[CRYPTO] api: Add cryptomgr

The cryptomgr module is a simple manager of crypto algorithm instances.
It ensures that parameterised algorithms of the type tmpl(alg) (e.g.,
cbc(aes)) are always created.

This is meant to satisfy the needs for most users.  For more complex
cases such as deeper combinations or multiple parameters, a netlink
module will be created which allows arbitrary expressions to be parsed
in user-space.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/crypto/Kconfig b/crypto/Kconfig
index aabc631952226b6639e769a0d087c6b054455cfc..4ce509dba329f2fae210c44e40206634403207e6 100644 (file)
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -16,6 +16,14 @@ config CRYPTO_ALGAPI
        help
          This option provides the API for cryptographic algorithms.
 
+config CRYPTO_MANAGER
+       tristate "Cryptographic algorithm manager"
+       select CRYPTO_ALGAPI
+       default m
+       help
+         Create default cryptographic template instantiations such as
+         cbc(aes).
+
 config CRYPTO_HMAC
        bool "HMAC support"
        help

diff --git a/crypto/Makefile b/crypto/Makefile
index 6d51f80753a13304ab19981039f413906d8e904e..b8745f3d359509e6deb0b950b2de24f2227fe481 100644 (file)
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -8,6 +8,7 @@ crypto_algapi-$(CONFIG_PROC_FS) += proc.o
 crypto_algapi-objs := algapi.o $(crypto_algapi-y)
 obj-$(CONFIG_CRYPTO_ALGAPI) += crypto_algapi.o
 
+obj-$(CONFIG_CRYPTO_MANAGER) += cryptomgr.o
 obj-$(CONFIG_CRYPTO_HMAC) += hmac.o
 obj-$(CONFIG_CRYPTO_NULL) += crypto_null.o
 obj-$(CONFIG_CRYPTO_MD4) += md4.o

diff --git a/crypto/api.c b/crypto/api.c
index 5a0d6a17cfd70ae0b47bb826981d496cceb4e51f..67cd6f87b74a5289d2ac7b3be0b9da2dc322c6a9 100644 (file)
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -18,6 +18,7 @@
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/kmod.h>
+#include <linux/module.h>
 #include <linux/param.h>
 #include <linux/slab.h>
 #include <linux/string.h>
@@ -170,6 +171,7 @@ static struct crypto_alg *crypto_alg_mod_lookup(const char *name)
 {
        struct crypto_alg *alg;
        struct crypto_alg *larval;
+       int ok;
 
        alg = try_then_request_module(crypto_alg_lookup(name), name);
        if (alg)
@@ -179,7 +181,13 @@ static struct crypto_alg *crypto_alg_mod_lookup(const char *name)
        if (!larval || !crypto_is_larval(larval))
                return larval;
 
-       if (crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval) == NOTIFY_STOP)
+       ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
+       if (ok == NOTIFY_DONE) {
+               request_module("cryptomgr");
+               ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
+       }
+
+       if (ok == NOTIFY_STOP)
                alg = crypto_larval_wait(larval);
        else {
                crypto_mod_put(larval);

diff --git a/crypto/cryptomgr.c b/crypto/cryptomgr.c
new file mode 100644 (file)
index 0000000..e0ebe1b
--- /dev/null
+++ b/crypto/cryptomgr.c
@@ -0,0 +1,146 @@
+/*
+ * Create default crypto algorithm instances.
+ *
+ * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#include <linux/crypto.h>
+#include <linux/ctype.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/rtnetlink.h>
+#include <linux/string.h>
+#include <linux/workqueue.h>
+
+#include "internal.h"
+
+struct cryptomgr_param {
+       struct work_struct work;
+
+       struct {
+               struct rtattr attr;
+               struct crypto_attr_alg data;
+       } alg;
+
+       struct {
+               char name[CRYPTO_MAX_ALG_NAME];
+       } larval;
+
+       char template[CRYPTO_MAX_ALG_NAME];
+};
+
+static void cryptomgr_probe(void *data)
+{
+       struct cryptomgr_param *param = data;
+       struct crypto_template *tmpl;
+       struct crypto_instance *inst;
+
+       tmpl = crypto_lookup_template(param->template);
+       if (!tmpl)
+               goto err;
+
+       inst = tmpl->alloc(&param->alg, sizeof(param->alg));
+       if (IS_ERR(inst))
+               goto err;
+       else if ((err = crypto_register_instance(tmpl, inst))) {
+               tmpl->free(inst);
+               goto err;
+       }
+
+       crypto_tmpl_put(tmpl);
+
+out:
+       kfree(param);
+       return;
+
+err:
+       crypto_larval_error(param->larval.name);
+       goto out;
+}
+
+static int cryptomgr_schedule_probe(struct crypto_larval *larval)
+{
+       struct cryptomgr_param *param;
+       const char *name = larval->alg.cra_name;
+       const char *p;
+       unsigned int len;
+
+       param = kmalloc(sizeof(*param), GFP_KERNEL);
+       if (!param)
+               goto err;
+
+       for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
+               ;
+
+       len = p - name;
+       if (!len || *p != '(')
+               goto err_free_param;
+
+       memcpy(param->template, name, len);
+       param->template[len] = 0;
+
+       name = p + 1;
+       for (p = name; isalnum(*p) || *p == '-' || *p == '_'; p++)
+               ;
+
+       len = p - name;
+       if (!len || *p != ')' || p[1])
+               goto err_free_param;
+
+       param->alg.attr.rta_len = sizeof(param->alg);
+       param->alg.attr.rta_type = CRYPTOA_ALG;
+       memcpy(param->alg.data.name, name, len);
+       param->alg.data.name[len] = 0;
+
+       memcpy(param->larval.name, larval->alg.cra_name, CRYPTO_MAX_ALG_NAME);
+
+       INIT_WORK(&param->work, cryptomgr_probe, param);
+       schedule_work(&param->work);
+
+       return NOTIFY_STOP;
+
+err_free_param:
+       kfree(param);
+err:
+       return NOTIFY_OK;
+}
+
+static int cryptomgr_notify(struct notifier_block *this, unsigned long msg,
+                           void *data)
+{
+       switch (msg) {
+       case CRYPTO_MSG_ALG_REQUEST:
+               return cryptomgr_schedule_probe(data);
+       }
+
+       return NOTIFY_DONE;
+}
+
+static struct notifier_block cryptomgr_notifier = {
+       .notifier_call = cryptomgr_notify,
+};
+
+static int __init cryptomgr_init(void)
+{
+       return crypto_register_notifier(&cryptomgr_notifier);
+}
+
+static void __exit cryptomgr_exit(void)
+{
+       int err = crypto_unregister_notifier(&cryptomgr_notifier);
+       BUG_ON(err);
+}
+
+module_init(cryptomgr_init);
+module_exit(cryptomgr_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Crypto Algorithm Manager");

diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 3e3e95aff133d9803dc03dad98db0edbda2b7257..85f73c381913921d2f9aebac8eef8f8af7ae6271 100644 (file)
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -260,6 +260,15 @@ struct crypto_tfm {
        void *__crt_ctx[] CRYPTO_MINALIGN_ATTR;
 };
 
+enum {
+       CRYPTOA_UNSPEC,
+       CRYPTOA_ALG,
+};
+
+struct crypto_attr_alg {
+       char name[CRYPTO_MAX_ALG_NAME];
+};
+
 /* 
  * Transform user interface.
  */