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
28static inline __u16
29WVAL_LH(__u8 * buf, int pos)
30{
31	return PVAL(buf, pos) | PVAL(buf, pos + 1) << 8;
32}
33static inline __u32
34DVAL_LH(__u8 * buf, int pos)
35{
36	return WVAL_LH(buf, pos) | WVAL_LH(buf, pos + 2) << 16;
37}
38static inline void
39WSET_LH(__u8 * buf, int pos, __u16 val)
40{
41	BSET(buf, pos, val & 0xff);
42	BSET(buf, pos + 1, val >> 8);
43}
44static inline void
45DSET_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
55static 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. */
96void sign_packet(struct ncp_server *server, int *size) {
97 char data[64];
98
99 memset(data,0,64);
100 memcpy(data,server->sign_root,8);
101 PUT_LE32(data+8,(*size));
102 memcpy(data+12,server->packet+sizeof(struct ncp_request_header)-1,
103  min_t(unsigned int,(*size)-sizeof(struct ncp_request_header)+1,52));
104
105 nwsign(server->sign_last,data,server->sign_last);
106
107 memcpy(server->packet+(*size),server->sign_last,8);
108 (*size)+=8;
109}
110
111#endif	/* CONFIG_NCPFS_PACKET_SIGNING */
112
113