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auth-bozo.c revision 1.17
      1 /*	$NetBSD: auth-bozo.c,v 1.17 2015/10/28 09:20:15 shm Exp $	*/
      2 
      3 /*	$eterna: auth-bozo.c,v 1.17 2011/11/18 09:21:15 mrg Exp $	*/
      4 
      5 /*
      6  * Copyright (c) 1997-2014 Matthew R. Green
      7  * All rights reserved.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer and
     16  *    dedication in the documentation and/or other materials provided
     17  *    with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  */
     32 
     33 /* this code implements "http basic authorisation" for bozohttpd */
     34 
     35 #ifdef DO_HTPASSWD
     36 
     37 #include <sys/param.h>
     38 
     39 #include <string.h>
     40 #include <stdlib.h>
     41 #include <unistd.h>
     42 
     43 #include "bozohttpd.h"
     44 
     45 #ifndef AUTH_FILE
     46 #define AUTH_FILE		".htpasswd"
     47 #endif
     48 
     49 static	ssize_t	base64_decode(const unsigned char *, size_t,
     50 			    unsigned char *, size_t);
     51 
     52 /*
     53  * Check if HTTP authentication is required
     54  */
     55 int
     56 bozo_auth_check(bozo_httpreq_t *request, const char *file)
     57 {
     58 	bozohttpd_t *httpd = request->hr_httpd;
     59 	struct stat sb;
     60 	char dir[MAXPATHLEN], authfile[MAXPATHLEN], *basename;
     61 	char user[BUFSIZ], *pass;
     62 	FILE *fp;
     63 	int len;
     64 
     65 			/* get dir=dirname(file) */
     66 	snprintf(dir, sizeof(dir), "%s", file);
     67 	if ((basename = strrchr(dir, '/')) == NULL)
     68 		strcpy(dir, ".");
     69 	else {
     70 		*basename++ = '\0';
     71 			/* ensure basename(file) != AUTH_FILE */
     72 		if (bozo_check_special_files(request, basename))
     73 			return 1;
     74 	}
     75 	request->hr_authrealm = bozostrdup(httpd, dir);
     76 
     77 	if ((size_t)snprintf(authfile, sizeof(authfile), "%s/%s", dir, AUTH_FILE) >=
     78 	  sizeof(authfile)) {
     79 		return bozo_http_error(httpd, 404, request,
     80 			"authfile path too long");
     81 	}
     82 	if (stat(authfile, &sb) < 0) {
     83 		debug((httpd, DEBUG_NORMAL,
     84 		    "bozo_auth_check realm `%s' dir `%s' authfile `%s' missing",
     85 		    dir, file, authfile));
     86 		return 0;
     87 	}
     88 	if ((fp = fopen(authfile, "r")) == NULL)
     89 		return bozo_http_error(httpd, 403, request,
     90 			"no permission to open authfile");
     91 	debug((httpd, DEBUG_NORMAL,
     92 	    "bozo_auth_check realm `%s' dir `%s' authfile `%s' open",
     93 	    dir, file, authfile));
     94 	if (request->hr_authuser && request->hr_authpass) {
     95 		while (fgets(user, sizeof(user), fp) != NULL) {
     96 			len = strlen(user);
     97 			if (len > 0 && user[len-1] == '\n')
     98 				user[--len] = '\0';
     99 			if ((pass = strchr(user, ':')) == NULL)
    100 				continue;
    101 			*pass++ = '\0';
    102 			debug((httpd, DEBUG_NORMAL,
    103 			    "bozo_auth_check authfile `%s':`%s' "
    104 			    	"client `%s':`%s'",
    105 			    user, pass, request->hr_authuser,
    106 			    request->hr_authpass));
    107 			if (strcmp(request->hr_authuser, user) != 0)
    108 				continue;
    109 			if (strcmp(crypt(request->hr_authpass, pass),
    110 					pass) != 0)
    111 				break;
    112 			fclose(fp);
    113 			return 0;
    114 		}
    115 	}
    116 	fclose(fp);
    117 	return bozo_http_error(httpd, 401, request, "bad auth");
    118 }
    119 
    120 void
    121 bozo_auth_init(bozo_httpreq_t *request)
    122 {
    123 	request->hr_authuser = NULL;
    124 	request->hr_authpass = NULL;
    125 }
    126 
    127 void
    128 bozo_auth_cleanup(bozo_httpreq_t *request)
    129 {
    130 
    131 	if (request == NULL)
    132 		return;
    133 	free(request->hr_authuser);
    134 	free(request->hr_authpass);
    135 	free(request->hr_authrealm);
    136 }
    137 
    138 int
    139 bozo_auth_check_headers(bozo_httpreq_t *request, char *val, char *str, ssize_t len)
    140 {
    141 	bozohttpd_t *httpd = request->hr_httpd;
    142 
    143 	if (strcasecmp(val, "authorization") == 0 &&
    144 	    strncasecmp(str, "Basic ", 6) == 0) {
    145 		char	authbuf[BUFSIZ];
    146 		char	*pass = NULL;
    147 		ssize_t	alen;
    148 
    149 		alen = base64_decode((unsigned char *)str + 6,
    150 					(size_t)(len - 6),
    151 					(unsigned char *)authbuf,
    152 					sizeof(authbuf) - 1);
    153 		if (alen != -1)
    154 			authbuf[alen] = '\0';
    155 		if (alen == -1 ||
    156 		    (pass = strchr(authbuf, ':')) == NULL)
    157 			return bozo_http_error(httpd, 400, request,
    158 			    "bad authorization field");
    159 		*pass++ = '\0';
    160 		free(request->hr_authuser);
    161 		free(request->hr_authpass);
    162 		request->hr_authuser = bozostrdup(httpd, authbuf);
    163 		request->hr_authpass = bozostrdup(httpd, pass);
    164 		debug((httpd, DEBUG_FAT,
    165 		    "decoded authorization `%s' as `%s':`%s'",
    166 		    str, request->hr_authuser, request->hr_authpass));
    167 			/* don't store in request->headers */
    168 		return 1;
    169 	}
    170 	return 0;
    171 }
    172 
    173 int
    174 bozo_auth_check_special_files(bozo_httpreq_t *request,
    175 				const char *name)
    176 {
    177 	bozohttpd_t *httpd = request->hr_httpd;
    178 
    179 	if (strcmp(name, AUTH_FILE) == 0)
    180 		return bozo_http_error(httpd, 403, request,
    181 				"no permission to open authfile");
    182 	return 0;
    183 }
    184 
    185 void
    186 bozo_auth_check_401(bozo_httpreq_t *request, int code)
    187 {
    188 	bozohttpd_t *httpd = request->hr_httpd;
    189 
    190 	if (code == 401)
    191 		bozo_printf(httpd,
    192 			"WWW-Authenticate: Basic realm=\"%s\"\r\n",
    193 			request->hr_authrealm ? request->hr_authrealm : "default realm");
    194 }
    195 
    196 #ifndef NO_CGIBIN_SUPPORT
    197 void
    198 bozo_auth_cgi_setenv(bozo_httpreq_t *request,
    199 			char ***curenvpp)
    200 {
    201 	bozohttpd_t *httpd = request->hr_httpd;
    202 
    203 	if (request->hr_authuser && *request->hr_authuser) {
    204 		bozo_setenv(httpd, "AUTH_TYPE", "Basic", (*curenvpp)++);
    205 		bozo_setenv(httpd, "REMOTE_USER", request->hr_authuser,
    206 				(*curenvpp)++);
    207 	}
    208 }
    209 
    210 int
    211 bozo_auth_cgi_count(bozo_httpreq_t *request)
    212 {
    213 	return (request->hr_authuser && *request->hr_authuser) ? 2 : 0;
    214 }
    215 #endif /* NO_CGIBIN_SUPPORT */
    216 
    217 /*
    218  * Decode len bytes starting at in using base64 encoding into out.
    219  * Result is *not* NUL terminated.
    220  * Written by Luke Mewburn <lukem (at) NetBSD.org>
    221  */
    222 const unsigned char decodetable[] = {
    223 	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
    224 	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
    225 	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,  62, 255, 255, 255,  63,
    226 	 52,  53,  54,  55,  56,  57,  58,  59,  60,  61, 255, 255, 255,   0, 255, 255,
    227 	255,   0,   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
    228 	 15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25, 255, 255, 255, 255, 255,
    229 	255,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,
    230 	 41,  42,  43,  44,  45,  46,  47,  48,  49,  50,  51, 255, 255, 255, 255, 255,
    231 };
    232 
    233 static ssize_t
    234 base64_decode(const unsigned char *in, size_t ilen, unsigned char *out,
    235 	      size_t olen)
    236 {
    237 	unsigned char *cp;
    238 	size_t	 i;
    239 
    240 	if (ilen == 0) {
    241 		if (olen)
    242 			*out = '\0';
    243 		return 0;
    244 	}
    245 
    246 	cp = out;
    247 	for (i = 0; i < ilen; i += 4) {
    248 		if (cp + 3 > out + olen)
    249 			return (-1);
    250 #define IN_CHECK(x) \
    251 		if ((x) > sizeof(decodetable) || decodetable[(x)] == 255) \
    252 			    return(-1)
    253 
    254 		IN_CHECK(in[i + 0]);
    255 		/*LINTED*/
    256 		*(cp++) = decodetable[in[i + 0]] << 2
    257 			| decodetable[in[i + 1]] >> 4;
    258 		IN_CHECK(in[i + 1]);
    259 		/*LINTED*/
    260 		*(cp++) = decodetable[in[i + 1]] << 4
    261 			| decodetable[in[i + 2]] >> 2;
    262 		IN_CHECK(in[i + 2]);
    263 		*(cp++) = decodetable[in[i + 2]] << 6
    264 			| decodetable[in[i + 3]];
    265 #undef IN_CHECK
    266 	}
    267 	while (i > 0 && in[i - 1] == '=')
    268 		cp--,i--;
    269 	return (cp - out);
    270 }
    271 #endif /* DO_HTPASSWD */
    272