yading@11: /*
yading@11:  * HTTP authentication
yading@11:  * Copyright (c) 2010 Martin Storsjo
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "httpauth.h"
yading@11: #include "libavutil/base64.h"
yading@11: #include "libavutil/avstring.h"
yading@11: #include "internal.h"
yading@11: #include "libavutil/random_seed.h"
yading@11: #include "libavutil/md5.h"
yading@11: #include "urldecode.h"
yading@11: #include "avformat.h"
yading@11: 
yading@11: static void handle_basic_params(HTTPAuthState *state, const char *key,
yading@11:                                 int key_len, char **dest, int *dest_len)
yading@11: {
yading@11:     if (!strncmp(key, "realm=", key_len)) {
yading@11:         *dest     =        state->realm;
yading@11:         *dest_len = sizeof(state->realm);
yading@11:     }
yading@11: }
yading@11: 
yading@11: static void handle_digest_params(HTTPAuthState *state, const char *key,
yading@11:                                  int key_len, char **dest, int *dest_len)
yading@11: {
yading@11:     DigestParams *digest = &state->digest_params;
yading@11: 
yading@11:     if (!strncmp(key, "realm=", key_len)) {
yading@11:         *dest     =        state->realm;
yading@11:         *dest_len = sizeof(state->realm);
yading@11:     } else if (!strncmp(key, "nonce=", key_len)) {
yading@11:         *dest     =        digest->nonce;
yading@11:         *dest_len = sizeof(digest->nonce);
yading@11:     } else if (!strncmp(key, "opaque=", key_len)) {
yading@11:         *dest     =        digest->opaque;
yading@11:         *dest_len = sizeof(digest->opaque);
yading@11:     } else if (!strncmp(key, "algorithm=", key_len)) {
yading@11:         *dest     =        digest->algorithm;
yading@11:         *dest_len = sizeof(digest->algorithm);
yading@11:     } else if (!strncmp(key, "qop=", key_len)) {
yading@11:         *dest     =        digest->qop;
yading@11:         *dest_len = sizeof(digest->qop);
yading@11:     } else if (!strncmp(key, "stale=", key_len)) {
yading@11:         *dest     =        digest->stale;
yading@11:         *dest_len = sizeof(digest->stale);
yading@11:     }
yading@11: }
yading@11: 
yading@11: static void handle_digest_update(HTTPAuthState *state, const char *key,
yading@11:                                  int key_len, char **dest, int *dest_len)
yading@11: {
yading@11:     DigestParams *digest = &state->digest_params;
yading@11: 
yading@11:     if (!strncmp(key, "nextnonce=", key_len)) {
yading@11:         *dest     =        digest->nonce;
yading@11:         *dest_len = sizeof(digest->nonce);
yading@11:     }
yading@11: }
yading@11: 
yading@11: static void choose_qop(char *qop, int size)
yading@11: {
yading@11:     char *ptr = strstr(qop, "auth");
yading@11:     char *end = ptr + strlen("auth");
yading@11: 
yading@11:     if (ptr && (!*end || av_isspace(*end) || *end == ',') &&
yading@11:         (ptr == qop || av_isspace(ptr[-1]) || ptr[-1] == ',')) {
yading@11:         av_strlcpy(qop, "auth", size);
yading@11:     } else {
yading@11:         qop[0] = 0;
yading@11:     }
yading@11: }
yading@11: 
yading@11: void ff_http_auth_handle_header(HTTPAuthState *state, const char *key,
yading@11:                                 const char *value)
yading@11: {
yading@11:     if (!strcmp(key, "WWW-Authenticate") || !strcmp(key, "Proxy-Authenticate")) {
yading@11:         const char *p;
yading@11:         if (av_stristart(value, "Basic ", &p) &&
yading@11:             state->auth_type <= HTTP_AUTH_BASIC) {
yading@11:             state->auth_type = HTTP_AUTH_BASIC;
yading@11:             state->realm[0] = 0;
yading@11:             state->stale = 0;
yading@11:             ff_parse_key_value(p, (ff_parse_key_val_cb) handle_basic_params,
yading@11:                                state);
yading@11:         } else if (av_stristart(value, "Digest ", &p) &&
yading@11:                    state->auth_type <= HTTP_AUTH_DIGEST) {
yading@11:             state->auth_type = HTTP_AUTH_DIGEST;
yading@11:             memset(&state->digest_params, 0, sizeof(DigestParams));
yading@11:             state->realm[0] = 0;
yading@11:             state->stale = 0;
yading@11:             ff_parse_key_value(p, (ff_parse_key_val_cb) handle_digest_params,
yading@11:                                state);
yading@11:             choose_qop(state->digest_params.qop,
yading@11:                        sizeof(state->digest_params.qop));
yading@11:             if (!av_strcasecmp(state->digest_params.stale, "true"))
yading@11:                 state->stale = 1;
yading@11:         }
yading@11:     } else if (!strcmp(key, "Authentication-Info")) {
yading@11:         ff_parse_key_value(value, (ff_parse_key_val_cb) handle_digest_update,
yading@11:                            state);
yading@11:     }
yading@11: }
yading@11: 
yading@11: 
yading@11: static void update_md5_strings(struct AVMD5 *md5ctx, ...)
yading@11: {
yading@11:     va_list vl;
yading@11: 
yading@11:     va_start(vl, md5ctx);
yading@11:     while (1) {
yading@11:         const char* str = va_arg(vl, const char*);
yading@11:         if (!str)
yading@11:             break;
yading@11:         av_md5_update(md5ctx, str, strlen(str));
yading@11:     }
yading@11:     va_end(vl);
yading@11: }
yading@11: 
yading@11: /* Generate a digest reply, according to RFC 2617. */
yading@11: static char *make_digest_auth(HTTPAuthState *state, const char *username,
yading@11:                               const char *password, const char *uri,
yading@11:                               const char *method)
yading@11: {
yading@11:     DigestParams *digest = &state->digest_params;
yading@11:     int len;
yading@11:     uint32_t cnonce_buf[2];
yading@11:     char cnonce[17];
yading@11:     char nc[9];
yading@11:     int i;
yading@11:     char A1hash[33], A2hash[33], response[33];
yading@11:     struct AVMD5 *md5ctx;
yading@11:     uint8_t hash[16];
yading@11:     char *authstr;
yading@11: 
yading@11:     digest->nc++;
yading@11:     snprintf(nc, sizeof(nc), "%08x", digest->nc);
yading@11: 
yading@11:     /* Generate a client nonce. */
yading@11:     for (i = 0; i < 2; i++)
yading@11:         cnonce_buf[i] = av_get_random_seed();
yading@11:     ff_data_to_hex(cnonce, (const uint8_t*) cnonce_buf, sizeof(cnonce_buf), 1);
yading@11:     cnonce[2*sizeof(cnonce_buf)] = 0;
yading@11: 
yading@11:     md5ctx = av_md5_alloc();
yading@11:     if (!md5ctx)
yading@11:         return NULL;
yading@11: 
yading@11:     av_md5_init(md5ctx);
yading@11:     update_md5_strings(md5ctx, username, ":", state->realm, ":", password, NULL);
yading@11:     av_md5_final(md5ctx, hash);
yading@11:     ff_data_to_hex(A1hash, hash, 16, 1);
yading@11:     A1hash[32] = 0;
yading@11: 
yading@11:     if (!strcmp(digest->algorithm, "") || !strcmp(digest->algorithm, "MD5")) {
yading@11:     } else if (!strcmp(digest->algorithm, "MD5-sess")) {
yading@11:         av_md5_init(md5ctx);
yading@11:         update_md5_strings(md5ctx, A1hash, ":", digest->nonce, ":", cnonce, NULL);
yading@11:         av_md5_final(md5ctx, hash);
yading@11:         ff_data_to_hex(A1hash, hash, 16, 1);
yading@11:         A1hash[32] = 0;
yading@11:     } else {
yading@11:         /* Unsupported algorithm */
yading@11:         av_free(md5ctx);
yading@11:         return NULL;
yading@11:     }
yading@11: 
yading@11:     av_md5_init(md5ctx);
yading@11:     update_md5_strings(md5ctx, method, ":", uri, NULL);
yading@11:     av_md5_final(md5ctx, hash);
yading@11:     ff_data_to_hex(A2hash, hash, 16, 1);
yading@11:     A2hash[32] = 0;
yading@11: 
yading@11:     av_md5_init(md5ctx);
yading@11:     update_md5_strings(md5ctx, A1hash, ":", digest->nonce, NULL);
yading@11:     if (!strcmp(digest->qop, "auth") || !strcmp(digest->qop, "auth-int")) {
yading@11:         update_md5_strings(md5ctx, ":", nc, ":", cnonce, ":", digest->qop, NULL);
yading@11:     }
yading@11:     update_md5_strings(md5ctx, ":", A2hash, NULL);
yading@11:     av_md5_final(md5ctx, hash);
yading@11:     ff_data_to_hex(response, hash, 16, 1);
yading@11:     response[32] = 0;
yading@11: 
yading@11:     av_free(md5ctx);
yading@11: 
yading@11:     if (!strcmp(digest->qop, "") || !strcmp(digest->qop, "auth")) {
yading@11:     } else if (!strcmp(digest->qop, "auth-int")) {
yading@11:         /* qop=auth-int not supported */
yading@11:         return NULL;
yading@11:     } else {
yading@11:         /* Unsupported qop value. */
yading@11:         return NULL;
yading@11:     }
yading@11: 
yading@11:     len = strlen(username) + strlen(state->realm) + strlen(digest->nonce) +
yading@11:               strlen(uri) + strlen(response) + strlen(digest->algorithm) +
yading@11:               strlen(digest->opaque) + strlen(digest->qop) + strlen(cnonce) +
yading@11:               strlen(nc) + 150;
yading@11: 
yading@11:     authstr = av_malloc(len);
yading@11:     if (!authstr)
yading@11:         return NULL;
yading@11:     snprintf(authstr, len, "Authorization: Digest ");
yading@11: 
yading@11:     /* TODO: Escape the quoted strings properly. */
yading@11:     av_strlcatf(authstr, len, "username=\"%s\"",   username);
yading@11:     av_strlcatf(authstr, len, ",realm=\"%s\"",     state->realm);
yading@11:     av_strlcatf(authstr, len, ",nonce=\"%s\"",     digest->nonce);
yading@11:     av_strlcatf(authstr, len, ",uri=\"%s\"",       uri);
yading@11:     av_strlcatf(authstr, len, ",response=\"%s\"",  response);
yading@11:     if (digest->algorithm[0])
yading@11:         av_strlcatf(authstr, len, ",algorithm=%s",  digest->algorithm);
yading@11:     if (digest->opaque[0])
yading@11:         av_strlcatf(authstr, len, ",opaque=\"%s\"", digest->opaque);
yading@11:     if (digest->qop[0]) {
yading@11:         av_strlcatf(authstr, len, ",qop=\"%s\"",    digest->qop);
yading@11:         av_strlcatf(authstr, len, ",cnonce=\"%s\"", cnonce);
yading@11:         av_strlcatf(authstr, len, ",nc=%s",         nc);
yading@11:     }
yading@11: 
yading@11:     av_strlcatf(authstr, len, "\r\n");
yading@11: 
yading@11:     return authstr;
yading@11: }
yading@11: 
yading@11: char *ff_http_auth_create_response(HTTPAuthState *state, const char *auth,
yading@11:                                    const char *path, const char *method)
yading@11: {
yading@11:     char *authstr = NULL;
yading@11: 
yading@11:     /* Clear the stale flag, we assume the auth is ok now. It is reset
yading@11:      * by the server headers if there's a new issue. */
yading@11:     state->stale = 0;
yading@11:     if (!auth || !strchr(auth, ':'))
yading@11:         return NULL;
yading@11: 
yading@11:     if (state->auth_type == HTTP_AUTH_BASIC) {
yading@11:         int auth_b64_len, len;
yading@11:         char *ptr, *decoded_auth = ff_urldecode(auth);
yading@11: 
yading@11:         if (!decoded_auth)
yading@11:             return NULL;
yading@11: 
yading@11:         auth_b64_len = AV_BASE64_SIZE(strlen(decoded_auth));
yading@11:         len = auth_b64_len + 30;
yading@11: 
yading@11:         authstr = av_malloc(len);
yading@11:         if (!authstr) {
yading@11:             av_free(decoded_auth);
yading@11:             return NULL;
yading@11:         }
yading@11: 
yading@11:         snprintf(authstr, len, "Authorization: Basic ");
yading@11:         ptr = authstr + strlen(authstr);
yading@11:         av_base64_encode(ptr, auth_b64_len, decoded_auth, strlen(decoded_auth));
yading@11:         av_strlcat(ptr, "\r\n", len - (ptr - authstr));
yading@11:         av_free(decoded_auth);
yading@11:     } else if (state->auth_type == HTTP_AUTH_DIGEST) {
yading@11:         char *username = ff_urldecode(auth), *password;
yading@11: 
yading@11:         if (!username)
yading@11:             return NULL;
yading@11: 
yading@11:         if ((password = strchr(username, ':'))) {
yading@11:             *password++ = 0;
yading@11:             authstr = make_digest_auth(state, username, password, path, method);
yading@11:         }
yading@11:         av_free(username);
yading@11:     }
yading@11:     return authstr;
yading@11: }