crypto: user - Fix lookup of algorithms with IV generator

We lookup algorithms with crypto_alg_mod_lookup() when instantiating via
crypto_add_alg(). However, algorithms that are wrapped by an IV genearator
(e.g. aead or genicv type algorithms) need special care. The userspace
process hangs until it gets a timeout when we use crypto_alg_mod_lookup()
to lookup these algorithms. So export the lookup functions for these
algorithms and use them in crypto_add_alg().

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

5 files changed, 79 insertions, 5 deletions

diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c
index a0f768c1d9a..8d3a056ebee 100644
--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -613,8 +613,7 @@ out:
         return err;
 }
 
-static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
-                                                 u32 mask)
+struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask)
 {
         struct crypto_alg *alg;
 
@@ -652,6 +651,7 @@ static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
 
         return ERR_PTR(crypto_givcipher_default(alg, type, mask));
 }
+EXPORT_SYMBOL_GPL(crypto_lookup_skcipher);
 
 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
                          u32 type, u32 mask)
diff --git a/crypto/aead.c b/crypto/aead.c
index 04add3dca6f..e4cb35159be 100644
--- a/crypto/aead.c
+++ b/crypto/aead.c
@@ -470,8 +470,7 @@ out:
         return err;
 }
 
-static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
-                                             u32 mask)
+struct crypto_alg *crypto_lookup_aead(const char *name, u32 type, u32 mask)
 {
         struct crypto_alg *alg;
 
@@ -503,6 +502,7 @@ static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
 
         return ERR_PTR(crypto_nivaead_default(alg, type, mask));
 }
+EXPORT_SYMBOL_GPL(crypto_lookup_aead);
 
 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
                      u32 type, u32 mask)
diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
index f76e42bcc6e..e91c16111ed 100644
--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -21,9 +21,13 @@
 #include <linux/module.h>
 #include <linux/crypto.h>
 #include <linux/cryptouser.h>
+#include <linux/sched.h>
 #include <net/netlink.h>
 #include <linux/security.h>
 #include <net/net_namespace.h>
+#include <crypto/internal/aead.h>
+#include <crypto/internal/skcipher.h>
+
 #include "internal.h"
 
 DEFINE_MUTEX(crypto_cfg_mutex);
@@ -301,6 +305,60 @@ static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
         return crypto_unregister_instance(alg);
 }
 
+static struct crypto_alg *crypto_user_skcipher_alg(const char *name, u32 type,
+                                                   u32 mask)
+{
+        int err;
+        struct crypto_alg *alg;
+
+        type = crypto_skcipher_type(type);
+        mask = crypto_skcipher_mask(mask);
+
+        for (;;) {
+                alg = crypto_lookup_skcipher(name,  type, mask);
+                if (!IS_ERR(alg))
+                        return alg;
+
+                err = PTR_ERR(alg);
+                if (err != -EAGAIN)
+                        break;
+                if (signal_pending(current)) {
+                        err = -EINTR;
+                        break;
+                }
+        }
+
+        return ERR_PTR(err);
+}
+
+static struct crypto_alg *crypto_user_aead_alg(const char *name, u32 type,
+                                               u32 mask)
+{
+        int err;
+        struct crypto_alg *alg;
+
+        type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
+        type |= CRYPTO_ALG_TYPE_AEAD;
+        mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
+        mask |= CRYPTO_ALG_TYPE_MASK;
+
+        for (;;) {
+                alg = crypto_lookup_aead(name,  type, mask);
+                if (!IS_ERR(alg))
+                        return alg;
+
+                err = PTR_ERR(alg);
+                if (err != -EAGAIN)
+                        break;
+                if (signal_pending(current)) {
+                        err = -EINTR;
+                        break;
+                }
+        }
+
+        return ERR_PTR(err);
+}
+
 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
                           struct nlattr **attrs)
 {
@@ -325,7 +383,19 @@ static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
         else
                 name = p->cru_name;
 
-        alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
+        switch (p->cru_type & p->cru_mask & CRYPTO_ALG_TYPE_MASK) {
+        case CRYPTO_ALG_TYPE_AEAD:
+                alg = crypto_user_aead_alg(name, p->cru_type, p->cru_mask);
+                break;
+        case CRYPTO_ALG_TYPE_GIVCIPHER:
+        case CRYPTO_ALG_TYPE_BLKCIPHER:
+        case CRYPTO_ALG_TYPE_ABLKCIPHER:
+                alg = crypto_user_skcipher_alg(name, p->cru_type, p->cru_mask);
+                break;
+        default:
+                alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
+        }
+
         if (IS_ERR(alg))
                 return PTR_ERR(alg);
 
diff --git a/include/crypto/internal/aead.h b/include/crypto/internal/aead.h
index d838c945575..2eba340230a 100644
--- a/include/crypto/internal/aead.h
+++ b/include/crypto/internal/aead.h
@@ -31,6 +31,8 @@ static inline void crypto_set_aead_spawn(
         crypto_set_spawn(&spawn->base, inst);
 }
 
+struct crypto_alg *crypto_lookup_aead(const char *name, u32 type, u32 mask);
+
 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
                      u32 type, u32 mask);
 
diff --git a/include/crypto/internal/skcipher.h b/include/crypto/internal/skcipher.h
index 3a748a6bf77..06e8b32d541 100644
--- a/include/crypto/internal/skcipher.h
+++ b/include/crypto/internal/skcipher.h
@@ -34,6 +34,8 @@ static inline void crypto_set_skcipher_spawn(
 int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
                          u32 type, u32 mask);
 
+struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask);
+
 static inline void crypto_drop_skcipher(struct crypto_skcipher_spawn *spawn)
 {
         crypto_drop_spawn(&spawn->base);