[CRYPTO] api: Split out low-level API

The crypto API is made up of the part facing users such as IPsec and the
low-level part which is used by cryptographic entities such as algorithms.
This patch splits out the latter so that the two APIs are more clearly
delineated.  As a bonus the low-level API can now be modularised if all
algorithms are built as modules.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

6 files changed, 184 insertions, 133 deletions

diff --git a/crypto/Kconfig b/crypto/Kconfig
index fa927a287a1d..aabc63195222 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -9,47 +9,54 @@ config CRYPTO
         help
           This option provides the core Cryptographic API.
 
+if CRYPTO
+
+config CRYPTO_ALGAPI
+        tristate
+        help
+          This option provides the API for cryptographic algorithms.
+
 config CRYPTO_HMAC
         bool "HMAC support"
-        depends on CRYPTO
         help
           HMAC: Keyed-Hashing for Message Authentication (RFC2104).
           This is required for IPSec.
 
 config CRYPTO_NULL
         tristate "Null algorithms"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           These are 'Null' algorithms, used by IPsec, which do nothing.
 
 config CRYPTO_MD4
         tristate "MD4 digest algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           MD4 message digest algorithm (RFC1320).
 
 config CRYPTO_MD5
         tristate "MD5 digest algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           MD5 message digest algorithm (RFC1321).
 
 config CRYPTO_SHA1
         tristate "SHA1 digest algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           SHA-1 secure hash standard (FIPS 180-1/DFIPS 180-2).
 
 config CRYPTO_SHA1_S390
         tristate "SHA1 digest algorithm (s390)"
-        depends on CRYPTO && S390
+        depends on S390
+        select CRYPTO_ALGAPI
         help
           This is the s390 hardware accelerated implementation of the
           SHA-1 secure hash standard (FIPS 180-1/DFIPS 180-2).
 
 config CRYPTO_SHA256
         tristate "SHA256 digest algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           SHA256 secure hash standard (DFIPS 180-2).
           
@@ -58,7 +65,8 @@ config CRYPTO_SHA256
 
 config CRYPTO_SHA256_S390
         tristate "SHA256 digest algorithm (s390)"
-        depends on CRYPTO && S390
+        depends on S390
+        select CRYPTO_ALGAPI
         help
           This is the s390 hardware accelerated implementation of the
           SHA256 secure hash standard (DFIPS 180-2).
@@ -68,7 +76,7 @@ config CRYPTO_SHA256_S390
 
 config CRYPTO_SHA512
         tristate "SHA384 and SHA512 digest algorithms"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           SHA512 secure hash standard (DFIPS 180-2).
           
@@ -80,7 +88,7 @@ config CRYPTO_SHA512
 
 config CRYPTO_WP512
         tristate "Whirlpool digest algorithms"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           Whirlpool hash algorithm 512, 384 and 256-bit hashes
 
@@ -92,7 +100,7 @@ config CRYPTO_WP512
 
 config CRYPTO_TGR192
         tristate "Tiger digest algorithms"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           Tiger hash algorithm 192, 160 and 128-bit hashes
 
@@ -105,19 +113,20 @@ config CRYPTO_TGR192
 
 config CRYPTO_DES
         tristate "DES and Triple DES EDE cipher algorithms"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           DES cipher algorithm (FIPS 46-2), and Triple DES EDE (FIPS 46-3).
 
 config CRYPTO_DES_S390
         tristate "DES and Triple DES cipher algorithms (s390)"
-        depends on CRYPTO && S390
+        depends on S390
+        select CRYPTO_ALGAPI
         help
           DES cipher algorithm (FIPS 46-2), and Triple DES EDE (FIPS 46-3).
 
 config CRYPTO_BLOWFISH
         tristate "Blowfish cipher algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           Blowfish cipher algorithm, by Bruce Schneier.
           
@@ -130,7 +139,7 @@ config CRYPTO_BLOWFISH
 
 config CRYPTO_TWOFISH
         tristate "Twofish cipher algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         select CRYPTO_TWOFISH_COMMON
         help
           Twofish cipher algorithm.
@@ -145,14 +154,14 @@ config CRYPTO_TWOFISH
 
 config CRYPTO_TWOFISH_COMMON
         tristate
-        depends on CRYPTO
         help
           Common parts of the Twofish cipher algorithm shared by the
           generic c and the assembler implementations.
 
 config CRYPTO_TWOFISH_586
         tristate "Twofish cipher algorithms (i586)"
-        depends on CRYPTO && ((X86 || UML_X86) && !64BIT)
+        depends on (X86 || UML_X86) && !64BIT
+        select CRYPTO_ALGAPI
         select CRYPTO_TWOFISH_COMMON
         help
           Twofish cipher algorithm.
@@ -167,7 +176,8 @@ config CRYPTO_TWOFISH_586
 
 config CRYPTO_TWOFISH_X86_64
         tristate "Twofish cipher algorithm (x86_64)"
-        depends on CRYPTO && ((X86 || UML_X86) && 64BIT)
+        depends on (X86 || UML_X86) && 64BIT
+        select CRYPTO_ALGAPI
         select CRYPTO_TWOFISH_COMMON
         help
           Twofish cipher algorithm (x86_64).
@@ -182,7 +192,7 @@ config CRYPTO_TWOFISH_X86_64
 
 config CRYPTO_SERPENT
         tristate "Serpent cipher algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           Serpent cipher algorithm, by Anderson, Biham & Knudsen.
 
@@ -195,7 +205,7 @@ config CRYPTO_SERPENT
 
 config CRYPTO_AES
         tristate "AES cipher algorithms"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           AES cipher algorithms (FIPS-197). AES uses the Rijndael 
           algorithm.
@@ -215,7 +225,8 @@ config CRYPTO_AES
 
 config CRYPTO_AES_586
         tristate "AES cipher algorithms (i586)"
-        depends on CRYPTO && ((X86 || UML_X86) && !64BIT)
+        depends on (X86 || UML_X86) && !64BIT
+        select CRYPTO_ALGAPI
         help
           AES cipher algorithms (FIPS-197). AES uses the Rijndael 
           algorithm.
@@ -235,7 +246,8 @@ config CRYPTO_AES_586
 
 config CRYPTO_AES_X86_64
         tristate "AES cipher algorithms (x86_64)"
-        depends on CRYPTO && ((X86 || UML_X86) && 64BIT)
+        depends on (X86 || UML_X86) && 64BIT
+        select CRYPTO_ALGAPI
         help
           AES cipher algorithms (FIPS-197). AES uses the Rijndael 
           algorithm.
@@ -255,7 +267,8 @@ config CRYPTO_AES_X86_64
 
 config CRYPTO_AES_S390
         tristate "AES cipher algorithms (s390)"
-        depends on CRYPTO && S390
+        depends on S390
+        select CRYPTO_ALGAPI
         help
           This is the s390 hardware accelerated implementation of the
           AES cipher algorithms (FIPS-197). AES uses the Rijndael
@@ -275,21 +288,21 @@ config CRYPTO_AES_S390
 
 config CRYPTO_CAST5
         tristate "CAST5 (CAST-128) cipher algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           The CAST5 encryption algorithm (synonymous with CAST-128) is
           described in RFC2144.
 
 config CRYPTO_CAST6
         tristate "CAST6 (CAST-256) cipher algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           The CAST6 encryption algorithm (synonymous with CAST-256) is
           described in RFC2612.
 
 config CRYPTO_TEA
         tristate "TEA, XTEA and XETA cipher algorithms"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           TEA cipher algorithm.
 
@@ -306,7 +319,7 @@ config CRYPTO_TEA
 
 config CRYPTO_ARC4
         tristate "ARC4 cipher algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           ARC4 cipher algorithm.
 
@@ -317,7 +330,7 @@ config CRYPTO_ARC4
 
 config CRYPTO_KHAZAD
         tristate "Khazad cipher algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           Khazad cipher algorithm.
 
@@ -330,7 +343,7 @@ config CRYPTO_KHAZAD
 
 config CRYPTO_ANUBIS
         tristate "Anubis cipher algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           Anubis cipher algorithm.
 
@@ -345,7 +358,7 @@ config CRYPTO_ANUBIS
 
 config CRYPTO_DEFLATE
         tristate "Deflate compression algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         select ZLIB_INFLATE
         select ZLIB_DEFLATE
         help
@@ -356,7 +369,7 @@ config CRYPTO_DEFLATE
 
 config CRYPTO_MICHAEL_MIC
         tristate "Michael MIC keyed digest algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         help
           Michael MIC is used for message integrity protection in TKIP
           (IEEE 802.11i). This algorithm is required for TKIP, but it
@@ -365,7 +378,7 @@ config CRYPTO_MICHAEL_MIC
 
 config CRYPTO_CRC32C
         tristate "CRC32c CRC algorithm"
-        depends on CRYPTO
+        select CRYPTO_ALGAPI
         select LIBCRC32C
         help
           Castagnoli, et al Cyclic Redundancy-Check Algorithm.  Used
@@ -375,10 +388,13 @@ config CRYPTO_CRC32C
 
 config CRYPTO_TEST
         tristate "Testing module"
-        depends on CRYPTO && m
+        depends on m
+        select CRYPTO_ALGAPI
         help
           Quick & dirty crypto test module.
 
 source "drivers/crypto/Kconfig"
-endmenu
 
+endif   # if CRYPTO
+
+endmenu
diff --git a/crypto/Makefile b/crypto/Makefile
index fe934f1001c6..6d51f80753a1 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -2,10 +2,11 @@
 # Cryptographic API
 #
 
-proc-crypto-$(CONFIG_PROC_FS) = proc.o
+obj-$(CONFIG_CRYPTO) += api.o scatterwalk.o cipher.o digest.o compress.o
 
-obj-$(CONFIG_CRYPTO) += api.o scatterwalk.o cipher.o digest.o compress.o \
-                        $(proc-crypto-y)
+crypto_algapi-$(CONFIG_PROC_FS) += proc.o
+crypto_algapi-objs := algapi.o $(crypto_algapi-y)
+obj-$(CONFIG_CRYPTO_ALGAPI) += crypto_algapi.o
 
 obj-$(CONFIG_CRYPTO_HMAC) += hmac.o
 obj-$(CONFIG_CRYPTO_NULL) += crypto_null.o
diff --git a/crypto/algapi.c b/crypto/algapi.c
new file mode 100644
index 000000000000..a65c6ccfbe17
--- /dev/null
+++ b/crypto/algapi.c
@@ -0,0 +1,118 @@
+/*
+ * Cryptographic API for algorithms (i.e., low-level API).
+ *
+ * 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/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include "internal.h"
+
+static inline int crypto_set_driver_name(struct crypto_alg *alg)
+{
+        static const char suffix[] = "-generic";
+        char *driver_name = alg->cra_driver_name;
+        int len;
+
+        if (*driver_name)
+                return 0;
+
+        len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
+        if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
+                return -ENAMETOOLONG;
+
+        memcpy(driver_name + len, suffix, sizeof(suffix));
+        return 0;
+}
+
+int crypto_register_alg(struct crypto_alg *alg)
+{
+        int ret;
+        struct crypto_alg *q;
+
+        if (alg->cra_alignmask & (alg->cra_alignmask + 1))
+                return -EINVAL;
+
+        if (alg->cra_alignmask & alg->cra_blocksize)
+                return -EINVAL;
+
+        if (alg->cra_blocksize > PAGE_SIZE / 8)
+                return -EINVAL;
+
+        if (alg->cra_priority < 0)
+                return -EINVAL;
+        
+        ret = crypto_set_driver_name(alg);
+        if (unlikely(ret))
+                return ret;
+
+        down_write(&crypto_alg_sem);
+        
+        list_for_each_entry(q, &crypto_alg_list, cra_list) {
+                if (q == alg) {
+                        ret = -EEXIST;
+                        goto out;
+                }
+        }
+        
+        list_add(&alg->cra_list, &crypto_alg_list);
+        atomic_set(&alg->cra_refcnt, 1);
+out:    
+        up_write(&crypto_alg_sem);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(crypto_register_alg);
+
+int crypto_unregister_alg(struct crypto_alg *alg)
+{
+        int ret = -ENOENT;
+        struct crypto_alg *q;
+        
+        down_write(&crypto_alg_sem);
+        list_for_each_entry(q, &crypto_alg_list, cra_list) {
+                if (alg == q) {
+                        list_del(&alg->cra_list);
+                        ret = 0;
+                        goto out;
+                }
+        }
+out:    
+        up_write(&crypto_alg_sem);
+
+        if (ret)
+                return ret;
+
+        BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
+        if (alg->cra_destroy)
+                alg->cra_destroy(alg);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_alg);
+
+static int __init crypto_algapi_init(void)
+{
+        crypto_init_proc();
+        return 0;
+}
+
+static void __exit crypto_algapi_exit(void)
+{
+        crypto_exit_proc();
+}
+
+module_init(crypto_algapi_init);
+module_exit(crypto_algapi_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cryptographic algorithms API");
diff --git a/crypto/api.c b/crypto/api.c
index 5994a58ef954..c922090b4842 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -15,19 +15,17 @@
  *
  */
 
-#include <linux/compiler.h>
-#include <linux/init.h>
-#include <linux/crypto.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/kmod.h>
-#include <linux/rwsem.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include "internal.h"
 
 LIST_HEAD(crypto_alg_list);
+EXPORT_SYMBOL_GPL(crypto_alg_list);
 DECLARE_RWSEM(crypto_alg_sem);
+EXPORT_SYMBOL_GPL(crypto_alg_sem);
 
 static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
 {
@@ -239,86 +237,6 @@ void crypto_free_tfm(struct crypto_tfm *tfm)
         kfree(tfm);
 }
 
-static inline int crypto_set_driver_name(struct crypto_alg *alg)
-{
-        static const char suffix[] = "-generic";
-        char *driver_name = alg->cra_driver_name;
-        int len;
-
-        if (*driver_name)
-                return 0;
-
-        len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
-        if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
-                return -ENAMETOOLONG;
-
-        memcpy(driver_name + len, suffix, sizeof(suffix));
-        return 0;
-}
-
-int crypto_register_alg(struct crypto_alg *alg)
-{
-        int ret;
-        struct crypto_alg *q;
-
-        if (alg->cra_alignmask & (alg->cra_alignmask + 1))
-                return -EINVAL;
-
-        if (alg->cra_alignmask & alg->cra_blocksize)
-                return -EINVAL;
-
-        if (alg->cra_blocksize > PAGE_SIZE / 8)
-                return -EINVAL;
-
-        if (alg->cra_priority < 0)
-                return -EINVAL;
-        
-        ret = crypto_set_driver_name(alg);
-        if (unlikely(ret))
-                return ret;
-
-        down_write(&crypto_alg_sem);
-        
-        list_for_each_entry(q, &crypto_alg_list, cra_list) {
-                if (q == alg) {
-                        ret = -EEXIST;
-                        goto out;
-                }
-        }
-        
-        list_add(&alg->cra_list, &crypto_alg_list);
-        atomic_set(&alg->cra_refcnt, 1);
-out:    
-        up_write(&crypto_alg_sem);
-        return ret;
-}
-
-int crypto_unregister_alg(struct crypto_alg *alg)
-{
-        int ret = -ENOENT;
-        struct crypto_alg *q;
-        
-        down_write(&crypto_alg_sem);
-        list_for_each_entry(q, &crypto_alg_list, cra_list) {
-                if (alg == q) {
-                        list_del(&alg->cra_list);
-                        ret = 0;
-                        goto out;
-                }
-        }
-out:    
-        up_write(&crypto_alg_sem);
-
-        if (ret)
-                return ret;
-
-        BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
-        if (alg->cra_destroy)
-                alg->cra_destroy(alg);
-
-        return 0;
-}
-
 int crypto_alg_available(const char *name, u32 flags)
 {
         int ret = 0;
@@ -332,17 +250,6 @@ int crypto_alg_available(const char *name, u32 flags)
         return ret;
 }
 
-static int __init init_crypto(void)
-{
-        printk(KERN_INFO "Initializing Cryptographic API\n");
-        crypto_init_proc();
-        return 0;
-}
-
-__initcall(init_crypto);
-
-EXPORT_SYMBOL_GPL(crypto_register_alg);
-EXPORT_SYMBOL_GPL(crypto_unregister_alg);
 EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
 EXPORT_SYMBOL_GPL(crypto_free_tfm);
 EXPORT_SYMBOL_GPL(crypto_alg_available);
diff --git a/crypto/internal.h b/crypto/internal.h
index 959e602909a6..26f47d331551 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -12,7 +12,8 @@
  */
 #ifndef _CRYPTO_INTERNAL_H
 #define _CRYPTO_INTERNAL_H
-#include <linux/crypto.h>
+
+#include <crypto/algapi.h>
 #include <linux/mm.h>
 #include <linux/highmem.h>
 #include <linux/interrupt.h>
@@ -64,9 +65,12 @@ static inline void crypto_free_hmac_block(struct crypto_tfm *tfm)
 
 #ifdef CONFIG_PROC_FS
 void __init crypto_init_proc(void);
+void __exit crypto_exit_proc(void);
 #else
 static inline void crypto_init_proc(void)
 { }
+static inline void crypto_exit_proc(void)
+{ }
 #endif
 
 static inline unsigned int crypto_digest_ctxsize(struct crypto_alg *alg,
diff --git a/crypto/proc.c b/crypto/proc.c
index 8543b7a157d6..9e573b17e887 100644
--- a/crypto/proc.c
+++ b/crypto/proc.c
@@ -113,3 +113,8 @@ void __init crypto_init_proc(void)
         if (proc)
                 proc->proc_fops = &proc_crypto_ops;
 }
+
+void __exit crypto_exit_proc(void)
+{
+        remove_proc_entry("crypto", NULL);
+}