FFmpeg: libavformat/httpauth.c Source File

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 handle_basic_params(HTTPAuthState *state, const char *key,
00032                                 int key_len, char **dest, int *dest_len)
00033 {
00034     if (!strncmp(key, "realm=", key_len)) {
00035         *dest     =        state->realm;
00036         *dest_len = sizeof(state->realm);
00037     }
00038 }
00039 
00040 static void handle_digest_params(HTTPAuthState *state, const char *key,
00041                                  int key_len, char **dest, int *dest_len)
00042 {
00043     DigestParams *digest = &state->digest_params;
00044 
00045     if (!strncmp(key, "realm=", key_len)) {
00046         *dest     =        state->realm;
00047         *dest_len = sizeof(state->realm);
00048     } else if (!strncmp(key, "nonce=", key_len)) {
00049         *dest     =        digest->nonce;
00050         *dest_len = sizeof(digest->nonce);
00051     } else if (!strncmp(key, "opaque=", key_len)) {
00052         *dest     =        digest->opaque;
00053         *dest_len = sizeof(digest->opaque);
00054     } else if (!strncmp(key, "algorithm=", key_len)) {
00055         *dest     =        digest->algorithm;
00056         *dest_len = sizeof(digest->algorithm);
00057     } else if (!strncmp(key, "qop=", key_len)) {
00058         *dest     =        digest->qop;
00059         *dest_len = sizeof(digest->qop);
00060     } else if (!strncmp(key, "stale=", key_len)) {
00061         *dest     =        digest->stale;
00062         *dest_len = sizeof(digest->stale);
00063     }
00064 }
00065 
00066 static void handle_digest_update(HTTPAuthState *state, const char *key,
00067                                  int key_len, char **dest, int *dest_len)
00068 {
00069     DigestParams *digest = &state->digest_params;
00070 
00071     if (!strncmp(key, "nextnonce=", key_len)) {
00072         *dest     =        digest->nonce;
00073         *dest_len = sizeof(digest->nonce);
00074     }
00075 }
00076 
00077 static void choose_qop(char *qop, int size)
00078 {
00079     char *ptr = strstr(qop, "auth");
00080     char *end = ptr + strlen("auth");
00081 
00082     if (ptr && (!*end || isspace(*end) || *end == ',') &&
00083         (ptr == qop || isspace(ptr[-1]) || ptr[-1] == ',')) {
00084         av_strlcpy(qop, "auth", size);
00085     } else {
00086         qop[0] = 0;
00087     }
00088 }
00089 
00090 void ff_http_auth_handle_header(HTTPAuthState *state, const char *key,
00091                                 const char *value)
00092 {
00093     if (!strcmp(key, "WWW-Authenticate") || !strcmp(key, "Proxy-Authenticate")) {
00094         const char *p;
00095         if (av_stristart(value, "Basic ", &p) &&
00096             state->auth_type <= HTTP_AUTH_BASIC) {
00097             state->auth_type = HTTP_AUTH_BASIC;
00098             state->realm[0] = 0;
00099             state->stale = 0;
00100             ff_parse_key_value(p, (ff_parse_key_val_cb) handle_basic_params,
00101                                state);
00102         } else if (av_stristart(value, "Digest ", &p) &&
00103                    state->auth_type <= HTTP_AUTH_DIGEST) {
00104             state->auth_type = HTTP_AUTH_DIGEST;
00105             memset(&state->digest_params, 0, sizeof(DigestParams));
00106             state->realm[0] = 0;
00107             state->stale = 0;
00108             ff_parse_key_value(p, (ff_parse_key_val_cb) handle_digest_params,
00109                                state);
00110             choose_qop(state->digest_params.qop,
00111                        sizeof(state->digest_params.qop));
00112             if (!av_strcasecmp(state->digest_params.stale, "true"))
00113                 state->stale = 1;
00114         }
00115     } else if (!strcmp(key, "Authentication-Info")) {
00116         ff_parse_key_value(value, (ff_parse_key_val_cb) handle_digest_update,
00117                            state);
00118     }
00119 }
00120 
00121 
00122 static void update_md5_strings(struct AVMD5 *md5ctx, ...)
00123 {
00124     va_list vl;
00125 
00126     va_start(vl, md5ctx);
00127     while (1) {
00128         const char* str = va_arg(vl, const char*);
00129         if (!str)
00130             break;
00131         av_md5_update(md5ctx, str, strlen(str));
00132     }
00133     va_end(vl);
00134 }
00135 
00136 /* Generate a digest reply, according to RFC 2617. */
00137 static char *make_digest_auth(HTTPAuthState *state, const char *username,
00138                               const char *password, const char *uri,
00139                               const char *method)
00140 {
00141     DigestParams *digest = &state->digest_params;
00142     int len;
00143     uint32_t cnonce_buf[2];
00144     char cnonce[17];
00145     char nc[9];
00146     int i;
00147     char A1hash[33], A2hash[33], response[33];
00148     struct AVMD5 *md5ctx;
00149     uint8_t hash[16];
00150     char *authstr;
00151 
00152     digest->nc++;
00153     snprintf(nc, sizeof(nc), "%08x", digest->nc);
00154 
00155     /* Generate a client nonce. */
00156     for (i = 0; i < 2; i++)
00157         cnonce_buf[i] = av_get_random_seed();
00158     ff_data_to_hex(cnonce, (const uint8_t*) cnonce_buf, sizeof(cnonce_buf), 1);
00159     cnonce[2*sizeof(cnonce_buf)] = 0;
00160 
00161     md5ctx = av_malloc(av_md5_size);
00162     if (!md5ctx)
00163         return NULL;
00164 
00165     av_md5_init(md5ctx);
00166     update_md5_strings(md5ctx, username, ":", state->realm, ":", password, NULL);
00167     av_md5_final(md5ctx, hash);
00168     ff_data_to_hex(A1hash, hash, 16, 1);
00169     A1hash[32] = 0;
00170 
00171     if (!strcmp(digest->algorithm, "") || !strcmp(digest->algorithm, "MD5")) {
00172     } else if (!strcmp(digest->algorithm, "MD5-sess")) {
00173         av_md5_init(md5ctx);
00174         update_md5_strings(md5ctx, A1hash, ":", digest->nonce, ":", cnonce, NULL);
00175         av_md5_final(md5ctx, hash);
00176         ff_data_to_hex(A1hash, hash, 16, 1);
00177         A1hash[32] = 0;
00178     } else {
00179         /* Unsupported algorithm */
00180         av_free(md5ctx);
00181         return NULL;
00182     }
00183 
00184     av_md5_init(md5ctx);
00185     update_md5_strings(md5ctx, method, ":", uri, NULL);
00186     av_md5_final(md5ctx, hash);
00187     ff_data_to_hex(A2hash, hash, 16, 1);
00188     A2hash[32] = 0;
00189 
00190     av_md5_init(md5ctx);
00191     update_md5_strings(md5ctx, A1hash, ":", digest->nonce, NULL);
00192     if (!strcmp(digest->qop, "auth") || !strcmp(digest->qop, "auth-int")) {
00193         update_md5_strings(md5ctx, ":", nc, ":", cnonce, ":", digest->qop, NULL);
00194     }
00195     update_md5_strings(md5ctx, ":", A2hash, NULL);
00196     av_md5_final(md5ctx, hash);
00197     ff_data_to_hex(response, hash, 16, 1);
00198     response[32] = 0;
00199 
00200     av_free(md5ctx);
00201 
00202     if (!strcmp(digest->qop, "") || !strcmp(digest->qop, "auth")) {
00203     } else if (!strcmp(digest->qop, "auth-int")) {
00204         /* qop=auth-int not supported */
00205         return NULL;
00206     } else {
00207         /* Unsupported qop value. */
00208         return NULL;
00209     }
00210 
00211     len = strlen(username) + strlen(state->realm) + strlen(digest->nonce) +
00212               strlen(uri) + strlen(response) + strlen(digest->algorithm) +
00213               strlen(digest->opaque) + strlen(digest->qop) + strlen(cnonce) +
00214               strlen(nc) + 150;
00215 
00216     authstr = av_malloc(len);
00217     if (!authstr)
00218         return NULL;
00219     snprintf(authstr, len, "Authorization: Digest ");
00220 
00221     /* TODO: Escape the quoted strings properly. */
00222     av_strlcatf(authstr, len, "username=\"%s\"",   username);
00223     av_strlcatf(authstr, len, ",realm=\"%s\"",     state->realm);
00224     av_strlcatf(authstr, len, ",nonce=\"%s\"",     digest->nonce);
00225     av_strlcatf(authstr, len, ",uri=\"%s\"",       uri);
00226     av_strlcatf(authstr, len, ",response=\"%s\"",  response);
00227     if (digest->algorithm[0])
00228         av_strlcatf(authstr, len, ",algorithm=%s",  digest->algorithm);
00229     if (digest->opaque[0])
00230         av_strlcatf(authstr, len, ",opaque=\"%s\"", digest->opaque);
00231     if (digest->qop[0]) {
00232         av_strlcatf(authstr, len, ",qop=\"%s\"",    digest->qop);
00233         av_strlcatf(authstr, len, ",cnonce=\"%s\"", cnonce);
00234         av_strlcatf(authstr, len, ",nc=%s",         nc);
00235     }
00236 
00237     av_strlcatf(authstr, len, "\r\n");
00238 
00239     return authstr;
00240 }
00241 
00242 char *ff_http_auth_create_response(HTTPAuthState *state, const char *auth,
00243                                    const char *path, const char *method)
00244 {
00245     char *authstr = NULL;
00246 
00247     /* Clear the stale flag, we assume the auth is ok now. It is reset
00248      * by the server headers if there's a new issue. */
00249     state->stale = 0;
00250     if (!auth || !strchr(auth, ':'))
00251         return NULL;
00252 
00253     if (state->auth_type == HTTP_AUTH_BASIC) {
00254         int auth_b64_len = AV_BASE64_SIZE(strlen(auth));
00255         int len = auth_b64_len + 30;
00256         char *ptr;
00257         authstr = av_malloc(len);
00258         if (!authstr)
00259             return NULL;
00260         snprintf(authstr, len, "Authorization: Basic ");
00261         ptr = authstr + strlen(authstr);
00262         av_base64_encode(ptr, auth_b64_len, auth, strlen(auth));
00263         av_strlcat(ptr, "\r\n", len - (ptr - authstr));
00264     } else if (state->auth_type == HTTP_AUTH_DIGEST) {
00265         char *username = av_strdup(auth), *password;
00266 
00267         if (!username)
00268             return NULL;
00269 
00270         if ((password = strchr(username, ':'))) {
00271             *password++ = 0;
00272             authstr = make_digest_auth(state, username, password, path, method);
00273         }
00274         av_free(username);
00275     }
00276     return authstr;
00277 }