[CRYPTO] aead: Create default givcipher instances
[linux-2.6.git] / crypto / aead.c
index 9f7aca8..f5b1add 100644 (file)
@@ -17,6 +17,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/rtnetlink.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 
@@ -328,5 +329,157 @@ void aead_geniv_exit(struct crypto_tfm *tfm)
 }
 EXPORT_SYMBOL_GPL(aead_geniv_exit);
 
+static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
+{
+       struct rtattr *tb[3];
+       struct {
+               struct rtattr attr;
+               struct crypto_attr_type data;
+       } ptype;
+       struct {
+               struct rtattr attr;
+               struct crypto_attr_alg data;
+       } palg;
+       struct crypto_template *tmpl;
+       struct crypto_instance *inst;
+       struct crypto_alg *larval;
+       const char *geniv;
+       int err;
+
+       larval = crypto_larval_lookup(alg->cra_driver_name,
+                                     CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
+                                     CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
+       err = PTR_ERR(larval);
+       if (IS_ERR(larval))
+               goto out;
+
+       err = -EAGAIN;
+       if (!crypto_is_larval(larval))
+               goto drop_larval;
+
+       ptype.attr.rta_len = sizeof(ptype);
+       ptype.attr.rta_type = CRYPTOA_TYPE;
+       ptype.data.type = type | CRYPTO_ALG_GENIV;
+       /* GENIV tells the template that we're making a default geniv. */
+       ptype.data.mask = mask | CRYPTO_ALG_GENIV;
+       tb[0] = &ptype.attr;
+
+       palg.attr.rta_len = sizeof(palg);
+       palg.attr.rta_type = CRYPTOA_ALG;
+       /* Must use the exact name to locate ourselves. */
+       memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
+       tb[1] = &palg.attr;
+
+       tb[2] = NULL;
+
+       geniv = alg->cra_aead.geniv;
+
+       tmpl = crypto_lookup_template(geniv);
+       err = -ENOENT;
+       if (!tmpl)
+               goto kill_larval;
+
+       inst = tmpl->alloc(tb);
+       err = PTR_ERR(inst);
+       if (IS_ERR(inst))
+               goto put_tmpl;
+
+       if ((err = crypto_register_instance(tmpl, inst))) {
+               tmpl->free(inst);
+               goto put_tmpl;
+       }
+
+       /* Redo the lookup to use the instance we just registered. */
+       err = -EAGAIN;
+
+put_tmpl:
+       crypto_tmpl_put(tmpl);
+kill_larval:
+       crypto_larval_kill(larval);
+drop_larval:
+       crypto_mod_put(larval);
+out:
+       crypto_mod_put(alg);
+       return err;
+}
+
+static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
+                                            u32 mask)
+{
+       struct crypto_alg *alg;
+
+       alg = crypto_alg_mod_lookup(name, type, mask);
+       if (IS_ERR(alg))
+               return alg;
+
+       if (alg->cra_type == &crypto_aead_type)
+               return alg;
+
+       if (!alg->cra_aead.ivsize)
+               return alg;
+
+       return ERR_PTR(crypto_nivaead_default(alg, type, mask));
+}
+
+int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
+                    u32 type, u32 mask)
+{
+       struct crypto_alg *alg;
+       int err;
+
+       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;
+
+       alg = crypto_lookup_aead(name, type, mask);
+       if (IS_ERR(alg))
+               return PTR_ERR(alg);
+
+       err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
+       crypto_mod_put(alg);
+       return err;
+}
+EXPORT_SYMBOL_GPL(crypto_grab_aead);
+
+struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
+{
+       struct crypto_tfm *tfm;
+       int err;
+
+       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 (;;) {
+               struct crypto_alg *alg;
+
+               alg = crypto_lookup_aead(alg_name, type, mask);
+               if (IS_ERR(alg)) {
+                       err = PTR_ERR(alg);
+                       goto err;
+               }
+
+               tfm = __crypto_alloc_tfm(alg, type, mask);
+               if (!IS_ERR(tfm))
+                       return __crypto_aead_cast(tfm);
+
+               crypto_mod_put(alg);
+               err = PTR_ERR(tfm);
+
+err:
+               if (err != -EAGAIN)
+                       break;
+               if (signal_pending(current)) {
+                       err = -EINTR;
+                       break;
+               }
+       }
+
+       return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_aead);
+
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");