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 "ncp_fs.h"
  15#include "ncpsign_kernel.h"
  16
  17/* i386: 32-bit, little endian, handles mis-alignment */
  18#ifdef __i386__
  19#define GET_LE32(p) (*(const int *)(p))
  20#define PUT_LE32(p,v) { *(int *)(p)=v; }
  21#else
  22/* from include/ncplib.h */
  23#define BVAL(buf,pos) (((const __u8 *)(buf))[pos])
  24#define PVAL(buf,pos) ((unsigned)BVAL(buf,pos))
  25#define BSET(buf,pos,val) (((__u8 *)(buf))[pos] = (val))
  26
  27static inline __u16
  28WVAL_LH(const __u8 * buf, int pos)
  29{
  30        return PVAL(buf, pos) | PVAL(buf, pos + 1) << 8;
  31}
  32static inline __u32
  33DVAL_LH(const __u8 * buf, int pos)
  34{
  35        return WVAL_LH(buf, pos) | WVAL_LH(buf, pos + 2) << 16;
  36}
  37static inline void
  38WSET_LH(__u8 * buf, int pos, __u16 val)
  39{
  40        BSET(buf, pos, val & 0xff);
  41        BSET(buf, pos + 1, val >> 8);
  42}
  43static inline void
  44DSET_LH(__u8 * buf, int pos, __u32 val)
  45{
  46        WSET_LH(buf, pos, val & 0xffff);
  47        WSET_LH(buf, pos + 2, val >> 16);
  48}
  49
  50#define GET_LE32(p) DVAL_LH(p,0)
  51#define PUT_LE32(p,v) DSET_LH(p,0,v)
  52#endif
  53
  54static void nwsign(char *r_data1, char *r_data2, char *outdata) {
  55 int i;
  56 unsigned int w0,w1,w2,w3;
  57 static int rbit[4]={0, 2, 1, 3};
  58#ifdef __i386__
  59 unsigned int *data2=(unsigned int *)r_data2;
  60#else
  61 unsigned int data2[16];
  62 for (i=0;i<16;i++)
  63  data2[i]=GET_LE32(r_data2+(i<<2));
  64#endif 
  65 w0=GET_LE32(r_data1);
  66 w1=GET_LE32(r_data1+4);
  67 w2=GET_LE32(r_data1+8);
  68 w3=GET_LE32(r_data1+12);
  69 for (i=0;i<16;i+=4) {
  70  w0=rol32(w0 + ((w1 & w2) | ((~w1) & w3)) + data2[i+0],3);
  71  w3=rol32(w3 + ((w0 & w1) | ((~w0) & w2)) + data2[i+1],7);
  72  w2=rol32(w2 + ((w3 & w0) | ((~w3) & w1)) + data2[i+2],11);
  73  w1=rol32(w1 + ((w2 & w3) | ((~w2) & w0)) + data2[i+3],19);
  74 }
  75 for (i=0;i<4;i++) {
  76  w0=rol32(w0 + (((w2 | w3) & w1) | (w2 & w3)) + 0x5a827999 + data2[i+0],3);
  77  w3=rol32(w3 + (((w1 | w2) & w0) | (w1 & w2)) + 0x5a827999 + data2[i+4],5);
  78  w2=rol32(w2 + (((w0 | w1) & w3) | (w0 & w1)) + 0x5a827999 + data2[i+8],9);
  79  w1=rol32(w1 + (((w3 | w0) & w2) | (w3 & w0)) + 0x5a827999 + data2[i+12],13);
  80 }
  81 for (i=0;i<4;i++) {
  82  w0=rol32(w0 + ((w1 ^ w2) ^ w3) + 0x6ed9eba1 + data2[rbit[i]+0],3);
  83  w3=rol32(w3 + ((w0 ^ w1) ^ w2) + 0x6ed9eba1 + data2[rbit[i]+8],9);
  84  w2=rol32(w2 + ((w3 ^ w0) ^ w1) + 0x6ed9eba1 + data2[rbit[i]+4],11);
  85  w1=rol32(w1 + ((w2 ^ w3) ^ w0) + 0x6ed9eba1 + data2[rbit[i]+12],15);
  86 }
  87 PUT_LE32(outdata,(w0+GET_LE32(r_data1)) & 0xffffffff);
  88 PUT_LE32(outdata+4,(w1+GET_LE32(r_data1+4)) & 0xffffffff);
  89 PUT_LE32(outdata+8,(w2+GET_LE32(r_data1+8)) & 0xffffffff);
  90 PUT_LE32(outdata+12,(w3+GET_LE32(r_data1+12)) & 0xffffffff);
  91}
  92
  93/* Make a signature for the current packet and add it at the end of the */
  94/* packet. */
  95void __sign_packet(struct ncp_server *server, const char *packet, size_t size, __u32 totalsize, void *sign_buff) {
  96        unsigned char data[64];
  97
  98        memcpy(data, server->sign_root, 8);
  99        *(__u32*)(data + 8) = totalsize;
 100        if (size < 52) {
 101                memcpy(data + 12, packet, size);
 102                memset(data + 12 + size, 0, 52 - size);
 103        } else {
 104                memcpy(data + 12, packet, 52);
 105        }
 106        nwsign(server->sign_last, data, server->sign_last);
 107        memcpy(sign_buff, server->sign_last, 8);
 108}
 109
 110int sign_verify_reply(struct ncp_server *server, const char *packet, size_t size, __u32 totalsize, const void *sign_buff) {
 111        unsigned char data[64];
 112        unsigned char hash[16];
 113
 114        memcpy(data, server->sign_root, 8);
 115        *(__u32*)(data + 8) = totalsize;
 116        if (size < 52) {
 117                memcpy(data + 12, packet, size);
 118                memset(data + 12 + size, 0, 52 - size);
 119        } else {
 120                memcpy(data + 12, packet, 52);
 121        }
 122        nwsign(server->sign_last, data, hash);
 123        return memcmp(sign_buff, hash, 8);
 124}
 125
 126#endif  /* CONFIG_NCPFS_PACKET_SIGNING */
 127
 128