zcrypt_pcicc.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/init.h>
#include <linux/gfp.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_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 */ },
};

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

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,
    .ids = zcrypt_pcicc_ids,
    .request_timeout = PCICC_CLEANUP_TIME,
};

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',' ',' ',' ',' '}
};

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;
}

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;
}

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;
}

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;
}

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 ? */
    unsigned short length;
    char text[0];
} __attribute__((packed));

static int convert_type86(struct zcrypt_device *zdev,
              struct ap_message *reply,
              char __user *outputdata,
              unsigned int outputdatalength)
{
    static unsigned char static_pad[] = {
        0x00,0x02,
        0x1B,0x7B,0x5D,0xB5,0x75,0x01,0x3D,0xFD,
        0x8D,0xD1,0xC7,0x03,0x2D,0x09,0x23,0x57,
        0x89,0x49,0xB9,0x3F,0xBB,0x99,0x41,0x5B,
        0x75,0x21,0x7B,0x9D,0x3B,0x6B,0x51,0x39,
        0xBB,0x0D,0x35,0xB9,0x89,0x0F,0x93,0xA5,
        0x0B,0x47,0xF1,0xD3,0xBB,0xCB,0xF1,0x9D,
        0x23,0x73,0x71,0xFF,0xF3,0xF5,0x45,0xFB,
        0x61,0x29,0x23,0xFD,0xF1,0x29,0x3F,0x7F,
        0x17,0xB7,0x1B,0xA9,0x19,0xBD,0x57,0xA9,
        0xD7,0x95,0xA3,0xCB,0xED,0x1D,0xDB,0x45,
        0x7D,0x11,0xD1,0x51,0x1B,0xED,0x71,0xE9,
        0xB1,0xD1,0xAB,0xAB,0x21,0x2B,0x1B,0x9F,
        0x3B,0x9F,0xF7,0xF7,0xBD,0x63,0xEB,0xAD,
        0xDF,0xB3,0x6F,0x5B,0xDB,0x8D,0xA9,0x5D,
        0xE3,0x7D,0x77,0x49,0x47,0xF5,0xA7,0xFD,
        0xAB,0x2F,0x27,0x35,0x77,0xD3,0x49,0xC9,
        0x09,0xEB,0xB1,0xF9,0xBF,0x4B,0xCB,0x2B,
        0xEB,0xEB,0x05,0xFF,0x7D,0xC7,0x91,0x8B,
        0x09,0x83,0xB9,0xB9,0x69,0x33,0x39,0x6B,
        0x79,0x75,0x19,0xBF,0xBB,0x07,0x1D,0xBD,
        0x29,0xBF,0x39,0x95,0x93,0x1D,0x35,0xC7,
        0xC9,0x4D,0xE5,0x97,0x0B,0x43,0x9B,0xF1,
        0x16,0x93,0x03,0x1F,0xA5,0xFB,0xDB,0xF3,
        0x27,0x4F,0x27,0x61,0x05,0x1F,0xB9,0x23,
        0x2F,0xC3,0x81,0xA9,0x23,0x71,0x55,0x55,
        0xEB,0xED,0x41,0xE5,0xF3,0x11,0xF1,0x43,
        0x69,0x03,0xBD,0x0B,0x37,0x0F,0x51,0x8F,
        0x0B,0xB5,0x89,0x5B,0x67,0xA9,0xD9,0x4F,
        0x01,0xF9,0x21,0x77,0x37,0x73,0x79,0xC5,
        0x7F,0x51,0xC1,0xCF,0x97,0xA1,0x75,0xAD,
        0x35,0x9D,0xD3,0xD3,0xA7,0x9D,0x5D,0x41,
        0x6F,0x65,0x1B,0xCF,0xA9,0x87,0x91,0x09
    };
    struct type86_reply *msg = reply->message;
    unsigned short service_rc, service_rs;
    unsigned int reply_len, pad_len;
    char *data;

    service_rc = le16_to_cpu(msg->cprb.ccp_rtcode);
    if (unlikely(service_rc != 0)) {
        service_rs = le16_to_cpu(msg->cprb.ccp_rscode);
        if (service_rc == 8 && service_rs == 66)
            return -EINVAL;
        if (service_rc == 8 && service_rs == 65)
            return -EINVAL;
        if (service_rc == 8 && service_rs == 770) {
            zdev->max_mod_size = PCICC_MAX_MOD_SIZE_OLD;
            return -EAGAIN;
        }
        if (service_rc == 8 && service_rs == 783) {
            zdev->max_mod_size = PCICC_MAX_MOD_SIZE_OLD;
            return -EAGAIN;
        }
        if (service_rc == 8 && service_rs == 72)
            return -EINVAL;
        zdev->online = 0;
        return -EAGAIN; /* repeat the request on a different device. */
    }
    data = msg->text;
    reply_len = le16_to_cpu(msg->length) - 2;
    if (reply_len > outputdatalength)
        return -EINVAL;
    /*
     * For all encipher requests, the length of the ciphertext (reply_len)
     * will always equal the modulus length. For MEX decipher requests
     * the output needs to get padded. Minimum pad size is 10.
     *
     * Currently, the cases where padding will be added is for:
     * - PCIXCC_MCL2 using a CRT form token (since PKD didn't support
     *   ZERO-PAD and CRT is only supported for PKD requests)
     * - PCICC, always
     */
    pad_len = outputdatalength - reply_len;
    if (pad_len > 0) {
        if (pad_len < 10)
            return -EINVAL;
        /* 'restore' padding left in the PCICC/PCIXCC card. */
        if (copy_to_user(outputdata, static_pad, pad_len - 1))
            return -EFAULT;
        if (put_user(0, outputdata + pad_len - 1))
            return -EFAULT;
    }
    /* Copy the crypto response to user space. */
    if (copy_to_user(outputdata + pad_len, data, reply_len))
        return -EFAULT;
    return 0;
}

static int convert_response(struct zcrypt_device *zdev,
                struct ap_message *reply,
                char __user *outputdata,
                unsigned int outputdatalength)
{
    struct type86_reply *msg = reply->message;

    /* Response type byte is the second byte in the response. */
    switch (msg->hdr.type) {
    case TYPE82_RSP_CODE:
    case TYPE88_RSP_CODE:
        return convert_error(zdev, reply);
    case TYPE86_RSP_CODE:
        if (msg->hdr.reply_code)
            return convert_error(zdev, reply);
        if (msg->cprb.cprb_ver_id == 0x01)
            return convert_type86(zdev, reply,
                          outputdata, outputdatalength);
        /* no break, incorrect cprb version is an unknown response */
    default: /* Unknown response type, this should NEVER EVER happen */
        zdev->online = 0;
        return -EAGAIN; /* repeat the request on a different device. */
    }
}

static void zcrypt_pcicc_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 type86_reply *t86r;
    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;
    }
    t86r = reply->message;
    if (t86r->hdr.type == TYPE86_RSP_CODE &&
         t86r->cprb.cprb_ver_id == 0x01) {
        length = sizeof(struct type86_reply) + t86r->length - 2;
        length = min(PCICC_MAX_RESPONSE_SIZE, length);
        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_pcicc_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 = (void *) get_zeroed_page(GFP_KERNEL);
    if (!ap_msg.message)
        return -ENOMEM;
    ap_msg.receive = zcrypt_pcicc_receive;
    ap_msg.length = PAGE_SIZE;
    ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
                atomic_inc_return(&zcrypt_step);
    ap_msg.private = &work;
    rc = ICAMEX_msg_to_type6MEX_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:
    free_page((unsigned long) ap_msg.message);
    return rc;
}

static long zcrypt_pcicc_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 = (void *) get_zeroed_page(GFP_KERNEL);
    if (!ap_msg.message)
        return -ENOMEM;
    ap_msg.receive = zcrypt_pcicc_receive;
    ap_msg.length = PAGE_SIZE;
    ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
                atomic_inc_return(&zcrypt_step);
    ap_msg.private = &work;
    rc = ICACRT_msg_to_type6CRT_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:
    free_page((unsigned long) ap_msg.message);
    return rc;
}

static struct zcrypt_ops zcrypt_pcicc_ops = {
    .rsa_modexpo = zcrypt_pcicc_modexpo,
    .rsa_modexpo_crt = zcrypt_pcicc_modexpo_crt,
};

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

    zdev = zcrypt_device_alloc(PCICC_MAX_RESPONSE_SIZE);
    if (!zdev)
        return -ENOMEM;
    zdev->ap_dev = ap_dev;
    zdev->ops = &zcrypt_pcicc_ops;
    zdev->online = 1;
    zdev->user_space_type = ZCRYPT_PCICC;
    zdev->type_string = "PCICC";
    zdev->min_mod_size = PCICC_MIN_MOD_SIZE;
    zdev->max_mod_size = PCICC_MAX_MOD_SIZE;
    zdev->speed_rating = PCICC_SPEED_RATING;
    zdev->max_exp_bit_length = PCICC_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_pcicc_remove(struct ap_device *ap_dev)
{
    struct zcrypt_device *zdev = ap_dev->private;

    zcrypt_device_unregister(zdev);
}

int __init zcrypt_pcicc_init(void)
{
    return ap_driver_register(&zcrypt_pcicc_driver, THIS_MODULE, "pcicc");
}

void zcrypt_pcicc_exit(void)
{
    ap_driver_unregister(&zcrypt_pcicc_driver);
}

module_init(zcrypt_pcicc_init);
module_exit(zcrypt_pcicc_exit);