path: root/drivers/s390/crypto/zcrypt_msgtype50.c

// SPDX-License-Identifier: GPL-2.0+
/*
 *  Copyright IBM Corp. 2001, 2012
 *  Author(s): Robert Burroughs
 *	       Eric Rossman (edrossma@us.ibm.com)
 *
 *  Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
 *  Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
 *				  Ralph Wuerthner <rwuerthn@de.ibm.com>
 *  MSGTYPE restruct:		  Holger Dengler <hd@linux.vnet.ibm.com>
 */

#define KMSG_COMPONENT "zcrypt"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/atomic.h>
#include <linux/uaccess.h>

#include "ap_bus.h"
#include "zcrypt_api.h"
#include "zcrypt_error.h"
#include "zcrypt_msgtype50.h"

/* >= CEX3A: 4096 bits */
#define CEX3A_MAX_MOD_SIZE 512

/* CEX2A: max outputdatalength + type80_hdr */
#define CEX2A_MAX_RESPONSE_SIZE 0x110

/* >= CEX3A: 512 bit modulus, (max outputdatalength) + type80_hdr */
#define CEX3A_MAX_RESPONSE_SIZE 0x210

MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("Cryptographic Accelerator (message type 50), " \
		   "Copyright IBM Corp. 2001, 2012");
MODULE_LICENSE("GPL");

/**
 * The type 50 message family is associated with a CEXxA cards.
 *
 * The four members of the family are described below.
 *
 * Note that all unsigned char arrays are right-justified and left-padded
 * with zeroes.
 *
 * Note that all reserved fields must be zeroes.
 */
struct type50_hdr {
	unsigned char	reserved1;
	unsigned char	msg_type_code;	/* 0x50 */
	unsigned short	msg_len;
	unsigned char	reserved2;
	unsigned char	ignored;
	unsigned short	reserved3;
} __packed;

#define TYPE50_TYPE_CODE	0x50

#define TYPE50_MEB1_FMT		0x0001
#define TYPE50_MEB2_FMT		0x0002
#define TYPE50_MEB3_FMT		0x0003
#define TYPE50_CRB1_FMT		0x0011
#define TYPE50_CRB2_FMT		0x0012
#define TYPE50_CRB3_FMT		0x0013

/* Mod-Exp, with a small modulus */
struct type50_meb1_msg {
	struct type50_hdr header;
	unsigned short	keyblock_type;	/* 0x0001 */
	unsigned char	reserved[6];
	unsigned char	exponent[128];
	unsigned char	modulus[128];
	unsigned char	message[128];
} __packed;

/* Mod-Exp, with a large modulus */
struct type50_meb2_msg {
	struct type50_hdr header;
	unsigned short	keyblock_type;	/* 0x0002 */
	unsigned char	reserved[6];
	unsigned char	exponent[256];
	unsigned char	modulus[256];
	unsigned char	message[256];
} __packed;

/* Mod-Exp, with a larger modulus */
struct type50_meb3_msg {
	struct type50_hdr header;
	unsigned short	keyblock_type;	/* 0x0003 */
	unsigned char	reserved[6];
	unsigned char	exponent[512];
	unsigned char	modulus[512];
	unsigned char	message[512];
} __packed;

/* CRT, with a small modulus */
struct type50_crb1_msg {
	struct type50_hdr header;
	unsigned short	keyblock_type;	/* 0x0011 */
	unsigned char	reserved[6];
	unsigned char	p[64];
	unsigned char	q[64];
	unsigned char	dp[64];
	unsigned char	dq[64];
	unsigned char	u[64];
	unsigned char	message[128];
} __packed;

/* CRT, with a large modulus */
struct type50_crb2_msg {
	struct type50_hdr header;
	unsigned short	keyblock_type;	/* 0x0012 */
	unsigned char	reserved[6];
	unsigned char	p[128];
	unsigned char	q[128];
	unsigned char	dp[128];
	unsigned char	dq[128];
	unsigned char	u[128];
	unsigned char	message[256];
} __packed;

/* CRT, with a larger modulus */
struct type50_crb3_msg {
	struct type50_hdr header;
	unsigned short	keyblock_type;	/* 0x0013 */
	unsigned char	reserved[6];
	unsigned char	p[256];
	unsigned char	q[256];
	unsigned char	dp[256];
	unsigned char	dq[256];
	unsigned char	u[256];
	unsigned char	message[512];
} __packed;

/**
 * The type 80 response family is associated with a CEXxA cards.
 *
 * Note that all unsigned char arrays are right-justified and left-padded
 * with zeroes.
 *
 * Note that all reserved fields must be zeroes.
 */

#define TYPE80_RSP_CODE 0x80

struct type80_hdr {
	unsigned char	reserved1;
	unsigned char	type;		/* 0x80 */
	unsigned short	len;
	unsigned char	code;		/* 0x00 */
	unsigned char	reserved2[3];
	unsigned char	reserved3[8];
} __packed;

unsigned int get_rsa_modex_fc(struct ica_rsa_modexpo *mex, int *fcode)
{

	if (!mex->inputdatalength)
		return -EINVAL;

	if (mex->inputdatalength <= 128)	/* 1024 bit */
		*fcode = MEX_1K;
	else if (mex->inputdatalength <= 256)	/* 2048 bit */
		*fcode = MEX_2K;
	else					/* 4096 bit */
		*fcode = MEX_4K;

	return 0;
}

unsigned int get_rsa_crt_fc(struct ica_rsa_modexpo_crt *crt, int *fcode)
{

	if (!crt->inputdatalength)
		return -EINVAL;

	if (crt->inputdatalength <= 128)	/* 1024 bit */
		*fcode = CRT_1K;
	else if (crt->inputdatalength <= 256)	/* 2048 bit */
		*fcode = CRT_2K;
	else					/* 4096 bit */
		*fcode = CRT_4K;

	return 0;
}

/**
 * Convert a ICAMEX message to a type50 MEX message.
 *
 * @zq: crypto queue pointer
 * @ap_msg: crypto request pointer
 * @mex: pointer to user input data
 *
 * Returns 0 on success or -EFAULT.
 */
static int ICAMEX_msg_to_type50MEX_msg(struct zcrypt_queue *zq,
				       struct ap_message *ap_msg,
				       struct ica_rsa_modexpo *mex)
{
	unsigned char *mod, *exp, *inp;
	int mod_len;

	mod_len = mex->inputdatalength;

	if (mod_len <= 128) {
		struct type50_meb1_msg *meb1 = ap_msg->msg;

		memset(meb1, 0, sizeof(*meb1));
		ap_msg->len = sizeof(*meb1);
		meb1->header.msg_type_code = TYPE50_TYPE_CODE;
		meb1->header.msg_len = sizeof(*meb1);
		meb1->keyblock_type = TYPE50_MEB1_FMT;
		mod = meb1->modulus + sizeof(meb1->modulus) - mod_len;
		exp = meb1->exponent + sizeof(meb1->exponent) - mod_len;
		inp = meb1->message + sizeof(meb1->message) - mod_len;
	} else if (mod_len <= 256) {
		struct type50_meb2_msg *meb2 = ap_msg->msg;

		memset(meb2, 0, sizeof(*meb2));
		ap_msg->len = sizeof(*meb2);
		meb2->header.msg_type_code = TYPE50_TYPE_CODE;
		meb2->header.msg_len = sizeof(*meb2);
		meb2->keyblock_type = TYPE50_MEB2_FMT;
		mod = meb2->modulus + sizeof(meb2->modulus) - mod_len;
		exp = meb2->exponent + sizeof(meb2->exponent) - mod_len;
		inp = meb2->message + sizeof(meb2->message) - mod_len;
	} else if (mod_len <= 512) {
		struct type50_meb3_msg *meb3 = ap_msg->msg;

		memset(meb3, 0, sizeof(*meb3));
		ap_msg->len = sizeof(*meb3);
		meb3->header.msg_type_code = TYPE50_TYPE_CODE;
		meb3->header.msg_len = sizeof(*meb3);
		meb3->keyblock_type = TYPE50_MEB3_FMT;
		mod = meb3->modulus + sizeof(meb3->modulus) - mod_len;
		exp<