[patch 3/8] tpm: Fix display of data in pubek sysfs entry

From: Stefan Berger
Date: Tue Mar 15 2011 - 07:16:35 EST


This patch fixes the TPM's pubek sysfs entry that is accessible as long
as the TPM doesn't have an owner. I shifted the access to the data
by -10 -- the first byte immediately follows the 10 byte header. The
line

data = tpm_cmd.params.readpubek_out_buffer;

sets it at the offset '10' in the packet, so we can read the data array
starting at offset '0'.

Before:

Algorithm: 00 0C 00 00
Encscheme: 08 00
Sigscheme: 00 00
Parameters: 00 00 00 00 01 00 AC E2 5E 3C A0 78
Modulus length: -563306801
Modulus:
28 21 08 0F 82 CD F2 B1 E7 49 F7 74 70 BE 59 8C
43 78 B1 24 EA 52 E2 FE 52 5C 3A 12 3B DC 61 71
[...]

After:

Algorithm: 00 00 00 01
Encscheme: 00 03
Sigscheme: 00 01
Parameters: 00 00 08 00 00 00 00 02 00 00 00 00
Modulus length: 256
Modulus:
AC E2 5E 3C A0 78 DE 6C 9E CF 28 21 08 0F 82 CD
F2 B1 E7 49 F7 74 70 BE 59 8C 43 78 B1 24 EA 52
[...]

Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>

---
drivers/char/tpm/tpm.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

Index: linux-2.6/drivers/char/tpm/tpm.c
===================================================================
--- linux-2.6.orig/drivers/char/tpm/tpm.c
+++ linux-2.6/drivers/char/tpm/tpm.c
@@ -871,18 +871,24 @@ ssize_t tpm_show_pubek(struct device *de
data = tpm_cmd.params.readpubek_out_buffer;
str +=
sprintf(str,
- "Algorithm: %02X %02X %02X %02X\nEncscheme: %02X %02X\n"
- "Sigscheme: %02X %02X\nParameters: %02X %02X %02X %02X"
- " %02X %02X %02X %02X %02X %02X %02X %02X\n"
- "Modulus length: %d\nModulus: \n",
- data[10], data[11], data[12], data[13], data[14],
- data[15], data[16], data[17], data[22], data[23],
- data[24], data[25], data[26], data[27], data[28],
- data[29], data[30], data[31], data[32], data[33],
- be32_to_cpu(*((__be32 *) (data + 34))));
+ "Algorithm: %02X %02X %02X %02X\n"
+ "Encscheme: %02X %02X\n"
+ "Sigscheme: %02X %02X\n"
+ "Parameters: %02X %02X %02X %02X "
+ "%02X %02X %02X %02X "
+ "%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))));

for (i = 0; i < 256; i++) {
- str += sprintf(str, "%02X ", data[i + 38]);
+ str += sprintf(str, "%02X ", data[i + 28]);
if ((i + 1) % 16 == 0)
str += sprintf(str, "\n");
}

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