fs/ncpfs/ncpsign_kernel.c

   1 /*
   2  *  ncpsign_kernel.c
   3  *
   4  *  Arne de Bruijn (arne@knoware.nl), 1997
   5  *
   6  */
   7
   8 #include <linux/config.h>
   9
  10 #ifdef CONFIG_NCPFS_PACKET_SIGNING
  11
  12 #include <linux/string.h>
  13 #include <linux/ncp.h>
  14 #include "ncpsign_kernel.h"
  15
  16 #define rol32(i,c) (((((i)&0xffffffff)<<c)&0xffffffff)| \
  17                     (((i)&0xffffffff)>>(32-c)))
  18 /* i386: 32-bit, little endian, handles mis-alignment */
  19 #ifdef __i386__
  20 #define GET_LE32(p) (*(int *)(p))
  21 #define PUT_LE32(p,v) { *(int *)(p)=v; }
  22 #else
  23 /* from include/ncplib.h */
  24 #define BVAL(buf,pos) (((__u8 *)(buf))[pos])
  25 #define PVAL(buf,pos) ((unsigned)BVAL(buf,pos))
  26 #define BSET(buf,pos,val) (BVAL(buf,pos) = (val))
  27
  28 static inline __u16
  29 WVAL_LH(__u8 * buf, int pos)
  30 {
  31         return PVAL(buf, pos) | PVAL(buf, pos + 1) << 8;
  32 }
  33 static inline __u32
  34 DVAL_LH(__u8 * buf, int pos)
  35 {
  36         return WVAL_LH(buf, pos) | WVAL_LH(buf, pos + 2) << 16;
  37 }
  38 static inline void
  39 WSET_LH(__u8 * buf, int pos, __u16 val)
  40 {
  41         BSET(buf, pos, val & 0xff);
  42         BSET(buf, pos + 1, val >> 8);
  43 }
  44 static inline void
  45 DSET_LH(__u8 * buf, int pos, __u32 val)
  46 {
  47         WSET_LH(buf, pos, val & 0xffff);
  48         WSET_LH(buf, pos + 2, val >> 16);
  49 }
  50
  51 #define GET_LE32(p) DVAL_LH(p,0)
  52 #define PUT_LE32(p,v) DSET_LH(p,0,v)
  53 #endif
  54
  55 static void nwsign(char *r_data1, char *r_data2, char *outdata) {
  56  int i;
  57  unsigned int w0,w1,w2,w3;
  58  static int rbit[4]={0, 2, 1, 3};
  59 #ifdef __i386__
  60  unsigned int *data2=(int *)r_data2;
  61 #else
  62  unsigned int data2[16];
  63  for (i=0;i<16;i++)
  64   data2[i]=GET_LE32(r_data2+(i<<2));
  65 #endif
  66  w0=GET_LE32(r_data1);
  67  w1=GET_LE32(r_data1+4);
  68  w2=GET_LE32(r_data1+8);
  69  w3=GET_LE32(r_data1+12);
  70  for (i=0;i<16;i+=4) {
  71   w0=rol32(w0 + ((w1 & w2) | ((~w1) & w3)) + data2[i+0],3);
  72   w3=rol32(w3 + ((w0 & w1) | ((~w0) & w2)) + data2[i+1],7);
  73   w2=rol32(w2 + ((w3 & w0) | ((~w3) & w1)) + data2[i+2],11);
  74   w1=rol32(w1 + ((w2 & w3) | ((~w2) & w0)) + data2[i+3],19);
  75  }
  76  for (i=0;i<4;i++) {
  77   w0=rol32(w0 + (((w2 | w3) & w1) | (w2 & w3)) + 0x5a827999 + data2[i+0],3);
  78   w3=rol32(w3 + (((w1 | w2) & w0) | (w1 & w2)) + 0x5a827999 + data2[i+4],5);
  79   w2=rol32(w2 + (((w0 | w1) & w3) | (w0 & w1)) + 0x5a827999 + data2[i+8],9);
  80   w1=rol32(w1 + (((w3 | w0) & w2) | (w3 & w0)) + 0x5a827999 + data2[i+12],13);
  81  }
  82  for (i=0;i<4;i++) {
  83   w0=rol32(w0 + ((w1 ^ w2) ^ w3) + 0x6ed9eba1 + data2[rbit[i]+0],3);
  84   w3=rol32(w3 + ((w0 ^ w1) ^ w2) + 0x6ed9eba1 + data2[rbit[i]+8],9);
  85   w2=rol32(w2 + ((w3 ^ w0) ^ w1) + 0x6ed9eba1 + data2[rbit[i]+4],11);
  86   w1=rol32(w1 + ((w2 ^ w3) ^ w0) + 0x6ed9eba1 + data2[rbit[i]+12],15);
  87  }
  88  PUT_LE32(outdata,(w0+GET_LE32(r_data1)) & 0xffffffff);
  89  PUT_LE32(outdata+4,(w1+GET_LE32(r_data1+4)) & 0xffffffff);
  90  PUT_LE32(outdata+8,(w2+GET_LE32(r_data1+8)) & 0xffffffff);
  91  PUT_LE32(outdata+12,(w3+GET_LE32(r_data1+12)) & 0xffffffff);
  92 }
  93
  94 /* Make a signature for the current packet and add it at the end of the */
  95 /* packet. */
  96 void __sign_packet(struct ncp_server *server, const char *packet, size_t size, __u32 totalsize, void *sign_buff) {
  97         unsigned char data[64];
  98
  99         memcpy(data, server->sign_root, 8);
 100         *(__u32*)(data + 8) = totalsize;
 101         if (size < 52) {
 102                 memcpy(data + 12, packet, size);
 103                 memset(data + 12 + size, 0, 52 - size);
 104         } else {
 105                 memcpy(data + 12, packet, 52);
 106         }
 107         nwsign(server->sign_last, data, server->sign_last);
 108         memcpy(sign_buff, server->sign_last, 8);
 109 }
 110
 111 int sign_verify_reply(struct ncp_server *server, const char *packet, size_t size, __u32 totalsize, const void *sign_buff) {
 112         unsigned char data[64];
 113         unsigned char hash[16];
 114
 115         memcpy(data, server->sign_root, 8);
 116         *(__u32*)(data + 8) = totalsize;
 117         if (size < 52) {
 118                 memcpy(data + 12, packet, size);
 119                 memset(data + 12 + size, 0, 52 - size);
 120         } else {
 121                 memcpy(data + 12, packet, 52);
 122         }
 123         nwsign(server->sign_last, data, hash);
 124         return memcmp(sign_buff, hash, 8);
 125 }
 126
 127 #endif  /* CONFIG_NCPFS_PACKET_SIGNING */
 128