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