path: root/drivers/crypto/caam/caamalg.c

/*
 * caam - Freescale FSL CAAM support for crypto API
 *
 * Copyright 2008-2011 Freescale Semiconductor, Inc.
 *
 * Based on talitos crypto API driver.
 *
 * relationship of job descriptors to shared descriptors (SteveC Dec 10 2008):
 *
 * ---------------                     ---------------
 * | JobDesc #1  |-------------------->|  ShareDesc  |
 * | *(packet 1) |                     |   (PDB)     |
 * ---------------      |------------->|  (hashKey)  |
 *       .              |              | (cipherKey) |
 *       .              |    |-------->| (operation) |
 * ---------------      |    |         ---------------
 * | JobDesc #2  |------|    |
 * | *(packet 2) |           |
 * ---------------           |
 *       .                   |
 *       .                   |
 * ---------------           |
 * | JobDesc #3  |------------
 * | *(packet 3) |
 * ---------------
 *
 * The SharedDesc never changes for a connection unless rekeyed, but
 * each packet will likely be in a different place. So all we need
 * to know to process the packet is where the input is, where the
 * output goes, and what context we want to process with. Context is
 * in the SharedDesc, packet references in the JobDesc.
 *
 * So, a job desc looks like:
 *
 * ---------------------
 * | Header            |
 * | ShareDesc Pointer |
 * | SEQ_OUT_PTR       |
 * | (output buffer)   |
 * | SEQ_IN_PTR        |
 * | (input buffer)    |
 * | LOAD (to DECO)    |
 * ---------------------
 */

#include "compat.h"

#include "regs.h"
#include "intern.h"
#include "desc_constr.h"
#include "jr.h"
#include "error.h"

/*
 * crypto alg
 */
#define CAAM_CRA_PRIORITY		3000
/* max key is sum of AES_MAX_KEY_SIZE, max split key size */
#define CAAM_MAX_KEY_SIZE		(AES_MAX_KEY_SIZE + \
					 SHA512_DIGEST_SIZE * 2)
/* max IV is max of AES_BLOCK_SIZE, DES3_EDE_BLOCK_SIZE */
#define CAAM_MAX_IV_LENGTH		16

/* length of descriptors text */
#define DESC_AEAD_SHARED_TEXT_LEN	4
#define DESC_AEAD_ENCRYPT_TEXT_LEN 	21
#define DESC_AEAD_DECRYPT_TEXT_LEN 	24
#define DESC_AEAD_GIVENCRYPT_TEXT_LEN 	27

#ifdef DEBUG
/* for print_hex_dumps with line references */
#define xstr(s) str(s)
#define str(s) #s
#define debug(format, arg...) printk(format, arg)
#else
#define debug(format, arg...)
#endif

/*
 * per-session context
 */
struct caam_ctx {
	struct device *jrdev;
	u32 *sh_desc;
	dma_addr_t shared_desc_phys;
	u32 class1_alg_type;
	u32 class2_alg_type;
	u32 alg_op;
	u8 *key;
	dma_addr_t key_dma;
	unsigned int enckeylen;
	unsigned int split_key_len;
	unsigned int split_key_pad_len;
	unsigned int authsize;
};

static int aead_setauthsize(struct crypto_aead *authenc,
				    unsigned int authsize)
{
	struct caam_ctx *ctx = crypto_aead_ctx(authenc);

	ctx->authsize = authsize;

	return 0;
}

struct split_key_result {
	struct completion completion;
	int err;
};

static void split_key_done(struct device *dev, u32 *desc, u32 err,
			   void *context)
{
	struct split_key_result *res = context;

#ifdef DEBUG
	dev_err(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
#endif
	if (err) {
		char tmp[CAAM_ERROR_STR_MAX];

		dev_err(dev, "%08x: %s\n", err, caam_jr_strstatus(tmp, err));
	}

	res->err = err;

	complete(&res->completion);
}

/*
get a split ipad/opad key

Split key generation-----------------------------------------------

[00] 0xb0810008    jobdesc: stidx=1 share=never len=8
[01] 0x04000014        key: class2->keyreg len=20
			@0xffe01000
[03] 0x84410014  operation: cls2-op sha1 hmac init dec
[04] 0x24940000     fifold: class2 msgdata-last2 len=0 imm
[05] 0xa4000001       jump: class2 local all ->1 [06]
[06] 0x64260028    fifostr: class2 mdsplit-jdk len=40
			@0xffe04000
*/<