[331] | 1 | /* GSSAPI/krb5 support for FTP - loosely based on old krb4.c
|
---|
| 2 | *
|
---|
| 3 | * Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska Högskolan
|
---|
| 4 | * (Royal Institute of Technology, Stockholm, Sweden).
|
---|
| 5 | * Copyright (c) 2004 - 2016 Daniel Stenberg
|
---|
| 6 | * All rights reserved.
|
---|
| 7 | *
|
---|
| 8 | * Redistribution and use in source and binary forms, with or without
|
---|
| 9 | * modification, are permitted provided that the following conditions
|
---|
| 10 | * are met:
|
---|
| 11 | *
|
---|
| 12 | * 1. Redistributions of source code must retain the above copyright
|
---|
| 13 | * notice, this list of conditions and the following disclaimer.
|
---|
| 14 | *
|
---|
| 15 | * 2. Redistributions in binary form must reproduce the above copyright
|
---|
| 16 | * notice, this list of conditions and the following disclaimer in the
|
---|
| 17 | * documentation and/or other materials provided with the distribution.
|
---|
| 18 | *
|
---|
| 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.
|
---|
| 22 | *
|
---|
| 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
|
---|
| 25 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
---|
| 26 | * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
|
---|
| 27 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
---|
| 28 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
---|
| 29 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
---|
| 30 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
---|
| 31 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
---|
| 32 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
---|
| 33 | * SUCH DAMAGE. */
|
---|
| 34 |
|
---|
| 35 | #include "curl_setup.h"
|
---|
| 36 |
|
---|
| 37 | #if defined(HAVE_GSSAPI) && !defined(CURL_DISABLE_FTP)
|
---|
| 38 |
|
---|
| 39 | #ifdef HAVE_NETDB_H
|
---|
| 40 | #include <netdb.h>
|
---|
| 41 | #endif
|
---|
| 42 |
|
---|
| 43 | #include "urldata.h"
|
---|
| 44 | #include "curl_base64.h"
|
---|
| 45 | #include "ftp.h"
|
---|
| 46 | #include "curl_gssapi.h"
|
---|
| 47 | #include "sendf.h"
|
---|
| 48 | #include "curl_sec.h"
|
---|
| 49 | #include "warnless.h"
|
---|
| 50 |
|
---|
| 51 | /* The last 3 #include files should be in this order */
|
---|
| 52 | #include "curl_printf.h"
|
---|
| 53 | #include "curl_memory.h"
|
---|
| 54 | #include "memdebug.h"
|
---|
| 55 |
|
---|
| 56 | static int
|
---|
| 57 | krb5_init(void *app_data)
|
---|
| 58 | {
|
---|
| 59 | gss_ctx_id_t *context = app_data;
|
---|
| 60 | /* Make sure our context is initialized for krb5_end. */
|
---|
| 61 | *context = GSS_C_NO_CONTEXT;
|
---|
| 62 | return 0;
|
---|
| 63 | }
|
---|
| 64 |
|
---|
| 65 | static int
|
---|
| 66 | krb5_check_prot(void *app_data, int level)
|
---|
| 67 | {
|
---|
| 68 | (void)app_data; /* unused */
|
---|
| 69 | if(level == PROT_CONFIDENTIAL)
|
---|
| 70 | return -1;
|
---|
| 71 | return 0;
|
---|
| 72 | }
|
---|
| 73 |
|
---|
| 74 | static int
|
---|
| 75 | krb5_decode(void *app_data, void *buf, int len,
|
---|
| 76 | int level UNUSED_PARAM,
|
---|
| 77 | struct connectdata *conn UNUSED_PARAM)
|
---|
| 78 | {
|
---|
| 79 | gss_ctx_id_t *context = app_data;
|
---|
| 80 | OM_uint32 maj, min;
|
---|
| 81 | gss_buffer_desc enc, dec;
|
---|
| 82 |
|
---|
| 83 | (void)level;
|
---|
| 84 | (void)conn;
|
---|
| 85 |
|
---|
| 86 | enc.value = buf;
|
---|
| 87 | enc.length = len;
|
---|
| 88 | maj = gss_unseal(&min, *context, &enc, &dec, NULL, NULL);
|
---|
| 89 | if(maj != GSS_S_COMPLETE) {
|
---|
| 90 | if(len >= 4)
|
---|
| 91 | strcpy(buf, "599 ");
|
---|
| 92 | return -1;
|
---|
| 93 | }
|
---|
| 94 |
|
---|
| 95 | memcpy(buf, dec.value, dec.length);
|
---|
| 96 | len = curlx_uztosi(dec.length);
|
---|
| 97 | gss_release_buffer(&min, &dec);
|
---|
| 98 |
|
---|
| 99 | return len;
|
---|
| 100 | }
|
---|
| 101 |
|
---|
| 102 | static int
|
---|
| 103 | krb5_overhead(void *app_data, int level, int len)
|
---|
| 104 | {
|
---|
| 105 | /* no arguments are used */
|
---|
| 106 | (void)app_data;
|
---|
| 107 | (void)level;
|
---|
| 108 | (void)len;
|
---|
| 109 | return 0;
|
---|
| 110 | }
|
---|
| 111 |
|
---|
| 112 | static int
|
---|
| 113 | krb5_encode(void *app_data, const void *from, int length, int level, void **to)
|
---|
| 114 | {
|
---|
| 115 | gss_ctx_id_t *context = app_data;
|
---|
| 116 | gss_buffer_desc dec, enc;
|
---|
| 117 | OM_uint32 maj, min;
|
---|
| 118 | int state;
|
---|
| 119 | int len;
|
---|
| 120 |
|
---|
| 121 | /* NOTE that the cast is safe, neither of the krb5, gnu gss and heimdal
|
---|
| 122 | * libraries modify the input buffer in gss_seal()
|
---|
| 123 | */
|
---|
| 124 | dec.value = (void *)from;
|
---|
| 125 | dec.length = length;
|
---|
| 126 | maj = gss_seal(&min, *context,
|
---|
| 127 | level == PROT_PRIVATE,
|
---|
| 128 | GSS_C_QOP_DEFAULT,
|
---|
| 129 | &dec, &state, &enc);
|
---|
| 130 |
|
---|
| 131 | if(maj != GSS_S_COMPLETE)
|
---|
| 132 | return -1;
|
---|
| 133 |
|
---|
| 134 | /* malloc a new buffer, in case gss_release_buffer doesn't work as
|
---|
| 135 | expected */
|
---|
| 136 | *to = malloc(enc.length);
|
---|
| 137 | if(!*to)
|
---|
| 138 | return -1;
|
---|
| 139 | memcpy(*to, enc.value, enc.length);
|
---|
| 140 | len = curlx_uztosi(enc.length);
|
---|
| 141 | gss_release_buffer(&min, &enc);
|
---|
| 142 | return len;
|
---|
| 143 | }
|
---|
| 144 |
|
---|
| 145 | static int
|
---|
| 146 | krb5_auth(void *app_data, struct connectdata *conn)
|
---|
| 147 | {
|
---|
| 148 | int ret = AUTH_OK;
|
---|
| 149 | char *p;
|
---|
| 150 | const char *host = conn->host.name;
|
---|
| 151 | ssize_t nread;
|
---|
| 152 | curl_socklen_t l = sizeof(conn->local_addr);
|
---|
| 153 | struct Curl_easy *data = conn->data;
|
---|
| 154 | CURLcode result;
|
---|
| 155 | const char *service = data->set.str[STRING_SERVICE_NAME] ?
|
---|
| 156 | data->set.str[STRING_SERVICE_NAME] :
|
---|
| 157 | "ftp";
|
---|
| 158 | const char *srv_host = "host";
|
---|
| 159 | gss_buffer_desc input_buffer, output_buffer, _gssresp, *gssresp;
|
---|
| 160 | OM_uint32 maj, min;
|
---|
| 161 | gss_name_t gssname;
|
---|
| 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;
|
---|
| 167 | char *stringp;
|
---|
| 168 |
|
---|
| 169 | if(getsockname(conn->sock[FIRSTSOCKET],
|
---|
| 170 | (struct sockaddr *)&conn->local_addr, &l) < 0)
|
---|
| 171 | perror("getsockname()");
|
---|
| 172 |
|
---|
| 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;
|
---|
| 181 |
|
---|
| 182 | /* this loop will execute twice (once for service, once for host) */
|
---|
| 183 | for(;;) {
|
---|
| 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");
|
---|
| 187 | if(result)
|
---|
| 188 | return -2;
|
---|
| 189 |
|
---|
| 190 | if(Curl_GetFTPResponse(&nread, conn, NULL))
|
---|
| 191 | return -1;
|
---|
| 192 |
|
---|
| 193 | if(data->state.buffer[0] != '3')
|
---|
| 194 | return -1;
|
---|
| 195 | }
|
---|
| 196 |
|
---|
| 197 | stringp = aprintf("%s@%s", service, host);
|
---|
| 198 | if(!stringp)
|
---|
| 199 | return -2;
|
---|
| 200 |
|
---|
| 201 | input_buffer.value = stringp;
|
---|
| 202 | input_buffer.length = strlen(stringp);
|
---|
| 203 | maj = gss_import_name(&min, &input_buffer, GSS_C_NT_HOSTBASED_SERVICE,
|
---|
| 204 | &gssname);
|
---|
| 205 | free(stringp);
|
---|
| 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);
|
---|
| 210 | return AUTH_ERROR;
|
---|
| 211 | }
|
---|
| 212 | service = srv_host;
|
---|
| 213 | continue;
|
---|
| 214 | }
|
---|
| 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;
|
---|
| 220 |
|
---|
| 221 | do {
|
---|
| 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);
|
---|
| 226 | ret = AUTH_OK;
|
---|
| 227 | maj = Curl_gss_init_sec_context(data,
|
---|
| 228 | &min,
|
---|
| 229 | context,
|
---|
| 230 | gssname,
|
---|
| 231 | &Curl_krb5_mech_oid,
|
---|
| 232 | &chan,
|
---|
| 233 | gssresp,
|
---|
| 234 | &output_buffer,
|
---|
| 235 | TRUE,
|
---|
| 236 | NULL);
|
---|
| 237 |
|
---|
| 238 | if(gssresp) {
|
---|
| 239 | free(_gssresp.value);
|
---|
| 240 | gssresp = NULL;
|
---|
| 241 | }
|
---|
| 242 |
|
---|
| 243 | if(GSS_ERROR(maj)) {
|
---|
| 244 | Curl_infof(data, "Error creating security context\n");
|
---|
| 245 | ret = AUTH_ERROR;
|
---|
| 246 | break;
|
---|
| 247 | }
|
---|
| 248 |
|
---|
| 249 | if(output_buffer.length != 0) {
|
---|
| 250 | char *cmd;
|
---|
| 251 |
|
---|
| 252 | result = Curl_base64_encode(data, (char *)output_buffer.value,
|
---|
| 253 | output_buffer.length, &p, &base64_sz);
|
---|
| 254 | if(result) {
|
---|
| 255 | Curl_infof(data, "base64-encoding: %s\n",
|
---|
| 256 | curl_easy_strerror(result));
|
---|
| 257 | ret = AUTH_ERROR;
|
---|
| 258 | break;
|
---|
| 259 | }
|
---|
| 260 |
|
---|
| 261 | cmd = aprintf("ADAT %s", p);
|
---|
| 262 | if(cmd)
|
---|
| 263 | result = Curl_ftpsend(conn, cmd);
|
---|
| 264 | else
|
---|
| 265 | result = CURLE_OUT_OF_MEMORY;
|
---|
| 266 |
|
---|
| 267 | free(p);
|
---|
| 268 |
|
---|
| 269 | if(result) {
|
---|
| 270 | ret = -2;
|
---|
| 271 | break;
|
---|
| 272 | }
|
---|
| 273 |
|
---|
| 274 | if(Curl_GetFTPResponse(&nread, conn, NULL)) {
|
---|
| 275 | ret = -1;
|
---|
| 276 | break;
|
---|
| 277 | }
|
---|
| 278 |
|
---|
| 279 | if(data->state.buffer[0] != '2' && data->state.buffer[0] != '3') {
|
---|
| 280 | Curl_infof(data, "Server didn't accept auth data\n");
|
---|
| 281 | ret = AUTH_ERROR;
|
---|
| 282 | break;
|
---|
| 283 | }
|
---|
| 284 |
|
---|
| 285 | p = data->state.buffer + 4;
|
---|
| 286 | p = strstr(p, "ADAT=");
|
---|
| 287 | if(p) {
|
---|
| 288 | result = Curl_base64_decode(p + 5,
|
---|
| 289 | (unsigned char **)&_gssresp.value,
|
---|
| 290 | &_gssresp.length);
|
---|
| 291 | if(result) {
|
---|
| 292 | Curl_failf(data, "base64-decoding: %s",
|
---|
| 293 | curl_easy_strerror(result));
|
---|
| 294 | ret = AUTH_CONTINUE;
|
---|
| 295 | break;
|
---|
| 296 | }
|
---|
| 297 | }
|
---|
| 298 |
|
---|
| 299 | gssresp = &_gssresp;
|
---|
| 300 | }
|
---|
| 301 | } while(maj == GSS_S_CONTINUE_NEEDED);
|
---|
| 302 |
|
---|
| 303 | gss_release_name(&min, &gssname);
|
---|
| 304 | gss_release_buffer(&min, &output_buffer);
|
---|
| 305 |
|
---|
| 306 | if(gssresp)
|
---|
| 307 | free(_gssresp.value);
|
---|
| 308 |
|
---|
| 309 | if(ret == AUTH_OK || service == srv_host)
|
---|
| 310 | return ret;
|
---|
| 311 |
|
---|
| 312 | service = srv_host;
|
---|
| 313 | }
|
---|
| 314 | return ret;
|
---|
| 315 | }
|
---|
| 316 |
|
---|
| 317 | static void krb5_end(void *app_data)
|
---|
| 318 | {
|
---|
| 319 | OM_uint32 min;
|
---|
| 320 | gss_ctx_id_t *context = app_data;
|
---|
| 321 | if(*context != GSS_C_NO_CONTEXT) {
|
---|
| 322 | #ifdef DEBUGBUILD
|
---|
| 323 | OM_uint32 maj =
|
---|
| 324 | #endif
|
---|
| 325 | gss_delete_sec_context(&min, context, GSS_C_NO_BUFFER);
|
---|
| 326 | DEBUGASSERT(maj == GSS_S_COMPLETE);
|
---|
| 327 | }
|
---|
| 328 | }
|
---|
| 329 |
|
---|
| 330 | struct Curl_sec_client_mech Curl_krb5_client_mech = {
|
---|
| 331 | "GSSAPI",
|
---|
| 332 | sizeof(gss_ctx_id_t),
|
---|
| 333 | krb5_init,
|
---|
| 334 | krb5_auth,
|
---|
| 335 | krb5_end,
|
---|
| 336 | krb5_check_prot,
|
---|
| 337 | krb5_overhead,
|
---|
| 338 | krb5_encode,
|
---|
| 339 | krb5_decode
|
---|
| 340 | };
|
---|
| 341 |
|
---|
| 342 | #endif /* HAVE_GSSAPI && !CURL_DISABLE_FTP */
|
---|