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