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
43struct 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
90OSSL_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
115void 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
137BIO *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
146size_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
155void 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 optional port) must be given if and only if
168 * a plain HTTP proxy is used and |path| does not begin with 'http://'.
169 */
170int OSSL_HTTP_REQ_CTX_set_request_line(OSSL_HTTP_REQ_CTX *rctx, int method_POST,
171                                       const char *server, const char *port,
172                                       const char *path)
173{
174    if (rctx == NULL) {
175        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
176        return 0;
177    }
178    BIO_free(rctx->mem);
179    if ((rctx->mem = BIO_new(BIO_s_mem())) == NULL)
180        return 0;
181
182    rctx->method_POST = method_POST != 0;
183    if (BIO_printf(rctx->mem, "%s ", rctx->method_POST ? "POST" : "GET") <= 0)
184        return 0;
185
186    if (server != NULL) { /* HTTP (but not HTTPS) proxy is used */
187        /*
188         * Section 5.1.2 of RFC 1945 states that the absoluteURI form is only
189         * allowed when using a proxy
190         */
191        if (BIO_printf(rctx->mem, OSSL_HTTP_PREFIX"%s", server) <= 0)
192            return 0;
193        if (port != NULL && BIO_printf(rctx->mem, ":%s", port) <= 0)
194            return 0;
195    }
196
197    /* Make sure path includes a forward slash (abs_path) */
198    if (path == NULL)  {
199        path = "/";
200    } else if (HAS_PREFIX(path, "http://")) { /* absoluteURI for proxy use */
201        if (server != NULL) {
202            ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_INVALID_ARGUMENT);
203            return 0;
204        }
205    } else if (path[0] != '/' && BIO_printf(rctx->mem, "/") <= 0) {
206        return 0;
207    }
208    /*
209     * Add (the rest of) the path and the HTTP version,
210     * which is fixed to 1.0 for straightforward implementation of keep-alive
211     */
212    if (BIO_printf(rctx->mem, "%s "HTTP_1_0"\r\n", path) <= 0)
213        return 0;
214
215    rctx->resp_len = 0;
216    rctx->state = OHS_ADD_HEADERS;
217    return 1;
218}
219
220int OSSL_HTTP_REQ_CTX_add1_header(OSSL_HTTP_REQ_CTX *rctx,
221                                  const char *name, const char *value)
222{
223    if (rctx == NULL || name == NULL) {
224        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
225        return 0;
226    }
227    if (rctx->mem == NULL) {
228        ERR_raise(ERR_LIB_HTTP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
229        return 0;
230    }
231
232    if (BIO_puts(rctx->mem, name) <= 0)
233        return 0;
234    if (value != NULL) {
235        if (BIO_write(rctx->mem, ": ", 2) != 2)
236            return 0;
237        if (BIO_puts(rctx->mem, value) <= 0)
238            return 0;
239    }
240    return BIO_write(rctx->mem, "\r\n", 2) == 2;
241}
242
243int OSSL_HTTP_REQ_CTX_set_expected(OSSL_HTTP_REQ_CTX *rctx,
244                                   const char *content_type, int asn1,
245                                   int timeout, int keep_alive)
246{
247    if (rctx == NULL) {
248        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
249        return 0;
250    }
251    if (keep_alive != 0
252            && rctx->state != OHS_ERROR && rctx->state != OHS_ADD_HEADERS) {
253        /* Cannot anymore set keep-alive in request header */
254        ERR_raise(ERR_LIB_HTTP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
255        return 0;
256    }
257
258    OPENSSL_free(rctx->expected_ct);
259    rctx->expected_ct = NULL;
260    if (content_type != NULL
261            && (rctx->expected_ct = OPENSSL_strdup(content_type)) == NULL)
262        return 0;
263
264    rctx->expect_asn1 = asn1;
265    if (timeout >= 0)
266        rctx->max_time = timeout > 0 ? time(NULL) + timeout : 0;
267    else /* take over any |overall_timeout| arg of OSSL_HTTP_open(), else 0 */
268        rctx->max_time = rctx->max_total_time;
269    rctx->keep_alive = keep_alive;
270    return 1;
271}
272
273static int set1_content(OSSL_HTTP_REQ_CTX *rctx,
274                        const char *content_type, BIO *req)
275{
276    long req_len = 0;
277#ifndef OPENSSL_NO_STDIO
278    FILE *fp = NULL;
279#endif
280
281    if (rctx == NULL || (req == NULL && content_type != NULL)) {
282        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
283        return 0;
284    }
285
286    if (rctx->keep_alive != 0
287            && !OSSL_HTTP_REQ_CTX_add1_header(rctx, "Connection", "keep-alive"))
288        return 0;
289
290    BIO_free(rctx->req);
291    rctx->req = NULL;
292    if (req == NULL)
293        return 1;
294    if (!rctx->method_POST) {
295        ERR_raise(ERR_LIB_HTTP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
296        return 0;
297    }
298
299    if (content_type != NULL
300            && BIO_printf(rctx->mem, "Content-Type: %s\r\n", content_type) <= 0)
301        return 0;
302
303    /*
304     * BIO_CTRL_INFO yields the data length at least for memory BIOs, but for
305     * file-based BIOs it gives the current position, which is not what we need.
306     */
307    if (BIO_method_type(req) == BIO_TYPE_FILE) {
308#ifndef OPENSSL_NO_STDIO
309        if (BIO_get_fp(req, &fp) == 1 && fseek(fp, 0, SEEK_END) == 0) {
310            req_len = ftell(fp);
311            (void)fseek(fp, 0, SEEK_SET);
312        } else {
313            fp = NULL;
314        }
315#endif
316    } else {
317        req_len = BIO_ctrl(req, BIO_CTRL_INFO, 0, NULL);
318        /*
319         * Streaming BIOs likely will not support querying the size at all,
320         * and we assume we got a correct value if req_len > 0.
321         */
322    }
323    if ((
324#ifndef OPENSSL_NO_STDIO
325         fp != NULL /* definitely correct req_len */ ||
326#endif
327         req_len > 0)
328            && BIO_printf(rctx->mem, "Content-Length: %ld\r\n", req_len) < 0)
329        return 0;
330
331    if (!BIO_up_ref(req))
332        return 0;
333    rctx->req = req;
334    return 1;
335}
336
337int OSSL_HTTP_REQ_CTX_set1_req(OSSL_HTTP_REQ_CTX *rctx, const char *content_type,
338                               const ASN1_ITEM *it, const ASN1_VALUE *req)
339{
340    BIO *mem = NULL;
341    int res = 1;
342
343    if (req != NULL)
344        res = (mem = ASN1_item_i2d_mem_bio(it, req)) != NULL;
345    res = res && set1_content(rctx, content_type, mem);
346    BIO_free(mem);
347    return res;
348}
349
350static int add1_headers(OSSL_HTTP_REQ_CTX *rctx,
351                        const STACK_OF(CONF_VALUE) *headers, const char *host)
352{
353    int i;
354    int add_host = host != NULL && *host != '\0';
355    CONF_VALUE *hdr;
356
357    for (i = 0; i < sk_CONF_VALUE_num(headers); i++) {
358        hdr = sk_CONF_VALUE_value(headers, i);
359        if (add_host && OPENSSL_strcasecmp("host", hdr->name) == 0)
360            add_host = 0;
361        if (!OSSL_HTTP_REQ_CTX_add1_header(rctx, hdr->name, hdr->value))
362            return 0;
363    }
364
365    if (add_host && !OSSL_HTTP_REQ_CTX_add1_header(rctx, "Host", host))
366        return 0;
367    return 1;
368}
369
370/* Create OSSL_HTTP_REQ_CTX structure using the values provided. */
371static OSSL_HTTP_REQ_CTX *http_req_ctx_new(int free_wbio, BIO *wbio, BIO *rbio,
372                                           OSSL_HTTP_bio_cb_t bio_update_fn,
373                                           void *arg, int use_ssl,
374                                           const char *proxy,
375                                           const char *server, const char *port,
376                                           int buf_size, int overall_timeout)
377{
378    OSSL_HTTP_REQ_CTX *rctx = OSSL_HTTP_REQ_CTX_new(wbio, rbio, buf_size);
379
380    if (rctx == NULL)
381        return NULL;
382    rctx->free_wbio = free_wbio;
383    rctx->upd_fn = bio_update_fn;
384    rctx->upd_arg = arg;
385    rctx->use_ssl = use_ssl;
386    if (proxy != NULL
387            && (rctx->proxy = OPENSSL_strdup(proxy)) == NULL)
388        goto err;
389    if (server != NULL
390            && (rctx->server = OPENSSL_strdup(server)) == NULL)
391        goto err;
392    if (port != NULL
393            && (rctx->port = OPENSSL_strdup(port)) == NULL)
394        goto err;
395    rctx->max_total_time =
396        overall_timeout > 0 ? time(NULL) + overall_timeout : 0;
397    return rctx;
398
399 err:
400    OSSL_HTTP_REQ_CTX_free(rctx);
401    return NULL;
402}
403
404/*
405 * Parse first HTTP response line. This should be like this: "HTTP/1.0 200 OK".
406 * We need to obtain the status code and (optional) informational message.
407 * Return any received HTTP response status code, or 0 on fatal error.
408 */
409
410static int parse_http_line1(char *line, int *found_keep_alive)
411{
412    int i, retcode, err;
413    char *code, *reason, *end;
414
415    if (!HAS_PREFIX(line, HTTP_PREFIX_VERSION))
416        goto err;
417    /* above HTTP 1.0, connection persistence is the default */
418    *found_keep_alive = line[strlen(HTTP_PREFIX_VERSION)] > '0';
419
420    /* Skip to first whitespace (past protocol info) */
421    for (code = line; *code != '\0' && !ossl_isspace(*code); code++)
422        continue;
423    if (*code == '\0')
424        goto err;
425
426    /* Skip past whitespace to start of response code */
427    while (*code != '\0' && ossl_isspace(*code))
428        code++;
429    if (*code == '\0')
430        goto err;
431
432    /* Find end of response code: first whitespace after start of code */
433    for (reason = code; *reason != '\0' && !ossl_isspace(*reason); reason++)
434        continue;
435
436    if (*reason == '\0')
437        goto err;
438
439    /* Set end of response code and start of message */
440    *reason++ = '\0';
441
442    /* Attempt to parse numeric code */
443    retcode = strtoul(code, &end, 10);
444    if (*end != '\0')
445        goto err;
446
447    /* Skip over any leading whitespace in message */
448    while (*reason != '\0' && ossl_isspace(*reason))
449        reason++;
450
451    if (*reason != '\0') {
452        /*
453         * Finally zap any trailing whitespace in message (include CRLF)
454         */
455
456        /* chop any trailing whitespace from reason */
457        /* We know reason has a non-whitespace character so this is OK */
458        for (end = reason + strlen(reason) - 1; ossl_isspace(*end); end--)
459            *end = '\0';
460    }
461
462    switch (retcode) {
463    case HTTP_STATUS_CODE_OK:
464    case HTTP_STATUS_CODE_MOVED_PERMANENTLY:
465    case HTTP_STATUS_CODE_FOUND:
466        return retcode;
467    default:
468        err = HTTP_R_RECEIVED_ERROR;
469        if (retcode < 400)
470            err = HTTP_R_STATUS_CODE_UNSUPPORTED;
471        if (*reason == '\0')
472            ERR_raise_data(ERR_LIB_HTTP, err, "code=%s", code);
473        else
474            ERR_raise_data(ERR_LIB_HTTP, err, "code=%s, reason=%s", code,
475                           reason);
476        return retcode;
477    }
478
479 err:
480    for (i = 0; i < 60 && line[i] != '\0'; i++)
481        if (!ossl_isprint(line[i]))
482            line[i] = ' ';
483    line[i] = '\0';
484    ERR_raise_data(ERR_LIB_HTTP, HTTP_R_HEADER_PARSE_ERROR, "content=%s", line);
485    return 0;
486}
487
488static int check_set_resp_len(OSSL_HTTP_REQ_CTX *rctx, size_t len)
489{
490    if (rctx->max_resp_len != 0 && len > rctx->max_resp_len) {
491        ERR_raise_data(ERR_LIB_HTTP, HTTP_R_MAX_RESP_LEN_EXCEEDED,
492                       "length=%zu, max=%zu", len, rctx->max_resp_len);
493        return 0;
494    }
495    if (rctx->resp_len != 0 && rctx->resp_len != len) {
496        ERR_raise_data(ERR_LIB_HTTP, HTTP_R_INCONSISTENT_CONTENT_LENGTH,
497                       "ASN.1 length=%zu, Content-Length=%zu",
498                       len, rctx->resp_len);
499        return 0;
500    }
501    rctx->resp_len = len;
502    return 1;
503}
504
505static int may_still_retry(time_t max_time, int *ptimeout)
506{
507    time_t time_diff, now = time(NULL);
508
509    if (max_time != 0) {
510        if (max_time < now) {
511            ERR_raise(ERR_LIB_HTTP, HTTP_R_RETRY_TIMEOUT);
512            return 0;
513        }
514        time_diff = max_time - now;
515        *ptimeout = time_diff > INT_MAX ? INT_MAX : (int)time_diff;
516    }
517    return 1;
518}
519
520/*
521 * Try exchanging request and response via HTTP on (non-)blocking BIO in rctx.
522 * Returns 1 on success, 0 on error or redirection, -1 on BIO_should_retry.
523 */
524int OSSL_HTTP_REQ_CTX_nbio(OSSL_HTTP_REQ_CTX *rctx)
525{
526    int i, found_expected_ct = 0, found_keep_alive = 0;
527    long n;
528    size_t resp_len;
529    const unsigned char *p;
530    char *buf, *key, *value, *line_end = NULL;
531
532    if (rctx == NULL) {
533        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
534        return 0;
535    }
536    if (rctx->mem == NULL || rctx->wbio == NULL || rctx->rbio == NULL) {
537        ERR_raise(ERR_LIB_HTTP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
538        return 0;
539    }
540
541    rctx->redirection_url = NULL;
542 next_io:
543    buf = (char *)rctx->buf;
544    if ((rctx->state & OHS_NOREAD) == 0) {
545        if (rctx->expect_asn1) {
546            n = BIO_read(rctx->rbio, rctx->buf, rctx->buf_size);
547        } else {
548            (void)ERR_set_mark();
549            n = BIO_gets(rctx->rbio, buf, rctx->buf_size);
550            if (n == -2) { /* unsupported method */
551                (void)ERR_pop_to_mark();
552                n = BIO_get_line(rctx->rbio, buf, rctx->buf_size);
553            } else {
554                (void)ERR_clear_last_mark();
555            }
556        }
557        if (n <= 0) {
558            if (BIO_should_retry(rctx->rbio))
559                return -1;
560            ERR_raise(ERR_LIB_HTTP, HTTP_R_FAILED_READING_DATA);
561            return 0;
562        }
563
564        /* Write data to memory BIO */
565        if (BIO_write(rctx->mem, rctx->buf, n) != n)
566            return 0;
567    }
568
569    switch (rctx->state) {
570    case OHS_ADD_HEADERS:
571        /* Last operation was adding headers: need a final \r\n */
572        if (BIO_write(rctx->mem, "\r\n", 2) != 2) {
573            rctx->state = OHS_ERROR;
574            return 0;
575        }
576        rctx->state = OHS_WRITE_INIT;
577
578        /* fall thru */
579    case OHS_WRITE_INIT:
580        rctx->len_to_send = BIO_get_mem_data(rctx->mem, &rctx->pos);
581        rctx->state = OHS_WRITE_HDR;
582
583        /* fall thru */
584    case OHS_WRITE_HDR:
585        /* Copy some chunk of data from rctx->mem to rctx->wbio */
586    case OHS_WRITE_REQ:
587        /* Copy some chunk of data from rctx->req to rctx->wbio */
588
589        if (rctx->len_to_send > 0) {
590            i = BIO_write(rctx->wbio, rctx->pos, rctx->len_to_send);
591            if (i <= 0) {
592                if (BIO_should_retry(rctx->wbio))
593                    return -1;
594                rctx->state = OHS_ERROR;
595                return 0;
596            }
597            rctx->pos += i;
598            rctx->len_to_send -= i;
599            goto next_io;
600        }
601        if (rctx->state == OHS_WRITE_HDR) {
602            (void)BIO_reset(rctx->mem);
603            rctx->state = OHS_WRITE_REQ;
604        }
605        if (rctx->req != NULL && !BIO_eof(rctx->req)) {
606            n = BIO_read(rctx->req, rctx->buf, rctx->buf_size);
607            if (n <= 0) {
608                if (BIO_should_retry(rctx->req))
609                    return -1;
610                ERR_raise(ERR_LIB_HTTP, HTTP_R_FAILED_READING_DATA);
611                return 0;
612            }
613            rctx->pos = rctx->buf;
614            rctx->len_to_send = n;
615            goto next_io;
616        }
617        rctx->state = OHS_FLUSH;
618
619        /* fall thru */
620    case OHS_FLUSH:
621
622        i = BIO_flush(rctx->wbio);
623
624        if (i > 0) {
625            rctx->state = OHS_FIRSTLINE;
626            goto next_io;
627        }
628
629        if (BIO_should_retry(rctx->wbio))
630            return -1;
631
632        rctx->state = OHS_ERROR;
633        return 0;
634
635    case OHS_ERROR:
636        return 0;
637
638    case OHS_FIRSTLINE:
639    case OHS_HEADERS:
640    case OHS_REDIRECT:
641
642        /* Attempt to read a line in */
643 next_line:
644        /*
645         * Due to strange memory BIO behavior with BIO_gets we have to check
646         * there's a complete line in there before calling BIO_gets or we'll
647         * just get a partial read.
648         */
649        n = BIO_get_mem_data(rctx->mem, &p);
650        if (n <= 0 || memchr(p, '\n', n) == 0) {
651            if (n >= rctx->buf_size) {
652                rctx->state = OHS_ERROR;
653                return 0;
654            }
655            goto next_io;
656        }
657        n = BIO_gets(rctx->mem, buf, rctx->buf_size);
658
659        if (n <= 0) {
660            if (BIO_should_retry(rctx->mem))
661                goto next_io;
662            rctx->state = OHS_ERROR;
663            return 0;
664        }
665
666        /* Don't allow excessive lines */
667        if (n == rctx->buf_size) {
668            ERR_raise(ERR_LIB_HTTP, HTTP_R_RESPONSE_LINE_TOO_LONG);
669            rctx->state = OHS_ERROR;
670            return 0;
671        }
672
673        /* First line */
674        if (rctx->state == OHS_FIRSTLINE) {
675            switch (parse_http_line1(buf, &found_keep_alive)) {
676            case HTTP_STATUS_CODE_OK:
677                rctx->state = OHS_HEADERS;
678                goto next_line;
679            case HTTP_STATUS_CODE_MOVED_PERMANENTLY:
680            case HTTP_STATUS_CODE_FOUND: /* i.e., moved temporarily */
681                if (!rctx->method_POST) { /* method is GET */
682                    rctx->state = OHS_REDIRECT;
683                    goto next_line;
684                }
685                ERR_raise(ERR_LIB_HTTP, HTTP_R_REDIRECTION_NOT_ENABLED);
686                /* redirection is not supported/recommended for POST */
687                /* fall through */
688            default:
689                rctx->state = OHS_ERROR;
690                goto next_line;
691            }
692        }
693        key = buf;
694        value = strchr(key, ':');
695        if (value != NULL) {
696            *(value++) = '\0';
697            while (ossl_isspace(*value))
698                value++;
699            line_end = strchr(value, '\r');
700            if (line_end == NULL)
701                line_end = strchr(value, '\n');
702            if (line_end != NULL)
703                *line_end = '\0';
704        }
705        if (value != NULL && line_end != NULL) {
706            if (rctx->state == OHS_REDIRECT
707                    && OPENSSL_strcasecmp(key, "Location") == 0) {
708                rctx->redirection_url = value;
709                return 0;
710            }
711            if (rctx->state == OHS_HEADERS && rctx->expected_ct != NULL
712                    && OPENSSL_strcasecmp(key, "Content-Type") == 0) {
713                if (OPENSSL_strcasecmp(rctx->expected_ct, value) != 0) {
714                    ERR_raise_data(ERR_LIB_HTTP, HTTP_R_UNEXPECTED_CONTENT_TYPE,
715                                   "expected=%s, actual=%s",
716                                   rctx->expected_ct, value);
717                    return 0;
718                }
719                found_expected_ct = 1;
720            }
721
722            /* https://tools.ietf.org/html/rfc7230#section-6.3 Persistence */
723            if (OPENSSL_strcasecmp(key, "Connection") == 0) {
724                if (OPENSSL_strcasecmp(value, "keep-alive") == 0)
725                    found_keep_alive = 1;
726                else if (OPENSSL_strcasecmp(value, "close") == 0)
727                    found_keep_alive = 0;
728            } else if (OPENSSL_strcasecmp(key, "Content-Length") == 0) {
729                resp_len = (size_t)strtoul(value, &line_end, 10);
730                if (line_end == value || *line_end != '\0') {
731                    ERR_raise_data(ERR_LIB_HTTP,
732                                   HTTP_R_ERROR_PARSING_CONTENT_LENGTH,
733                                   "input=%s", value);
734                    return 0;
735                }
736                if (!check_set_resp_len(rctx, resp_len))
737                    return 0;
738            }
739        }
740
741        /* Look for blank line indicating end of headers */
742        for (p = rctx->buf; *p != '\0'; p++) {
743            if (*p != '\r' && *p != '\n')
744                break;
745        }
746        if (*p != '\0') /* not end of headers */
747            goto next_line;
748
749        if (rctx->keep_alive != 0 /* do not let server initiate keep_alive */
750                && !found_keep_alive /* otherwise there is no change */) {
751            if (rctx->keep_alive == 2) {
752                rctx->keep_alive = 0;
753                ERR_raise(ERR_LIB_HTTP, HTTP_R_SERVER_CANCELED_CONNECTION);
754                return 0;
755            }
756            rctx->keep_alive = 0;
757        }
758
759        if (rctx->state == OHS_ERROR)
760            return 0;
761
762        if (rctx->expected_ct != NULL && !found_expected_ct) {
763            ERR_raise_data(ERR_LIB_HTTP, HTTP_R_MISSING_CONTENT_TYPE,
764                           "expected=%s", rctx->expected_ct);
765            return 0;
766        }
767        if (rctx->state == OHS_REDIRECT) {
768            /* http status code indicated redirect but there was no Location */
769            ERR_raise(ERR_LIB_HTTP, HTTP_R_MISSING_REDIRECT_LOCATION);
770            return 0;
771        }
772
773        if (!rctx->expect_asn1) {
774            rctx->state = OHS_STREAM;
775            return 1;
776        }
777
778        rctx->state = OHS_ASN1_HEADER;
779
780        /* Fall thru */
781    case OHS_ASN1_HEADER:
782        /*
783         * Now reading ASN1 header: can read at least 2 bytes which is enough
784         * for ASN1 SEQUENCE header and either length field or at least the
785         * length of the length field.
786         */
787        n = BIO_get_mem_data(rctx->mem, &p);
788        if (n < 2)
789            goto next_io;
790
791        /* Check it is an ASN1 SEQUENCE */
792        if (*p++ != (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {
793            ERR_raise(ERR_LIB_HTTP, HTTP_R_MISSING_ASN1_ENCODING);
794            return 0;
795        }
796
797        /* Check out length field */
798        if ((*p & 0x80) != 0) {
799            /*
800             * If MSB set on initial length octet we can now always read 6
801             * octets: make sure we have them.
802             */
803            if (n < 6)
804                goto next_io;
805            n = *p & 0x7F;
806            /* Not NDEF or excessive length */
807            if (n == 0 || (n > 4)) {
808                ERR_raise(ERR_LIB_HTTP, HTTP_R_ERROR_PARSING_ASN1_LENGTH);
809                return 0;
810            }
811            p++;
812            resp_len = 0;
813            for (i = 0; i < n; i++) {
814                resp_len <<= 8;
815                resp_len |= *p++;
816            }
817            resp_len += n + 2;
818        } else {
819            resp_len = *p + 2;
820        }
821        if (!check_set_resp_len(rctx, resp_len))
822            return 0;
823
824        rctx->state = OHS_ASN1_CONTENT;
825
826        /* Fall thru */
827    case OHS_ASN1_CONTENT:
828    default:
829        n = BIO_get_mem_data(rctx->mem, NULL);
830        if (n < 0 || (size_t)n < rctx->resp_len)
831            goto next_io;
832
833        rctx->state = OHS_ASN1_DONE;
834        return 1;
835    }
836}
837
838int OSSL_HTTP_REQ_CTX_nbio_d2i(OSSL_HTTP_REQ_CTX *rctx,
839                               ASN1_VALUE **pval, const ASN1_ITEM *it)
840{
841    const unsigned char *p;
842    int rv;
843
844    *pval = NULL;
845    if ((rv = OSSL_HTTP_REQ_CTX_nbio(rctx)) != 1)
846        return rv;
847    *pval = ASN1_item_d2i(NULL, &p, BIO_get_mem_data(rctx->mem, &p), it);
848    return *pval != NULL;
849
850}
851
852#ifndef OPENSSL_NO_SOCK
853
854/* set up a new connection BIO, to HTTP server or to HTTP(S) proxy if given */
855static BIO *http_new_bio(const char *server /* optionally includes ":port" */,
856                         const char *server_port /* explicit server port */,
857                         int use_ssl,
858                         const char *proxy /* optionally includes ":port" */,
859                         const char *proxy_port /* explicit proxy port */)
860{
861    const char *host = server;
862    const char *port = server_port;
863    BIO *cbio;
864
865    if (!ossl_assert(server != NULL))
866        return NULL;
867
868    if (proxy != NULL) {
869        host = proxy;
870        port = proxy_port;
871    }
872
873    if (port == NULL && strchr(host, ':') == NULL)
874        port = use_ssl ? OSSL_HTTPS_PORT : OSSL_HTTP_PORT;
875
876    cbio = BIO_new_connect(host /* optionally includes ":port" */);
877    if (cbio == NULL)
878        goto end;
879    if (port != NULL)
880        (void)BIO_set_conn_port(cbio, port);
881
882 end:
883    return cbio;
884}
885#endif /* OPENSSL_NO_SOCK */
886
887/* Exchange request and response via HTTP on (non-)blocking BIO */
888BIO *OSSL_HTTP_REQ_CTX_exchange(OSSL_HTTP_REQ_CTX *rctx)
889{
890    int rv;
891
892    if (rctx == NULL) {
893        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
894        return NULL;
895    }
896
897    for (;;) {
898        rv = OSSL_HTTP_REQ_CTX_nbio(rctx);
899        if (rv != -1)
900            break;
901        /* BIO_should_retry was true */
902        /* will not actually wait if rctx->max_time == 0 */
903        if (BIO_wait(rctx->rbio, rctx->max_time, 100 /* milliseconds */) <= 0)
904            return NULL;
905    }
906
907    if (rv == 0) {
908        if (rctx->redirection_url == NULL) { /* an error occurred */
909            if (rctx->len_to_send > 0)
910                ERR_raise(ERR_LIB_HTTP, HTTP_R_ERROR_SENDING);
911            else
912                ERR_raise(ERR_LIB_HTTP, HTTP_R_ERROR_RECEIVING);
913        }
914        return NULL;
915    }
916    return rctx->state == OHS_STREAM ? rctx->rbio : rctx->mem;
917}
918
919int OSSL_HTTP_is_alive(const OSSL_HTTP_REQ_CTX *rctx)
920{
921    return rctx != NULL && rctx->keep_alive != 0;
922}
923
924/* High-level HTTP API implementation */
925
926/* Initiate an HTTP session using bio, else use given server, proxy, etc. */
927OSSL_HTTP_REQ_CTX *OSSL_HTTP_open(const char *server, const char *port,
928                                  const char *proxy, const char *no_proxy,
929                                  int use_ssl, BIO *bio, BIO *rbio,
930                                  OSSL_HTTP_bio_cb_t bio_update_fn, void *arg,
931                                  int buf_size, int overall_timeout)
932{
933    BIO *cbio; /* == bio if supplied, used as connection BIO if rbio is NULL */
934    OSSL_HTTP_REQ_CTX *rctx = NULL;
935
936    if (use_ssl && bio_update_fn == NULL) {
937        ERR_raise(ERR_LIB_HTTP, HTTP_R_TLS_NOT_ENABLED);
938        return NULL;
939    }
940    if (rbio != NULL && (bio == NULL || bio_update_fn != NULL)) {
941        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_INVALID_ARGUMENT);
942        return NULL;
943    }
944
945    if (bio != NULL) {
946        cbio = bio;
947        if (proxy != NULL || no_proxy != NULL) {
948            ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_INVALID_ARGUMENT);
949            return NULL;
950        }
951    } else {
952#ifndef OPENSSL_NO_SOCK
953        char *proxy_host = NULL, *proxy_port = NULL;
954
955        if (server == NULL) {
956            ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
957            return NULL;
958        }
959        if (port != NULL && *port == '\0')
960            port = NULL;
961        if (port == NULL && strchr(server, ':') == NULL)
962            port = use_ssl ? OSSL_HTTPS_PORT : OSSL_HTTP_PORT;
963        proxy = OSSL_HTTP_adapt_proxy(proxy, no_proxy, server, use_ssl);
964        if (proxy != NULL
965            && !OSSL_HTTP_parse_url(proxy, NULL /* use_ssl */, NULL /* user */,
966                                    &proxy_host, &proxy_port, NULL /* num */,
967                                    NULL /* path */, NULL, NULL))
968            return NULL;
969        cbio = http_new_bio(server, port, use_ssl, proxy_host, proxy_port);
970        OPENSSL_free(proxy_host);
971        OPENSSL_free(proxy_port);
972        if (cbio == NULL)
973            return NULL;
974#else
975        ERR_raise(ERR_LIB_HTTP, HTTP_R_SOCK_NOT_SUPPORTED);
976        return NULL;
977#endif
978    }
979
980    (void)ERR_set_mark(); /* prepare removing any spurious libssl errors */
981    if (rbio == NULL && BIO_do_connect_retry(cbio, overall_timeout, -1) <= 0) {
982        if (bio == NULL) /* cbio was not provided by caller */
983            BIO_free_all(cbio);
984        goto end;
985    }
986    /* now overall_timeout is guaranteed to be >= 0 */
987
988    /* adapt in order to fix callback design flaw, see #17088 */
989    /* callback can be used to wrap or prepend TLS session */
990    if (bio_update_fn != NULL) {
991        BIO *orig_bio = cbio;
992
993        cbio = (*bio_update_fn)(cbio, arg, 1 /* connect */, use_ssl != 0);
994        if (cbio == NULL) {
995            if (bio == NULL) /* cbio was not provided by caller */
996                BIO_free_all(orig_bio);
997            goto end;
998        }
999    }
1000
1001    rctx = http_req_ctx_new(bio == NULL, cbio, rbio != NULL ? rbio : cbio,
1002                            bio_update_fn, arg, use_ssl, proxy, server, port,
1003                            buf_size, overall_timeout);
1004
1005 end:
1006    if (rctx != NULL)
1007        /* remove any spurious error queue entries by ssl_add_cert_chain() */
1008        (void)ERR_pop_to_mark();
1009    else
1010        (void)ERR_clear_last_mark();
1011
1012    return rctx;
1013}
1014
1015int OSSL_HTTP_set1_request(OSSL_HTTP_REQ_CTX *rctx, const char *path,
1016                           const STACK_OF(CONF_VALUE) *headers,
1017                           const char *content_type, BIO *req,
1018                           const char *expected_content_type, int expect_asn1,
1019                           size_t max_resp_len, int timeout, int keep_alive)
1020{
1021    int use_http_proxy;
1022
1023    if (rctx == NULL) {
1024        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
1025        return 0;
1026    }
1027    use_http_proxy = rctx->proxy != NULL && !rctx->use_ssl;
1028    if (use_http_proxy && rctx->server == NULL) {
1029        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_INVALID_ARGUMENT);
1030        return 0;
1031    }
1032    rctx->max_resp_len = max_resp_len; /* allows for 0: indefinite */
1033
1034    return OSSL_HTTP_REQ_CTX_set_request_line(rctx, req != NULL,
1035                                              use_http_proxy ? rctx->server
1036                                              : NULL, rctx->port, path)
1037        && add1_headers(rctx, headers, rctx->server)
1038        && OSSL_HTTP_REQ_CTX_set_expected(rctx, expected_content_type,
1039                                          expect_asn1, timeout, keep_alive)
1040        && set1_content(rctx, content_type, req);
1041}
1042
1043/*-
1044 * Exchange single HTTP request and response according to rctx.
1045 * If rctx->method_POST then use POST, else use GET and ignore content_type.
1046 * The redirection_url output (freed by caller) parameter is used only for GET.
1047 */
1048BIO *OSSL_HTTP_exchange(OSSL_HTTP_REQ_CTX *rctx, char **redirection_url)
1049{
1050    BIO *resp;
1051
1052    if (rctx == NULL) {
1053        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
1054        return NULL;
1055    }
1056
1057    if (redirection_url != NULL)
1058        *redirection_url = NULL; /* do this beforehand to prevent dbl free */
1059
1060    resp = OSSL_HTTP_REQ_CTX_exchange(rctx);
1061    if (resp == NULL) {
1062        if (rctx->redirection_url != NULL) {
1063            if (redirection_url == NULL)
1064                ERR_raise(ERR_LIB_HTTP, HTTP_R_REDIRECTION_NOT_ENABLED);
1065            else
1066                /* may be NULL if out of memory: */
1067                *redirection_url = OPENSSL_strdup(rctx->redirection_url);
1068        } else {
1069            char buf[200];
1070            unsigned long err = ERR_peek_error();
1071            int lib = ERR_GET_LIB(err);
1072            int reason = ERR_GET_REASON(err);
1073
1074            if (lib == ERR_LIB_SSL || lib == ERR_LIB_HTTP
1075                    || (lib == ERR_LIB_BIO && reason == BIO_R_CONNECT_TIMEOUT)
1076                    || (lib == ERR_LIB_BIO && reason == BIO_R_CONNECT_ERROR)
1077#ifndef OPENSSL_NO_CMP
1078                    || (lib == ERR_LIB_CMP
1079                        && reason == CMP_R_POTENTIALLY_INVALID_CERTIFICATE)
1080#endif
1081                ) {
1082                if (rctx->server != NULL) {
1083                    BIO_snprintf(buf, sizeof(buf), "server=http%s://%s%s%s",
1084                                 rctx->use_ssl ? "s" : "", rctx->server,
1085                                 rctx->port != NULL ? ":" : "",
1086                                 rctx->port != NULL ? rctx->port : "");
1087                    ERR_add_error_data(1, buf);
1088                }
1089                if (rctx->proxy != NULL)
1090                    ERR_add_error_data(2, " proxy=", rctx->proxy);
1091                if (err == 0) {
1092                    BIO_snprintf(buf, sizeof(buf), " peer has disconnected%s",
1093                                 rctx->use_ssl ? " violating the protocol" :
1094                                 ", likely because it requires the use of TLS");
1095                    ERR_add_error_data(1, buf);
1096                }
1097            }
1098        }
1099    }
1100
1101    if (resp != NULL && !BIO_up_ref(resp))
1102        resp = NULL;
1103    return resp;
1104}
1105
1106static int redirection_ok(int n_redir, const char *old_url, const char *new_url)
1107{
1108    if (n_redir >= HTTP_VERSION_MAX_REDIRECTIONS) {
1109        ERR_raise(ERR_LIB_HTTP, HTTP_R_TOO_MANY_REDIRECTIONS);
1110        return 0;
1111    }
1112    if (*new_url == '/') /* redirection to same server => same protocol */
1113        return 1;
1114    if (HAS_PREFIX(old_url, OSSL_HTTPS_NAME":") &&
1115        !HAS_PREFIX(new_url, OSSL_HTTPS_NAME":")) {
1116        ERR_raise(ERR_LIB_HTTP, HTTP_R_REDIRECTION_FROM_HTTPS_TO_HTTP);
1117        return 0;
1118    }
1119    return 1;
1120}
1121
1122/* Get data via HTTP from server at given URL, potentially with redirection */
1123BIO *OSSL_HTTP_get(const char *url, const char *proxy, const char *no_proxy,
1124                   BIO *bio, BIO *rbio,
1125                   OSSL_HTTP_bio_cb_t bio_update_fn, void *arg,
1126                   int buf_size, const STACK_OF(CONF_VALUE) *headers,
1127                   const char *expected_ct, int expect_asn1,
1128                   size_t max_resp_len, int timeout)
1129{
1130    char *current_url, *redirection_url = NULL;
1131    int n_redirs = 0;
1132    char *host;
1133    char *port;
1134    char *path;
1135    int use_ssl;
1136    OSSL_HTTP_REQ_CTX *rctx = NULL;
1137    BIO *resp = NULL;
1138    time_t max_time = timeout > 0 ? time(NULL) + timeout : 0;
1139
1140    if (url == NULL) {
1141        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
1142        return NULL;
1143    }
1144    if ((current_url = OPENSSL_strdup(url)) == NULL)
1145        return NULL;
1146
1147    for (;;) {
1148        if (!OSSL_HTTP_parse_url(current_url, &use_ssl, NULL /* user */, &host,
1149                                 &port, NULL /* port_num */, &path, NULL, NULL))
1150            break;
1151
1152        rctx = OSSL_HTTP_open(host, port, proxy, no_proxy,
1153                              use_ssl, bio, rbio, bio_update_fn, arg,
1154                              buf_size, timeout);
1155    new_rpath:
1156        if (rctx != NULL) {
1157            if (!OSSL_HTTP_set1_request(rctx, path, headers,
1158                                        NULL /* content_type */,
1159                                        NULL /* req */,
1160                                        expected_ct, expect_asn1, max_resp_len,
1161                                        -1 /* use same max time (timeout) */,
1162                                        0 /* no keep_alive */)) {
1163                OSSL_HTTP_REQ_CTX_free(rctx);
1164                rctx = NULL;
1165           } else {
1166                resp = OSSL_HTTP_exchange(rctx, &redirection_url);
1167           }
1168        }
1169        OPENSSL_free(path);
1170        if (resp == NULL && redirection_url != NULL) {
1171            if (redirection_ok(++n_redirs, current_url, redirection_url)
1172                    && may_still_retry(max_time, &timeout)) {
1173                (void)BIO_reset(bio);
1174                OPENSSL_free(current_url);
1175                current_url = redirection_url;
1176                if (*redirection_url == '/') { /* redirection to same server */
1177                    path = OPENSSL_strdup(redirection_url);
1178                    if (path == NULL) {
1179                        OPENSSL_free(host);
1180                        OPENSSL_free(port);
1181                        (void)OSSL_HTTP_close(rctx, 1);
1182                        rctx = NULL;
1183                        BIO_free(resp);
1184                        OPENSSL_free(current_url);
1185                        return NULL;
1186                    }
1187                    goto new_rpath;
1188                }
1189                OPENSSL_free(host);
1190                OPENSSL_free(port);
1191                (void)OSSL_HTTP_close(rctx, 1);
1192                rctx = NULL;
1193                continue;
1194            }
1195            /* if redirection not allowed, ignore it */
1196            OPENSSL_free(redirection_url);
1197        }
1198        OPENSSL_free(host);
1199        OPENSSL_free(port);
1200        if (!OSSL_HTTP_close(rctx, resp != NULL)) {
1201            BIO_free(resp);
1202            rctx = NULL;
1203            resp = NULL;
1204        }
1205        break;
1206    }
1207    OPENSSL_free(current_url);
1208    return resp;
1209}
1210
1211/* Exchange request and response over a connection managed via |prctx| */
1212BIO *OSSL_HTTP_transfer(OSSL_HTTP_REQ_CTX **prctx,
1213                        const char *server, const char *port,
1214                        const char *path, int use_ssl,
1215                        const char *proxy, const char *no_proxy,
1216                        BIO *bio, BIO *rbio,
1217                        OSSL_HTTP_bio_cb_t bio_update_fn, void *arg,
1218                        int buf_size, const STACK_OF(CONF_VALUE) *headers,
1219                        const char *content_type, BIO *req,
1220                        const char *expected_ct, int expect_asn1,
1221                        size_t max_resp_len, int timeout, int keep_alive)
1222{
1223    OSSL_HTTP_REQ_CTX *rctx = prctx == NULL ? NULL : *prctx;
1224    BIO *resp = NULL;
1225
1226    if (rctx == NULL) {
1227        rctx = OSSL_HTTP_open(server, port, proxy, no_proxy,
1228                              use_ssl, bio, rbio, bio_update_fn, arg,
1229                              buf_size, timeout);
1230        timeout = -1; /* Already set during opening the connection */
1231    }
1232    if (rctx != NULL) {
1233        if (OSSL_HTTP_set1_request(rctx, path, headers, content_type, req,
1234                                   expected_ct, expect_asn1,
1235                                   max_resp_len, timeout, keep_alive))
1236            resp = OSSL_HTTP_exchange(rctx, NULL);
1237        if (resp == NULL || !OSSL_HTTP_is_alive(rctx)) {
1238            if (!OSSL_HTTP_close(rctx, resp != NULL)) {
1239                BIO_free(resp);
1240                resp = NULL;
1241            }
1242            rctx = NULL;
1243        }
1244    }
1245    if (prctx != NULL)
1246        *prctx = rctx;
1247    return resp;
1248}
1249
1250int OSSL_HTTP_close(OSSL_HTTP_REQ_CTX *rctx, int ok)
1251{
1252    BIO *wbio;
1253    int ret = 1;
1254
1255    /* callback can be used to finish TLS session and free its BIO */
1256    if (rctx != NULL && rctx->upd_fn != NULL) {
1257        wbio = (*rctx->upd_fn)(rctx->wbio, rctx->upd_arg,
1258                               0 /* disconnect */, ok);
1259        ret = wbio != NULL;
1260        if (ret)
1261            rctx->wbio = wbio;
1262    }
1263    OSSL_HTTP_REQ_CTX_free(rctx);
1264    return ret;
1265}
1266
1267/* BASE64 encoder used for encoding basic proxy authentication credentials */
1268static char *base64encode(const void *buf, size_t len)
1269{
1270    int i;
1271    size_t outl;
1272    char *out;
1273
1274    /* Calculate size of encoded data */
1275    outl = (len / 3);
1276    if (len % 3 > 0)
1277        outl++;
1278    outl <<= 2;
1279    out = OPENSSL_malloc(outl + 1);
1280    if (out == NULL)
1281        return 0;
1282
1283    i = EVP_EncodeBlock((unsigned char *)out, buf, len);
1284    if (!ossl_assert(0 <= i && (size_t)i <= outl)) {
1285        OPENSSL_free(out);
1286        return NULL;
1287    }
1288    return out;
1289}
1290
1291/*
1292 * Promote the given connection BIO using the CONNECT method for a TLS proxy.
1293 * This is typically called by an app, so bio_err and prog are used unless NULL
1294 * to print additional diagnostic information in a user-oriented way.
1295 */
1296int OSSL_HTTP_proxy_connect(BIO *bio, const char *server, const char *port,
1297                            const char *proxyuser, const char *proxypass,
1298                            int timeout, BIO *bio_err, const char *prog)
1299{
1300#undef BUF_SIZE
1301#define BUF_SIZE (8 * 1024)
1302    char *mbuf = OPENSSL_malloc(BUF_SIZE);
1303    char *mbufp;
1304    int read_len = 0;
1305    int ret = 0;
1306    BIO *fbio = BIO_new(BIO_f_buffer());
1307    int rv;
1308    time_t max_time = timeout > 0 ? time(NULL) + timeout : 0;
1309
1310    if (bio == NULL || server == NULL
1311            || (bio_err != NULL && prog == NULL)) {
1312        ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
1313        goto end;
1314    }
1315    if (port == NULL || *port == '\0')
1316        port = OSSL_HTTPS_PORT;
1317
1318    if (mbuf == NULL || fbio == NULL) {
1319        BIO_printf(bio_err /* may be NULL */, "%s: out of memory", prog);
1320        goto end;
1321    }
1322    BIO_push(fbio, bio);
1323
1324    BIO_printf(fbio, "CONNECT %s:%s "HTTP_1_0"\r\n", server, port);
1325
1326    /*
1327     * Workaround for broken proxies which would otherwise close
1328     * the connection when entering tunnel mode (e.g., Squid 2.6)
1329     */
1330    BIO_printf(fbio, "Proxy-Connection: Keep-Alive\r\n");
1331
1332    /* Support for basic (base64) proxy authentication */
1333    if (proxyuser != NULL) {
1334        size_t len = strlen(proxyuser) + 1;
1335        char *proxyauth, *proxyauthenc = NULL;
1336
1337        if (proxypass != NULL)
1338            len += strlen(proxypass);
1339        proxyauth = OPENSSL_malloc(len + 1);
1340        if (proxyauth == NULL)
1341            goto end;
1342        if (BIO_snprintf(proxyauth, len + 1, "%s:%s", proxyuser,
1343                         proxypass != NULL ? proxypass : "") != (int)len)
1344            goto proxy_end;
1345        proxyauthenc = base64encode(proxyauth, len);
1346        if (proxyauthenc != NULL) {
1347            BIO_printf(fbio, "Proxy-Authorization: Basic %s\r\n", proxyauthenc);
1348            OPENSSL_clear_free(proxyauthenc, strlen(proxyauthenc));
1349        }
1350    proxy_end:
1351        OPENSSL_clear_free(proxyauth, len);
1352        if (proxyauthenc == NULL)
1353            goto end;
1354    }
1355
1356    /* Terminate the HTTP CONNECT request */
1357    BIO_printf(fbio, "\r\n");
1358
1359    for (;;) {
1360        if (BIO_flush(fbio) != 0)
1361            break;
1362        /* potentially needs to be retried if BIO is non-blocking */
1363        if (!BIO_should_retry(fbio))
1364            break;
1365    }
1366
1367    for (;;) {
1368        /* will not actually wait if timeout == 0 */
1369        rv = BIO_wait(fbio, max_time, 100 /* milliseconds */);
1370        if (rv <= 0) {
1371            BIO_printf(bio_err, "%s: HTTP CONNECT %s\n", prog,
1372                       rv == 0 ? "timed out" : "failed waiting for data");
1373            goto end;
1374        }
1375
1376        /*-
1377         * The first line is the HTTP response.
1378         * According to RFC 7230, it is formatted exactly like this:
1379         * HTTP/d.d ddd reason text\r\n
1380         */
1381        read_len = BIO_gets(fbio, mbuf, BUF_SIZE);
1382        /* the BIO may not block, so we must wait for the 1st line to come in */
1383        if (read_len < (int)HTTP_LINE1_MINLEN)
1384            continue;
1385
1386        /* Check for HTTP/1.x */
1387        if (!HAS_PREFIX(mbuf, HTTP_PREFIX) != 0) {
1388            ERR_raise(ERR_LIB_HTTP, HTTP_R_HEADER_PARSE_ERROR);
1389            BIO_printf(bio_err, "%s: HTTP CONNECT failed, non-HTTP response\n",
1390                       prog);
1391            /* Wrong protocol, not even HTTP, so stop reading headers */
1392            goto end;
1393        }
1394        mbufp = mbuf + strlen(HTTP_PREFIX);
1395        if (!HAS_PREFIX(mbufp, HTTP_VERSION_PATT) != 0) {
1396            ERR_raise(ERR_LIB_HTTP, HTTP_R_RECEIVED_WRONG_HTTP_VERSION);
1397            BIO_printf(bio_err,
1398                       "%s: HTTP CONNECT failed, bad HTTP version %.*s\n",
1399                       prog, (int)HTTP_VERSION_STR_LEN, mbufp);
1400            goto end;
1401        }
1402        mbufp += HTTP_VERSION_STR_LEN;
1403
1404        /* RFC 7231 4.3.6: any 2xx status code is valid */
1405        if (!HAS_PREFIX(mbufp, " 2")) {
1406            /* chop any trailing whitespace */
1407            while (read_len > 0 && ossl_isspace(mbuf[read_len - 1]))
1408                read_len--;
1409            mbuf[read_len] = '\0';
1410            ERR_raise_data(ERR_LIB_HTTP, HTTP_R_CONNECT_FAILURE,
1411                           "reason=%s", mbufp);
1412            BIO_printf(bio_err, "%s: HTTP CONNECT failed, reason=%s\n",
1413                       prog, mbufp);
1414            goto end;
1415        }
1416        ret = 1;
1417        break;
1418    }
1419
1420    /* Read past all following headers */
1421    do {
1422        /*
1423         * This does not necessarily catch the case when the full
1424         * HTTP response came in in more than a single TCP message.
1425         */
1426        read_len = BIO_gets(fbio, mbuf, BUF_SIZE);
1427    } while (read_len > 2);
1428
1429 end:
1430    if (fbio != NULL) {
1431        (void)BIO_flush(fbio);
1432        BIO_pop(fbio);
1433        BIO_free(fbio);
1434    }
1435    OPENSSL_free(mbuf);
1436    return ret;
1437#undef BUF_SIZE
1438}
1439