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