Re: [linux-minidisc] compiling libnetmd and netmdcli on windows
Am 14/09/2011 21:41, schrieb Michael Karcher:
Am Mittwoch, den 14.09.2011, 09:06 +0200 schrieb Thomas Arp:
In netmd.cli the random number is used for creating a nonce in this
way:
unsigned char hostnonce[8] = { 0 };
unsigned char *buf;
uint64_t rand;
.
.
rand = (uint64_t)random();
buf = hostnonce;
netmd_copy_quadword_to_buffer(&buf, rand);
.
.
As far as i know random() and rand() are 32bit only.
What about using "gcry_create_nonce(unsigned char *buffer, size_t length)" from libgcrypt instead?
unsigned char hostnonce[8] = { 0 };
.
.
gcry_create_nonce(hostnonce, sizeof(hostnonce));
Yes, go that way. Sounds nice, and we already do depend on libgcrypt.
Regards,
Michael Karcher
O.K., here is my patch, please review.
Regards
Thomas
From 78e8e1fc7c5cdac273aa1fcc4a74fb6fec4d4076 Mon Sep 17 00:00:00 2001
From: Thomas Arp <manner.moe@gmx.de>
Date: Wed, 14 Sep 2011 23:43:21 +0200
Subject: [PATCH] make libnetmd platform independent and make use of libgcrypt
to generate random numbers
---
libnetmd/common.c | 2 +-
libnetmd/secure.c | 22 ++++++----------------
libnetmd/utils.c | 9 ---------
libnetmd/utils.h | 5 ++++-
netmdcli/netmdcli.c | 6 +-----
5 files changed, 12 insertions(+), 32 deletions(-)
diff --git a/libnetmd/common.c b/libnetmd/common.c
index 1f7b660..7e039ed 100644
--- a/libnetmd/common.c
+++ b/libnetmd/common.c
@@ -62,7 +62,7 @@ static int netmd_poll(libusb_device_handle *dev, unsigned char *buf, int tries)
}
if (i > 0) {
- sleep(1);
+ usleep(200000);
}
}
diff --git a/libnetmd/secure.c b/libnetmd/secure.c
index fce60c5..a940d9d 100644
--- a/libnetmd/secure.c
+++ b/libnetmd/secure.c
@@ -385,15 +385,6 @@ void netmd_transfer_song_packets(netmd_dev_handle *dev,
}
}
-uint64_t generate_64bit_random()
-{
- uint64_t high, low;
- high = ((uint64_t)random() & 0xffffffffU) << 32U;
- low = ((uint64_t)random() & 0xffffffffU);
-
- return high + low;
-}
-
netmd_error netmd_prepare_packets(unsigned char* data, size_t data_lenght,
netmd_track_packets **packets,
size_t *packet_count,
@@ -403,11 +394,11 @@ netmd_error netmd_prepare_packets(unsigned char* data, size_t data_lenght,
size_t chunksize = 0xffffffffU;
netmd_track_packets *last = NULL;
netmd_track_packets *next = NULL;
- uint64_t rand;
gcry_cipher_hd_t key_handle;
gcry_cipher_hd_t data_handle;
unsigned char iv[8] = { 0 };
+ unsigned char rand[8] = { 0 };
netmd_error error = NETMD_NO_ERROR;
@@ -418,8 +409,7 @@ netmd_error netmd_prepare_packets(unsigned char* data, size_t data_lenght,
/* generate initial iv */
- rand = generate_64bit_random();
- memcpy(iv, &rand, sizeof(rand));
+ gcry_create_nonce(iv, sizeof(iv));
*packet_count = 0;
while (position < data_lenght) {
@@ -450,13 +440,13 @@ netmd_error netmd_prepare_packets(unsigned char* data, size_t data_lenght,
}
/* generate key */
- rand = generate_64bit_random();
- gcry_cipher_decrypt(key_handle, next->key, 8, &rand, sizeof(rand));
+ gcry_randomize(rand, sizeof(rand), GCRY_STRONG_RANDOM);
+ gcry_cipher_decrypt(key_handle, next->key, 8, rand, sizeof(rand));
/* crypt data */
memcpy(next->iv, iv, 8);
gcry_cipher_setiv(data_handle, iv, 8);
- gcry_cipher_setkey(data_handle, &rand, sizeof(rand));
+ gcry_cipher_setkey(data_handle, rand, sizeof(rand));
gcry_cipher_encrypt(data_handle, next->data, chunksize, data + position, chunksize);
memcpy(iv, data + position - 8, 8);
@@ -577,7 +567,7 @@ netmd_error netmd_secure_real_recv_track(netmd_dev_handle *dev, uint32_t length,
netmd_log(NETMD_LOG_DEBUG, "%.1f%%\n", (double)done/(double)length * 100);
}
- else if (read != -ETIMEDOUT) {
+ else if (read != -LIBUSB_ERROR_TIMEOUT) {
error = NETMD_USB_ERROR;
}
}
diff --git a/libnetmd/utils.c b/libnetmd/utils.c
index 9b12167..0d9e65e 100644
--- a/libnetmd/utils.c
+++ b/libnetmd/utils.c
@@ -26,15 +26,6 @@
#include "utils.h"
#include "log.h"
-inline int min(int a,int b)
-{
- if (a < b) {
- return a;
- }
-
- return b;
-}
-
inline unsigned char proper_to_bcd_single(unsigned char value)
{
unsigned char high, low;
diff --git a/libnetmd/utils.h b/libnetmd/utils.h
index a389b03..58996f3 100644
--- a/libnetmd/utils.h
+++ b/libnetmd/utils.h
@@ -12,7 +12,10 @@ typedef struct {
size_t position;
} netmd_response;
-int min(int a,int b);
+#ifndef min
+ #define min(a,b) ((a)<(b)?(a):(b))
+#endif
+
unsigned char proper_to_bcd_single(unsigned char value);
unsigned char* proper_to_bcd(unsigned int value, unsigned char* target, size_t len);
unsigned char bcd_to_proper_single(unsigned char value);
diff --git a/netmdcli/netmdcli.c b/netmdcli/netmdcli.c
index 55ad3f0..b4e0ee3 100644
--- a/netmdcli/netmdcli.c
+++ b/netmdcli/netmdcli.c
@@ -426,8 +426,6 @@ int main(int argc, char* argv[])
unsigned char hostnonce[8] = { 0 };
unsigned char devnonce[8] = { 0 };
unsigned char sessionkey[8] = { 0 };
- unsigned char *buf;
- uint64_t rand;
unsigned char kek[] = { 0x14, 0xe3, 0x83, 0x4e, 0xe2, 0xd3, 0xcc, 0xa5 };
unsigned char contentid[] = { 0x01, 0x0F, 0x50, 0x00, 0x00, 0x04,
0x00, 0x00, 0x00, 0x48, 0xA2, 0x8D,
@@ -491,9 +489,7 @@ int main(int argc, char* argv[])
}
/* exchange nonces */
- rand = (uint64_t)random();
- buf = hostnonce;
- netmd_copy_quadword_to_buffer(&buf, rand);
+ gcry_create_nonce(hostnonce, sizeof(hostnonce));
error = netmd_secure_session_key_exchange(devh, hostnonce, devnonce);
puts(netmd_strerror(error));
--
1.7.6.msysgit.0
