xref: /freebsd/crypto/openssl/crypto/http/http_lib.c (revision 78e936b2d0b5e6554425009199be31e76bc67c10)
1 /*
2  * Copyright 2001-2026 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <stdio.h> /* for sscanf() */
11 #include <string.h>
12 #include <openssl/http.h>
13 #include <openssl/httperr.h>
14 #include <openssl/bio.h> /* for BIO_snprintf() */
15 #include <openssl/err.h>
16 #include "internal/cryptlib.h" /* for ossl_assert() */
17 #ifndef OPENSSL_NO_SOCK
18 #include "internal/bio_addr.h" /* for NI_MAXHOST */
19 #endif
20 #ifndef NI_MAXHOST
21 #define NI_MAXHOST 255
22 #endif
23 #include "crypto/ctype.h" /* for ossl_isspace() */
24 #define OSSL_URL_SCHEME_SUFFIX "://"
25 
init_pstring(char ** pstr)26 static void init_pstring(char **pstr)
27 {
28     if (pstr != NULL) {
29         *pstr = NULL;
30     }
31 }
32 
init_pint(int * pint)33 static void init_pint(int *pint)
34 {
35     if (pint != NULL) {
36         *pint = 0;
37     }
38 }
39 
copy_substring(char ** dest,const char * start,const char * end)40 static int copy_substring(char **dest, const char *start, const char *end)
41 {
42     return dest == NULL
43         || (*dest = OPENSSL_strndup(start, end - start)) != NULL;
44 }
45 
free_pstring(char ** pstr)46 static void free_pstring(char **pstr)
47 {
48     if (pstr != NULL) {
49         OPENSSL_free(*pstr);
50         *pstr = NULL;
51     }
52 }
53 
OSSL_parse_url(const char * url,char ** pscheme,char ** puser,char ** phost,char ** pport,int * pport_num,char ** ppath,char ** pquery,char ** pfrag)54 int OSSL_parse_url(const char *url, char **pscheme, char **puser, char **phost,
55     char **pport, int *pport_num,
56     char **ppath, char **pquery, char **pfrag)
57 {
58     const char *p, *tmp;
59     const char *authority_end;
60     const char *scheme, *scheme_end;
61     const char *user, *user_end;
62     const char *host, *host_end;
63     const char *port, *port_end;
64     unsigned int portnum = 0;
65     const char *path, *path_end;
66     const char *query, *query_end;
67     const char *frag, *frag_end;
68 
69     init_pstring(pscheme);
70     init_pstring(puser);
71     init_pstring(phost);
72     init_pstring(pport);
73     init_pint(pport_num);
74     init_pstring(ppath);
75     init_pstring(pfrag);
76     init_pstring(pquery);
77 
78     if (url == NULL) {
79         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
80         return 0;
81     }
82 
83     /* check for optional prefix "<scheme>://" as per RFC 3986: */
84     scheme = scheme_end = p = url;
85     if (ossl_isalpha(*p)) {
86         while (*p != '\0'
87             && (ossl_isalpha(*p)
88                 || ossl_isdigit(*p)
89                 || strchr("+-.", *p) != NULL))
90             p++;
91         if (HAS_PREFIX(p, OSSL_URL_SCHEME_SUFFIX)) {
92             scheme_end = p;
93             p += sizeof(OSSL_URL_SCHEME_SUFFIX) - 1;
94         } else {
95             p = url;
96         }
97     }
98 
99     /* parse optional "userinfo@" */
100     user = user_end = host = p;
101     authority_end = strpbrk(p, "/?#");
102     if (authority_end == NULL)
103         authority_end = p + strlen(p);
104     host = memchr(p, '@', authority_end - p);
105     if (host != NULL)
106         user_end = host++;
107     else
108         host = p;
109 
110     /* parse hostname/address as far as needed here */
111     if (host[0] == '[') {
112         /* IPv6 literal, which may include ':' */
113         host_end = memchr(host + 1, ']', authority_end - host - 1);
114         if (host_end == NULL)
115             goto parse_err;
116         p = ++host_end;
117     } else {
118         /* look for start of optional port, path, query, or fragment */
119         host_end = strpbrk(host, ":/?#");
120         if (host_end == NULL) /* the remaining string is just the hostname */
121             host_end = host + strlen(host);
122         p = host_end;
123     }
124 
125     /* parse optional port specification starting with ':' */
126     port = "0"; /* default */
127     if (*p == ':')
128         port = ++p;
129     /* remaining port spec handling is also done for the default values */
130     /* make sure a decimal port number is given */
131     if (sscanf(port, "%u", &portnum) <= 0 || portnum > 65535) {
132         ERR_raise_data(ERR_LIB_HTTP, HTTP_R_INVALID_PORT_NUMBER, "%s", port);
133         goto err;
134     }
135     for (port_end = port; '0' <= *port_end && *port_end <= '9'; port_end++)
136         ;
137     if (port == p) /* port was given explicitly */
138         p += port_end - port;
139 
140     /* check for optional path starting with '/' or '?'. Else must start '#' */
141     path = p;
142     if (*path != '\0' && *path != '/' && *path != '?' && *path != '#') {
143         ERR_raise(ERR_LIB_HTTP, HTTP_R_INVALID_URL_PATH);
144         goto parse_err;
145     }
146     path_end = query = query_end = frag = frag_end = path + strlen(path);
147 
148     /* parse optional "?query" */
149     tmp = strchr(p, '?');
150     if (tmp != NULL) {
151         p = tmp;
152         if (pquery != NULL) {
153             path_end = p;
154             query = p + 1;
155         }
156     }
157 
158     /* parse optional "#fragment" */
159     tmp = strchr(p, '#');
160     if (tmp != NULL) {
161         if (query == path_end) /* we did not record a query component */
162             path_end = tmp;
163         query_end = tmp;
164         frag = tmp + 1;
165     }
166 
167     if (!copy_substring(pscheme, scheme, scheme_end)
168         || !copy_substring(phost, host, host_end)
169         || !copy_substring(pport, port, port_end)
170         || !copy_substring(puser, user, user_end)
171         || !copy_substring(pquery, query, query_end)
172         || !copy_substring(pfrag, frag, frag_end))
173         goto err;
174     if (pport_num != NULL)
175         *pport_num = (int)portnum;
176     if (*path == '/') {
177         if (!copy_substring(ppath, path, path_end))
178             goto err;
179     } else if (ppath != NULL) { /* must prepend '/' */
180         size_t buflen = 1 + path_end - path + 1;
181 
182         if ((*ppath = OPENSSL_malloc(buflen)) == NULL)
183             goto err;
184         BIO_snprintf(*ppath, buflen, "/%s", path);
185     }
186     return 1;
187 
188 parse_err:
189     ERR_raise(ERR_LIB_HTTP, HTTP_R_ERROR_PARSING_URL);
190 
191 err:
192     free_pstring(pscheme);
193     free_pstring(puser);
194     free_pstring(phost);
195     free_pstring(pport);
196     free_pstring(ppath);
197     free_pstring(pquery);
198     free_pstring(pfrag);
199     return 0;
200 }
201 
202 #ifndef OPENSSL_NO_HTTP
203 
OSSL_HTTP_parse_url(const char * url,int * pssl,char ** puser,char ** phost,char ** pport,int * pport_num,char ** ppath,char ** pquery,char ** pfrag)204 int OSSL_HTTP_parse_url(const char *url, int *pssl, char **puser, char **phost,
205     char **pport, int *pport_num,
206     char **ppath, char **pquery, char **pfrag)
207 {
208     char *scheme, *port;
209     int ssl = 0, portnum;
210 
211     init_pstring(pport);
212     if (pssl != NULL)
213         *pssl = 0;
214     if (!OSSL_parse_url(url, &scheme, puser, phost, &port, pport_num,
215             ppath, pquery, pfrag))
216         return 0;
217 
218     /* check for optional HTTP scheme "http[s]" */
219     if (strcmp(scheme, OSSL_HTTPS_NAME) == 0) {
220         ssl = 1;
221         if (pssl != NULL)
222             *pssl = ssl;
223     } else if (*scheme != '\0' && strcmp(scheme, OSSL_HTTP_NAME) != 0) {
224         ERR_raise(ERR_LIB_HTTP, HTTP_R_INVALID_URL_SCHEME);
225         OPENSSL_free(scheme);
226         OPENSSL_free(port);
227         goto err;
228     }
229     OPENSSL_free(scheme);
230 
231     if (strcmp(port, "0") == 0) {
232         /* set default port */
233         OPENSSL_free(port);
234         port = ssl ? OSSL_HTTPS_PORT : OSSL_HTTP_PORT;
235         if (!ossl_assert(sscanf(port, "%d", &portnum) == 1))
236             goto err;
237         if (pport_num != NULL)
238             *pport_num = portnum;
239         if (pport != NULL) {
240             *pport = OPENSSL_strdup(port);
241             if (*pport == NULL)
242                 goto err;
243         }
244     } else {
245         if (pport != NULL)
246             *pport = port;
247         else
248             OPENSSL_free(port);
249     }
250     return 1;
251 
252 err:
253     free_pstring(puser);
254     free_pstring(phost);
255     free_pstring(ppath);
256     free_pstring(pquery);
257     free_pstring(pfrag);
258     return 0;
259 }
260 
261 /* Respect no_proxy, taking default value from environment variable(s) */
use_proxy(const char * no_proxy,const char * server)262 static int use_proxy(const char *no_proxy, const char *server)
263 {
264     size_t sl;
265     const char *found = NULL;
266     char host[NI_MAXHOST];
267 
268     if (!ossl_assert(server != NULL))
269         return 0;
270     sl = strlen(server);
271     if (sl >= 2 && sl < sizeof(host) + 2 && server[0] == '[' && server[sl - 1] == ']') {
272         /* strip leading '[' and trailing ']' from escaped IPv6 address */
273         sl -= 2;
274         strncpy(host, server + 1, sl);
275         host[sl] = '\0';
276         server = host;
277     }
278 
279     if (sl == 0)
280         return 1;
281 
282     /*
283      * using environment variable names, both lowercase and uppercase variants,
284      * compatible with other HTTP client implementations like wget, curl and git
285      */
286     if (no_proxy == NULL)
287         no_proxy = ossl_safe_getenv("no_proxy");
288     if (no_proxy == NULL)
289         no_proxy = ossl_safe_getenv(OPENSSL_NO_PROXY);
290 
291     if (no_proxy != NULL)
292         found = strstr(no_proxy, server);
293     while (found != NULL
294         && ((found != no_proxy && !ossl_isspace(found[-1]) && found[-1] != ',')
295             || (found[sl] != '\0' && !ossl_isspace(found[sl]) && found[sl] != ',')))
296         found = strstr(found + 1, server);
297     return found == NULL;
298 }
299 
300 /* Take default value from environment variable(s), respect no_proxy */
OSSL_HTTP_adapt_proxy(const char * proxy,const char * no_proxy,const char * server,int use_ssl)301 const char *OSSL_HTTP_adapt_proxy(const char *proxy, const char *no_proxy,
302     const char *server, int use_ssl)
303 {
304     /*
305      * using environment variable names, both lowercase and uppercase variants,
306      * compatible with other HTTP client implementations like wget, curl and git
307      */
308     if (proxy == NULL)
309         proxy = ossl_safe_getenv(use_ssl ? "https_proxy" : "http_proxy");
310     if (proxy == NULL)
311         proxy = ossl_safe_getenv(use_ssl ? OPENSSL_HTTPS_PROXY : OPENSSL_HTTP_PROXY);
312 
313     if (proxy == NULL || *proxy == '\0' || !use_proxy(no_proxy, server))
314         return NULL;
315     return proxy;
316 }
317 
318 #endif /* !defined(OPENSSL_NO_HTTP) */
319