xref: /freebsd/crypto/openssl/crypto/http/http_lib.c (revision e7be843b4a162e68651d3911f0357ed464915629)
1 /*
2  * Copyright 2001-2025 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 
init_pstring(char ** pstr)25 static void init_pstring(char **pstr)
26 {
27     if (pstr != NULL) {
28         *pstr = NULL;
29     }
30 }
31 
init_pint(int * pint)32 static void init_pint(int *pint)
33 {
34     if (pint != NULL) {
35         *pint = 0;
36     }
37 }
38 
copy_substring(char ** dest,const char * start,const char * end)39 static int copy_substring(char **dest, const char *start, const char *end)
40 {
41     return dest == NULL
42         || (*dest = OPENSSL_strndup(start, end - start)) != NULL;
43 }
44 
free_pstring(char ** pstr)45 static void free_pstring(char **pstr)
46 {
47     if (pstr != NULL) {
48         OPENSSL_free(*pstr);
49         *pstr = NULL;
50     }
51 }
52 
OSSL_parse_url(const char * url,char ** pscheme,char ** puser,char ** phost,char ** pport,int * pport_num,char ** ppath,char ** pquery,char ** pfrag)53 int OSSL_parse_url(const char *url, char **pscheme, char **puser, char **phost,
54                    char **pport, int *pport_num,
55                    char **ppath, char **pquery, char **pfrag)
56 {
57     const char *p, *tmp;
58     const char *scheme, *scheme_end;
59     const char *user, *user_end;
60     const char *host, *host_end;
61     const char *port, *port_end;
62     unsigned int portnum = 0;
63     const char *path, *path_end;
64     const char *query, *query_end;
65     const char *frag, *frag_end;
66 
67     init_pstring(pscheme);
68     init_pstring(puser);
69     init_pstring(phost);
70     init_pstring(pport);
71     init_pint(pport_num);
72     init_pstring(ppath);
73     init_pstring(pfrag);
74     init_pstring(pquery);
75 
76     if (url == NULL) {
77         ERR_raise(ERR_LIB_HTTP, ERR_R_PASSED_NULL_PARAMETER);
78         return 0;
79     }
80 
81     /* check for optional prefix "<scheme>://" */
82     scheme = scheme_end = url;
83     p = strstr(url, "://");
84     if (p == NULL) {
85         p = url;
86     } else {
87         scheme_end = p;
88         if (scheme_end == scheme)
89             goto parse_err;
90         p += strlen("://");
91     }
92 
93     /* parse optional "userinfo@" */
94     user = user_end = host = p;
95     host = strchr(p, '@');
96     if (host != NULL)
97         user_end = host++;
98     else
99         host = p;
100 
101     /* parse hostname/address as far as needed here */
102     if (host[0] == '[') {
103         /* IPv6 literal, which may include ':' */
104         host_end = strchr(host + 1, ']');
105         if (host_end == NULL)
106             goto parse_err;
107         p = ++host_end;
108     } else {
109         /* look for start of optional port, path, query, or fragment */
110         host_end = strpbrk(host, ":/?#");
111         if (host_end == NULL) /* the remaining string is just the hostname */
112             host_end = host + strlen(host);
113         p = host_end;
114     }
115 
116     /* parse optional port specification starting with ':' */
117     port = "0"; /* default */
118     if (*p == ':')
119         port = ++p;
120     /* remaining port spec handling is also done for the default values */
121     /* make sure a decimal port number is given */
122     if (sscanf(port, "%u", &portnum) <= 0 || portnum > 65535) {
123         ERR_raise_data(ERR_LIB_HTTP, HTTP_R_INVALID_PORT_NUMBER, "%s", port);
124         goto err;
125     }
126     for (port_end = port; '0' <= *port_end && *port_end <= '9'; port_end++)
127         ;
128     if (port == p) /* port was given explicitly */
129         p += port_end - port;
130 
131     /* check for optional path starting with '/' or '?'. Else must start '#' */
132     path = p;
133     if (*path != '\0' && *path != '/' && *path != '?' && *path != '#') {
134         ERR_raise(ERR_LIB_HTTP, HTTP_R_INVALID_URL_PATH);
135         goto parse_err;
136     }
137     path_end = query = query_end = frag = frag_end = path + strlen(path);
138 
139     /* parse optional "?query" */
140     tmp = strchr(p, '?');
141     if (tmp != NULL) {
142         p = tmp;
143         if (pquery != NULL) {
144             path_end = p;
145             query = p + 1;
146         }
147     }
148 
149     /* parse optional "#fragment" */
150     tmp = strchr(p, '#');
151     if (tmp != NULL) {
152         if (query == path_end) /* we did not record a query component */
153             path_end = tmp;
154         query_end = tmp;
155         frag = tmp + 1;
156     }
157 
158     if (!copy_substring(pscheme, scheme, scheme_end)
159             || !copy_substring(phost, host, host_end)
160             || !copy_substring(pport, port, port_end)
161             || !copy_substring(puser, user, user_end)
162             || !copy_substring(pquery, query, query_end)
163             || !copy_substring(pfrag, frag, frag_end))
164         goto err;
165     if (pport_num != NULL)
166         *pport_num = (int)portnum;
167     if (*path == '/') {
168         if (!copy_substring(ppath, path, path_end))
169             goto err;
170     } else if (ppath != NULL) { /* must prepend '/' */
171         size_t buflen = 1 + path_end - path + 1;
172 
173         if ((*ppath = OPENSSL_malloc(buflen)) == NULL)
174             goto err;
175         BIO_snprintf(*ppath, buflen, "/%s", path);
176     }
177     return 1;
178 
179  parse_err:
180     ERR_raise(ERR_LIB_HTTP, HTTP_R_ERROR_PARSING_URL);
181 
182  err:
183     free_pstring(pscheme);
184     free_pstring(puser);
185     free_pstring(phost);
186     free_pstring(pport);
187     free_pstring(ppath);
188     free_pstring(pquery);
189     free_pstring(pfrag);
190     return 0;
191 }
192 
193 #ifndef OPENSSL_NO_HTTP
194 
OSSL_HTTP_parse_url(const char * url,int * pssl,char ** puser,char ** phost,char ** pport,int * pport_num,char ** ppath,char ** pquery,char ** pfrag)195 int OSSL_HTTP_parse_url(const char *url, int *pssl, char **puser, char **phost,
196                         char **pport, int *pport_num,
197                         char **ppath, char **pquery, char **pfrag)
198 {
199     char *scheme, *port;
200     int ssl = 0, portnum;
201 
202     init_pstring(pport);
203     if (pssl != NULL)
204         *pssl = 0;
205     if (!OSSL_parse_url(url, &scheme, puser, phost, &port, pport_num,
206                         ppath, pquery, pfrag))
207         return 0;
208 
209     /* check for optional HTTP scheme "http[s]" */
210     if (strcmp(scheme, OSSL_HTTPS_NAME) == 0) {
211         ssl = 1;
212         if (pssl != NULL)
213             *pssl = ssl;
214     } else if (*scheme != '\0' && strcmp(scheme, OSSL_HTTP_NAME) != 0) {
215         ERR_raise(ERR_LIB_HTTP, HTTP_R_INVALID_URL_SCHEME);
216         OPENSSL_free(scheme);
217         OPENSSL_free(port);
218         goto err;
219     }
220     OPENSSL_free(scheme);
221 
222     if (strcmp(port, "0") == 0) {
223         /* set default port */
224         OPENSSL_free(port);
225         port = ssl ? OSSL_HTTPS_PORT : OSSL_HTTP_PORT;
226         if (!ossl_assert(sscanf(port, "%d", &portnum) == 1))
227             goto err;
228         if (pport_num != NULL)
229             *pport_num = portnum;
230         if (pport != NULL) {
231             *pport = OPENSSL_strdup(port);
232             if (*pport == NULL)
233                 goto err;
234         }
235     } else {
236         if (pport != NULL)
237             *pport = port;
238         else
239             OPENSSL_free(port);
240     }
241     return 1;
242 
243  err:
244     free_pstring(puser);
245     free_pstring(phost);
246     free_pstring(ppath);
247     free_pstring(pquery);
248     free_pstring(pfrag);
249     return 0;
250 }
251 
252 /* Respect no_proxy, taking default value from environment variable(s) */
use_proxy(const char * no_proxy,const char * server)253 static int use_proxy(const char *no_proxy, const char *server)
254 {
255     size_t sl;
256     const char *found = NULL;
257     char host[NI_MAXHOST];
258 
259     if (!ossl_assert(server != NULL))
260         return 0;
261     sl = strlen(server);
262     if (sl >= 2 && sl < sizeof(host) + 2 && server[0] == '[' && server[sl - 1] == ']') {
263         /* strip leading '[' and trailing ']' from escaped IPv6 address */
264         sl -= 2;
265         strncpy(host, server + 1, sl);
266         server = host;
267     }
268 
269     /*
270      * using environment variable names, both lowercase and uppercase variants,
271      * compatible with other HTTP client implementations like wget, curl and git
272      */
273     if (no_proxy == NULL)
274         no_proxy = ossl_safe_getenv("no_proxy");
275     if (no_proxy == NULL)
276         no_proxy = ossl_safe_getenv(OPENSSL_NO_PROXY);
277 
278     if (no_proxy != NULL)
279         found = strstr(no_proxy, server);
280     while (found != NULL
281            && ((found != no_proxy && !ossl_isspace(found[-1]) && found[-1] != ',')
282                || (found[sl] != '\0' && !ossl_isspace(found[sl]) && found[sl] != ',')))
283         found = strstr(found + 1, server);
284     return found == NULL;
285 }
286 
287 /* 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)288 const char *OSSL_HTTP_adapt_proxy(const char *proxy, const char *no_proxy,
289                                   const char *server, int use_ssl)
290 {
291     /*
292      * using environment variable names, both lowercase and uppercase variants,
293      * compatible with other HTTP client implementations like wget, curl and git
294      */
295     if (proxy == NULL)
296         proxy = ossl_safe_getenv(use_ssl ? "https_proxy" : "http_proxy");
297     if (proxy == NULL)
298         proxy = ossl_safe_getenv(use_ssl ? OPENSSL_HTTPS_PROXY : OPENSSL_HTTP_PROXY);
299 
300     if (proxy == NULL || *proxy == '\0' || !use_proxy(no_proxy, server))
301         return NULL;
302     return proxy;
303 }
304 
305 #endif /* !defined(OPENSSL_NO_HTTP) */
306