Libav
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00001 /* 00002 * HTTP authentication 00003 * Copyright (c) 2010 Martin Storsjo 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * FFmpeg is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with FFmpeg; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "httpauth.h" 00023 #include "libavutil/base64.h" 00024 #include "libavutil/avstring.h" 00025 #include "internal.h" 00026 #include "libavutil/random_seed.h" 00027 #include "libavutil/md5.h" 00028 #include "avformat.h" 00029 #include <ctype.h> 00030 00031 static void parse_key_value(const char *params, 00032 void (*callback_get_buf)(HTTPAuthState *state, 00033 const char *key, int key_len, 00034 char **dest, int *dest_len), HTTPAuthState *state) 00035 { 00036 const char *ptr = params; 00037 00038 /* Parse key=value pairs. */ 00039 for (;;) { 00040 const char *key; 00041 char *dest = NULL, *dest_end; 00042 int key_len, dest_len = 0; 00043 00044 /* Skip whitespace and potential commas. */ 00045 while (*ptr && (isspace(*ptr) || *ptr == ',')) 00046 ptr++; 00047 if (!*ptr) 00048 break; 00049 00050 key = ptr; 00051 00052 if (!(ptr = strchr(key, '='))) 00053 break; 00054 ptr++; 00055 key_len = ptr - key; 00056 00057 callback_get_buf(state, key, key_len, &dest, &dest_len); 00058 dest_end = dest + dest_len - 1; 00059 00060 if (*ptr == '\"') { 00061 ptr++; 00062 while (*ptr && *ptr != '\"') { 00063 if (*ptr == '\\') { 00064 if (!ptr[1]) 00065 break; 00066 if (dest && dest < dest_end) 00067 *dest++ = ptr[1]; 00068 ptr += 2; 00069 } else { 00070 if (dest && dest < dest_end) 00071 *dest++ = *ptr; 00072 ptr++; 00073 } 00074 } 00075 if (*ptr == '\"') 00076 ptr++; 00077 } else { 00078 for (; *ptr && !(isspace(*ptr) || *ptr == ','); ptr++) 00079 if (dest && dest < dest_end) 00080 *dest++ = *ptr; 00081 } 00082 if (dest) 00083 *dest = 0; 00084 } 00085 } 00086 00087 static void handle_basic_params(HTTPAuthState *state, const char *key, 00088 int key_len, char **dest, int *dest_len) 00089 { 00090 if (!strncmp(key, "realm=", key_len)) { 00091 *dest = state->realm; 00092 *dest_len = sizeof(state->realm); 00093 } 00094 } 00095 00096 static void handle_digest_params(HTTPAuthState *state, const char *key, 00097 int key_len, char **dest, int *dest_len) 00098 { 00099 DigestParams *digest = &state->digest_params; 00100 00101 if (!strncmp(key, "realm=", key_len)) { 00102 *dest = state->realm; 00103 *dest_len = sizeof(state->realm); 00104 } else if (!strncmp(key, "nonce=", key_len)) { 00105 *dest = digest->nonce; 00106 *dest_len = sizeof(digest->nonce); 00107 } else if (!strncmp(key, "opaque=", key_len)) { 00108 *dest = digest->opaque; 00109 *dest_len = sizeof(digest->opaque); 00110 } else if (!strncmp(key, "algorithm=", key_len)) { 00111 *dest = digest->algorithm; 00112 *dest_len = sizeof(digest->algorithm); 00113 } else if (!strncmp(key, "qop=", key_len)) { 00114 *dest = digest->qop; 00115 *dest_len = sizeof(digest->qop); 00116 } 00117 } 00118 00119 static void handle_digest_update(HTTPAuthState *state, const char *key, 00120 int key_len, char **dest, int *dest_len) 00121 { 00122 DigestParams *digest = &state->digest_params; 00123 00124 if (!strncmp(key, "nextnonce=", key_len)) { 00125 *dest = digest->nonce; 00126 *dest_len = sizeof(digest->nonce); 00127 } 00128 } 00129 00130 static void choose_qop(char *qop, int size) 00131 { 00132 char *ptr = strstr(qop, "auth"); 00133 char *end = ptr + strlen("auth"); 00134 00135 if (ptr && (!*end || isspace(*end) || *end == ',') && 00136 (ptr == qop || isspace(ptr[-1]) || ptr[-1] == ',')) { 00137 av_strlcpy(qop, "auth", size); 00138 } else { 00139 qop[0] = 0; 00140 } 00141 } 00142 00143 void ff_http_auth_handle_header(HTTPAuthState *state, const char *key, 00144 const char *value) 00145 { 00146 if (!strcmp(key, "WWW-Authenticate")) { 00147 const char *p; 00148 if (av_stristart(value, "Basic ", &p) && 00149 state->auth_type <= HTTP_AUTH_BASIC) { 00150 state->auth_type = HTTP_AUTH_BASIC; 00151 state->realm[0] = 0; 00152 parse_key_value(p, handle_basic_params, state); 00153 } else if (av_stristart(value, "Digest ", &p) && 00154 state->auth_type <= HTTP_AUTH_DIGEST) { 00155 state->auth_type = HTTP_AUTH_DIGEST; 00156 memset(&state->digest_params, 0, sizeof(DigestParams)); 00157 state->realm[0] = 0; 00158 parse_key_value(p, handle_digest_params, state); 00159 choose_qop(state->digest_params.qop, 00160 sizeof(state->digest_params.qop)); 00161 } 00162 } else if (!strcmp(key, "Authentication-Info")) { 00163 parse_key_value(value, handle_digest_update, state); 00164 } 00165 } 00166 00167 00168 static void update_md5_strings(struct AVMD5 *md5ctx, ...) 00169 { 00170 va_list vl; 00171 00172 va_start(vl, md5ctx); 00173 while (1) { 00174 const char* str = va_arg(vl, const char*); 00175 if (!str) 00176 break; 00177 av_md5_update(md5ctx, str, strlen(str)); 00178 } 00179 va_end(vl); 00180 } 00181 00182 /* Generate a digest reply, according to RFC 2617. */ 00183 static char *make_digest_auth(HTTPAuthState *state, const char *username, 00184 const char *password, const char *uri, 00185 const char *method) 00186 { 00187 DigestParams *digest = &state->digest_params; 00188 int len; 00189 uint32_t cnonce_buf[2]; 00190 char cnonce[17]; 00191 char nc[9]; 00192 int i; 00193 char A1hash[33], A2hash[33], response[33]; 00194 struct AVMD5 *md5ctx; 00195 uint8_t hash[16]; 00196 char *authstr; 00197 00198 digest->nc++; 00199 snprintf(nc, sizeof(nc), "%08x", digest->nc); 00200 00201 /* Generate a client nonce. */ 00202 for (i = 0; i < 2; i++) 00203 cnonce_buf[i] = ff_random_get_seed(); 00204 ff_data_to_hex(cnonce, (const uint8_t*) cnonce_buf, sizeof(cnonce_buf), 1); 00205 cnonce[2*sizeof(cnonce_buf)] = 0; 00206 00207 md5ctx = av_malloc(av_md5_size); 00208 if (!md5ctx) 00209 return NULL; 00210 00211 av_md5_init(md5ctx); 00212 update_md5_strings(md5ctx, username, ":", state->realm, ":", password, NULL); 00213 av_md5_final(md5ctx, hash); 00214 ff_data_to_hex(A1hash, hash, 16, 1); 00215 A1hash[32] = 0; 00216 00217 if (!strcmp(digest->algorithm, "") || !strcmp(digest->algorithm, "MD5")) { 00218 } else if (!strcmp(digest->algorithm, "MD5-sess")) { 00219 av_md5_init(md5ctx); 00220 update_md5_strings(md5ctx, A1hash, ":", digest->nonce, ":", cnonce, NULL); 00221 av_md5_final(md5ctx, hash); 00222 ff_data_to_hex(A1hash, hash, 16, 1); 00223 A1hash[32] = 0; 00224 } else { 00225 /* Unsupported algorithm */ 00226 av_free(md5ctx); 00227 return NULL; 00228 } 00229 00230 av_md5_init(md5ctx); 00231 update_md5_strings(md5ctx, method, ":", uri, NULL); 00232 av_md5_final(md5ctx, hash); 00233 ff_data_to_hex(A2hash, hash, 16, 1); 00234 A2hash[32] = 0; 00235 00236 av_md5_init(md5ctx); 00237 update_md5_strings(md5ctx, A1hash, ":", digest->nonce, NULL); 00238 if (!strcmp(digest->qop, "auth") || !strcmp(digest->qop, "auth-int")) { 00239 update_md5_strings(md5ctx, ":", nc, ":", cnonce, ":", digest->qop, NULL); 00240 } 00241 update_md5_strings(md5ctx, ":", A2hash, NULL); 00242 av_md5_final(md5ctx, hash); 00243 ff_data_to_hex(response, hash, 16, 1); 00244 response[32] = 0; 00245 00246 av_free(md5ctx); 00247 00248 if (!strcmp(digest->qop, "") || !strcmp(digest->qop, "auth")) { 00249 } else if (!strcmp(digest->qop, "auth-int")) { 00250 /* qop=auth-int not supported */ 00251 return NULL; 00252 } else { 00253 /* Unsupported qop value. */ 00254 return NULL; 00255 } 00256 00257 len = strlen(username) + strlen(state->realm) + strlen(digest->nonce) + 00258 strlen(uri) + strlen(response) + strlen(digest->algorithm) + 00259 strlen(digest->opaque) + strlen(digest->qop) + strlen(cnonce) + 00260 strlen(nc) + 150; 00261 00262 authstr = av_malloc(len); 00263 if (!authstr) 00264 return NULL; 00265 snprintf(authstr, len, "Authorization: Digest "); 00266 00267 /* TODO: Escape the quoted strings properly. */ 00268 av_strlcatf(authstr, len, "username=\"%s\"", username); 00269 av_strlcatf(authstr, len, ",realm=\"%s\"", state->realm); 00270 av_strlcatf(authstr, len, ",nonce=\"%s\"", digest->nonce); 00271 av_strlcatf(authstr, len, ",uri=\"%s\"", uri); 00272 av_strlcatf(authstr, len, ",response=\"%s\"", response); 00273 if (digest->algorithm[0]) 00274 av_strlcatf(authstr, len, ",algorithm=%s", digest->algorithm); 00275 if (digest->opaque[0]) 00276 av_strlcatf(authstr, len, ",opaque=\"%s\"", digest->opaque); 00277 if (digest->qop[0]) { 00278 av_strlcatf(authstr, len, ",qop=\"%s\"", digest->qop); 00279 av_strlcatf(authstr, len, ",cnonce=\"%s\"", cnonce); 00280 av_strlcatf(authstr, len, ",nc=%s", nc); 00281 } 00282 00283 av_strlcatf(authstr, len, "\r\n"); 00284 00285 return authstr; 00286 } 00287 00288 char *ff_http_auth_create_response(HTTPAuthState *state, const char *auth, 00289 const char *path, const char *method) 00290 { 00291 char *authstr = NULL; 00292 00293 if (!auth || !strchr(auth, ':')) 00294 return NULL; 00295 00296 if (state->auth_type == HTTP_AUTH_BASIC) { 00297 int auth_b64_len = (strlen(auth) + 2) / 3 * 4 + 1; 00298 int len = auth_b64_len + 30; 00299 char *ptr; 00300 authstr = av_malloc(len); 00301 if (!authstr) 00302 return NULL; 00303 snprintf(authstr, len, "Authorization: Basic "); 00304 ptr = authstr + strlen(authstr); 00305 av_base64_encode(ptr, auth_b64_len, auth, strlen(auth)); 00306 av_strlcat(ptr, "\r\n", len); 00307 } else if (state->auth_type == HTTP_AUTH_DIGEST) { 00308 char *username = av_strdup(auth), *password; 00309 00310 if (!username) 00311 return NULL; 00312 00313 if ((password = strchr(username, ':'))) { 00314 *password++ = 0; 00315 authstr = make_digest_auth(state, username, password, path, method); 00316 } 00317 av_free(username); 00318 } 00319 return authstr; 00320 } 00321