[CRYPTO] api: Add aead crypto type

This patch adds crypto_aead which is the interface for AEAD
(Authenticated Encryption with Associated Data) algorithms.

AEAD algorithms perform authentication and encryption in one
step.  Traditionally users (such as IPsec) would use two
different crypto algorithms to perform these.  With AEAD
this comes down to one algorithm and one operation.

Of course if traditional algorithms were used we'd still
be doing two operations underneath.  However, real AEAD
algorithms may allow the underlying operations to be
optimised as well.

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

crypto/Kconfig

@@ -28,6 +28,10 @@ config CRYPTO_ABLKCIPHER
 	tristate
 	select CRYPTO_BLKCIPHER
 
+config CRYPTO_AEAD
+	tristate
+	select CRYPTO_ALGAPI
+
 config CRYPTO_BLKCIPHER
 	tristate
 	select CRYPTO_ALGAPI

crypto/Makefile

@@ -9,6 +9,7 @@ crypto_algapi-objs := algapi.o $(crypto_algapi-y)
 obj-$(CONFIG_CRYPTO_ALGAPI) += crypto_algapi.o
 
 obj-$(CONFIG_CRYPTO_ABLKCIPHER) += ablkcipher.o
+obj-$(CONFIG_CRYPTO_AEAD) += aead.o
 obj-$(CONFIG_CRYPTO_BLKCIPHER) += blkcipher.o
 
 crypto_hash-objs := hash.o

crypto/aead.c

@@ -0,0 +1,101 @@
+/*
+ * AEAD: Authenticated Encryption with Associated Data
+ * 
+ * This file provides API support for AEAD algorithms.
+ *
+ * Copyright (c) 2007 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 <crypto/algapi.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+
+static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
+			    unsigned int keylen)
+{
+	struct aead_alg *aead = crypto_aead_alg(tfm);
+	unsigned long alignmask = crypto_aead_alignmask(tfm);
+	int ret;
+	u8 *buffer, *alignbuffer;
+	unsigned long absize;
+
+	absize = keylen + alignmask;
+	buffer = kmalloc(absize, GFP_ATOMIC);
+	if (!buffer)
+		return -ENOMEM;
+
+	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
+	memcpy(alignbuffer, key, keylen);
+	ret = aead->setkey(tfm, alignbuffer, keylen);
+	memset(alignbuffer, 0, keylen);
+	kfree(buffer);
+	return ret;
+}
+
+static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)
+{
+	struct aead_alg *aead = crypto_aead_alg(tfm);
+	unsigned long alignmask = crypto_aead_alignmask(tfm);
+
+	if ((unsigned long)key & alignmask)
+		return setkey_unaligned(tfm, key, keylen);
+
+	return aead->setkey(tfm, key, keylen);
+}
+
+static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
+					u32 mask)
+{
+	return alg->cra_ctxsize;
+}
+
+static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
+{
+	struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
+	struct aead_tfm *crt = &tfm->crt_aead;
+
+	if (max(alg->authsize, alg->ivsize) > PAGE_SIZE / 8)
+		return -EINVAL;
+
+	crt->setkey = setkey;
+	crt->encrypt = alg->encrypt;
+	crt->decrypt = alg->decrypt;
+	crt->ivsize = alg->ivsize;
+	crt->authsize = alg->authsize;
+
+	return 0;
+}
+
+static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
+	__attribute__ ((unused));
+static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
+{
+	struct aead_alg *aead = &alg->cra_aead;
+
+	seq_printf(m, "type         : aead\n");
+	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
+	seq_printf(m, "ivsize       : %u\n", aead->ivsize);
+	seq_printf(m, "authsize     : %u\n", aead->authsize);
+}
+
+const struct crypto_type crypto_aead_type = {
+	.ctxsize = crypto_aead_ctxsize,
+	.init = crypto_init_aead_ops,
+#ifdef CONFIG_PROC_FS
+	.show = crypto_aead_show,
+#endif
+};
+EXPORT_SYMBOL_GPL(crypto_aead_type);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");

include/crypto/algapi.h

@@ -94,6 +94,7 @@ struct blkcipher_walk {
 };
 
 extern const struct crypto_type crypto_ablkcipher_type;
+extern const struct crypto_type crypto_aead_type;
 extern const struct crypto_type crypto_blkcipher_type;
 extern const struct crypto_type crypto_hash_type;
 
@@ -165,6 +166,11 @@ static inline void *crypto_ablkcipher_ctx_aligned(struct crypto_ablkcipher *tfm)
 	return crypto_tfm_ctx_aligned(&tfm->base);
 }
 
+static inline struct aead_alg *crypto_aead_alg(struct crypto_aead *tfm)
+{
+	return &crypto_aead_tfm(tfm)->__crt_alg->cra_aead;
+}
+
 static inline struct crypto_blkcipher *crypto_spawn_blkcipher(
 	struct crypto_spawn *spawn)
 {

include/linux/crypto.h

@@ -34,6 +34,7 @@
 #define CRYPTO_ALG_TYPE_HASH		0x00000003
 #define CRYPTO_ALG_TYPE_BLKCIPHER	0x00000004
 #define CRYPTO_ALG_TYPE_COMPRESS	0x00000005
+#define CRYPTO_ALG_TYPE_AEAD		0x00000006
 
 #define CRYPTO_ALG_TYPE_HASH_MASK	0x0000000e
 
@@ -91,6 +92,7 @@
 struct scatterlist;
 struct crypto_ablkcipher;
 struct crypto_async_request;
+struct crypto_aead;
 struct crypto_blkcipher;
 struct crypto_hash;
 struct crypto_queue;
@@ -121,6 +123,32 @@ struct ablkcipher_request {
 	void *__ctx[] CRYPTO_MINALIGN_ATTR;
 };
 
+/**
+ *	struct aead_request - AEAD request
+ *	@base: Common attributes for async crypto requests
+ *	@assoclen: Length in bytes of associated data for authentication
+ *	@cryptlen: Length of data to be encrypted or decrypted
+ *	@iv: Initialisation vector
+ *	@assoc: Associated data
+ *	@src: Source data
+ *	@dst: Destination data
+ *	@__ctx: Start of private context data
+ */
+struct aead_request {
+	struct crypto_async_request base;
+
+	unsigned int assoclen;
+	unsigned int cryptlen;
+
+	u8 *iv;
+
+	struct scatterlist *assoc;
+	struct scatterlist *src;
+	struct scatterlist *dst;
+
+	void *__ctx[] CRYPTO_MINALIGN_ATTR;
+};
+
 struct blkcipher_desc {
 	struct crypto_blkcipher *tfm;
 	void *info;
@@ -157,6 +185,16 @@ struct ablkcipher_alg {
 	unsigned int ivsize;
 };
 
+struct aead_alg {
+	int (*setkey)(struct crypto_aead *tfm, const u8 *key,
+	              unsigned int keylen);
+	int (*encrypt)(struct aead_request *req);
+	int (*decrypt)(struct aead_request *req);
+
+	unsigned int ivsize;
+	unsigned int authsize;
+};
+
 struct blkcipher_alg {
 	int (*setkey)(struct crypto_tfm *tfm, const u8 *key,
 	              unsigned int keylen);
@@ -212,6 +250,7 @@ struct compress_alg {
 };
 
 #define cra_ablkcipher	cra_u.ablkcipher
+#define cra_aead	cra_u.aead
 #define cra_blkcipher	cra_u.blkcipher
 #define cra_cipher	cra_u.cipher
 #define cra_digest	cra_u.digest
@@ -237,6 +276,7 @@ struct crypto_alg {
 
 	union {
 		struct ablkcipher_alg ablkcipher;
+		struct aead_alg aead;
 		struct blkcipher_alg blkcipher;
 		struct cipher_alg cipher;
 		struct digest_alg digest;
@@ -284,6 +324,16 @@ struct ablkcipher_tfm {
 	unsigned int reqsize;
 };
 
+struct aead_tfm {
+	int (*setkey)(struct crypto_aead *tfm, const u8 *key,
+	              unsigned int keylen);
+	int (*encrypt)(struct aead_request *req);
+	int (*decrypt)(struct aead_request *req);
+	unsigned int ivsize;
+	unsigned int authsize;
+	unsigned int reqsize;
+};
+
 struct blkcipher_tfm {
 	void *iv;
 	int (*setkey)(struct crypto_tfm *tfm, const u8 *key,
@@ -323,6 +373,7 @@ struct compress_tfm {
 };
 
 #define crt_ablkcipher	crt_u.ablkcipher
+#define crt_aead	crt_u.aead
 #define crt_blkcipher	crt_u.blkcipher
 #define crt_cipher	crt_u.cipher
 #define crt_hash	crt_u.hash
@@ -334,6 +385,7 @@ struct crypto_tfm {
 	
 	union {
 		struct ablkcipher_tfm ablkcipher;
+		struct aead_tfm aead;
 		struct blkcipher_tfm blkcipher;
 		struct cipher_tfm cipher;
 		struct hash_tfm hash;
@@ -349,6 +401,10 @@ struct crypto_ablkcipher {
 	struct crypto_tfm base;
 };
 
+struct crypto_aead {
+	struct crypto_tfm base;
+};
+
 struct crypto_blkcipher {
 	struct crypto_tfm base;
 };
@@ -619,6 +675,150 @@ static inline void ablkcipher_request_set_crypt(
 	req->info = iv;
 }
 
+static inline struct crypto_aead *__crypto_aead_cast(struct crypto_tfm *tfm)
+{
+	return (struct crypto_aead *)tfm;
+}
+
+static inline struct crypto_aead *crypto_alloc_aead(const char *alg_name,
+						    u32 type, u32 mask)
+{
+	type &= ~CRYPTO_ALG_TYPE_MASK;
+	type |= CRYPTO_ALG_TYPE_AEAD;
+	mask |= CRYPTO_ALG_TYPE_MASK;
+
+	return __crypto_aead_cast(crypto_alloc_base(alg_name, type, mask));
+}
+
+static inline struct crypto_tfm *crypto_aead_tfm(struct crypto_aead *tfm)
+{
+	return &tfm->base;
+}
+
+static inline void crypto_free_aead(struct crypto_aead *tfm)
+{
+	crypto_free_tfm(crypto_aead_tfm(tfm));
+}
+
+static inline struct aead_tfm *crypto_aead_crt(struct crypto_aead *tfm)
+{
+	return &crypto_aead_tfm(tfm)->crt_aead;
+}
+
+static inline unsigned int crypto_aead_ivsize(struct crypto_aead *tfm)
+{
+	return crypto_aead_crt(tfm)->ivsize;
+}
+
+static inline unsigned int crypto_aead_authsize(struct crypto_aead *tfm)
+{
+	return crypto_aead_crt(tfm)->authsize;
+}
+
+static inline unsigned int crypto_aead_blocksize(struct crypto_aead *tfm)
+{
+	return crypto_tfm_alg_blocksize(crypto_aead_tfm(tfm));
+}
+
+static inline unsigned int crypto_aead_alignmask(struct crypto_aead *tfm)
+{
+	return crypto_tfm_alg_alignmask(crypto_aead_tfm(tfm));
+}
+
+static inline u32 crypto_aead_get_flags(struct crypto_aead *tfm)
+{
+	return crypto_tfm_get_flags(crypto_aead_tfm(tfm));
+}
+
+static inline void crypto_aead_set_flags(struct crypto_aead *tfm, u32 flags)
+{
+	crypto_tfm_set_flags(crypto_aead_tfm(tfm), flags);
+}
+
+static inline void crypto_aead_clear_flags(struct crypto_aead *tfm, u32 flags)
+{
+	crypto_tfm_clear_flags(crypto_aead_tfm(tfm), flags);
+}
+
+static inline int crypto_aead_setkey(struct crypto_aead *tfm, const u8 *key,
+				     unsigned int keylen)
+{
+	return crypto_aead_crt(tfm)->setkey(tfm, key, keylen);
+}
+
+static inline struct crypto_aead *crypto_aead_reqtfm(struct aead_request *req)
+{
+	return __crypto_aead_cast(req->base.tfm);
+}
+
+static inline int crypto_aead_encrypt(struct aead_request *req)
+{
+	return crypto_aead_crt(crypto_aead_reqtfm(req))->encrypt(req);
+}
+
+static inline int crypto_aead_decrypt(struct aead_request *req)
+{
+	return crypto_aead_crt(crypto_aead_reqtfm(req))->decrypt(req);
+}
+
+static inline int crypto_aead_reqsize(struct crypto_aead *tfm)
+{
+	return crypto_aead_crt(tfm)->reqsize;
+}
+
+static inline void aead_request_set_tfm(struct aead_request *req,
+					struct crypto_aead *tfm)
+{
+	req->base.tfm = crypto_aead_tfm(tfm);
+}
+
+static inline struct aead_request *aead_request_alloc(struct crypto_aead *tfm,
+						      gfp_t gfp)
+{
+	struct aead_request *req;
+
+	req = kmalloc(sizeof(*req) + crypto_aead_reqsize(tfm), gfp);
+
+	if (likely(req))
+		aead_request_set_tfm(req, tfm);
+
+	return req;
+}
+
+static inline void aead_request_free(struct aead_request *req)
+{
+	kfree(req);
+}
+
+static inline void aead_request_set_callback(struct aead_request *req,
+					     u32 flags,
+					     crypto_completion_t complete,
+					     void *data)
+{
+	req->base.complete = complete;
+	req->base.data = data;
+	req->base.flags = flags;
+}
+
+static inline void aead_request_set_crypt(struct aead_request *req,
+					  struct scatterlist *src,
+					  struct scatterlist *dst,
+					  unsigned int cryptlen, u8 *iv)
+{
+	req->src = src;
+	req->dst = dst;
+	req->cryptlen = cryptlen;
+	req->iv = iv;
+}
+
+static inline void aead_request_set_assoc(struct aead_request *req,
+					  struct scatterlist *assoc,
+					  unsigned int assoclen)
+{
+	req->assoc = assoc;
+	req->assoclen = assoclen;
+}
+
 static inline struct crypto_blkcipher *__crypto_blkcipher_cast(
 	struct crypto_tfm *tfm)
 {