1 /*
2 * Copyright 2001-2017 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include "e_os.h"
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include "crypto/ctype.h"
14 #include <string.h>
15 #include <openssl/asn1.h>
16 #include <openssl/ocsp.h>
17 #include <openssl/err.h>
18 #include <openssl/buffer.h>
19
20 /* Stateful OCSP request code, supporting non-blocking I/O */
21
22 /* Opaque OCSP request status structure */
23
24 struct ocsp_req_ctx_st {
25 int state; /* Current I/O state */
26 unsigned char *iobuf; /* Line buffer */
27 int iobuflen; /* Line buffer length */
28 BIO *io; /* BIO to perform I/O with */
29 BIO *mem; /* Memory BIO response is built into */
30 unsigned long asn1_len; /* ASN1 length of response */
31 unsigned long max_resp_len; /* Maximum length of response */
32 };
33
34 #define OCSP_MAX_RESP_LENGTH (100 * 1024)
35 #define OCSP_MAX_LINE_LEN 4096;
36
37 /* OCSP states */
38
39 /* If set no reading should be performed */
40 #define OHS_NOREAD 0x1000
41 /* Error condition */
42 #define OHS_ERROR (0 | OHS_NOREAD)
43 /* First line being read */
44 #define OHS_FIRSTLINE 1
45 /* MIME headers being read */
46 #define OHS_HEADERS 2
47 /* OCSP initial header (tag + length) being read */
48 #define OHS_ASN1_HEADER 3
49 /* OCSP content octets being read */
50 #define OHS_ASN1_CONTENT 4
51 /* First call: ready to start I/O */
52 #define OHS_ASN1_WRITE_INIT (5 | OHS_NOREAD)
53 /* Request being sent */
54 #define OHS_ASN1_WRITE (6 | OHS_NOREAD)
55 /* Request being flushed */
56 #define OHS_ASN1_FLUSH (7 | OHS_NOREAD)
57 /* Completed */
58 #define OHS_DONE (8 | OHS_NOREAD)
59 /* Headers set, no final \r\n included */
60 #define OHS_HTTP_HEADER (9 | OHS_NOREAD)
61
62 static int parse_http_line1(char *line);
63
OCSP_REQ_CTX_new(BIO * io,int maxline)64 OCSP_REQ_CTX *OCSP_REQ_CTX_new(BIO *io, int maxline)
65 {
66 OCSP_REQ_CTX *rctx = OPENSSL_zalloc(sizeof(*rctx));
67
68 if (rctx == NULL)
69 return NULL;
70 rctx->state = OHS_ERROR;
71 rctx->max_resp_len = OCSP_MAX_RESP_LENGTH;
72 rctx->mem = BIO_new(BIO_s_mem());
73 rctx->io = io;
74 if (maxline > 0)
75 rctx->iobuflen = maxline;
76 else
77 rctx->iobuflen = OCSP_MAX_LINE_LEN;
78 rctx->iobuf = OPENSSL_malloc(rctx->iobuflen);
79 if (rctx->iobuf == NULL || rctx->mem == NULL) {
80 OCSP_REQ_CTX_free(rctx);
81 return NULL;
82 }
83 return rctx;
84 }
85
OCSP_REQ_CTX_free(OCSP_REQ_CTX * rctx)86 void OCSP_REQ_CTX_free(OCSP_REQ_CTX *rctx)
87 {
88 if (!rctx)
89 return;
90 BIO_free(rctx->mem);
91 OPENSSL_free(rctx->iobuf);
92 OPENSSL_free(rctx);
93 }
94
OCSP_REQ_CTX_get0_mem_bio(OCSP_REQ_CTX * rctx)95 BIO *OCSP_REQ_CTX_get0_mem_bio(OCSP_REQ_CTX *rctx)
96 {
97 return rctx->mem;
98 }
99
OCSP_set_max_response_length(OCSP_REQ_CTX * rctx,unsigned long len)100 void OCSP_set_max_response_length(OCSP_REQ_CTX *rctx, unsigned long len)
101 {
102 if (len == 0)
103 rctx->max_resp_len = OCSP_MAX_RESP_LENGTH;
104 else
105 rctx->max_resp_len = len;
106 }
107
OCSP_REQ_CTX_i2d(OCSP_REQ_CTX * rctx,const ASN1_ITEM * it,ASN1_VALUE * val)108 int OCSP_REQ_CTX_i2d(OCSP_REQ_CTX *rctx, const ASN1_ITEM *it, ASN1_VALUE *val)
109 {
110 static const char req_hdr[] =
111 "Content-Type: application/ocsp-request\r\n"
112 "Content-Length: %d\r\n\r\n";
113 int reqlen = ASN1_item_i2d(val, NULL, it);
114 if (BIO_printf(rctx->mem, req_hdr, reqlen) <= 0)
115 return 0;
116 if (ASN1_item_i2d_bio(it, rctx->mem, val) <= 0)
117 return 0;
118 rctx->state = OHS_ASN1_WRITE_INIT;
119 return 1;
120 }
121
OCSP_REQ_CTX_nbio_d2i(OCSP_REQ_CTX * rctx,ASN1_VALUE ** pval,const ASN1_ITEM * it)122 int OCSP_REQ_CTX_nbio_d2i(OCSP_REQ_CTX *rctx,
123 ASN1_VALUE **pval, const ASN1_ITEM *it)
124 {
125 int rv, len;
126 const unsigned char *p;
127
128 rv = OCSP_REQ_CTX_nbio(rctx);
129 if (rv != 1)
130 return rv;
131
132 len = BIO_get_mem_data(rctx->mem, &p);
133 *pval = ASN1_item_d2i(NULL, &p, len, it);
134 if (*pval == NULL) {
135 rctx->state = OHS_ERROR;
136 return 0;
137 }
138 return 1;
139 }
140
OCSP_REQ_CTX_http(OCSP_REQ_CTX * rctx,const char * op,const char * path)141 int OCSP_REQ_CTX_http(OCSP_REQ_CTX *rctx, const char *op, const char *path)
142 {
143 static const char http_hdr[] = "%s %s HTTP/1.0\r\n";
144
145 if (!path)
146 path = "/";
147
148 if (BIO_printf(rctx->mem, http_hdr, op, path) <= 0)
149 return 0;
150 rctx->state = OHS_HTTP_HEADER;
151 return 1;
152 }
153
OCSP_REQ_CTX_set1_req(OCSP_REQ_CTX * rctx,OCSP_REQUEST * req)154 int OCSP_REQ_CTX_set1_req(OCSP_REQ_CTX *rctx, OCSP_REQUEST *req)
155 {
156 return OCSP_REQ_CTX_i2d(rctx, ASN1_ITEM_rptr(OCSP_REQUEST),
157 (ASN1_VALUE *)req);
158 }
159
OCSP_REQ_CTX_add1_header(OCSP_REQ_CTX * rctx,const char * name,const char * value)160 int OCSP_REQ_CTX_add1_header(OCSP_REQ_CTX *rctx,
161 const char *name, const char *value)
162 {
163 if (!name)
164 return 0;
165 if (BIO_puts(rctx->mem, name) <= 0)
166 return 0;
167 if (value) {
168 if (BIO_write(rctx->mem, ": ", 2) != 2)
169 return 0;
170 if (BIO_puts(rctx->mem, value) <= 0)
171 return 0;
172 }
173 if (BIO_write(rctx->mem, "\r\n", 2) != 2)
174 return 0;
175 rctx->state = OHS_HTTP_HEADER;
176 return 1;
177 }
178
OCSP_sendreq_new(BIO * io,const char * path,OCSP_REQUEST * req,int maxline)179 OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, const char *path, OCSP_REQUEST *req,
180 int maxline)
181 {
182
183 OCSP_REQ_CTX *rctx = NULL;
184 rctx = OCSP_REQ_CTX_new(io, maxline);
185 if (rctx == NULL)
186 return NULL;
187
188 if (!OCSP_REQ_CTX_http(rctx, "POST", path))
189 goto err;
190
191 if (req && !OCSP_REQ_CTX_set1_req(rctx, req))
192 goto err;
193
194 return rctx;
195
196 err:
197 OCSP_REQ_CTX_free(rctx);
198 return NULL;
199 }
200
201 /*
202 * Parse the HTTP response. This will look like this: "HTTP/1.0 200 OK". We
203 * need to obtain the numeric code and (optional) informational message.
204 */
205
parse_http_line1(char * line)206 static int parse_http_line1(char *line)
207 {
208 int retcode;
209 char *p, *q, *r;
210 /* Skip to first white space (passed protocol info) */
211
212 for (p = line; *p && !ossl_isspace(*p); p++)
213 continue;
214 if (!*p) {
215 OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
216 return 0;
217 }
218
219 /* Skip past white space to start of response code */
220 while (*p && ossl_isspace(*p))
221 p++;
222
223 if (!*p) {
224 OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
225 return 0;
226 }
227
228 /* Find end of response code: first whitespace after start of code */
229 for (q = p; *q && !ossl_isspace(*q); q++)
230 continue;
231
232 if (!*q) {
233 OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_PARSE_ERROR);
234 return 0;
235 }
236
237 /* Set end of response code and start of message */
238 *q++ = 0;
239
240 /* Attempt to parse numeric code */
241 retcode = strtoul(p, &r, 10);
242
243 if (*r)
244 return 0;
245
246 /* Skip over any leading white space in message */
247 while (*q && ossl_isspace(*q))
248 q++;
249
250 if (*q) {
251 /*
252 * Finally zap any trailing white space in message (include CRLF)
253 */
254
255 /* We know q has a non white space character so this is OK */
256 for (r = q + strlen(q) - 1; ossl_isspace(*r); r--)
257 *r = 0;
258 }
259 if (retcode != 200) {
260 OCSPerr(OCSP_F_PARSE_HTTP_LINE1, OCSP_R_SERVER_RESPONSE_ERROR);
261 if (!*q)
262 ERR_add_error_data(2, "Code=", p);
263 else
264 ERR_add_error_data(4, "Code=", p, ",Reason=", q);
265 return 0;
266 }
267
268 return 1;
269
270 }
271
OCSP_REQ_CTX_nbio(OCSP_REQ_CTX * rctx)272 int OCSP_REQ_CTX_nbio(OCSP_REQ_CTX *rctx)
273 {
274 int i, n;
275 const unsigned char *p;
276 next_io:
277 if (!(rctx->state & OHS_NOREAD)) {
278 n = BIO_read(rctx->io, rctx->iobuf, rctx->iobuflen);
279
280 if (n <= 0) {
281 if (BIO_should_retry(rctx->io))
282 return -1;
283 return 0;
284 }
285
286 /* Write data to memory BIO */
287
288 if (BIO_write(rctx->mem, rctx->iobuf, n) != n)
289 return 0;
290 }
291
292 switch (rctx->state) {
293 case OHS_HTTP_HEADER:
294 /* Last operation was adding headers: need a final \r\n */
295 if (BIO_write(rctx->mem, "\r\n", 2) != 2) {
296 rctx->state = OHS_ERROR;
297 return 0;
298 }
299 rctx->state = OHS_ASN1_WRITE_INIT;
300
301 /* fall thru */
302 case OHS_ASN1_WRITE_INIT:
303 rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
304 rctx->state = OHS_ASN1_WRITE;
305
306 /* fall thru */
307 case OHS_ASN1_WRITE:
308 n = BIO_get_mem_data(rctx->mem, &p);
309
310 i = BIO_write(rctx->io, p + (n - rctx->asn1_len), rctx->asn1_len);
311
312 if (i <= 0) {
313 if (BIO_should_retry(rctx->io))
314 return -1;
315 rctx->state = OHS_ERROR;
316 return 0;
317 }
318
319 rctx->asn1_len -= i;
320
321 if (rctx->asn1_len > 0)
322 goto next_io;
323
324 rctx->state = OHS_ASN1_FLUSH;
325
326 (void)BIO_reset(rctx->mem);
327
328 /* fall thru */
329 case OHS_ASN1_FLUSH:
330
331 i = BIO_flush(rctx->io);
332
333 if (i > 0) {
334 rctx->state = OHS_FIRSTLINE;
335 goto next_io;
336 }
337
338 if (BIO_should_retry(rctx->io))
339 return -1;
340
341 rctx->state = OHS_ERROR;
342 return 0;
343
344 case OHS_ERROR:
345 return 0;
346
347 case OHS_FIRSTLINE:
348 case OHS_HEADERS:
349
350 /* Attempt to read a line in */
351
352 next_line:
353 /*
354 * Due to &%^*$" memory BIO behaviour with BIO_gets we have to check
355 * there's a complete line in there before calling BIO_gets or we'll
356 * just get a partial read.
357 */
358 n = BIO_get_mem_data(rctx->mem, &p);
359 if ((n <= 0) || !memchr(p, '\n', n)) {
360 if (n >= rctx->iobuflen) {
361 rctx->state = OHS_ERROR;
362 return 0;
363 }
364 goto next_io;
365 }
366 n = BIO_gets(rctx->mem, (char *)rctx->iobuf, rctx->iobuflen);
367
368 if (n <= 0) {
369 if (BIO_should_retry(rctx->mem))
370 goto next_io;
371 rctx->state = OHS_ERROR;
372 return 0;
373 }
374
375 /* Don't allow excessive lines */
376 if (n == rctx->iobuflen) {
377 rctx->state = OHS_ERROR;
378 return 0;
379 }
380
381 /* First line */
382 if (rctx->state == OHS_FIRSTLINE) {
383 if (parse_http_line1((char *)rctx->iobuf)) {
384 rctx->state = OHS_HEADERS;
385 goto next_line;
386 } else {
387 rctx->state = OHS_ERROR;
388 return 0;
389 }
390 } else {
391 /* Look for blank line: end of headers */
392 for (p = rctx->iobuf; *p; p++) {
393 if ((*p != '\r') && (*p != '\n'))
394 break;
395 }
396 if (*p)
397 goto next_line;
398
399 rctx->state = OHS_ASN1_HEADER;
400
401 }
402
403 /* Fall thru */
404
405 case OHS_ASN1_HEADER:
406 /*
407 * Now reading ASN1 header: can read at least 2 bytes which is enough
408 * for ASN1 SEQUENCE header and either length field or at least the
409 * length of the length field.
410 */
411 n = BIO_get_mem_data(rctx->mem, &p);
412 if (n < 2)
413 goto next_io;
414
415 /* Check it is an ASN1 SEQUENCE */
416 if (*p++ != (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {
417 rctx->state = OHS_ERROR;
418 return 0;
419 }
420
421 /* Check out length field */
422 if (*p & 0x80) {
423 /*
424 * If MSB set on initial length octet we can now always read 6
425 * octets: make sure we have them.
426 */
427 if (n < 6)
428 goto next_io;
429 n = *p & 0x7F;
430 /* Not NDEF or excessive length */
431 if (!n || (n > 4)) {
432 rctx->state = OHS_ERROR;
433 return 0;
434 }
435 p++;
436 rctx->asn1_len = 0;
437 for (i = 0; i < n; i++) {
438 rctx->asn1_len <<= 8;
439 rctx->asn1_len |= *p++;
440 }
441
442 if (rctx->asn1_len > rctx->max_resp_len) {
443 rctx->state = OHS_ERROR;
444 return 0;
445 }
446
447 rctx->asn1_len += n + 2;
448 } else
449 rctx->asn1_len = *p + 2;
450
451 rctx->state = OHS_ASN1_CONTENT;
452
453 /* Fall thru */
454
455 case OHS_ASN1_CONTENT:
456 n = BIO_get_mem_data(rctx->mem, NULL);
457 if (n < (int)rctx->asn1_len)
458 goto next_io;
459
460 rctx->state = OHS_DONE;
461 return 1;
462
463 case OHS_DONE:
464 return 1;
465
466 }
467
468 return 0;
469
470 }
471
OCSP_sendreq_nbio(OCSP_RESPONSE ** presp,OCSP_REQ_CTX * rctx)472 int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
473 {
474 return OCSP_REQ_CTX_nbio_d2i(rctx,
475 (ASN1_VALUE **)presp,
476 ASN1_ITEM_rptr(OCSP_RESPONSE));
477 }
478
479 /* Blocking OCSP request handler: now a special case of non-blocking I/O */
480
OCSP_sendreq_bio(BIO * b,const char * path,OCSP_REQUEST * req)481 OCSP_RESPONSE *OCSP_sendreq_bio(BIO *b, const char *path, OCSP_REQUEST *req)
482 {
483 OCSP_RESPONSE *resp = NULL;
484 OCSP_REQ_CTX *ctx;
485 int rv;
486
487 ctx = OCSP_sendreq_new(b, path, req, -1);
488
489 if (ctx == NULL)
490 return NULL;
491
492 do {
493 rv = OCSP_sendreq_nbio(&resp, ctx);
494 } while ((rv == -1) && BIO_should_retry(b));
495
496 OCSP_REQ_CTX_free(ctx);
497
498 if (rv)
499 return resp;
500
501 return NULL;
502 }
503