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1 | /* |
2 | * SSH agent client code. |
3 | */ |
4 | |
5 | #include <stdio.h> |
6 | #include <stdlib.h> |
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7 | #include <assert.h> |
8 | #include <unistd.h> |
9 | #include <sys/socket.h> |
10 | #include <sys/un.h> |
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11 | |
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12 | #include "putty.h" |
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13 | #include "misc.h" |
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14 | #include "tree234.h" |
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15 | #include "puttymem.h" |
16 | |
17 | #define GET_32BIT(cp) \ |
18 | (((unsigned long)(unsigned char)(cp)[0] << 24) | \ |
19 | ((unsigned long)(unsigned char)(cp)[1] << 16) | \ |
20 | ((unsigned long)(unsigned char)(cp)[2] << 8) | \ |
21 | ((unsigned long)(unsigned char)(cp)[3])) |
22 | |
23 | int agent_exists(void) |
24 | { |
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25 | if (getenv("SSH_AUTH_SOCK") != NULL) |
26 | return TRUE; |
27 | return FALSE; |
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28 | } |
29 | |
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30 | static tree234 *agent_connections; |
31 | struct agent_connection { |
32 | int fd; |
33 | char *retbuf; |
34 | char sizebuf[4]; |
35 | int retsize, retlen; |
36 | void (*callback)(void *, void *, int); |
37 | void *callback_ctx; |
38 | }; |
39 | static int agent_conncmp(void *av, void *bv) |
40 | { |
41 | struct agent_connection *a = (struct agent_connection *) av; |
42 | struct agent_connection *b = (struct agent_connection *) bv; |
43 | if (a->fd < b->fd) |
44 | return -1; |
45 | if (a->fd > b->fd) |
46 | return +1; |
47 | return 0; |
48 | } |
49 | static int agent_connfind(void *av, void *bv) |
50 | { |
51 | int afd = *(int *) av; |
52 | struct agent_connection *b = (struct agent_connection *) bv; |
53 | if (afd < b->fd) |
54 | return -1; |
55 | if (afd > b->fd) |
56 | return +1; |
57 | return 0; |
58 | } |
59 | |
60 | static int agent_select_result(int fd, int event) |
61 | { |
62 | int ret; |
63 | struct agent_connection *conn; |
64 | |
65 | assert(event == 1); /* not selecting for anything but R */ |
66 | |
67 | conn = find234(agent_connections, &fd, agent_connfind); |
68 | if (!conn) { |
69 | uxsel_del(fd); |
70 | return 1; |
71 | } |
72 | |
73 | ret = read(fd, conn->retbuf+conn->retlen, conn->retsize-conn->retlen); |
74 | if (ret <= 0) { |
75 | if (conn->retbuf != conn->sizebuf) sfree(conn->retbuf); |
76 | conn->retbuf = NULL; |
77 | conn->retlen = 0; |
78 | goto done; |
79 | } |
80 | conn->retlen += ret; |
81 | if (conn->retsize == 4 && conn->retlen == 4) { |
82 | conn->retsize = GET_32BIT(conn->retbuf); |
83 | if (conn->retsize <= 0) { |
84 | conn->retbuf = NULL; |
85 | conn->retlen = 0; |
86 | goto done; |
87 | } |
88 | conn->retsize += 4; |
89 | assert(conn->retbuf == conn->sizebuf); |
90 | conn->retbuf = snewn(conn->retsize, char); |
91 | memcpy(conn->retbuf, conn->sizebuf, 4); |
92 | } |
93 | |
94 | if (conn->retlen < conn->retsize) |
95 | return 0; /* more data to come */ |
96 | |
97 | done: |
98 | /* |
99 | * We have now completed the agent query. Do the callback, and |
100 | * clean up. (Of course we don't free retbuf, since ownership |
101 | * of that passes to the callback.) |
102 | */ |
103 | conn->callback(conn->callback_ctx, conn->retbuf, conn->retlen); |
104 | uxsel_del(fd); |
105 | close(fd); |
106 | del234(agent_connections, conn); |
107 | sfree(conn); |
108 | return 0; |
109 | } |
110 | |
111 | int agent_query(void *in, int inlen, void **out, int *outlen, |
112 | void (*callback)(void *, void *, int), void *callback_ctx) |
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113 | { |
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114 | char *name; |
115 | int sock; |
116 | struct sockaddr_un addr; |
117 | int done; |
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118 | struct agent_connection *conn; |
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119 | |
120 | name = getenv("SSH_AUTH_SOCK"); |
121 | if (!name) |
122 | goto failure; |
123 | |
124 | sock = socket(PF_UNIX, SOCK_STREAM, 0); |
125 | if (sock < 0) { |
126 | perror("socket(PF_UNIX)"); |
127 | exit(1); |
128 | } |
129 | |
130 | addr.sun_family = AF_UNIX; |
131 | strncpy(addr.sun_path, name, sizeof(addr.sun_path)); |
132 | if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) { |
133 | close(sock); |
134 | goto failure; |
135 | } |
136 | |
137 | for (done = 0; done < inlen ;) { |
138 | int ret = write(sock, (char *)in + done, inlen - done); |
139 | if (ret <= 0) { |
140 | close(sock); |
141 | goto failure; |
142 | } |
143 | done += ret; |
144 | } |
145 | |
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146 | if (!agent_connections) |
147 | agent_connections = newtree234(agent_conncmp); |
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148 | |
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149 | conn = snew(struct agent_connection); |
150 | conn->fd = sock; |
151 | conn->retbuf = conn->sizebuf; |
152 | conn->retsize = 4; |
153 | conn->retlen = 0; |
154 | conn->callback = callback; |
155 | conn->callback_ctx = callback_ctx; |
156 | add234(agent_connections, conn); |
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157 | |
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158 | uxsel_set(sock, 1, agent_select_result); |
159 | return 0; |
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160 | |
161 | failure: |
162 | *out = NULL; |
163 | *outlen = 0; |
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164 | return 1; |
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165 | } |