1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
/* ks-engine-http.c - HTTP OpenPGP key access
* Copyright (C) 2011 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "dirmngr.h"
#include "misc.h"
#include "ks-engine.h"
/* How many redirections do we allow. */
#define MAX_REDIRECTS 2
/* Print a help output for the schemata supported by this module. */
gpg_error_t
ks_http_help (ctrl_t ctrl, parsed_uri_t uri)
{
const char data[] =
"Handler for HTTP URLs:\n"
" http://\n"
#if HTTP_USE_GNUTLS || HTTP_USE_NTBTLS
" https://\n"
#endif
"Supported methods: fetch\n";
gpg_error_t err;
#if HTTP_USE_GNUTLS || HTTP_USE_NTBTLS
const char data2[] = " http\n https";
#else
const char data2[] = " http";
#endif
if (!uri)
err = ks_print_help (ctrl, data2);
else if (uri->is_http && strcmp (uri->scheme, "hkp"))
err = ks_print_help (ctrl, data);
else
err = 0;
return err;
}
/* Get the key from URL which is expected to specify a http style
scheme. On success R_FP has an open stream to read the data. */
gpg_error_t
ks_http_fetch (ctrl_t ctrl, const char *url, estream_t *r_fp)
{
gpg_error_t err;
http_session_t session = NULL;
http_t http = NULL;
int redirects_left = MAX_REDIRECTS;
estream_t fp = NULL;
char *request_buffer = NULL;
once_more:
/* Note that we only use the system provided certificates with the
* fetch command. */
err = http_session_new (&session, NULL, NULL, HTTP_FLAG_TRUST_SYS);
if (err)
goto leave;
http_session_set_log_cb (session, cert_log_cb);
*r_fp = NULL;
err = http_open (&http,
HTTP_REQ_GET,
url,
/* httphost */ NULL,
/* fixme: AUTH */ NULL,
((opt.honor_http_proxy? HTTP_FLAG_TRY_PROXY:0)
| (opt.use_tor? HTTP_FLAG_FORCE_TOR:0)),
ctrl->http_proxy,
session,
NULL,
/*FIXME curl->srvtag*/NULL);
if (!err)
{
fp = http_get_write_ptr (http);
/* Avoid caches to get the most recent copy of the key. We set
both the Pragma and Cache-Control versions of the header, so
we're good with both HTTP 1.0 and 1.1. */
es_fputs ("Pragma: no-cache\r\n"
"Cache-Control: no-cache\r\n", fp);
http_start_data (http);
if (es_ferror (fp))
err = gpg_error_from_syserror ();
}
if (err)
{
/* Fixme: After a redirection we show the old host name. */
log_error (_("error connecting to '%s': %s\n"),
url, gpg_strerror (err));
goto leave;
}
/* Wait for the response. */
dirmngr_tick (ctrl);
err = http_wait_response (http);
if (err)
{
log_error (_("error reading HTTP response for '%s': %s\n"),
url, gpg_strerror (err));
goto leave;
}
switch (http_get_status_code (http))
{
case 200:
err = 0;
break; /* Success. */
case 301:
case 302:
case 307:
{
const char *s = http_get_header (http, "Location");
log_info (_("URL '%s' redirected to '%s' (%u)\n"),
url, s?s:"[none]", http_get_status_code (http));
if (s && *s && redirects_left-- )
{
xfree (request_buffer);
request_buffer = xtrystrdup (s);
if (request_buffer)
{
url = request_buffer;
http_close (http, 0);
http = NULL;
http_session_release (session);
goto once_more;
}
err = gpg_error_from_syserror ();
}
else
err = gpg_error (GPG_ERR_NO_DATA);
log_error (_("too many redirections\n"));
}
goto leave;
default:
log_error (_("error accessing '%s': http status %u\n"),
url, http_get_status_code (http));
err = gpg_error (GPG_ERR_NO_DATA);
goto leave;
}
fp = http_get_read_ptr (http);
if (!fp)
{
err = gpg_error (GPG_ERR_BUG);
goto leave;
}
/* Return the read stream and close the HTTP context. */
*r_fp = fp;
http_close (http, 1);
http = NULL;
leave:
http_close (http, 0);
http_session_release (session);
xfree (request_buffer);
return err;
}
|
