1 #include <u.h>
2 #include <libc.h>
3 #include <fcall.h>
4 #include <auth.h>
5 #include "authlocal.h"
6
7 enum {
8 ARgiveup = 100,
9 };
10
11 static uchar*
gstring(uchar * p,uchar * ep,char ** s)12 gstring(uchar *p, uchar *ep, char **s)
13 {
14 uint n;
15
16 if(p == nil)
17 return nil;
18 if(p+BIT16SZ > ep)
19 return nil;
20 n = GBIT16(p);
21 p += BIT16SZ;
22 if(p+n > ep)
23 return nil;
24 *s = malloc(n+1);
25 memmove((*s), p, n);
26 (*s)[n] = '\0';
27 p += n;
28 return p;
29 }
30
31 static uchar*
gcarray(uchar * p,uchar * ep,uchar ** s,int * np)32 gcarray(uchar *p, uchar *ep, uchar **s, int *np)
33 {
34 uint n;
35
36 if(p == nil)
37 return nil;
38 if(p+BIT16SZ > ep)
39 return nil;
40 n = GBIT16(p);
41 p += BIT16SZ;
42 if(p+n > ep)
43 return nil;
44 *s = malloc(n);
45 if(*s == nil)
46 return nil;
47 memmove((*s), p, n);
48 *np = n;
49 p += n;
50 return p;
51 }
52
53 void
auth_freeAI(AuthInfo * ai)54 auth_freeAI(AuthInfo *ai)
55 {
56 if(ai == nil)
57 return;
58 free(ai->cuid);
59 free(ai->suid);
60 free(ai->cap);
61 free(ai->secret);
62 free(ai);
63 }
64
65 static uchar*
convM2AI(uchar * p,int n,AuthInfo ** aip)66 convM2AI(uchar *p, int n, AuthInfo **aip)
67 {
68 uchar *e = p+n;
69 AuthInfo *ai;
70
71 ai = mallocz(sizeof(*ai), 1);
72 if(ai == nil)
73 return nil;
74
75 p = gstring(p, e, &ai->cuid);
76 p = gstring(p, e, &ai->suid);
77 p = gstring(p, e, &ai->cap);
78 p = gcarray(p, e, &ai->secret, &ai->nsecret);
79 if(p == nil)
80 auth_freeAI(ai);
81 else
82 *aip = ai;
83 return p;
84 }
85
86 AuthInfo*
auth_getinfo(AuthRpc * rpc)87 auth_getinfo(AuthRpc *rpc)
88 {
89 AuthInfo *a;
90
91 if(auth_rpc(rpc, "authinfo", nil, 0) != ARok)
92 return nil;
93 a = nil;
94 if(convM2AI((uchar*)rpc->arg, rpc->narg, &a) == nil){
95 werrstr("bad auth info from factotum");
96 return nil;
97 }
98 return a;
99 }
100
101 static int
dorpc(AuthRpc * rpc,char * verb,char * val,int len,AuthGetkey * getkey)102 dorpc(AuthRpc *rpc, char *verb, char *val, int len, AuthGetkey *getkey)
103 {
104 int ret;
105
106 for(;;){
107 if((ret = auth_rpc(rpc, verb, val, len)) != ARneedkey && ret != ARbadkey)
108 return ret;
109 if(getkey == 0)
110 return ARgiveup; /* don't know how */
111 if((*getkey)(rpc->arg) < 0)
112 return ARgiveup; /* user punted */
113 }
114 }
115
116 /*
117 * this just proxies what the factotum tells it to.
118 */
119 AuthInfo*
fauth_proxy(int fd,AuthRpc * rpc,AuthGetkey * getkey,char * params)120 fauth_proxy(int fd, AuthRpc *rpc, AuthGetkey *getkey, char *params)
121 {
122 char *buf;
123 int m, n, ret;
124 AuthInfo *a;
125 char oerr[ERRMAX];
126
127 rerrstr(oerr, sizeof oerr);
128 werrstr("UNKNOWN AUTH ERROR");
129
130 if(dorpc(rpc, "start", params, strlen(params), getkey) != ARok){
131 werrstr("fauth_proxy start: %r");
132 return nil;
133 }
134
135 buf = malloc(AuthRpcMax);
136 if(buf == nil)
137 return nil;
138 for(;;){
139 switch(dorpc(rpc, "read", nil, 0, getkey)){
140 case ARdone:
141 free(buf);
142 a = auth_getinfo(rpc);
143 errstr(oerr, sizeof oerr); /* no error, restore whatever was there */
144 return a;
145 case ARok:
146 if(write(fd, rpc->arg, rpc->narg) != rpc->narg){
147 werrstr("auth_proxy write fd: %r");
148 goto Error;
149 }
150 break;
151 case ARphase:
152 n = 0;
153 memset(buf, 0, AuthRpcMax);
154 while((ret = dorpc(rpc, "write", buf, n, getkey)) == ARtoosmall){
155 if(atoi(rpc->arg) > AuthRpcMax)
156 break;
157 m = read(fd, buf+n, atoi(rpc->arg)-n);
158 if(m <= 0){
159 if(m == 0)
160 werrstr("auth_proxy short read: %s", buf);
161 goto Error;
162 }
163 n += m;
164 }
165 if(ret != ARok){
166 werrstr("auth_proxy rpc write: %s: %r", buf);
167 goto Error;
168 }
169 break;
170 default:
171 werrstr("auth_proxy rpc: %r");
172 goto Error;
173 }
174 }
175 Error:
176 free(buf);
177 return nil;
178 }
179
180 AuthInfo*
auth_proxy(int fd,AuthGetkey * getkey,char * fmt,...)181 auth_proxy(int fd, AuthGetkey *getkey, char *fmt, ...)
182 {
183 int afd;
184 char *p;
185 va_list arg;
186 AuthInfo *ai;
187 AuthRpc *rpc;
188
189 quotefmtinstall(); /* just in case */
190 va_start(arg, fmt);
191 p = vsmprint(fmt, arg);
192 va_end(arg);
193
194 afd = open("/mnt/factotum/rpc", ORDWR);
195 if(afd < 0){
196 werrstr("opening /mnt/factotum/rpc: %r");
197 free(p);
198 return nil;
199 }
200
201 rpc = auth_allocrpc(afd);
202 if(rpc == nil){
203 free(p);
204 return nil;
205 }
206
207 ai = fauth_proxy(fd, rpc, getkey, p);
208 free(p);
209 auth_freerpc(rpc);
210 close(afd);
211 return ai;
212 }
213
214