[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>

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

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

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");

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);

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,

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);
+}

drivers/crypto/Kconfig

@@ -2,7 +2,8 @@ menu "Hardware crypto devices"
 
 config CRYPTO_DEV_PADLOCK
 	tristate "Support for VIA PadLock ACE"
-	depends on CRYPTO && X86_32
+	depends on X86_32
+	select CRYPTO_ALGAPI
 	help
 	  Some VIA processors come with an integrated crypto engine
 	  (so called VIA PadLock ACE, Advanced Cryptography Engine)

include/crypto/algapi.h

@@ -0,0 +1,18 @@
+/*
+ * 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.
+ *
+ */
+#ifndef _CRYPTO_ALGAPI_H
+#define _CRYPTO_ALGAPI_H
+
+#include <linux/crypto.h>
+
+#endif	/* _CRYPTO_ALGAPI_H */
+