LXR linux/fs/ncpfs/ncpsign

   1/*
   2 *  ncpsign_kernel.c
   3 *
   4 *  Arne de Bruijn (arne@knoware.nl), 1997
   5 *
   6 */
   7
   8
   9#ifdef CONFIG_NCPFS_PACKET_SIGNING
  10
  11#include <linux/string.h>
  12#include <linux/ncp.h>
  13#include <linux/bitops.h>
  14#include "ncpsign_kernel.h"
  15
  16/* i386: 32-bit, little endian, handles mis-alignment */
  17#ifdef __i386__
  18#define GET_LE32(p) (*(int *)(p))
  19#define PUT_LE32(p,v) { *(int *)(p)=v; }
  20#else
  21/* from include/ncplib.h */
  22#define BVAL(buf,pos) (((__u8 *)(buf))[pos])
  23#define PVAL(buf,pos) ((unsigned)BVAL(buf,pos))
  24#define BSET(buf,pos,val) (BVAL(buf,pos) = (val))
  25
  26static inline __u16
  27WVAL_LH(__u8 * buf, int pos)
  28{
  29        return PVAL(buf, pos) | PVAL(buf, pos + 1) << 8;
  30}
  31static inline __u32
  32DVAL_LH(__u8 * buf, int pos)
  33{
  34        return WVAL_LH(buf, pos) | WVAL_LH(buf, pos + 2) << 16;
  35}
  36static inline void
  37WSET_LH(__u8 * buf, int pos, __u16 val)
  38{
  39        BSET(buf, pos, val & 0xff);
  40        BSET(buf, pos + 1, val >> 8);
  41}
  42static inline void
  43DSET_LH(__u8 * buf, int pos, __u32 val)
  44{
  45        WSET_LH(buf, pos, val & 0xffff);
  46        WSET_LH(buf, pos + 2, val >> 16);
  47}
  48
  49#define GET_LE32(p) DVAL_LH(p,0)
  50#define PUT_LE32(p,v) DSET_LH(p,0,v)
  51#endif
  52
  53static void nwsign(char *r_data1, char *r_data2, char *outdata) {
  54 int i;
  55 unsigned int w0,w1,w2,w3;
  56 static int rbit[4]={0, 2, 1, 3};
  57#ifdef __i386__
  58 unsigned int *data2=(unsigned int *)r_data2;
  59#else
  60 unsigned int data2[16];
  61 for (i=0;i<16;i++)
  62  data2[i]=GET_LE32(r_data2+(i<<2));
  63#endif 
  64 w0=GET_LE32(r_data1);
  65 w1=GET_LE32(r_data1+4);
  66 w2=GET_LE32(r_data1+8);
  67 w3=GET_LE32(r_data1+12);
  68 for (i=0;i<16;i+=4) {
  69  w0=rol32(w0 + ((w1 & w2) | ((~w1) & w3)) + data2[i+0],3);
  70  w3=rol32(w3 + ((w0 & w1) | ((~w0) & w2)) + data2[i+1],7);
  71  w2=rol32(w2 + ((w3 & w0) | ((~w3) & w1)) + data2[i+2],11);
  72  w1=rol32(w1 + ((w2 & w3) | ((~w2) & w0)) + data2[i+3],19);
  73 }
  74 for (i=0;i<4;i++) {
  75  w0=rol32(w0 + (((w2 | w3) & w1) | (w2 & w3)) + 0x5a827999 + data2[i+0],3);
  76  w3=rol32(w3 + (((w1 | w2) & w0) | (w1 & w2)) + 0x5a827999 + data2[i+4],5);
  77  w2=rol32(w2 + (((w0 | w1) & w3) | (w0 & w1)) + 0x5a827999 + data2[i+8],9);
  78  w1=rol32(w1 + (((w3 | w0) & w2) | (w3 & w0)) + 0x5a827999 + data2[i+12],13);
  79 }
  80 for (i=0;i<4;i++) {
  81  w0=rol32(w0 + ((w1 ^ w2) ^ w3) + 0x6ed9eba1 + data2[rbit[i]+0],3);
  82  w3=rol32(w3 + ((w0 ^ w1) ^ w2) + 0x6ed9eba1 + data2[rbit[i]+8],9);
  83  w2=rol32(w2 + ((w3 ^ w0) ^ w1) + 0x6ed9eba1 + data2[rbit[i]+4],11);
  84  w1=rol32(w1 + ((w2 ^ w3) ^ w0) + 0x6ed9eba1 + data2[rbit[i]+12],15);
  85 }
  86 PUT_LE32(outdata,(w0+GET_LE32(r_data1)) & 0xffffffff);
  87 PUT_LE32(outdata+4,(w1+GET_LE32(r_data1+4)) & 0xffffffff);
  88 PUT_LE32(outdata+8,(w2+GET_LE32(r_data1+8)) & 0xffffffff);
  89 PUT_LE32(outdata+12,(w3+GET_LE32(r_data1+12)) & 0xffffffff);
  90}
  91
  92/* Make a signature for the current packet and add it at the end of the */
  93/* packet. */
  94void __sign_packet(struct ncp_server *server, const char *packet, size_t size, __u32 totalsize, void *sign_buff) {
  95        unsigned char data[64];
  96
  97        memcpy(data, server->sign_root, 8);
  98        *(__u32*)(data + 8) = totalsize;
  99        if (size < 52) {
 100                memcpy(data + 12, packet, size);
 101                memset(data + 12 + size, 0, 52 - size);
 102        } else {
 103                memcpy(data + 12, packet, 52);
 104        }
 105        nwsign(server->sign_last, data, server->sign_last);
 106        memcpy(sign_buff, server->sign_last, 8);
 107}
 108
 109int sign_verify_reply(struct ncp_server *server, const char *packet, size_t size, __u32 totalsize, const void *sign_buff) {
 110        unsigned char data[64];
 111        unsigned char hash[16];
 112
 113        memcpy(data, server->sign_root, 8);
 114        *(__u32*)(data + 8) = totalsize;
 115        if (size < 52) {
 116                memcpy(data + 12, packet, size);
 117                memset(data + 12 + size, 0, 52 - size);
 118        } else {
 119                memcpy(data + 12, packet, 52);
 120        }
 121        nwsign(server->sign_last, data, hash);
 122        return memcmp(sign_buff, hash, 8);
 123}
 124
 125#endif  /* CONFIG_NCPFS_PACKET_SIGNING */
 126
 127