1 /* GSSAPI/krb5 support for FTP - loosely based on old krb4.c
3 * Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska Högskolan
4 * (Royal Institute of Technology, Stockholm, Sweden).
5 * Copyright (c) 2004 - 2017 Daniel Stenberg
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9 * modification, are permitted provided that the following conditions
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13 * notice, this list of conditions and the following disclaimer.
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19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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35 #include "curl_setup.h"
37 #if defined(HAVE_GSSAPI) && !defined(CURL_DISABLE_FTP)
44 #include "curl_base64.h"
46 #include "curl_gssapi.h"
51 /* The last 3 #include files should be in this order */
52 #include "curl_printf.h"
53 #include "curl_memory.h"
57 krb5_init(void *app_data)
59 gss_ctx_id_t *context = app_data;
60 /* Make sure our context is initialized for krb5_end. */
61 *context = GSS_C_NO_CONTEXT;
66 krb5_check_prot(void *app_data, int level)
68 (void)app_data; /* unused */
69 if(level == PROT_CONFIDENTIAL)
75 krb5_decode(void *app_data, void *buf, int len,
76 int level UNUSED_PARAM,
77 struct connectdata *conn UNUSED_PARAM)
79 gss_ctx_id_t *context = app_data;
81 gss_buffer_desc enc, dec;
88 maj = gss_unwrap(&min, *context, &enc, &dec, NULL, NULL);
89 if(maj != GSS_S_COMPLETE) {
95 memcpy(buf, dec.value, dec.length);
96 len = curlx_uztosi(dec.length);
97 gss_release_buffer(&min, &dec);
103 krb5_overhead(void *app_data, int level, int len)
105 /* no arguments are used */
113 krb5_encode(void *app_data, const void *from, int length, int level, void **to)
115 gss_ctx_id_t *context = app_data;
116 gss_buffer_desc dec, enc;
121 /* NOTE that the cast is safe, neither of the krb5, gnu gss and heimdal
122 * libraries modify the input buffer in gss_wrap()
124 dec.value = (void *)from;
126 maj = gss_wrap(&min, *context,
127 level == PROT_PRIVATE,
131 if(maj != GSS_S_COMPLETE)
134 /* malloc a new buffer, in case gss_release_buffer doesn't work as
136 *to = malloc(enc.length);
139 memcpy(*to, enc.value, enc.length);
140 len = curlx_uztosi(enc.length);
141 gss_release_buffer(&min, &enc);
146 krb5_auth(void *app_data, struct connectdata *conn)
150 const char *host = conn->host.name;
152 curl_socklen_t l = sizeof(conn->local_addr);
153 struct Curl_easy *data = conn->data;
155 const char *service = data->set.str[STRING_SERVICE_NAME] ?
156 data->set.str[STRING_SERVICE_NAME] :
158 const char *srv_host = "host";
159 gss_buffer_desc input_buffer, output_buffer, _gssresp, *gssresp;
162 gss_ctx_id_t *context = app_data;
163 struct gss_channel_bindings_struct chan;
164 size_t base64_sz = 0;
165 struct sockaddr_in **remote_addr =
166 (struct sockaddr_in **)&conn->ip_addr->ai_addr;
169 if(getsockname(conn->sock[FIRSTSOCKET],
170 (struct sockaddr *)&conn->local_addr, &l) < 0)
171 perror("getsockname()");
173 chan.initiator_addrtype = GSS_C_AF_INET;
174 chan.initiator_address.length = l - 4;
175 chan.initiator_address.value = &conn->local_addr.sin_addr.s_addr;
176 chan.acceptor_addrtype = GSS_C_AF_INET;
177 chan.acceptor_address.length = l - 4;
178 chan.acceptor_address.value = &(*remote_addr)->sin_addr.s_addr;
179 chan.application_data.length = 0;
180 chan.application_data.value = NULL;
182 /* this loop will execute twice (once for service, once for host) */
184 /* this really shouldn't be repeated here, but can't help it */
185 if(service == srv_host) {
186 result = Curl_ftpsend(conn, "AUTH GSSAPI");
190 if(Curl_GetFTPResponse(&nread, conn, NULL))
193 if(data->state.buffer[0] != '3')
197 stringp = aprintf("%s@%s", service, host);
201 input_buffer.value = stringp;
202 input_buffer.length = strlen(stringp);
203 maj = gss_import_name(&min, &input_buffer, GSS_C_NT_HOSTBASED_SERVICE,
206 if(maj != GSS_S_COMPLETE) {
207 gss_release_name(&min, &gssname);
208 if(service == srv_host) {
209 Curl_failf(data, "Error importing service name %s@%s", service, host);
215 /* We pass NULL as |output_name_type| to avoid a leak. */
216 gss_display_name(&min, gssname, &output_buffer, NULL);
217 Curl_infof(data, "Trying against %s\n", output_buffer.value);
218 gssresp = GSS_C_NO_BUFFER;
219 *context = GSS_C_NO_CONTEXT;
222 /* Release the buffer at each iteration to avoid leaking: the first time
223 we are releasing the memory from gss_display_name. The last item is
224 taken care by a final gss_release_buffer. */
225 gss_release_buffer(&min, &output_buffer);
227 maj = Curl_gss_init_sec_context(data,
239 free(_gssresp.value);
244 Curl_infof(data, "Error creating security context\n");
249 if(output_buffer.length != 0) {
252 result = Curl_base64_encode(data, (char *)output_buffer.value,
253 output_buffer.length, &p, &base64_sz);
255 Curl_infof(data, "base64-encoding: %s\n",
256 curl_easy_strerror(result));
261 cmd = aprintf("ADAT %s", p);
263 result = Curl_ftpsend(conn, cmd);
265 result = CURLE_OUT_OF_MEMORY;
274 if(Curl_GetFTPResponse(&nread, conn, NULL)) {
279 if(data->state.buffer[0] != '2' && data->state.buffer[0] != '3') {
280 Curl_infof(data, "Server didn't accept auth data\n");
285 _gssresp.value = NULL; /* make sure it is initialized */
286 p = data->state.buffer + 4;
287 p = strstr(p, "ADAT=");
289 result = Curl_base64_decode(p + 5,
290 (unsigned char **)&_gssresp.value,
293 Curl_failf(data, "base64-decoding: %s",
294 curl_easy_strerror(result));
302 } while(maj == GSS_S_CONTINUE_NEEDED);
304 gss_release_name(&min, &gssname);
305 gss_release_buffer(&min, &output_buffer);
308 free(_gssresp.value);
310 if(ret == AUTH_OK || service == srv_host)
318 static void krb5_end(void *app_data)
321 gss_ctx_id_t *context = app_data;
322 if(*context != GSS_C_NO_CONTEXT) {
326 gss_delete_sec_context(&min, context, GSS_C_NO_BUFFER);
327 DEBUGASSERT(maj == GSS_S_COMPLETE);
331 struct Curl_sec_client_mech Curl_krb5_client_mech = {
333 sizeof(gss_ctx_id_t),
343 #endif /* HAVE_GSSAPI && !CURL_DISABLE_FTP */