X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Finclude%2Fcrypto%2Faead.h;h=077cae1e6b516779eb4bb7e4e35058838bd019d8;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=94b19be67574495c9270bcd29c55292554c8cbe9;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git

diff --git a/kernel/include/crypto/aead.h b/kernel/include/crypto/aead.h
index 94b19be67..077cae1e6 100644
--- a/kernel/include/crypto/aead.h
+++ b/kernel/include/crypto/aead.h
@@ -1,7 +1,7 @@
 /*
  * AEAD: Authenticated Encryption with Associated Data
  * 
- * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
+ * Copyright (c) 2007-2015 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
@@ -18,88 +18,517 @@
 #include <linux/slab.h>
 
 /**
- *	struct aead_givcrypt_request - AEAD request with IV generation
- *	@seq: Sequence number for IV generation
- *	@giv: Space for generated IV
- *	@areq: The AEAD request itself
+ * DOC: Authenticated Encryption With Associated Data (AEAD) Cipher API
+ *
+ * The AEAD cipher API is used with the ciphers of type CRYPTO_ALG_TYPE_AEAD
+ * (listed as type "aead" in /proc/crypto)
+ *
+ * The most prominent examples for this type of encryption is GCM and CCM.
+ * However, the kernel supports other types of AEAD ciphers which are defined
+ * with the following cipher string:
+ *
+ *	authenc(keyed message digest, block cipher)
+ *
+ * For example: authenc(hmac(sha256), cbc(aes))
+ *
+ * The example code provided for the asynchronous block cipher operation
+ * applies here as well. Naturally all *ablkcipher* symbols must be exchanged
+ * the *aead* pendants discussed in the following. In addition, for the AEAD
+ * operation, the aead_request_set_assoc function must be used to set the
+ * pointer to the associated data memory location before performing the
+ * encryption or decryption operation. In case of an encryption, the associated
+ * data memory is filled during the encryption operation. For decryption, the
+ * associated data memory must contain data that is used to verify the integrity
+ * of the decrypted data. Another deviation from the asynchronous block cipher
+ * operation is that the caller should explicitly check for -EBADMSG of the
+ * crypto_aead_decrypt. That error indicates an authentication error, i.e.
+ * a breach in the integrity of the message. In essence, that -EBADMSG error
+ * code is the key bonus an AEAD cipher has over "standard" block chaining
+ * modes.
+ *
+ * Memory Structure:
+ *
+ * To support the needs of the most prominent user of AEAD ciphers, namely
+ * IPSEC, the AEAD ciphers have a special memory layout the caller must adhere
+ * to.
+ *
+ * The scatter list pointing to the input data must contain:
+ *
+ * * for RFC4106 ciphers, the concatenation of
+ * associated authentication data || IV || plaintext or ciphertext. Note, the
+ * same IV (buffer) is also set with the aead_request_set_crypt call. Note,
+ * the API call of aead_request_set_ad must provide the length of the AAD and
+ * the IV. The API call of aead_request_set_crypt only points to the size of
+ * the input plaintext or ciphertext.
+ *
+ * * for "normal" AEAD ciphers, the concatenation of
+ * associated authentication data || plaintext or ciphertext.
+ *
+ * It is important to note that if multiple scatter gather list entries form
+ * the input data mentioned above, the first entry must not point to a NULL
+ * buffer. If there is any potential where the AAD buffer can be NULL, the
+ * calling code must contain a precaution to ensure that this does not result
+ * in the first scatter gather list entry pointing to a NULL buffer.
+ */
+
+struct crypto_aead;
+
+/**
+ *	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
+ *	@src: Source data
+ *	@dst: Destination data
+ *	@__ctx: Start of private context data
  */
-struct aead_givcrypt_request {
-	u64 seq;
-	u8 *giv;
+struct aead_request {
+	struct crypto_async_request base;
 
-	struct aead_request areq;
+	unsigned int assoclen;
+	unsigned int cryptlen;
+
+	u8 *iv;
+
+	struct scatterlist *src;
+	struct scatterlist *dst;
+
+	void *__ctx[] CRYPTO_MINALIGN_ATTR;
 };
 
-static inline struct crypto_aead *aead_givcrypt_reqtfm(
-	struct aead_givcrypt_request *req)
+/**
+ * struct aead_alg - AEAD cipher definition
+ * @maxauthsize: Set the maximum authentication tag size supported by the
+ *		 transformation. A transformation may support smaller tag sizes.
+ *		 As the authentication tag is a message digest to ensure the
+ *		 integrity of the encrypted data, a consumer typically wants the
+ *		 largest authentication tag possible as defined by this
+ *		 variable.
+ * @setauthsize: Set authentication size for the AEAD transformation. This
+ *		 function is used to specify the consumer requested size of the
+ * 		 authentication tag to be either generated by the transformation
+ *		 during encryption or the size of the authentication tag to be
+ *		 supplied during the decryption operation. This function is also
+ *		 responsible for checking the authentication tag size for
+ *		 validity.
+ * @setkey: see struct ablkcipher_alg
+ * @encrypt: see struct ablkcipher_alg
+ * @decrypt: see struct ablkcipher_alg
+ * @geniv: see struct ablkcipher_alg
+ * @ivsize: see struct ablkcipher_alg
+ * @init: Initialize the cryptographic transformation object. This function
+ *	  is used to initialize the cryptographic transformation object.
+ *	  This function is called only once at the instantiation time, right
+ *	  after the transformation context was allocated. In case the
+ *	  cryptographic hardware has some special requirements which need to
+ *	  be handled by software, this function shall check for the precise
+ *	  requirement of the transformation and put any software fallbacks
+ *	  in place.
+ * @exit: Deinitialize the cryptographic transformation object. This is a
+ *	  counterpart to @init, used to remove various changes set in
+ *	  @init.
+ *
+ * All fields except @ivsize is mandatory and must be filled.
+ */
+struct aead_alg {
+	int (*setkey)(struct crypto_aead *tfm, const u8 *key,
+	              unsigned int keylen);
+	int (*setauthsize)(struct crypto_aead *tfm, unsigned int authsize);
+	int (*encrypt)(struct aead_request *req);
+	int (*decrypt)(struct aead_request *req);
+	int (*init)(struct crypto_aead *tfm);
+	void (*exit)(struct crypto_aead *tfm);
+
+	const char *geniv;
+
+	unsigned int ivsize;
+	unsigned int maxauthsize;
+
+	struct crypto_alg base;
+};
+
+struct crypto_aead {
+	unsigned int authsize;
+	unsigned int reqsize;
+
+	struct crypto_tfm base;
+};
+
+static inline struct crypto_aead *__crypto_aead_cast(struct crypto_tfm *tfm)
 {
-	return crypto_aead_reqtfm(&req->areq);
+	return container_of(tfm, struct crypto_aead, base);
 }
 
-static inline int crypto_aead_givencrypt(struct aead_givcrypt_request *req)
+/**
+ * crypto_alloc_aead() - allocate AEAD cipher handle
+ * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
+ *	     AEAD cipher
+ * @type: specifies the type of the cipher
+ * @mask: specifies the mask for the cipher
+ *
+ * Allocate a cipher handle for an AEAD. The returned struct
+ * crypto_aead is the cipher handle that is required for any subsequent
+ * API invocation for that AEAD.
+ *
+ * Return: allocated cipher handle in case of success; IS_ERR() is true in case
+ *	   of an error, PTR_ERR() returns the error code.
+ */
+struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask);
+
+static inline struct crypto_tfm *crypto_aead_tfm(struct crypto_aead *tfm)
 {
-	struct aead_tfm *crt = crypto_aead_crt(aead_givcrypt_reqtfm(req));
-	return crt->givencrypt(req);
-};
+	return &tfm->base;
+}
+
+/**
+ * crypto_free_aead() - zeroize and free aead handle
+ * @tfm: cipher handle to be freed
+ */
+static inline void crypto_free_aead(struct crypto_aead *tfm)
+{
+	crypto_destroy_tfm(tfm, crypto_aead_tfm(tfm));
+}
 
-static inline int crypto_aead_givdecrypt(struct aead_givcrypt_request *req)
+static inline struct aead_alg *crypto_aead_alg(struct crypto_aead *tfm)
 {
-	struct aead_tfm *crt = crypto_aead_crt(aead_givcrypt_reqtfm(req));
-	return crt->givdecrypt(req);
-};
+	return container_of(crypto_aead_tfm(tfm)->__crt_alg,
+			    struct aead_alg, base);
+}
 
-static inline void aead_givcrypt_set_tfm(struct aead_givcrypt_request *req,
-					 struct crypto_aead *tfm)
+static inline unsigned int crypto_aead_alg_ivsize(struct aead_alg *alg)
 {
-	req->areq.base.tfm = crypto_aead_tfm(tfm);
+	return alg->ivsize;
 }
 
-static inline struct aead_givcrypt_request *aead_givcrypt_alloc(
-	struct crypto_aead *tfm, gfp_t gfp)
+/**
+ * crypto_aead_ivsize() - obtain IV size
+ * @tfm: cipher handle
+ *
+ * The size of the IV for the aead referenced by the cipher handle is
+ * returned. This IV size may be zero if the cipher does not need an IV.
+ *
+ * Return: IV size in bytes
+ */
+static inline unsigned int crypto_aead_ivsize(struct crypto_aead *tfm)
 {
-	struct aead_givcrypt_request *req;
+	return crypto_aead_alg_ivsize(crypto_aead_alg(tfm));
+}
 
-	req = kmalloc(sizeof(struct aead_givcrypt_request) +
-		      crypto_aead_reqsize(tfm), gfp);
+/**
+ * crypto_aead_authsize() - obtain maximum authentication data size
+ * @tfm: cipher handle
+ *
+ * The maximum size of the authentication data for the AEAD cipher referenced
+ * by the AEAD cipher handle is returned. The authentication data size may be
+ * zero if the cipher implements a hard-coded maximum.
+ *
+ * The authentication data may also be known as "tag value".
+ *
+ * Return: authentication data size / tag size in bytes
+ */
+static inline unsigned int crypto_aead_authsize(struct crypto_aead *tfm)
+{
+	return tfm->authsize;
+}
 
-	if (likely(req))
-		aead_givcrypt_set_tfm(req, tfm);
+/**
+ * crypto_aead_blocksize() - obtain block size of cipher
+ * @tfm: cipher handle
+ *
+ * The block size for the AEAD referenced with the cipher handle is returned.
+ * The caller may use that information to allocate appropriate memory for the
+ * data returned by the encryption or decryption operation
+ *
+ * Return: block size of cipher
+ */
+static inline unsigned int crypto_aead_blocksize(struct crypto_aead *tfm)
+{
+	return crypto_tfm_alg_blocksize(crypto_aead_tfm(tfm));
+}
 
-	return req;
+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);
+}
+
+/**
+ * crypto_aead_setkey() - set key for cipher
+ * @tfm: cipher handle
+ * @key: buffer holding the key
+ * @keylen: length of the key in bytes
+ *
+ * The caller provided key is set for the AEAD referenced by the cipher
+ * handle.
+ *
+ * Note, the key length determines the cipher type. Many block ciphers implement
+ * different cipher modes depending on the key size, such as AES-128 vs AES-192
+ * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
+ * is performed.
+ *
+ * Return: 0 if the setting of the key was successful; < 0 if an error occurred
+ */
+int crypto_aead_setkey(struct crypto_aead *tfm,
+		       const u8 *key, unsigned int keylen);
+
+/**
+ * crypto_aead_setauthsize() - set authentication data size
+ * @tfm: cipher handle
+ * @authsize: size of the authentication data / tag in bytes
+ *
+ * Set the authentication data size / tag size. AEAD requires an authentication
+ * tag (or MAC) in addition to the associated data.
+ *
+ * Return: 0 if the setting of the key was successful; < 0 if an error occurred
+ */
+int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize);
+
+static inline struct crypto_aead *crypto_aead_reqtfm(struct aead_request *req)
+{
+	return __crypto_aead_cast(req->base.tfm);
+}
+
+/**
+ * crypto_aead_encrypt() - encrypt plaintext
+ * @req: reference to the aead_request handle that holds all information
+ *	 needed to perform the cipher operation
+ *
+ * Encrypt plaintext data using the aead_request handle. That data structure
+ * and how it is filled with data is discussed with the aead_request_*
+ * functions.
+ *
+ * IMPORTANT NOTE The encryption operation creates the authentication data /
+ *		  tag. That data is concatenated with the created ciphertext.
+ *		  The ciphertext memory size is therefore the given number of
+ *		  block cipher blocks + the size defined by the
+ *		  crypto_aead_setauthsize invocation. The caller must ensure
+ *		  that sufficient memory is available for the ciphertext and
+ *		  the authentication tag.
+ *
+ * Return: 0 if the cipher operation was successful; < 0 if an error occurred
+ */
+static inline int crypto_aead_encrypt(struct aead_request *req)
+{
+	return crypto_aead_alg(crypto_aead_reqtfm(req))->encrypt(req);
+}
+
+/**
+ * crypto_aead_decrypt() - decrypt ciphertext
+ * @req: reference to the ablkcipher_request handle that holds all information
+ *	 needed to perform the cipher operation
+ *
+ * Decrypt ciphertext data using the aead_request handle. That data structure
+ * and how it is filled with data is discussed with the aead_request_*
+ * functions.
+ *
+ * IMPORTANT NOTE The caller must concatenate the ciphertext followed by the
+ *		  authentication data / tag. That authentication data / tag
+ *		  must have the size defined by the crypto_aead_setauthsize
+ *		  invocation.
+ *
+ *
+ * Return: 0 if the cipher operation was successful; -EBADMSG: The AEAD
+ *	   cipher operation performs the authentication of the data during the
+ *	   decryption operation. Therefore, the function returns this error if
+ *	   the authentication of the ciphertext was unsuccessful (i.e. the
+ *	   integrity of the ciphertext or the associated data was violated);
+ *	   < 0 if an error occurred.
+ */
+static inline int crypto_aead_decrypt(struct aead_request *req)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+
+	if (req->cryptlen < crypto_aead_authsize(aead))
+		return -EINVAL;
+
+	return crypto_aead_alg(aead)->decrypt(req);
+}
+
+/**
+ * DOC: Asynchronous AEAD Request Handle
+ *
+ * The aead_request data structure contains all pointers to data required for
+ * the AEAD cipher operation. This includes the cipher handle (which can be
+ * used by multiple aead_request instances), pointer to plaintext and
+ * ciphertext, asynchronous callback function, etc. It acts as a handle to the
+ * aead_request_* API calls in a similar way as AEAD handle to the
+ * crypto_aead_* API calls.
+ */
+
+/**
+ * crypto_aead_reqsize() - obtain size of the request data structure
+ * @tfm: cipher handle
+ *
+ * Return: number of bytes
+ */
+static inline unsigned int crypto_aead_reqsize(struct crypto_aead *tfm)
+{
+	return tfm->reqsize;
 }
 
-static inline void aead_givcrypt_free(struct aead_givcrypt_request *req)
+/**
+ * aead_request_set_tfm() - update cipher handle reference in request
+ * @req: request handle to be modified
+ * @tfm: cipher handle that shall be added to the request handle
+ *
+ * Allow the caller to replace the existing aead handle in the request
+ * data structure with a different one.
+ */
+static inline void aead_request_set_tfm(struct aead_request *req,
+					struct crypto_aead *tfm)
 {
-	kfree(req);
+	req->base.tfm = crypto_aead_tfm(tfm);
 }
 
-static inline void aead_givcrypt_set_callback(
-	struct aead_givcrypt_request *req, u32 flags,
-	crypto_completion_t compl, void *data)
+/**
+ * aead_request_alloc() - allocate request data structure
+ * @tfm: cipher handle to be registered with the request
+ * @gfp: memory allocation flag that is handed to kmalloc by the API call.
+ *
+ * Allocate the request data structure that must be used with the AEAD
+ * encrypt and decrypt API calls. During the allocation, the provided aead
+ * handle is registered in the request data structure.
+ *
+ * Return: allocated request handle in case of success; IS_ERR() is true in case
+ *	   of an error, PTR_ERR() returns the error code.
+ */
+static inline struct aead_request *aead_request_alloc(struct crypto_aead *tfm,
+						      gfp_t gfp)
 {
-	aead_request_set_callback(&req->areq, flags, compl, data);
+	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_givcrypt_set_crypt(struct aead_givcrypt_request *req,
-					   struct scatterlist *src,
-					   struct scatterlist *dst,
-					   unsigned int nbytes, void *iv)
+/**
+ * aead_request_free() - zeroize and free request data structure
+ * @req: request data structure cipher handle to be freed
+ */
+static inline void aead_request_free(struct aead_request *req)
 {
-	aead_request_set_crypt(&req->areq, src, dst, nbytes, iv);
+	kzfree(req);
 }
 
-static inline void aead_givcrypt_set_assoc(struct aead_givcrypt_request *req,
-					   struct scatterlist *assoc,
-					   unsigned int assoclen)
+/**
+ * aead_request_set_callback() - set asynchronous callback function
+ * @req: request handle
+ * @flags: specify zero or an ORing of the flags
+ *	   CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
+ *	   increase the wait queue beyond the initial maximum size;
+ *	   CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
+ * @compl: callback function pointer to be registered with the request handle
+ * @data: The data pointer refers to memory that is not used by the kernel
+ *	  crypto API, but provided to the callback function for it to use. Here,
+ *	  the caller can provide a reference to memory the callback function can
+ *	  operate on. As the callback function is invoked asynchronously to the
+ *	  related functionality, it may need to access data structures of the
+ *	  related functionality which can be referenced using this pointer. The
+ *	  callback function can access the memory via the "data" field in the
+ *	  crypto_async_request data structure provided to the callback function.
+ *
+ * Setting the callback function that is triggered once the cipher operation
+ * completes
+ *
+ * The callback function is registered with the aead_request handle and
+ * must comply with the following template
+ *
+ *	void callback_function(struct crypto_async_request *req, int error)
+ */
+static inline void aead_request_set_callback(struct aead_request *req,
+					     u32 flags,
+					     crypto_completion_t compl,
+					     void *data)
+{
+	req->base.complete = compl;
+	req->base.data = data;
+	req->base.flags = flags;
+}
+
+/**
+ * aead_request_set_crypt - set data buffers
+ * @req: request handle
+ * @src: source scatter / gather list
+ * @dst: destination scatter / gather list
+ * @cryptlen: number of bytes to process from @src
+ * @iv: IV for the cipher operation which must comply with the IV size defined
+ *      by crypto_aead_ivsize()
+ *
+ * Setting the source data and destination data scatter / gather lists which
+ * hold the associated data concatenated with the plaintext or ciphertext. See
+ * below for the authentication tag.
+ *
+ * For encryption, the source is treated as the plaintext and the
+ * destination is the ciphertext. For a decryption operation, the use is
+ * reversed - the source is the ciphertext and the destination is the plaintext.
+ *
+ * For both src/dst the layout is associated data, plain/cipher text,
+ * authentication tag.
+ *
+ * The content of the AD in the destination buffer after processing
+ * will either be untouched, or it will contain a copy of the AD
+ * from the source buffer.  In order to ensure that it always has
+ * a copy of the AD, the user must copy the AD over either before
+ * or after processing.  Of course this is not relevant if the user
+ * is doing in-place processing where src == dst.
+ *
+ * IMPORTANT NOTE AEAD requires an authentication tag (MAC). For decryption,
+ *		  the caller must concatenate the ciphertext followed by the
+ *		  authentication tag and provide the entire data stream to the
+ *		  decryption operation (i.e. the data length used for the
+ *		  initialization of the scatterlist and the data length for the
+ *		  decryption operation is identical). For encryption, however,
+ *		  the authentication tag is created while encrypting the data.
+ *		  The destination buffer must hold sufficient space for the
+ *		  ciphertext and the authentication tag while the encryption
+ *		  invocation must only point to the plaintext data size. The
+ *		  following code snippet illustrates the memory usage
+ *		  buffer = kmalloc(ptbuflen + (enc ? authsize : 0));
+ *		  sg_init_one(&sg, buffer, ptbuflen + (enc ? authsize : 0));
+ *		  aead_request_set_crypt(req, &sg, &sg, ptbuflen, iv);
+ */
+static inline void aead_request_set_crypt(struct aead_request *req,
+					  struct scatterlist *src,
+					  struct scatterlist *dst,
+					  unsigned int cryptlen, u8 *iv)
 {
-	aead_request_set_assoc(&req->areq, assoc, assoclen);
+	req->src = src;
+	req->dst = dst;
+	req->cryptlen = cryptlen;
+	req->iv = iv;
 }
 
-static inline void aead_givcrypt_set_giv(struct aead_givcrypt_request *req,
-					 u8 *giv, u64 seq)
+/**
+ * aead_request_set_ad - set associated data information
+ * @req: request handle
+ * @assoclen: number of bytes in associated data
+ *
+ * Setting the AD information.  This function sets the length of
+ * the associated data.
+ */
+static inline void aead_request_set_ad(struct aead_request *req,
+				       unsigned int assoclen)
 {
-	req->giv = giv;
-	req->seq = seq;
+	req->assoclen = assoclen;
 }
 
 #endif	/* _CRYPTO_AEAD_H */