zcrypt_pcicc.c

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/*
 *  linux/drivers/s390/crypto/zcrypt_pcicc.c
 *
 *  zcrypt 2.1.0
 *
 *  Copyright (C)  2001, 2006 IBM Corporation
 *  Author(s): Robert Burroughs
 *	       Eric Rossman ([e-mail])
 *
 *  Hotplug & misc device support: Jochen Roehrig ([e-mail])
 *  Major cleanup & driver split: Martin Schwidefsky <[e-mail]>
 *				  Ralph Wuerthner <[e-mail]>
 *
 * 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, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

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

#include "ap_bus.h"
#include "zcrypt_api.h"
#include "zcrypt_error.h"
#include "zcrypt_pcicc.h"
#include "zcrypt_cca_key.h"

#define PCICC_MIN_MOD_SIZE	 64	/*  512 bits */
#define PCICC_MAX_MOD_SIZE_OLD	128	/* 1024 bits */
#define PCICC_MAX_MOD_SIZE	256	/* 2048 bits */

/**
 * PCICC cards need a speed rating of 0. This keeps them at the end of
 * the zcrypt device list (see zcrypt_api.c). PCICC cards are only
 * used if no other cards are present because they are slow and can only
 * cope with PKCS12 padded requests. The logic is queer. PKCS11 padded
 * requests are rejected. The modexpo function encrypts PKCS12 padded data
 * and decrypts any non-PKCS12 padded data (except PKCS11) in the assumption
 * that it's encrypted PKCS12 data. The modexpo_crt function always decrypts
 * the data in the assumption that its PKCS12 encrypted data.
 */
#define PCICC_SPEED_RATING	0

#define PCICC_MAX_MESSAGE_SIZE 0x710	/* max size type6 v1 crt message */
#define PCICC_MAX_RESPONSE_SIZE 0x710	/* max size type86 v1 reply	 */

#define PCICC_CLEANUP_TIME	(15*HZ)

static struct ap_device_id zcrypt_pcicc_ids[] = {
	{ AP_DEVICE(AP_DEVICE_TYPE_PCICC) },
	{ /* end of list */ },
};

#ifndef CONFIG_ZCRYPT_MONOLITHIC
MODULE_DEVICE_TABLE(ap, zcrypt_pcicc_ids);
MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("PCICC Cryptographic Coprocessor device driver, "
		   "Copyright 2001, 2006 IBM Corporation");
MODULE_LICENSE("GPL");
#endif

static int zcrypt_pcicc_probe(struct ap_device *ap_dev);
static void zcrypt_pcicc_remove(struct ap_device *ap_dev);
static void zcrypt_pcicc_receive(struct ap_device *, struct ap_message *,
				 struct ap_message *);

static struct ap_driver zcrypt_pcicc_driver = {
	.probe = zcrypt_pcicc_probe,
	.remove = zcrypt_pcicc_remove,
	.receive = zcrypt_pcicc_receive,
	.ids = zcrypt_pcicc_ids,
	.request_timeout = PCICC_CLEANUP_TIME,
};

/**
 * The following is used to initialize the CPRB passed to the PCICC card
 * in a type6 message. The 3 fields that must be filled in at execution
 * time are  req_parml, rpl_parml and usage_domain. Note that all three
 * fields are *little*-endian. Actually, everything about this interface
 * is ascii/little-endian, since the device has 'Intel inside'.
 *
 * The CPRB is followed immediately by the parm block.
 * The parm block contains:
 * - function code ('PD' 0x5044 or 'PK' 0x504B)
 * - rule block (0x0A00 'PKCS-1.2' or 0x0A00 'ZERO-PAD')
 * - VUD block
 */
static struct CPRB static_cprb = {
	.cprb_len	= __constant_cpu_to_le16(0x0070),
	.cprb_ver_id	=  0x41,
	.func_id	= {0x54,0x32},
	.checkpoint_flag=  0x01,
	.svr_namel	= __constant_cpu_to_le16(0x0008),
	.svr_name	= {'I','C','S','F',' ',' ',' ',' '}
};

/**
 * Check the message for PKCS11 padding.
 */
static inline int is_PKCS11_padded(unsigned char *buffer, int length)
{
	int i;
	if ((buffer[0] != 0x00) || (buffer[1] != 0x01))
		return 0;
	for (i = 2; i < length; i++)
		if (buffer[i] != 0xFF)
			break;
	if (i < 10 || i == length)
		return 0;
	if (buffer[i] != 0x00)
		return 0;
	return 1;
}

/**
 * Check the message for PKCS12 padding.
 */
static inline int is_PKCS12_padded(unsigned char *buffer, int length)
{
	int i;
	if ((buffer[0] != 0x00) || (buffer[1] != 0x02))
		return 0;
	for (i = 2; i < length; i++)
		if (buffer[i] == 0x00)
			break;
	if ((i < 10) || (i == length))
		return 0;
	if (buffer[i] != 0x00)
		return 0;
	return 1;
}

/**
 * Convert a ICAMEX message to a type6 MEX message.
 *
 * @zdev: crypto device pointer
 * @zreq: crypto request pointer
 * @mex: pointer to user input data
 *
 * Returns 0 on success or -EFAULT.
 */
static int ICAMEX_msg_to_type6MEX_msg(struct zcrypt_device *zdev,
				      struct ap_message *ap_msg,
				      struct ica_rsa_modexpo *mex)
{
	static struct type6_hdr static_type6_hdr = {
		.type		=  0x06,
		.offset1	=  0x00000058,
		.agent_id	= {0x01,0x00,0x43,0x43,0x41,0x2D,0x41,0x50,
				   0x50,0x4C,0x20,0x20,0x20,0x01,0x01,0x01},
		.function_code	= {'P','K'},
	};
	static struct function_and_rules_block static_pke_function_and_rules ={
		.function_code	= {'P','K'},
		.ulen		= __constant_cpu_to_le16(10),
		.only_rule	= {'P','K','C','S','-','1','.','2'}
	};
	struct {
		struct type6_hdr hdr;
		struct CPRB cprb;
		struct function_and_rules_block fr;
		unsigned short length;
		char text[0];
	} __attribute__((packed)) *msg = ap_msg->message;
	int vud_len, pad_len, size;

	/* VUD.ciphertext */
	if (copy_from_user(msg->text, mex->inputdata, mex->inputdatalength))
		return -EFAULT;

	if (is_PKCS11_padded(msg->text, mex->inputdatalength))
		return -EINVAL;

	/* static message header and f&r */
	msg->hdr = static_type6_hdr;
	msg->fr = static_pke_function_and_rules;

	if (is_PKCS12_padded(msg->text, mex->inputdatalength)) {
		/* strip the padding and adjust the data length */
		pad_len = strnlen(msg->text + 2, mex->inputdatalength - 2) + 3;
		if (pad_len <= 9 || pad_len >= mex->inputdatalength)
			return -ENODEV;
		vud_len = mex->inputdatalength - pad_len;
		memmove(msg->text, msg->text + pad_len, vud_len);
		msg->length = cpu_to_le16(vud_len + 2);

		/* Set up key after the variable length text. */
		size = zcrypt_type6_mex_key_en(mex, msg->text + vud_len, 0);
		if (size < 0)
			return size;
		size += sizeof(*msg) + vud_len;	/* total size of msg */
	} else {
		vud_len = mex->inputdatalength;
		msg->length = cpu_to_le16(2 + vud_len);

		msg->hdr.function_code[1] = 'D';
		msg->fr.function_code[1] = 'D';

		/* Set up key after the variable length text. */
		size = zcrypt_type6_mex_key_de(mex, msg->text + vud_len, 0);
		if (size < 0)
			return size;
		size += sizeof(*msg) + vud_len;	/* total size of msg */
	}

	/* message header, cprb and f&r */
	msg->hdr.ToCardLen1 = (size - sizeof(msg->hdr) + 3) & -4;
	msg->hdr.FromCardLen1 = PCICC_MAX_RESPONSE_SIZE - sizeof(msg->hdr);

	msg->cprb = static_cprb;
	msg->cprb.usage_domain[0]= AP_QID_QUEUE(zdev->ap_dev->qid);
	msg->cprb.req_parml = cpu_to_le16(size - sizeof(msg->hdr) -
					   sizeof(msg->cprb));
	msg->cprb.rpl_parml = cpu_to_le16(msg->hdr.FromCardLen1);

	ap_msg->length = (size + 3) & -4;
	return 0;
}

/**
 * Convert a ICACRT message to a type6 CRT message.
 *
 * @zdev: crypto device pointer
 * @zreq: crypto request pointer
 * @crt: pointer to user input data
 *
 * Returns 0 on success or -EFAULT.
 */
static int ICACRT_msg_to_type6CRT_msg(struct zcrypt_device *zdev,
				      struct ap_message *ap_msg,
				      struct ica_rsa_modexpo_crt *crt)
{
	static struct type6_hdr static_type6_hdr = {
		.type		=  0x06,
		.offset1	=  0x00000058,
		.agent_id	= {0x01,0x00,0x43,0x43,0x41,0x2D,0x41,0x50,
				   0x50,0x4C,0x20,0x20,0x20,0x01,0x01,0x01},
		.function_code	= {'P','D'},
	};
	static struct function_and_rules_block static_pkd_function_and_rules ={
		.function_code	= {'P','D'},
		.ulen		= __constant_cpu_to_le16(10),
		.only_rule	= {'P','K','C','S','-','1','.','2'}
	};
	struct {
		struct type6_hdr hdr;
		struct CPRB cprb;
		struct function_and_rules_block fr;
		unsigned short length;
		char text[0];
	} __attribute__((packed)) *msg = ap_msg->message;
	int size;

	/* VUD.ciphertext */
	msg->length = cpu_to_le16(2 + crt->inputdatalength);
	if (copy_from_user(msg->text, crt->inputdata, crt->inputdatalength))
		return -EFAULT;

	if (is_PKCS11_padded(msg->text, crt->inputdatalength))
		return -EINVAL;

	/* Set up key after the variable length text. */
	size = zcrypt_type6_crt_key(crt, msg->text + crt->inputdatalength, 0);
	if (size < 0)
		return size;
	size += sizeof(*msg) + crt->inputdatalength;	/* total size of msg */

	/* message header, cprb and f&r */
	msg->hdr = static_type6_hdr;
	msg->hdr.ToCardLen1 = (size -  sizeof(msg->hdr) + 3) & -4;
	msg->hdr.FromCardLen1 = PCICC_MAX_RESPONSE_SIZE - sizeof(msg->hdr);

	msg->cprb = static_cprb;
	msg->cprb.usage_domain[0] = AP_QID_QUEUE(zdev->ap_dev->qid);
	msg->cprb.req_parml = msg->cprb.rpl_parml =
		cpu_to_le16(size - sizeof(msg->hdr) - sizeof(msg->cprb));

	msg->fr = static_pkd_function_and_rules;

	ap_msg->length = (size + 3) & -4;
	return 0;
}

/**
 * Copy results from a type 86 reply message back to user space.
 *
 * @zdev: crypto device pointer
 * @reply: reply AP message.
 * @data: pointer to user output data
 * @length: size of user output data
 *
 * Returns 0 on success or -EINVAL, -EFAULT, -EAGAIN in case of an error.
 */
struct type86_reply {
	struct type86_hdr hdr;
	struct type86_fmt2_ext fmt2;
	struct CPRB cprb;
	unsigned char pad[4];	/* 4 byte function code/rules block ? */