fs/ncpfs/ncpsign_kernel.c

   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
  26 static inline __u16
  27 WVAL_LH(__u8 * buf, int pos)
  28 {
  29         return PVAL(buf, pos) | PVAL(buf, pos + 1) << 8;
  30 }
  31 static inline __u32
  32 DVAL_LH(__u8 * buf, int pos)
  33 {
  34         return WVAL_LH(buf, pos) | WVAL_LH(buf, pos + 2) << 16;
  35 }
  36 static inline void
  37 WSET_LH(__u8 * buf, int pos, __u16 val)
  38 {
  39         BSET(buf, pos, val & 0xff);
  40         BSET(buf, pos + 1, val >> 8);
  41 }
  42 static inline void
  43 DSET_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
  53 static 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. */
  94 void __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
 109 int 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