1 /*
2  * Copyright 2001-2023 The OpenSSL Project Authors. All Rights Reserved.
3  * Copyright Siemens AG 2018-2020
4  *
5  * Licensed under the Apache License 2.0 (the "License").  You may not use
6  * this file except in compliance with the License.  You can obtain a copy
7  * in the file LICENSE in the source distribution or at
8  * https://www.openssl.org/source/license.html
9  */
10 
11 #include "e_os.h"
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include "crypto/ctype.h"
15 #include <string.h>
16 #include <openssl/asn1.h>
17 #include <openssl/evp.h>
18 #include <openssl/err.h>
19 #include <openssl/httperr.h>
20 #include <openssl/cmperr.h>
21 #include <openssl/buffer.h>
22 #include <openssl/http.h>
23 #include "internal/sockets.h"
24 #include "internal/cryptlib.h" /* for ossl_assert() */
25 
26 #define HAS_PREFIX(str, prefix) (strncmp(str, prefix, sizeof(prefix) - 1) == 0)
27 #define HTTP_PREFIX "HTTP/"
28 #define HTTP_VERSION_PATT "1." /* allow 1.x */
29 #define HTTP_VERSION_STR_LEN sizeof(HTTP_VERSION_PATT) /* == strlen("1.0") */
30 #define HTTP_PREFIX_VERSION HTTP_PREFIX""HTTP_VERSION_PATT
31 #define HTTP_1_0 HTTP_PREFIX_VERSION"0" /* "HTTP/1.0" */
32 #define HTTP_LINE1_MINLEN (sizeof(HTTP_PREFIX_VERSION "x 200\n") - 1)
33 #define HTTP_VERSION_MAX_REDIRECTIONS 50
34 
35 #define HTTP_STATUS_CODE_OK                200
36 #define HTTP_STATUS_CODE_MOVED_PERMANENTLY 301
37 #define HTTP_STATUS_CODE_FOUND             302
38 
39 /* Stateful HTTP request code, supporting blocking and non-blocking I/O */
40 
41 /* Opaque HTTP request status structure */
42 
43 struct ossl_http_req_ctx_st {
44     int state;                  /* Current I/O state */
45     unsigned char *buf;         /* Buffer to write request or read response */
46     int buf_size;               /* Buffer size */
47     int free_wbio;              /* wbio allocated internally, free with ctx */
48     BIO *wbio;                  /* BIO to write/send request to */
49     BIO *rbio;                  /* BIO to read/receive response from */
50     OSSL_HTTP_bio_cb_t upd_fn;  /* Optional BIO update callback used for TLS */
51     void *upd_arg;              /* Optional arg for update callback function */
52     int use_ssl;                /* Use HTTPS */
53     char *proxy;                /* Optional proxy name or URI */
54     char *server;               /* Optional server host name */
55     char *port;                 /* Optional server port */
56     BIO *mem;                   /* Mem BIO holding request header or response */
57     BIO *req;                   /* BIO holding the request provided by caller */
58     int method_POST;            /* HTTP method is POST (else GET) */
59     char *expected_ct;          /* Optional expected Content-Type */
60     int expect_asn1;            /* Response must be ASN.1-encoded */
61     unsigned char *pos;         /* Current position sending data */
62     long len_to_send;           /* Number of bytes still to send */
63     size_t resp_len;            /* Length of response */
64     size_t max_resp_len;        /* Maximum length of response, or 0 */
65     int keep_alive;             /* Persistent conn. 0=no, 1=prefer, 2=require */
66     time_t max_time;            /* Maximum end time of current transfer, or 0 */
67     time_t max_total_time;      /* Maximum end time of total transfer, or 0 */
68     char *redirection_url;      /* Location obtained from HTTP status 301/302 */
69 };
70 
71 /* HTTP states */
72 
73 #define OHS_NOREAD         0x1000 /* If set no reading should be performed */
74 #define OHS_ERROR          (0 | OHS_NOREAD) /* Error condition */
75 #define OHS_ADD_HEADERS    (1 | OHS_NOREAD) /* Adding header lines to request */
76 #define OHS_WRITE_INIT     (2 | OHS_NOREAD) /* 1st call: ready to start send */
77 #define OHS_WRITE_HDR      (3 | OHS_NOREAD) /* Request header being sent */
78 #define OHS_WRITE_REQ      (4 | OHS_NOREAD) /* Request contents being sent */
79 #define OHS_FLUSH          (5 | OHS_NOREAD) /* Request being flushed */
80 #define OHS_FIRSTLINE       1 /* First line of response being read */
81 #define OHS_HEADERS         2 /* MIME headers of response being read */
82 #define OHS_REDIRECT        3 /* MIME headers being read, expecting Location */
83 #define OHS_ASN1_HEADER     4 /* ASN1 sequence header (tag+length) being read */
84 #define OHS_ASN1_CONTENT    5 /* ASN1 content octets being read */
85 #define OHS_ASN1_DONE      (6 | OHS_NOREAD) /* ASN1 content read completed */
86 #define OHS_STREAM         (7 | OHS_NOREAD) /* HTTP content stream to be read */
87 
88 /* Low-level HTTP API implementation */
89 
90 OSSL_HTTP_REQ_CTX *OSSL_HTTP_REQ_CTX_new(BIO *wbio, BIO *rbio, int buf_size)
91 {
92     OSSL_HTTP_REQ_CTX *rctx;
93 
94     if (wbio == NULL || rbio == NULL) {
95         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
96         return NULL;
97     }
98 
99     if ((rctx = OPENSSL_zalloc(sizeof(*rctx))) == NULL)
100         return NULL;
101     rctx->state = OHS_ERROR;
102     rctx->buf_size = buf_size > 0 ? buf_size : OSSL_HTTP_DEFAULT_MAX_LINE_LEN;
103     rctx->buf = OPENSSL_malloc(rctx->buf_size);
104     rctx->wbio = wbio;
105     rctx->rbio = rbio;
106     if (rctx->buf == NULL) {
107         OPENSSL_free(rctx);
108         return NULL;
109     }
110     rctx->max_resp_len = OSSL_HTTP_DEFAULT_MAX_RESP_LEN;
111     /* everything else is 0, e.g. rctx->len_to_send, or NULL, e.g. rctx->mem  */
112     return rctx;
113 }
114 
115 void OSSL_HTTP_REQ_CTX_free(OSSL_HTTP_REQ_CTX *rctx)
116 {
117     if (rctx == NULL)
118         return;
119     /*
120      * Use BIO_free_all() because bio_update_fn may prepend or append to cbio.
121      * This also frees any (e.g., SSL/TLS) BIOs linked with bio and,
122      * like BIO_reset(bio), calls SSL_shutdown() to notify/alert the peer.
123      */
124     if (rctx->free_wbio)
125         BIO_free_all(rctx->wbio);
126     /* do not free rctx->rbio */
127     BIO_free(rctx->mem);
128     BIO_free(rctx->req);
129     OPENSSL_free(rctx->buf);
130     OPENSSL_free(rctx->proxy);
131     OPENSSL_free(rctx->server);
132     OPENSSL_free(rctx->port);
133     OPENSSL_free(rctx->expected_ct);
134     OPENSSL_free(rctx);
135 }
136 
137 BIO *OSSL_HTTP_REQ_CTX_get0_mem_bio(const OSSL_HTTP_REQ_CTX *rctx)
138 {
139     if (rctx == NULL) {
140         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
141         return NULL;
142     }
143     return rctx->mem;
144 }
145 
146 size_t OSSL_HTTP_REQ_CTX_get_resp_len(const OSSL_HTTP_REQ_CTX *rctx)
147 {
148     if (rctx == NULL) {
149         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
150         return 0;
151     }
152     return rctx->resp_len;
153 }
154 
155 void OSSL_HTTP_REQ_CTX_set_max_response_length(OSSL_HTTP_REQ_CTX *rctx,
156                                                unsigned long len)
157 {
158     if (rctx == NULL) {
159         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
160         return;
161     }
162     rctx->max_resp_len = len != 0 ? (size_t)len : OSSL_HTTP_DEFAULT_MAX_RESP_LEN;
163 }
164 
165 /*
166  * Create request line using |rctx| and |path| (or "/" in case |path| is NULL).
167  * Server name (and port) must be given if and only if plain HTTP proxy is used.
168  */
169 int OSSL_HTTP_REQ_CTX_set_request_line(OSSL_HTTP_REQ_CTX *rctx, int method_POST,
170                                        const char *server, const char *port,
171                                        const char *path)
172 {
173     if (rctx == NULL) {
174         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
175         return 0;
176     }
177     BIO_free(rctx->mem);
178     if ((rctx->mem = BIO_new(BIO_s_mem())) == NULL)
179         return 0;
180 
181     rctx->method_POST = method_POST != 0;
182     if (BIO_printf(rctx->mem, "%s ", rctx->method_POST ? "POST" : "GET") <= 0)
183         return 0;
184 
185     if (server != NULL) { /* HTTP (but not HTTPS) proxy is used */
186         /*
187          * Section 5.1.2 of RFC 1945 states that the absoluteURI form is only
188          * allowed when using a proxy
189          */
190         if (BIO_printf(rctx->mem, OSSL_HTTP_PREFIX"%s", server) <= 0)
191             return 0;
192         if (port != NULL && BIO_printf(rctx->mem, ":%s", port) <= 0)
193             return 0;
194     }
195 
196     /* Make sure path includes a forward slash */
197     if (path == NULL)
198         path = "/";
199     if (path[0] != '/' && BIO_printf(rctx->mem, "/") <= 0)
200         return 0;
201     /*
202      * Add (the rest of) the path and the HTTP version,
203      * which is fixed to 1.0 for straightforward implementation of keep-alive
204      */
205     if (BIO_printf(rctx->mem, "%s "HTTP_1_0"\r\n", path) <= 0)
206         return 0;
207 
208     rctx->resp_len = 0;
209     rctx->state = OHS_ADD_HEADERS;
210     return 1;
211 }
212 
213 int OSSL_HTTP_REQ_CTX_add1_header(OSSL_HTTP_REQ_CTX *rctx,
214                                   const char *name, const char *value)
215 {
216     if (rctx == NULL || name == NULL) {
217         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
218         return 0;
219     }
220     if (rctx->mem == NULL) {
221         ERR_raise(ERR_LIB_HTTP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
222         return 0;
223     }
224 
225     if (BIO_puts(rctx->mem, name) <= 0)
226         return 0;
227     if (value != NULL) {
228         if (BIO_write(rctx->mem, ": ", 2) != 2)
229             return 0;
230         if (BIO_puts(rctx->mem, value) <= 0)
231             return 0;
232     }
233     return BIO_write(rctx->mem, "\r\n", 2) == 2;
234 }
235 
236 int OSSL_HTTP_REQ_CTX_set_expected(OSSL_HTTP_REQ_CTX *rctx,
237                                    const char *content_type, int asn1,
238                                    int timeout, int keep_alive)
239 {
240     if (rctx == NULL) {
241         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
242         return 0;
243     }
244     if (keep_alive != 0
245             && rctx->state != OHS_ERROR && rctx->state != OHS_ADD_HEADERS) {
246         /* Cannot anymore set keep-alive in request header */
247         ERR_raise(ERR_LIB_HTTP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
248         return 0;
249     }
250 
251     OPENSSL_free(rctx->expected_ct);
252     rctx->expected_ct = NULL;
253     if (content_type != NULL
254             && (rctx->expected_ct = OPENSSL_strdup(content_type)) == NULL)
255         return 0;
256 
257     rctx->expect_asn1 = asn1;
258     if (timeout >= 0)
259         rctx->max_time = timeout > 0 ? time(NULL) + timeout : 0;
260     else /* take over any |overall_timeout| arg of OSSL_HTTP_open(), else 0 */
261         rctx->max_time = rctx->max_total_time;
262     rctx->keep_alive = keep_alive;
263     return 1;
264 }
265 
266 static int set1_content(OSSL_HTTP_REQ_CTX *rctx,
267                         const char *content_type, BIO *req)
268 {
269     long req_len = 0;
270 #ifndef OPENSSL_NO_STDIO
271     FILE *fp = NULL;
272 #endif
273 
274     if (rctx == NULL || (req == NULL && content_type != NULL)) {
275         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
276         return 0;
277     }
278 
279     if (rctx->keep_alive != 0
280             && !OSSL_HTTP_REQ_CTX_add1_header(rctx, "Connection", "keep-alive"))
281         return 0;
282 
283     BIO_free(rctx->req);
284     rctx->req = NULL;
285     if (req == NULL)
286         return 1;
287     if (!rctx->method_POST) {
288         ERR_raise(ERR_LIB_HTTP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
289         return 0;
290     }
291 
292     if (content_type != NULL
293             && BIO_printf(rctx->mem, "Content-Type: %s\r\n", content_type) <= 0)
294         return 0;
295 
296     /*
297      * BIO_CTRL_INFO yields the data length at least for memory BIOs, but for
298      * file-based BIOs it gives the current position, which is not what we need.
299      */
300     if (BIO_method_type(req) == BIO_TYPE_FILE) {
301 #ifndef OPENSSL_NO_STDIO
302         if (BIO_get_fp(req, &fp) == 1 && fseek(fp, 0, SEEK_END) == 0) {
303             req_len = ftell(fp);
304             (void)fseek(fp, 0, SEEK_SET);
305         } else {
306             fp = NULL;
307         }
308 #endif
309     } else {
310         req_len = BIO_ctrl(req, BIO_CTRL_INFO, 0, NULL);
311         /*
312          * Streaming BIOs likely will not support querying the size at all,
313          * and we assume we got a correct value if req_len > 0.
314          */
315     }
316     if ((
317 #ifndef OPENSSL_NO_STDIO
318          fp != NULL /* definitely correct req_len */ ||
319 #endif
320          req_len > 0)
321             && BIO_printf(rctx->mem, "Content-Length: %ld\r\n", req_len) < 0)
322         return 0;
323 
324     if (!BIO_up_ref(req))
325         return 0;
326     rctx->req = req;
327     return 1;
328 }
329 
330 int OSSL_HTTP_REQ_CTX_set1_req(OSSL_HTTP_REQ_CTX *rctx, const char *content_type,
331                                const ASN1_ITEM *it, const ASN1_VALUE *req)
332 {
333     BIO *mem = NULL;
334     int res = 1;
335 
336     if (req != NULL)
337         res = (mem = ASN1_item_i2d_mem_bio(it, req)) != NULL;
338     res = res && set1_content(rctx, content_type, mem);
339     BIO_free(mem);
340     return res;
341 }
342 
343 static int add1_headers(OSSL_HTTP_REQ_CTX *rctx,
344                         const STACK_OF(CONF_VALUE) *headers, const char *host)
345 {
346     int i;
347     int add_host = host != NULL && *host != '\0';
348     CONF_VALUE *hdr;
349 
350     for (i = 0; i < sk_CONF_VALUE_num(headers); i++) {
351         hdr = sk_CONF_VALUE_value(headers, i);
352         if (add_host && OPENSSL_strcasecmp("host", hdr->name) == 0)
353             add_host = 0;
354         if (!OSSL_HTTP_REQ_CTX_add1_header(rctx, hdr->name, hdr->value))
355             return 0;
356     }
357 
358     if (add_host && !OSSL_HTTP_REQ_CTX_add1_header(rctx, "Host", host))
359         return 0;
360     return 1;
361 }
362 
363 /* Create OSSL_HTTP_REQ_CTX structure using the values provided. */
364 static OSSL_HTTP_REQ_CTX *http_req_ctx_new(int free_wbio, BIO *wbio, BIO *rbio,
365                                            OSSL_HTTP_bio_cb_t bio_update_fn,
366                                            void *arg, int use_ssl,
367                                            const char *proxy,
368                                            const char *server, const char *port,
369                                            int buf_size, int overall_timeout)
370 {
371     OSSL_HTTP_REQ_CTX *rctx = OSSL_HTTP_REQ_CTX_new(wbio, rbio, buf_size);
372 
373     if (rctx == NULL)
374         return NULL;
375     rctx->free_wbio = free_wbio;
376     rctx->upd_fn = bio_update_fn;
377     rctx->upd_arg = arg;
378     rctx->use_ssl = use_ssl;
379     if (proxy != NULL
380             && (rctx->proxy = OPENSSL_strdup(proxy)) == NULL)
381         goto err;
382     if (server != NULL
383             && (rctx->server = OPENSSL_strdup(server)) == NULL)
384         goto err;
385     if (port != NULL
386             && (rctx->port = OPENSSL_strdup(port)) == NULL)
387         goto err;
388     rctx->max_total_time =
389         overall_timeout > 0 ? time(NULL) + overall_timeout : 0;
390     return rctx;
391 
392  err:
393     OSSL_HTTP_REQ_CTX_free(rctx);
394     return NULL;
395 }
396 
397 /*
398  * Parse first HTTP response line. This should be like this: "HTTP/1.0 200 OK".
399  * We need to obtain the status code and (optional) informational message.
400  * Return any received HTTP response status code, or 0 on fatal error.
401  */
402 
403 static int parse_http_line1(char *line, int *found_keep_alive)
404 {
405     int i, retcode, err;
406     char *code, *reason, *end;
407 
408     if (!HAS_PREFIX(line, HTTP_PREFIX_VERSION))
409         goto err;
410     /* above HTTP 1.0, connection persistence is the default */
411     *found_keep_alive = line[strlen(HTTP_PREFIX_VERSION)] > '0';
412 
413     /* Skip to first whitespace (past protocol info) */
414     for (code = line; *code != '\0' && !ossl_isspace(*code); code++)
415         continue;
416     if (*code == '\0')
417         goto err;
418 
419     /* Skip past whitespace to start of response code */
420     while (*code != '\0' && ossl_isspace(*code))
421         code++;
422     if (*code == '\0')
423         goto err;
424 
425     /* Find end of response code: first whitespace after start of code */
426     for (reason = code; *reason != '\0' && !ossl_isspace(*reason); reason++)
427         continue;
428 
429     if (*reason == '\0')
430         goto err;
431 
432     /* Set end of response code and start of message */
433     *reason++ = '\0';
434 
435     /* Attempt to parse numeric code */
436     retcode = strtoul(code, &end, 10);
437     if (*end != '\0')
438         goto err;
439 
440     /* Skip over any leading whitespace in message */
441     while (*reason != '\0' && ossl_isspace(*reason))
442         reason++;
443 
444     if (*reason != '\0') {
445         /*
446          * Finally zap any trailing whitespace in message (include CRLF)
447          */
448 
449         /* chop any trailing whitespace from reason */
450         /* We know reason has a non-whitespace character so this is OK */
451         for (end = reason + strlen(reason) - 1; ossl_isspace(*end); end--)
452             *end = '\0';
453     }
454 
455     switch (retcode) {
456     case HTTP_STATUS_CODE_OK:
457     case HTTP_STATUS_CODE_MOVED_PERMANENTLY:
458     case HTTP_STATUS_CODE_FOUND:
459         return retcode;
460     default:
461         err = HTTP_R_RECEIVED_ERROR;
462         if (retcode < 400)
463             err = HTTP_R_STATUS_CODE_UNSUPPORTED;
464         if (*reason == '\0')
465             ERR_raise_data(ERR_LIB_HTTP, err, "code=%s", code);
466         else
467             ERR_raise_data(ERR_LIB_HTTP, err, "code=%s, reason=%s", code,
468                            reason);
469         return retcode;
470     }
471 
472  err:
473     for (i = 0; i < 60 && line[i] != '\0'; i++)
474         if (!ossl_isprint(line[i]))
475             line[i] = ' ';
476     line[i] = '\0';
477     ERR_raise_data(ERR_LIB_HTTP, HTTP_R_HEADER_PARSE_ERROR, "content=%s", line);
478     return 0;
479 }
480 
481 static int check_set_resp_len(OSSL_HTTP_REQ_CTX *rctx, size_t len)
482 {
483     if (rctx->max_resp_len != 0 && len > rctx->max_resp_len)
484         ERR_raise_data(ERR_LIB_HTTP, HTTP_R_MAX_RESP_LEN_EXCEEDED,
485                        "length=%zu, max=%zu", len, rctx->max_resp_len);
486     if (rctx->resp_len != 0 && rctx->resp_len != len)
487         ERR_raise_data(ERR_LIB_HTTP, HTTP_R_INCONSISTENT_CONTENT_LENGTH,
488                        "ASN.1 length=%zu, Content-Length=%zu",
489                        len, rctx->resp_len);
490     rctx->resp_len = len;
491     return 1;
492 }
493 
494 static int may_still_retry(time_t max_time, int *ptimeout)
495 {
496     time_t time_diff, now = time(NULL);
497 
498     if (max_time != 0) {
499         if (max_time < now) {
500             ERR_raise(ERR_LIB_HTTP, HTTP_R_RETRY_TIMEOUT);
501             return 0;
502         }
503         time_diff = max_time - now;
504         *ptimeout = time_diff > INT_MAX ? INT_MAX : (int)time_diff;
505     }
506     return 1;
507 }
508 
509 /*
510  * Try exchanging request and response via HTTP on (non-)blocking BIO in rctx.
511  * Returns 1 on success, 0 on error or redirection, -1 on BIO_should_retry.
512  */
513 int OSSL_HTTP_REQ_CTX_nbio(OSSL_HTTP_REQ_CTX *rctx)
514 {
515     int i, found_expected_ct = 0, found_keep_alive = 0;
516     long n;
517     size_t resp_len;
518     const unsigned char *p;
519     char *buf, *key, *value, *line_end = NULL;
520 
521     if (rctx == NULL) {
522         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
523         return 0;
524     }
525     if (rctx->mem == NULL || rctx->wbio == NULL || rctx->rbio == NULL) {
526         ERR_raise(ERR_LIB_HTTP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
527         return 0;
528     }
529 
530     rctx->redirection_url = NULL;
531  next_io:
532     buf = (char *)rctx->buf;
533     if ((rctx->state & OHS_NOREAD) == 0) {
534         if (rctx->expect_asn1) {
535             n = BIO_read(rctx->rbio, rctx->buf, rctx->buf_size);
536         } else {
537             (void)ERR_set_mark();
538             n = BIO_gets(rctx->rbio, buf, rctx->buf_size);
539             if (n == -2) { /* unsupported method */
540                 (void)ERR_pop_to_mark();
541                 n = BIO_get_line(rctx->rbio, buf, rctx->buf_size);
542             } else {
543                 (void)ERR_clear_last_mark();
544             }
545         }
546         if (n <= 0) {
547             if (BIO_should_retry(rctx->rbio))
548                 return -1;
549             ERR_raise(ERR_LIB_HTTP, HTTP_R_FAILED_READING_DATA);
550             return 0;
551         }
552 
553         /* Write data to memory BIO */
554         if (BIO_write(rctx->mem, rctx->buf, n) != n)
555             return 0;
556     }
557 
558     switch (rctx->state) {
559     case OHS_ADD_HEADERS:
560         /* Last operation was adding headers: need a final \r\n */
561         if (BIO_write(rctx->mem, "\r\n", 2) != 2) {
562             rctx->state = OHS_ERROR;
563             return 0;
564         }
565         rctx->state = OHS_WRITE_INIT;
566 
567         /* fall thru */
568     case OHS_WRITE_INIT:
569         rctx->len_to_send = BIO_get_mem_data(rctx->mem, &rctx->pos);
570         rctx->state = OHS_WRITE_HDR;
571 
572         /* fall thru */
573     case OHS_WRITE_HDR:
574         /* Copy some chunk of data from rctx->mem to rctx->wbio */
575     case OHS_WRITE_REQ:
576         /* Copy some chunk of data from rctx->req to rctx->wbio */
577 
578         if (rctx->len_to_send > 0) {
579             i = BIO_write(rctx->wbio, rctx->pos, rctx->len_to_send);
580             if (i <= 0) {
581                 if (BIO_should_retry(rctx->wbio))
582                     return -1;
583                 rctx->state = OHS_ERROR;
584                 return 0;
585             }
586             rctx->pos += i;
587             rctx->len_to_send -= i;
588             goto next_io;
589         }
590         if (rctx->state == OHS_WRITE_HDR) {
591             (void)BIO_reset(rctx->mem);
592             rctx->state = OHS_WRITE_REQ;
593         }
594         if (rctx->req != NULL && !BIO_eof(rctx->req)) {
595             n = BIO_read(rctx->req, rctx->buf, rctx->buf_size);
596             if (n <= 0) {
597                 if (BIO_should_retry(rctx->req))
598                     return -1;
599                 ERR_raise(ERR_LIB_HTTP, HTTP_R_FAILED_READING_DATA);
600                 return 0;
601             }
602             rctx->pos = rctx->buf;
603             rctx->len_to_send = n;
604             goto next_io;
605         }
606         rctx->state = OHS_FLUSH;
607 
608         /* fall thru */
609     case OHS_FLUSH:
610 
611         i = BIO_flush(rctx->wbio);
612 
613         if (i > 0) {
614             rctx->state = OHS_FIRSTLINE;
615             goto next_io;
616         }
617 
618         if (BIO_should_retry(rctx->wbio))
619             return -1;
620 
621         rctx->state = OHS_ERROR;
622         return 0;
623 
624     case OHS_ERROR:
625         return 0;
626 
627     case OHS_FIRSTLINE:
628     case OHS_HEADERS:
629     case OHS_REDIRECT:
630 
631         /* Attempt to read a line in */
632  next_line:
633         /*
634          * Due to strange memory BIO behavior with BIO_gets we have to check
635          * there's a complete line in there before calling BIO_gets or we'll
636          * just get a partial read.
637          */
638         n = BIO_get_mem_data(rctx->mem, &p);
639         if (n <= 0 || memchr(p, '\n', n) == 0) {
640             if (n >= rctx->buf_size) {
641                 rctx->state = OHS_ERROR;
642                 return 0;
643             }
644             goto next_io;
645         }
646         n = BIO_gets(rctx->mem, buf, rctx->buf_size);
647 
648         if (n <= 0) {
649             if (BIO_should_retry(rctx->mem))
650                 goto next_io;
651             rctx->state = OHS_ERROR;
652             return 0;
653         }
654 
655         /* Don't allow excessive lines */
656         if (n == rctx->buf_size) {
657             ERR_raise(ERR_LIB_HTTP, HTTP_R_RESPONSE_LINE_TOO_LONG);
658             rctx->state = OHS_ERROR;
659             return 0;
660         }
661 
662         /* First line */
663         if (rctx->state == OHS_FIRSTLINE) {
664             switch (parse_http_line1(buf, &found_keep_alive)) {
665             case HTTP_STATUS_CODE_OK:
666                 rctx->state = OHS_HEADERS;
667                 goto next_line;
668             case HTTP_STATUS_CODE_MOVED_PERMANENTLY:
669             case HTTP_STATUS_CODE_FOUND: /* i.e., moved temporarily */
670                 if (!rctx->method_POST) { /* method is GET */
671                     rctx->state = OHS_REDIRECT;
672                     goto next_line;
673                 }
674                 ERR_raise(ERR_LIB_HTTP, HTTP_R_REDIRECTION_NOT_ENABLED);
675                 /* redirection is not supported/recommended for POST */
676                 /* fall through */
677             default:
678                 rctx->state = OHS_ERROR;
679                 goto next_line;
680             }
681         }
682         key = buf;
683         value = strchr(key, ':');
684         if (value != NULL) {
685             *(value++) = '\0';
686             while (ossl_isspace(*value))
687                 value++;
688             line_end = strchr(value, '\r');
689             if (line_end == NULL)
690                 line_end = strchr(value, '\n');
691             if (line_end != NULL)
692                 *line_end = '\0';
693         }
694         if (value != NULL && line_end != NULL) {
695             if (rctx->state == OHS_REDIRECT
696                     && OPENSSL_strcasecmp(key, "Location") == 0) {
697                 rctx->redirection_url = value;
698                 return 0;
699             }
700             if (rctx->state == OHS_HEADERS && rctx->expected_ct != NULL
701                     && OPENSSL_strcasecmp(key, "Content-Type") == 0) {
702                 if (OPENSSL_strcasecmp(rctx->expected_ct, value) != 0) {
703                     ERR_raise_data(ERR_LIB_HTTP, HTTP_R_UNEXPECTED_CONTENT_TYPE,
704                                    "expected=%s, actual=%s",
705                                    rctx->expected_ct, value);
706                     return 0;
707                 }
708                 found_expected_ct = 1;
709             }
710 
711             /* https://tools.ietf.org/html/rfc7230#section-6.3 Persistence */
712             if (OPENSSL_strcasecmp(key, "Connection") == 0) {
713                 if (OPENSSL_strcasecmp(value, "keep-alive") == 0)
714                     found_keep_alive = 1;
715                 else if (OPENSSL_strcasecmp(value, "close") == 0)
716                     found_keep_alive = 0;
717             } else if (OPENSSL_strcasecmp(key, "Content-Length") == 0) {
718                 resp_len = (size_t)strtoul(value, &line_end, 10);
719                 if (line_end == value || *line_end != '\0') {
720                     ERR_raise_data(ERR_LIB_HTTP,
721                                    HTTP_R_ERROR_PARSING_CONTENT_LENGTH,
722                                    "input=%s", value);
723                     return 0;
724                 }
725                 if (!check_set_resp_len(rctx, resp_len))
726                     return 0;
727             }
728         }
729 
730         /* Look for blank line indicating end of headers */
731         for (p = rctx->buf; *p != '\0'; p++) {
732             if (*p != '\r' && *p != '\n')
733                 break;
734         }
735         if (*p != '\0') /* not end of headers */
736             goto next_line;
737 
738         if (rctx->keep_alive != 0 /* do not let server initiate keep_alive */
739                 && !found_keep_alive /* otherwise there is no change */) {
740             if (rctx->keep_alive == 2) {
741                 rctx->keep_alive = 0;
742                 ERR_raise(ERR_LIB_HTTP, HTTP_R_SERVER_CANCELED_CONNECTION);
743                 return 0;
744             }
745             rctx->keep_alive = 0;
746         }
747 
748         if (rctx->state == OHS_ERROR)
749             return 0;
750 
751         if (rctx->expected_ct != NULL && !found_expected_ct) {
752             ERR_raise_data(ERR_LIB_HTTP, HTTP_R_MISSING_CONTENT_TYPE,
753                            "expected=%s", rctx->expected_ct);
754             return 0;
755         }
756         if (rctx->state == OHS_REDIRECT) {
757             /* http status code indicated redirect but there was no Location */
758             ERR_raise(ERR_LIB_HTTP, HTTP_R_MISSING_REDIRECT_LOCATION);
759             return 0;
760         }
761 
762         if (!rctx->expect_asn1) {
763             rctx->state = OHS_STREAM;
764             return 1;
765         }
766 
767         rctx->state = OHS_ASN1_HEADER;
768 
769         /* Fall thru */
770     case OHS_ASN1_HEADER:
771         /*
772          * Now reading ASN1 header: can read at least 2 bytes which is enough
773          * for ASN1 SEQUENCE header and either length field or at least the
774          * length of the length field.
775          */
776         n = BIO_get_mem_data(rctx->mem, &p);
777         if (n < 2)
778             goto next_io;
779 
780         /* Check it is an ASN1 SEQUENCE */
781         if (*p++ != (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {
782             ERR_raise(ERR_LIB_HTTP, HTTP_R_MISSING_ASN1_ENCODING);
783             return 0;
784         }
785 
786         /* Check out length field */
787         if ((*p & 0x80) != 0) {
788             /*
789              * If MSB set on initial length octet we can now always read 6
790              * octets: make sure we have them.
791              */
792             if (n < 6)
793                 goto next_io;
794             n = *p & 0x7F;
795             /* Not NDEF or excessive length */
796             if (n == 0 || (n > 4)) {
797                 ERR_raise(ERR_LIB_HTTP, HTTP_R_ERROR_PARSING_ASN1_LENGTH);
798                 return 0;
799             }
800             p++;
801             resp_len = 0;
802             for (i = 0; i < n; i++) {
803                 resp_len <<= 8;
804                 resp_len |= *p++;
805             }
806             resp_len += n + 2;
807         } else {
808             resp_len = *p + 2;
809         }
810         if (!check_set_resp_len(rctx, resp_len))
811             return 0;
812 
813         rctx->state = OHS_ASN1_CONTENT;
814 
815         /* Fall thru */
816     case OHS_ASN1_CONTENT:
817     default:
818         n = BIO_get_mem_data(rctx->mem, NULL);
819         if (n < 0 || (size_t)n < rctx->resp_len)
820             goto next_io;
821 
822         rctx->state = OHS_ASN1_DONE;
823         return 1;
824     }
825 }
826 
827 int OSSL_HTTP_REQ_CTX_nbio_d2i(OSSL_HTTP_REQ_CTX *rctx,
828                                ASN1_VALUE **pval, const ASN1_ITEM *it)
829 {
830     const unsigned char *p;
831     int rv;
832 
833     *pval = NULL;
834     if ((rv = OSSL_HTTP_REQ_CTX_nbio(rctx)) != 1)
835         return rv;
836     *pval = ASN1_item_d2i(NULL, &p, BIO_get_mem_data(rctx->mem, &p), it);
837     return *pval != NULL;
838 
839 }
840 
841 #ifndef OPENSSL_NO_SOCK
842 
843 /* set up a new connection BIO, to HTTP server or to HTTP(S) proxy if given */
844 static BIO *http_new_bio(const char *server /* optionally includes ":port" */,
845                          const char *server_port /* explicit server port */,
846                          int use_ssl,
847                          const char *proxy /* optionally includes ":port" */,
848                          const char *proxy_port /* explicit proxy port */)
849 {
850     const char *host = server;
851     const char *port = server_port;
852     BIO *cbio;
853 
854     if (!ossl_assert(server != NULL))
855         return NULL;
856 
857     if (proxy != NULL) {
858         host = proxy;
859         port = proxy_port;
860     }
861 
862     if (port == NULL && strchr(host, ':') == NULL)
863         port = use_ssl ? OSSL_HTTPS_PORT : OSSL_HTTP_PORT;
864 
865     cbio = BIO_new_connect(host /* optionally includes ":port" */);
866     if (cbio == NULL)
867         goto end;
868     if (port != NULL)
869         (void)BIO_set_conn_port(cbio, port);
870 
871  end:
872     return cbio;
873 }
874 #endif /* OPENSSL_NO_SOCK */
875 
876 /* Exchange request and response via HTTP on (non-)blocking BIO */
877 BIO *OSSL_HTTP_REQ_CTX_exchange(OSSL_HTTP_REQ_CTX *rctx)
878 {
879     int rv;
880 
881     if (rctx == NULL) {
882         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
883         return NULL;
884     }
885 
886     for (;;) {
887         rv = OSSL_HTTP_REQ_CTX_nbio(rctx);
888         if (rv != -1)
889             break;
890         /* BIO_should_retry was true */
891         /* will not actually wait if rctx->max_time == 0 */
892         if (BIO_wait(rctx->rbio, rctx->max_time, 100 /* milliseconds */) <= 0)
893             return NULL;
894     }
895 
896     if (rv == 0) {
897         if (rctx->redirection_url == NULL) { /* an error occurred */
898             if (rctx->len_to_send > 0)
899                 ERR_raise(ERR_LIB_HTTP, HTTP_R_ERROR_SENDING);
900             else
901                 ERR_raise(ERR_LIB_HTTP, HTTP_R_ERROR_RECEIVING);
902         }
903         return NULL;
904     }
905     return rctx->state == OHS_STREAM ? rctx->rbio : rctx->mem;
906 }
907 
908 int OSSL_HTTP_is_alive(const OSSL_HTTP_REQ_CTX *rctx)
909 {
910     return rctx != NULL && rctx->keep_alive != 0;
911 }
912 
913 /* High-level HTTP API implementation */
914 
915 /* Initiate an HTTP session using bio, else use given server, proxy, etc. */
916 OSSL_HTTP_REQ_CTX *OSSL_HTTP_open(const char *server, const char *port,
917                                   const char *proxy, const char *no_proxy,
918                                   int use_ssl, BIO *bio, BIO *rbio,
919                                   OSSL_HTTP_bio_cb_t bio_update_fn, void *arg,
920                                   int buf_size, int overall_timeout)
921 {
922     BIO *cbio; /* == bio if supplied, used as connection BIO if rbio is NULL */
923     OSSL_HTTP_REQ_CTX *rctx = NULL;
924 
925     if (use_ssl && bio_update_fn == NULL) {
926         ERR_raise(ERR_LIB_HTTP, HTTP_R_TLS_NOT_ENABLED);
927         return NULL;
928     }
929     if (rbio != NULL && (bio == NULL || bio_update_fn != NULL)) {
930         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_INVALID_ARGUMENT);
931         return NULL;
932     }
933 
934     if (bio != NULL) {
935         cbio = bio;
936         if (proxy != NULL || no_proxy != NULL) {
937             ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_INVALID_ARGUMENT);
938             return NULL;
939         }
940     } else {
941 #ifndef OPENSSL_NO_SOCK
942         char *proxy_host = NULL, *proxy_port = NULL;
943 
944         if (server == NULL) {
945             ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
946             return NULL;
947         }
948         if (port != NULL && *port == '\0')
949             port = NULL;
950         if (port == NULL && strchr(server, ':') == NULL)
951             port = use_ssl ? OSSL_HTTPS_PORT : OSSL_HTTP_PORT;
952         proxy = OSSL_HTTP_adapt_proxy(proxy, no_proxy, server, use_ssl);
953         if (proxy != NULL
954             && !OSSL_HTTP_parse_url(proxy, NULL /* use_ssl */, NULL /* user */,
955                                     &proxy_host, &proxy_port, NULL /* num */,
956                                     NULL /* path */, NULL, NULL))
957             return NULL;
958         cbio = http_new_bio(server, port, use_ssl, proxy_host, proxy_port);
959         OPENSSL_free(proxy_host);
960         OPENSSL_free(proxy_port);
961         if (cbio == NULL)
962             return NULL;
963 #else
964         ERR_raise(ERR_LIB_HTTP, HTTP_R_SOCK_NOT_SUPPORTED);
965         return NULL;
966 #endif
967     }
968 
969     (void)ERR_set_mark(); /* prepare removing any spurious libssl errors */
970     if (rbio == NULL && BIO_do_connect_retry(cbio, overall_timeout, -1) <= 0) {
971         if (bio == NULL) /* cbio was not provided by caller */
972             BIO_free_all(cbio);
973         goto end;
974     }
975     /* now overall_timeout is guaranteed to be >= 0 */
976 
977     /* adapt in order to fix callback design flaw, see #17088 */
978     /* callback can be used to wrap or prepend TLS session */
979     if (bio_update_fn != NULL) {
980         BIO *orig_bio = cbio;
981 
982         cbio = (*bio_update_fn)(cbio, arg, 1 /* connect */, use_ssl != 0);
983         if (cbio == NULL) {
984             if (bio == NULL) /* cbio was not provided by caller */
985                 BIO_free_all(orig_bio);
986             goto end;
987         }
988     }
989 
990     rctx = http_req_ctx_new(bio == NULL, cbio, rbio != NULL ? rbio : cbio,
991                             bio_update_fn, arg, use_ssl, proxy, server, port,
992                             buf_size, overall_timeout);
993 
994  end:
995     if (rctx != NULL)
996         /* remove any spurious error queue entries by ssl_add_cert_chain() */
997         (void)ERR_pop_to_mark();
998     else
999         (void)ERR_clear_last_mark();
1000 
1001     return rctx;
1002 }
1003 
1004 int OSSL_HTTP_set1_request(OSSL_HTTP_REQ_CTX *rctx, const char *path,
1005                            const STACK_OF(CONF_VALUE) *headers,
1006                            const char *content_type, BIO *req,
1007                            const char *expected_content_type, int expect_asn1,
1008                            size_t max_resp_len, int timeout, int keep_alive)
1009 {
1010     int use_http_proxy;
1011 
1012     if (rctx == NULL) {
1013         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
1014         return 0;
1015     }
1016     use_http_proxy = rctx->proxy != NULL && !rctx->use_ssl;
1017     if (use_http_proxy && rctx->server == NULL) {
1018         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_INVALID_ARGUMENT);
1019         return 0;
1020     }
1021     rctx->max_resp_len = max_resp_len; /* allows for 0: indefinite */
1022 
1023     return OSSL_HTTP_REQ_CTX_set_request_line(rctx, req != NULL,
1024                                               use_http_proxy ? rctx->server
1025                                               : NULL, rctx->port, path)
1026         && add1_headers(rctx, headers, rctx->server)
1027         && OSSL_HTTP_REQ_CTX_set_expected(rctx, expected_content_type,
1028                                           expect_asn1, timeout, keep_alive)
1029         && set1_content(rctx, content_type, req);
1030 }
1031 
1032 /*-
1033  * Exchange single HTTP request and response according to rctx.
1034  * If rctx->method_POST then use POST, else use GET and ignore content_type.
1035  * The redirection_url output (freed by caller) parameter is used only for GET.
1036  */
1037 BIO *OSSL_HTTP_exchange(OSSL_HTTP_REQ_CTX *rctx, char **redirection_url)
1038 {
1039     BIO *resp;
1040 
1041     if (rctx == NULL) {
1042         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
1043         return NULL;
1044     }
1045 
1046     if (redirection_url != NULL)
1047         *redirection_url = NULL; /* do this beforehand to prevent dbl free */
1048 
1049     resp = OSSL_HTTP_REQ_CTX_exchange(rctx);
1050     if (resp == NULL) {
1051         if (rctx->redirection_url != NULL) {
1052             if (redirection_url == NULL)
1053                 ERR_raise(ERR_LIB_HTTP, HTTP_R_REDIRECTION_NOT_ENABLED);
1054             else
1055                 /* may be NULL if out of memory: */
1056                 *redirection_url = OPENSSL_strdup(rctx->redirection_url);
1057         } else {
1058             char buf[200];
1059             unsigned long err = ERR_peek_error();
1060             int lib = ERR_GET_LIB(err);
1061             int reason = ERR_GET_REASON(err);
1062 
1063             if (lib == ERR_LIB_SSL || lib == ERR_LIB_HTTP
1064                     || (lib == ERR_LIB_BIO && reason == BIO_R_CONNECT_TIMEOUT)
1065                     || (lib == ERR_LIB_BIO && reason == BIO_R_CONNECT_ERROR)
1066 #ifndef OPENSSL_NO_CMP
1067                     || (lib == ERR_LIB_CMP
1068                         && reason == CMP_R_POTENTIALLY_INVALID_CERTIFICATE)
1069 #endif
1070                 ) {
1071                 if (rctx->server != NULL) {
1072                     BIO_snprintf(buf, sizeof(buf), "server=http%s://%s%s%s",
1073                                  rctx->use_ssl ? "s" : "", rctx->server,
1074                                  rctx->port != NULL ? ":" : "",
1075                                  rctx->port != NULL ? rctx->port : "");
1076                     ERR_add_error_data(1, buf);
1077                 }
1078                 if (rctx->proxy != NULL)
1079                     ERR_add_error_data(2, " proxy=", rctx->proxy);
1080                 if (err == 0) {
1081                     BIO_snprintf(buf, sizeof(buf), " peer has disconnected%s",
1082                                  rctx->use_ssl ? " violating the protocol" :
1083                                  ", likely because it requires the use of TLS");
1084                     ERR_add_error_data(1, buf);
1085                 }
1086             }
1087         }
1088     }
1089 
1090     if (resp != NULL && !BIO_up_ref(resp))
1091         resp = NULL;
1092     return resp;
1093 }
1094 
1095 static int redirection_ok(int n_redir, const char *old_url, const char *new_url)
1096 {
1097     if (n_redir >= HTTP_VERSION_MAX_REDIRECTIONS) {
1098         ERR_raise(ERR_LIB_HTTP, HTTP_R_TOO_MANY_REDIRECTIONS);
1099         return 0;
1100     }
1101     if (*new_url == '/') /* redirection to same server => same protocol */
1102         return 1;
1103     if (HAS_PREFIX(old_url, OSSL_HTTPS_NAME":") &&
1104         !HAS_PREFIX(new_url, OSSL_HTTPS_NAME":")) {
1105         ERR_raise(ERR_LIB_HTTP, HTTP_R_REDIRECTION_FROM_HTTPS_TO_HTTP);
1106         return 0;
1107     }
1108     return 1;
1109 }
1110 
1111 /* Get data via HTTP from server at given URL, potentially with redirection */
1112 BIO *OSSL_HTTP_get(const char *url, const char *proxy, const char *no_proxy,
1113                    BIO *bio, BIO *rbio,
1114                    OSSL_HTTP_bio_cb_t bio_update_fn, void *arg,
1115                    int buf_size, const STACK_OF(CONF_VALUE) *headers,
1116                    const char *expected_ct, int expect_asn1,
1117                    size_t max_resp_len, int timeout)
1118 {
1119     char *current_url, *redirection_url = NULL;
1120     int n_redirs = 0;
1121     char *host;
1122     char *port;
1123     char *path;
1124     int use_ssl;
1125     OSSL_HTTP_REQ_CTX *rctx = NULL;
1126     BIO *resp = NULL;
1127     time_t max_time = timeout > 0 ? time(NULL) + timeout : 0;
1128 
1129     if (url == NULL) {
1130         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
1131         return NULL;
1132     }
1133     if ((current_url = OPENSSL_strdup(url)) == NULL)
1134         return NULL;
1135 
1136     for (;;) {
1137         if (!OSSL_HTTP_parse_url(current_url, &use_ssl, NULL /* user */, &host,
1138                                  &port, NULL /* port_num */, &path, NULL, NULL))
1139             break;
1140 
1141         rctx = OSSL_HTTP_open(host, port, proxy, no_proxy,
1142                               use_ssl, bio, rbio, bio_update_fn, arg,
1143                               buf_size, timeout);
1144     new_rpath:
1145         if (rctx != NULL) {
1146             if (!OSSL_HTTP_set1_request(rctx, path, headers,
1147                                         NULL /* content_type */,
1148                                         NULL /* req */,
1149                                         expected_ct, expect_asn1, max_resp_len,
1150                                         -1 /* use same max time (timeout) */,
1151                                         0 /* no keep_alive */)) {
1152                 OSSL_HTTP_REQ_CTX_free(rctx);
1153                 rctx = NULL;
1154            } else {
1155                 resp = OSSL_HTTP_exchange(rctx, &redirection_url);
1156            }
1157         }
1158         OPENSSL_free(path);
1159         if (resp == NULL && redirection_url != NULL) {
1160             if (redirection_ok(++n_redirs, current_url, redirection_url)
1161                     && may_still_retry(max_time, &timeout)) {
1162                 (void)BIO_reset(bio);
1163                 OPENSSL_free(current_url);
1164                 current_url = redirection_url;
1165                 if (*redirection_url == '/') { /* redirection to same server */
1166                     path = OPENSSL_strdup(redirection_url);
1167                     if (path == NULL) {
1168                         OPENSSL_free(host);
1169                         OPENSSL_free(port);
1170                         (void)OSSL_HTTP_close(rctx, 1);
1171                         rctx = NULL;
1172                         BIO_free(resp);
1173                         OPENSSL_free(current_url);
1174                         return NULL;
1175                     }
1176                     goto new_rpath;
1177                 }
1178                 OPENSSL_free(host);
1179                 OPENSSL_free(port);
1180                 (void)OSSL_HTTP_close(rctx, 1);
1181                 rctx = NULL;
1182                 continue;
1183             }
1184             /* if redirection not allowed, ignore it */
1185             OPENSSL_free(redirection_url);
1186         }
1187         OPENSSL_free(host);
1188         OPENSSL_free(port);
1189         if (!OSSL_HTTP_close(rctx, resp != NULL)) {
1190             BIO_free(resp);
1191             rctx = NULL;
1192             resp = NULL;
1193         }
1194         break;
1195     }
1196     OPENSSL_free(current_url);
1197     return resp;
1198 }
1199 
1200 /* Exchange request and response over a connection managed via |prctx| */
1201 BIO *OSSL_HTTP_transfer(OSSL_HTTP_REQ_CTX **prctx,
1202                         const char *server, const char *port,
1203                         const char *path, int use_ssl,
1204                         const char *proxy, const char *no_proxy,
1205                         BIO *bio, BIO *rbio,
1206                         OSSL_HTTP_bio_cb_t bio_update_fn, void *arg,
1207                         int buf_size, const STACK_OF(CONF_VALUE) *headers,
1208                         const char *content_type, BIO *req,
1209                         const char *expected_ct, int expect_asn1,
1210                         size_t max_resp_len, int timeout, int keep_alive)
1211 {
1212     OSSL_HTTP_REQ_CTX *rctx = prctx == NULL ? NULL : *prctx;
1213     BIO *resp = NULL;
1214 
1215     if (rctx == NULL) {
1216         rctx = OSSL_HTTP_open(server, port, proxy, no_proxy,
1217                               use_ssl, bio, rbio, bio_update_fn, arg,
1218                               buf_size, timeout);
1219         timeout = -1; /* Already set during opening the connection */
1220     }
1221     if (rctx != NULL) {
1222         if (OSSL_HTTP_set1_request(rctx, path, headers, content_type, req,
1223                                    expected_ct, expect_asn1,
1224                                    max_resp_len, timeout, keep_alive))
1225             resp = OSSL_HTTP_exchange(rctx, NULL);
1226         if (resp == NULL || !OSSL_HTTP_is_alive(rctx)) {
1227             if (!OSSL_HTTP_close(rctx, resp != NULL)) {
1228                 BIO_free(resp);
1229                 resp = NULL;
1230             }
1231             rctx = NULL;
1232         }
1233     }
1234     if (prctx != NULL)
1235         *prctx = rctx;
1236     return resp;
1237 }
1238 
1239 int OSSL_HTTP_close(OSSL_HTTP_REQ_CTX *rctx, int ok)
1240 {
1241     BIO *wbio;
1242     int ret = 1;
1243 
1244     /* callback can be used to finish TLS session and free its BIO */
1245     if (rctx != NULL && rctx->upd_fn != NULL) {
1246         wbio = (*rctx->upd_fn)(rctx->wbio, rctx->upd_arg,
1247                                0 /* disconnect */, ok);
1248         ret = wbio != NULL;
1249         if (ret)
1250             rctx->wbio = wbio;
1251     }
1252     OSSL_HTTP_REQ_CTX_free(rctx);
1253     return ret;
1254 }
1255 
1256 /* BASE64 encoder used for encoding basic proxy authentication credentials */
1257 static char *base64encode(const void *buf, size_t len)
1258 {
1259     int i;
1260     size_t outl;
1261     char *out;
1262 
1263     /* Calculate size of encoded data */
1264     outl = (len / 3);
1265     if (len % 3 > 0)
1266         outl++;
1267     outl <<= 2;
1268     out = OPENSSL_malloc(outl + 1);
1269     if (out == NULL)
1270         return 0;
1271 
1272     i = EVP_EncodeBlock((unsigned char *)out, buf, len);
1273     if (!ossl_assert(0 <= i && (size_t)i <= outl)) {
1274         OPENSSL_free(out);
1275         return NULL;
1276     }
1277     return out;
1278 }
1279 
1280 /*
1281  * Promote the given connection BIO using the CONNECT method for a TLS proxy.
1282  * This is typically called by an app, so bio_err and prog are used unless NULL
1283  * to print additional diagnostic information in a user-oriented way.
1284  */
1285 int OSSL_HTTP_proxy_connect(BIO *bio, const char *server, const char *port,
1286                             const char *proxyuser, const char *proxypass,
1287                             int timeout, BIO *bio_err, const char *prog)
1288 {
1289 #undef BUF_SIZE
1290 #define BUF_SIZE (8 * 1024)
1291     char *mbuf = OPENSSL_malloc(BUF_SIZE);
1292     char *mbufp;
1293     int read_len = 0;
1294     int ret = 0;
1295     BIO *fbio = BIO_new(BIO_f_buffer());
1296     int rv;
1297     time_t max_time = timeout > 0 ? time(NULL) + timeout : 0;
1298 
1299     if (bio == NULL || server == NULL
1300             || (bio_err != NULL && prog == NULL)) {
1301         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
1302         goto end;
1303     }
1304     if (port == NULL || *port == '\0')
1305         port = OSSL_HTTPS_PORT;
1306 
1307     if (mbuf == NULL || fbio == NULL) {
1308         BIO_printf(bio_err /* may be NULL */, "%s: out of memory", prog);
1309         goto end;
1310     }
1311     BIO_push(fbio, bio);
1312 
1313     BIO_printf(fbio, "CONNECT %s:%s "HTTP_1_0"\r\n", server, port);
1314 
1315     /*
1316      * Workaround for broken proxies which would otherwise close
1317      * the connection when entering tunnel mode (e.g., Squid 2.6)
1318      */
1319     BIO_printf(fbio, "Proxy-Connection: Keep-Alive\r\n");
1320 
1321     /* Support for basic (base64) proxy authentication */
1322     if (proxyuser != NULL) {
1323         size_t len = strlen(proxyuser) + 1;
1324         char *proxyauth, *proxyauthenc = NULL;
1325 
1326         if (proxypass != NULL)
1327             len += strlen(proxypass);
1328         proxyauth = OPENSSL_malloc(len + 1);
1329         if (proxyauth == NULL)
1330             goto end;
1331         if (BIO_snprintf(proxyauth, len + 1, "%s:%s", proxyuser,
1332                          proxypass != NULL ? proxypass : "") != (int)len)
1333             goto proxy_end;
1334         proxyauthenc = base64encode(proxyauth, len);
1335         if (proxyauthenc != NULL) {
1336             BIO_printf(fbio, "Proxy-Authorization: Basic %s\r\n", proxyauthenc);
1337             OPENSSL_clear_free(proxyauthenc, strlen(proxyauthenc));
1338         }
1339     proxy_end:
1340         OPENSSL_clear_free(proxyauth, len);
1341         if (proxyauthenc == NULL)
1342             goto end;
1343     }
1344 
1345     /* Terminate the HTTP CONNECT request */
1346     BIO_printf(fbio, "\r\n");
1347 
1348     for (;;) {
1349         if (BIO_flush(fbio) != 0)
1350             break;
1351         /* potentially needs to be retried if BIO is non-blocking */
1352         if (!BIO_should_retry(fbio))
1353             break;
1354     }
1355 
1356     for (;;) {
1357         /* will not actually wait if timeout == 0 */
1358         rv = BIO_wait(fbio, max_time, 100 /* milliseconds */);
1359         if (rv <= 0) {
1360             BIO_printf(bio_err, "%s: HTTP CONNECT %s\n", prog,
1361                        rv == 0 ? "timed out" : "failed waiting for data");
1362             goto end;
1363         }
1364 
1365         /*-
1366          * The first line is the HTTP response.
1367          * According to RFC 7230, it is formatted exactly like this:
1368          * HTTP/d.d ddd reason text\r\n
1369          */
1370         read_len = BIO_gets(fbio, mbuf, BUF_SIZE);
1371         /* the BIO may not block, so we must wait for the 1st line to come in */
1372         if (read_len < (int)HTTP_LINE1_MINLEN)
1373             continue;
1374 
1375         /* Check for HTTP/1.x */
1376         if (!HAS_PREFIX(mbuf, HTTP_PREFIX) != 0) {
1377             ERR_raise(ERR_LIB_HTTP, HTTP_R_HEADER_PARSE_ERROR);
1378             BIO_printf(bio_err, "%s: HTTP CONNECT failed, non-HTTP response\n",
1379                        prog);
1380             /* Wrong protocol, not even HTTP, so stop reading headers */
1381             goto end;
1382         }
1383         mbufp = mbuf + strlen(HTTP_PREFIX);
1384         if (!HAS_PREFIX(mbufp, HTTP_VERSION_PATT) != 0) {
1385             ERR_raise(ERR_LIB_HTTP, HTTP_R_RECEIVED_WRONG_HTTP_VERSION);
1386             BIO_printf(bio_err,
1387                        "%s: HTTP CONNECT failed, bad HTTP version %.*s\n",
1388                        prog, (int)HTTP_VERSION_STR_LEN, mbufp);
1389             goto end;
1390         }
1391         mbufp += HTTP_VERSION_STR_LEN;
1392 
1393         /* RFC 7231 4.3.6: any 2xx status code is valid */
1394         if (!HAS_PREFIX(mbufp, " 2")) {
1395             /* chop any trailing whitespace */
1396             while (read_len > 0 && ossl_isspace(mbuf[read_len - 1]))
1397                 read_len--;
1398             mbuf[read_len] = '\0';
1399             ERR_raise_data(ERR_LIB_HTTP, HTTP_R_CONNECT_FAILURE,
1400                            "reason=%s", mbufp);
1401             BIO_printf(bio_err, "%s: HTTP CONNECT failed, reason=%s\n",
1402                        prog, mbufp);
1403             goto end;
1404         }
1405         ret = 1;
1406         break;
1407     }
1408 
1409     /* Read past all following headers */
1410     do {
1411         /*
1412          * This does not necessarily catch the case when the full
1413          * HTTP response came in in more than a single TCP message.
1414          */
1415         read_len = BIO_gets(fbio, mbuf, BUF_SIZE);
1416     } while (read_len > 2);
1417 
1418  end:
1419     if (fbio != NULL) {
1420         (void)BIO_flush(fbio);
1421         BIO_pop(fbio);
1422         BIO_free(fbio);
1423     }
1424     OPENSSL_free(mbuf);
1425     return ret;
1426 #undef BUF_SIZE
1427 }
1428