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 if(convM2AI((uchar*)rpc->arg, rpc->narg, &a) == nil){
94 werrstr("bad auth info from factotum");
95 return nil;
96 }
97 return a;
98 }
99
100 static int
dorpc(AuthRpc * rpc,char * verb,char * val,int len,AuthGetkey * getkey)101 dorpc(AuthRpc *rpc, char *verb, char *val, int len, AuthGetkey *getkey)
102 {
103 int ret;
104
105 for(;;){
106 if((ret = auth_rpc(rpc, verb, val, len)) != ARneedkey && ret != ARbadkey)
107 return ret;
108 if(getkey == nil)
109 return ARgiveup; /* don't know how */
110 if((*getkey)(rpc->arg) < 0)
111 return ARgiveup; /* user punted */
112 }
113 }
114
115 /*
116 * this just proxies what the factotum tells it to.
117 */
118 AuthInfo*
fauth_proxy(int fd,AuthRpc * rpc,AuthGetkey * getkey,char * params)119 fauth_proxy(int fd, AuthRpc *rpc, AuthGetkey *getkey, char *params)
120 {
121 char *buf;
122 int m, n, ret;
123 AuthInfo *a;
124 char oerr[ERRMAX];
125
126 if(rpc == nil){
127 werrstr("fauth_proxy - no factotum");
128 return nil;
129 }
130
131 rerrstr(oerr, sizeof oerr);
132 werrstr("UNKNOWN AUTH ERROR");
133
134 if(dorpc(rpc, "start", params, strlen(params), getkey) != ARok){
135 werrstr("fauth_proxy start: %r");
136 return nil;
137 }
138
139 buf = malloc(AuthRpcMax);
140 if(buf == nil)
141 return nil;
142 for(;;){
143 switch(dorpc(rpc, "read", nil, 0, getkey)){
144 case ARdone:
145 free(buf);
146 a = auth_getinfo(rpc);
147 /* no error, restore whatever was there */
148 errstr(oerr, sizeof oerr);
149 return a;
150 case ARok:
151 if(write(fd, rpc->arg, rpc->narg) != rpc->narg){
152 werrstr("auth_proxy write fd: %r");
153 goto Error;
154 }
155 break;
156 case ARphase:
157 n = 0;
158 memset(buf, 0, AuthRpcMax);
159 while((ret = dorpc(rpc, "write", buf, n, getkey)) == ARtoosmall){
160 if(atoi(rpc->arg) > AuthRpcMax)
161 break;
162 m = read(fd, buf + n, atoi(rpc->arg) - n);
163 if(m <= 0){
164 if(m == 0)
165 werrstr("auth_proxy short read: %s",
166 buf);
167 goto Error;
168 }
169 n += m;
170 }
171 if(ret != ARok){
172 werrstr("auth_proxy rpc write: %s: %r", buf);
173 goto Error;
174 }
175 break;
176 default:
177 werrstr("auth_proxy rpc: %r");
178 goto Error;
179 }
180 }
181 Error:
182 free(buf);
183 return nil;
184 }
185
186 AuthInfo*
auth_proxy(int fd,AuthGetkey * getkey,char * fmt,...)187 auth_proxy(int fd, AuthGetkey *getkey, char *fmt, ...)
188 {
189 int afd;
190 char *p;
191 va_list arg;
192 AuthInfo *ai;
193 AuthRpc *rpc;
194
195 quotefmtinstall(); /* just in case */
196 va_start(arg, fmt);
197 p = vsmprint(fmt, arg);
198 va_end(arg);
199
200 ai = nil;
201 afd = open("/mnt/factotum/rpc", ORDWR);
202 if(afd < 0){
203 werrstr("opening /mnt/factotum/rpc: %r");
204 free(p);
205 return nil;
206 }
207
208 rpc = auth_allocrpc(afd);
209 if(rpc){
210 ai = fauth_proxy(fd, rpc, getkey, p);
211 auth_freerpc(rpc);
212 }
213 close(afd);
214 free(p);
215 return ai;
216 }
217