr **tb)
if (!crypto_requires_sync(algt->type, algt->mask)) {
inst->alg.cra_flags |= CRYPTO_ALG_ASYNC;
- inst->alg.cra_ablkcipher.givencrypt = async_chainiv_givencrypt;
-
inst->alg.cra_init = async_chainiv_init;
inst->alg.cra_exit = async_chainiv_exit;
@@ -277,22 +290,12 @@ static struct crypto_instance *chainiv_alloc(struct rtattr **tb)
out:
return inst;
-
-put_rng:
- crypto_put_default_rng();
- goto out;
-}
-
-static void chainiv_free(struct crypto_instance *inst)
-{
- skcipher_geniv_free(inst);
- crypto_put_default_rng();
}
static struct crypto_template chainiv_tmpl = {
.name = "chainiv",
.alloc = chainiv_alloc,
- .free = chainiv_free,
+ .free = skcipher_geniv_free,
.module = THIS_MODULE,
};