#include <linux/device.h>
 #include "tpm.h"
 
-#define READ_PUBEK_RESULT_SIZE 314
+struct tpm_readpubek_out {
+       u8 algorithm[4];
+       u8 encscheme[2];
+       u8 sigscheme[2];
+       __be32 paramsize;
+       u8 parameters[12];
+       __be32 keysize;
+       u8 modulus[256];
+       u8 checksum[20];
+} __packed;
+
 #define READ_PUBEK_RESULT_MIN_BODY_SIZE (28 + 256)
 #define TPM_ORD_READPUBEK 124
-static const struct tpm_input_header tpm_readpubek_header = {
-       .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
-       .length = cpu_to_be32(30),
-       .ordinal = cpu_to_be32(TPM_ORD_READPUBEK)
-};
+
 static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
                          char *buf)
 {
-       u8 *data;
-       struct tpm_cmd_t tpm_cmd;
-       ssize_t err;
-       int i, rc;
+       struct tpm_buf tpm_buf;
+       struct tpm_readpubek_out *out;
+       ssize_t rc;
+       int i;
        char *str = buf;
        struct tpm_chip *chip = to_tpm_chip(dev);
+       char anti_replay[20];
 
-       memset(&tpm_cmd, 0, sizeof(tpm_cmd));
-
-       tpm_cmd.header.in = tpm_readpubek_header;
-       err = tpm_transmit_cmd(chip, NULL, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
-                              READ_PUBEK_RESULT_MIN_BODY_SIZE, 0,
-                              "attempting to read the PUBEK");
-       if (err)
-               goto out;
-
-       /*
-          ignore header 10 bytes
-          algorithm 32 bits (1 == RSA )
-          encscheme 16 bits
-          sigscheme 16 bits
-          parameters (RSA 12->bytes: keybit, #primes, expbit)
-          keylenbytes 32 bits
-          256 byte modulus
-          ignore checksum 20 bytes
-        */
-       data = tpm_cmd.params.readpubek_out_buffer;
+       memset(&anti_replay, 0, sizeof(anti_replay));
+
+       rc = tpm_buf_init(&tpm_buf, TPM_TAG_RQU_COMMAND, TPM_ORD_READPUBEK);
+       if (rc)
+               return rc;
+
+       tpm_buf_append(&tpm_buf, anti_replay, sizeof(anti_replay));
+
+       rc = tpm_transmit_cmd(chip, NULL, tpm_buf.data, PAGE_SIZE,
+                             READ_PUBEK_RESULT_MIN_BODY_SIZE, 0,
+                             "attempting to read the PUBEK");
+       if (rc) {
+               tpm_buf_destroy(&tpm_buf);
+               return 0;
+       }
+
+       out = (struct tpm_readpubek_out *)&tpm_buf.data[10];
        str +=
            sprintf(str,
                    "Algorithm: %02X %02X %02X %02X\n"
                    "%02X %02X %02X %02X\n"
                    "Modulus length: %d\n"
                    "Modulus:\n",
-                   data[0], data[1], data[2], data[3],
-                   data[4], data[5],
-                   data[6], data[7],
-                   data[12], data[13], data[14], data[15],
-                   data[16], data[17], data[18], data[19],
-                   data[20], data[21], data[22], data[23],
-                   be32_to_cpu(*((__be32 *) (data + 24))));
+                   out->algorithm[0], out->algorithm[1], out->algorithm[2],
+                   out->algorithm[3],
+                   out->encscheme[0], out->encscheme[1],
+                   out->sigscheme[0], out->sigscheme[1],
+                   out->parameters[0], out->parameters[1],
+                   out->parameters[2], out->parameters[3],
+                   out->parameters[4], out->parameters[5],
+                   out->parameters[6], out->parameters[7],
+                   out->parameters[8], out->parameters[9],
+                   out->parameters[10], out->parameters[11],
+                   be32_to_cpu(out->keysize));
 
        for (i = 0; i < 256; i++) {
-               str += sprintf(str, "%02X ", data[i + 28]);
+               str += sprintf(str, "%02X ", out->modulus[i]);
                if ((i + 1) % 16 == 0)
                        str += sprintf(str, "\n");
        }
-out:
+
        rc = str - buf;
+       tpm_buf_destroy(&tpm_buf);
        return rc;
 }
 static DEVICE_ATTR_RO(pubek);