zcrypt_pcica.c

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/*
 *  zcrypt 2.1.0
 *
 *  Copyright IBM Corp. 2001, 2006
 *  Author(s): Robert Burroughs
 *         Eric Rossman ([email protected])
 *
 *  Hotplug & misc device support: Jochen Roehrig ([email protected])
 *  Major cleanup & driver split: Martin Schwidefsky <[email protected]>
 *                Ralph Wuerthner <[email protected]>
 *
 * 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/slab.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/atomic.h>
#include <asm/uaccess.h>

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

#define PCICA_MIN_MOD_SIZE    1 /*    8 bits    */
#define PCICA_MAX_MOD_SIZE  256 /* 2048 bits    */

#define PCICA_SPEED_RATING  2800

#define PCICA_MAX_MESSAGE_SIZE  0x3a0   /* sizeof(struct type4_lcr)      */
#define PCICA_MAX_RESPONSE_SIZE 0x110   /* max outputdatalength + type80_hdr */

#define PCICA_CLEANUP_TIME  (15*HZ)

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

MODULE_DEVICE_TABLE(ap, zcrypt_pcica_ids);
MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("PCICA Cryptographic Coprocessor device driver, "
           "Copyright IBM Corp. 2001, 2006");
MODULE_LICENSE("GPL");

static int zcrypt_pcica_probe(struct ap_device *ap_dev);
static void zcrypt_pcica_remove(struct ap_device *ap_dev);
static void zcrypt_pcica_receive(struct ap_device *, struct ap_message *,
                 struct ap_message *);

static struct ap_driver zcrypt_pcica_driver = {
    .probe = zcrypt_pcica_probe,
    .remove = zcrypt_pcica_remove,
    .ids = zcrypt_pcica_ids,
    .request_timeout = PCICA_CLEANUP_TIME,
};

static int ICAMEX_msg_to_type4MEX_msg(struct zcrypt_device *zdev,
                      struct ap_message *ap_msg,
                      struct ica_rsa_modexpo *mex)
{
    unsigned char *modulus, *exponent, *message;
    int mod_len;

    mod_len = mex->inputdatalength;

    if (mod_len <= 128) {
        struct type4_sme *sme = ap_msg->message;
        memset(sme, 0, sizeof(*sme));
        ap_msg->length = sizeof(*sme);
        sme->header.msg_fmt = TYPE4_SME_FMT;
        sme->header.msg_len = sizeof(*sme);
        sme->header.msg_type_code = TYPE4_TYPE_CODE;
        sme->header.request_code = TYPE4_REQU_CODE;
        modulus = sme->modulus + sizeof(sme->modulus) - mod_len;
        exponent = sme->exponent + sizeof(sme->exponent) - mod_len;
        message = sme->message + sizeof(sme->message) - mod_len;
    } else {
        struct type4_lme *lme = ap_msg->message;
        memset(lme, 0, sizeof(*lme));
        ap_msg->length = sizeof(*lme);
        lme->header.msg_fmt = TYPE4_LME_FMT;
        lme->header.msg_len = sizeof(*lme);
        lme->header.msg_type_code = TYPE4_TYPE_CODE;
        lme->header.request_code = TYPE4_REQU_CODE;
        modulus = lme->modulus + sizeof(lme->modulus) - mod_len;
        exponent = lme->exponent + sizeof(lme->exponent) - mod_len;
        message = lme->message + sizeof(lme->message) - mod_len;
    }

    if (copy_from_user(modulus, mex->n_modulus, mod_len) ||
        copy_from_user(exponent, mex->b_key, mod_len) ||
        copy_from_user(message, mex->inputdata, mod_len))
        return -EFAULT;
    return 0;
}

static int ICACRT_msg_to_type4CRT_msg(struct zcrypt_device *zdev,
                      struct ap_message *ap_msg,
                      struct ica_rsa_modexpo_crt *crt)
{
    unsigned char *p, *q, *dp, *dq, *u, *inp;
    int mod_len, short_len, long_len;

    mod_len = crt->inputdatalength;
    short_len = mod_len / 2;
    long_len = mod_len / 2 + 8;

    if (mod_len <= 128) {
        struct type4_scr *scr = ap_msg->message;
        memset(scr, 0, sizeof(*scr));
        ap_msg->length = sizeof(*scr);
        scr->header.msg_type_code = TYPE4_TYPE_CODE;
        scr->header.request_code = TYPE4_REQU_CODE;
        scr->header.msg_fmt = TYPE4_SCR_FMT;
        scr->header.msg_len = sizeof(*scr);
        p = scr->p + sizeof(scr->p) - long_len;
        q = scr->q + sizeof(scr->q) - short_len;
        dp = scr->dp + sizeof(scr->dp) - long_len;
        dq = scr->dq + sizeof(scr->dq) - short_len;
        u = scr->u + sizeof(scr->u) - long_len;
        inp = scr->message + sizeof(scr->message) - mod_len;
    } else {
        struct type4_lcr *lcr = ap_msg->message;
        memset(lcr, 0, sizeof(*lcr));
        ap_msg->length = sizeof(*lcr);
        lcr->header.msg_type_code = TYPE4_TYPE_CODE;
        lcr->header.request_code = TYPE4_REQU_CODE;
        lcr->header.msg_fmt = TYPE4_LCR_FMT;
        lcr->header.msg_len = sizeof(*lcr);
        p = lcr->p + sizeof(lcr->p) - long_len;
        q = lcr->q + sizeof(lcr->q) - short_len;
        dp = lcr->dp + sizeof(lcr->dp) - long_len;
        dq = lcr->dq + sizeof(lcr->dq) - short_len;
        u = lcr->u + sizeof(lcr->u) - long_len;
        inp = lcr->message + sizeof(lcr->message) - mod_len;
    }

    if (copy_from_user(p, crt->np_prime, long_len) ||
        copy_from_user(q, crt->nq_prime, short_len) ||
        copy_from_user(dp, crt->bp_key, long_len) ||
        copy_from_user(dq, crt->bq_key, short_len) ||
        copy_from_user(u, crt->u_mult_inv, long_len) ||
        copy_from_user(inp, crt->inputdata, mod_len))
        return -EFAULT;
    return 0;
}

static int convert_type84(struct zcrypt_device *zdev,
              struct ap_message *reply,
              char __user *outputdata,
              unsigned int outputdatalength)
{
    struct type84_hdr *t84h = reply->message;
    char *data;

    if (t84h->len < sizeof(*t84h) + outputdatalength) {
        /* The result is too short, the PCICA card may not do that.. */
        zdev->online = 0;
        return -EAGAIN; /* repeat the request on a different device. */
    }
    BUG_ON(t84h->len > PCICA_MAX_RESPONSE_SIZE);
    data = reply->message + t84h->len - outputdatalength;
    if (copy_to_user(outputdata, data, outputdatalength))
        return -EFAULT;
    return 0;
}

static int convert_response(struct zcrypt_device *zdev,
                struct ap_message *reply,
                char __user *outputdata,
                unsigned int outputdatalength)
{
    /* Response type byte is the second byte in the response. */
    switch (((unsigned char *) reply->message)[1]) {
    case TYPE82_RSP_CODE:
    case TYPE88_RSP_CODE:
        return convert_error(zdev, reply);
    case TYPE84_RSP_CODE:
        return convert_type84(zdev, reply,
                      outputdata, outputdatalength);
    default: /* Unknown response type, this should NEVER EVER happen */
        zdev->online = 0;
        return -EAGAIN; /* repeat the request on a different device. */
    }
}

static void zcrypt_pcica_receive(struct ap_device *ap_dev,
                 struct ap_message *msg,
                 struct ap_message *reply)
{
    static struct error_hdr error_reply = {
        .type = TYPE82_RSP_CODE,
        .reply_code = REP82_ERROR_MACHINE_FAILURE,
    };
    struct type84_hdr *t84h;
    int length;

    /* Copy the reply message to the request message buffer. */
    if (IS_ERR(reply)) {
        memcpy(msg->message, &error_reply, sizeof(error_reply));
        goto out;
    }
    t84h = reply->message;
    if (t84h->code == TYPE84_RSP_CODE) {
        length = min(PCICA_MAX_RESPONSE_SIZE, (int) t84h->len);
        memcpy(msg->message, reply->message, length);
    } else
        memcpy(msg->message, reply->message, sizeof error_reply);
out:
    complete((struct completion *) msg->private);
}

static atomic_t zcrypt_step = ATOMIC_INIT(0);

static long zcrypt_pcica_modexpo(struct zcrypt_device *zdev,
                 struct ica_rsa_modexpo *mex)
{
    struct ap_message ap_msg;
    struct completion work;
    int rc;

    ap_init_message(&ap_msg);
    ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
    if (!ap_msg.message)
        return -ENOMEM;
    ap_msg.receive = zcrypt_pcica_receive;
    ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
                atomic_inc_return(&zcrypt_step);
    ap_msg.private = &work;
    rc = ICAMEX_msg_to_type4MEX_msg(zdev, &ap_msg, mex);
    if (rc)
        goto out_free;
    init_completion(&work);
    ap_queue_message(zdev->ap_dev, &ap_msg);
    rc = wait_for_completion_interruptible(&work);
    if (rc == 0)
        rc = convert_response(zdev, &ap_msg, mex->outputdata,
                      mex->outputdatalength);
    else
        /* Signal pending. */
        ap_cancel_message(zdev->ap_dev, &ap_msg);
out_free:
    kfree(ap_msg.message);
    return rc;
}

static long zcrypt_pcica_modexpo_crt(struct zcrypt_device *zdev,
                     struct ica_rsa_modexpo_crt *crt)
{
    struct ap_message ap_msg;
    struct completion work;
    int rc;

    ap_init_message(&ap_msg);
    ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
    if (!ap_msg.message)
        return -ENOMEM;
    ap_msg.receive = zcrypt_pcica_receive;
    ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
                atomic_inc_return(&zcrypt_step);
    ap_msg.private = &work;
    rc = ICACRT_msg_to_type4CRT_msg(zdev, &ap_msg, crt);
    if (rc)
        goto out_free;
    init_completion(&work);
    ap_queue_message(zdev->ap_dev, &ap_msg);
    rc = wait_for_completion_interruptible(&work);
    if (rc == 0)
        rc = convert_response(zdev, &ap_msg, crt->outputdata,
                      crt->outputdatalength);
    else
        /* Signal pending. */
        ap_cancel_message(zdev->ap_dev, &ap_msg);
out_free:
    kfree(ap_msg.message);
    return rc;
}

static struct zcrypt_ops zcrypt_pcica_ops = {
    .rsa_modexpo = zcrypt_pcica_modexpo,
    .rsa_modexpo_crt = zcrypt_pcica_modexpo_crt,
};

static int zcrypt_pcica_probe(struct ap_device *ap_dev)
{
    struct zcrypt_device *zdev;
    int rc;

    zdev = zcrypt_device_alloc(PCICA_MAX_RESPONSE_SIZE);
    if (!zdev)
        return -ENOMEM;
    zdev->ap_dev = ap_dev;
    zdev->ops = &zcrypt_pcica_ops;
    zdev->online = 1;
    zdev->user_space_type = ZCRYPT_PCICA;
    zdev->type_string = "PCICA";
    zdev->min_mod_size = PCICA_MIN_MOD_SIZE;
    zdev->max_mod_size = PCICA_MAX_MOD_SIZE;
    zdev->speed_rating = PCICA_SPEED_RATING;
    zdev->max_exp_bit_length = PCICA_MAX_MOD_SIZE;
    ap_dev->reply = &zdev->reply;
    ap_dev->private = zdev;
    rc = zcrypt_device_register(zdev);
    if (rc)
        goto out_free;
    return 0;

out_free:
    ap_dev->private = NULL;
    zcrypt_device_free(zdev);
    return rc;
}

static void zcrypt_pcica_remove(struct ap_device *ap_dev)
{
    struct zcrypt_device *zdev = ap_dev->private;

    zcrypt_device_unregister(zdev);
}

int __init zcrypt_pcica_init(void)
{
    return ap_driver_register(&zcrypt_pcica_driver, THIS_MODULE, "pcica");
}

void zcrypt_pcica_exit(void)
{
    ap_driver_unregister(&zcrypt_pcica_driver);
}

module_init(zcrypt_pcica_init);
module_exit(zcrypt_pcica_exit);