ffmpeg/libavformat/httpauth.c

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/*
* HTTP authentication
* Copyright (c) 2010 Martin Storsjo
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "httpauth.h"
#include "libavutil/base64.h"
#include "libavutil/avstring.h"
#include "internal.h"
#include "libavutil/random_seed.h"
#include "libavutil/md5.h"
#include "avformat.h"
#include <ctype.h>
static void parse_key_value(const char *params,
void (*callback_get_buf)(HTTPAuthState *state,
const char *key, int key_len,
char **dest, int *dest_len), HTTPAuthState *state)
{
const char *ptr = params;
/* Parse key=value pairs. */
for (;;) {
const char *key;
char *dest = NULL, *dest_end;
int key_len, dest_len = 0;
/* Skip whitespace and potential commas. */
while (*ptr && (isspace(*ptr) || *ptr == ','))
ptr++;
if (!*ptr)
break;
key = ptr;
if (!(ptr = strchr(key, '=')))
break;
ptr++;
key_len = ptr - key;
callback_get_buf(state, key, key_len, &dest, &dest_len);
dest_end = dest + dest_len - 1;
if (*ptr == '\"') {
ptr++;
while (*ptr && *ptr != '\"') {
if (*ptr == '\\') {
if (!ptr[1])
break;
if (dest && dest < dest_end)
*dest++ = ptr[1];
ptr += 2;
} else {
if (dest && dest < dest_end)
*dest++ = *ptr;
ptr++;
}
}
if (*ptr == '\"')
ptr++;
} else {
for (; *ptr && !(isspace(*ptr) || *ptr == ','); ptr++)
if (dest && dest < dest_end)
*dest++ = *ptr;
}
if (dest)
*dest = 0;
}
}
static void handle_basic_params(HTTPAuthState *state, const char *key,
int key_len, char **dest, int *dest_len)
{
if (!strncmp(key, "realm=", key_len)) {
*dest = state->realm;
*dest_len = sizeof(state->realm);
}
}
static void handle_digest_params(HTTPAuthState *state, const char *key,
int key_len, char **dest, int *dest_len)
{
DigestParams *digest = &state->digest_params;
if (!strncmp(key, "realm=", key_len)) {
*dest = state->realm;
*dest_len = sizeof(state->realm);
} else if (!strncmp(key, "nonce=", key_len)) {
*dest = digest->nonce;
*dest_len = sizeof(digest->nonce);
} else if (!strncmp(key, "opaque=", key_len)) {
*dest = digest->opaque;
*dest_len = sizeof(digest->opaque);
} else if (!strncmp(key, "algorithm=", key_len)) {
*dest = digest->algorithm;
*dest_len = sizeof(digest->algorithm);
} else if (!strncmp(key, "qop=", key_len)) {
*dest = digest->qop;
*dest_len = sizeof(digest->qop);
}
}
static void handle_digest_update(HTTPAuthState *state, const char *key,
int key_len, char **dest, int *dest_len)
{
DigestParams *digest = &state->digest_params;
if (!strncmp(key, "nextnonce=", key_len)) {
*dest = digest->nonce;
*dest_len = sizeof(digest->nonce);
}
}
static void choose_qop(char *qop, int size)
{
char *ptr = strstr(qop, "auth");
char *end = ptr + strlen("auth");
if (ptr && (!*end || isspace(*end) || *end == ',') &&
(ptr == qop || isspace(ptr[-1]) || ptr[-1] == ',')) {
av_strlcpy(qop, "auth", size);
} else {
qop[0] = 0;
}
}
void ff_http_auth_handle_header(HTTPAuthState *state, const char *key,
const char *value)
{
if (!strcmp(key, "WWW-Authenticate")) {
const char *p;
if (av_stristart(value, "Basic ", &p) &&
state->auth_type <= HTTP_AUTH_BASIC) {
state->auth_type = HTTP_AUTH_BASIC;
state->realm[0] = 0;
parse_key_value(p, handle_basic_params, state);
} else if (av_stristart(value, "Digest ", &p) &&
state->auth_type <= HTTP_AUTH_DIGEST) {
state->auth_type = HTTP_AUTH_DIGEST;
memset(&state->digest_params, 0, sizeof(DigestParams));
state->realm[0] = 0;
parse_key_value(p, handle_digest_params, state);
choose_qop(state->digest_params.qop,
sizeof(state->digest_params.qop));
}
} else if (!strcmp(key, "Authentication-Info")) {
parse_key_value(value, handle_digest_update, state);
}
}
static void update_md5_strings(struct AVMD5 *md5ctx, ...)
{
va_list vl;
va_start(vl, md5ctx);
while (1) {
const char* str = va_arg(vl, const char*);
if (!str)
break;
av_md5_update(md5ctx, str, strlen(str));
}
va_end(vl);
}
/* Generate a digest reply, according to RFC 2617. */
static char *make_digest_auth(HTTPAuthState *state, const char *username,
const char *password, const char *uri,
const char *method)
{
DigestParams *digest = &state->digest_params;
int len;
uint32_t cnonce_buf[2];
char cnonce[17];
char nc[9];
int i;
char A1hash[33], A2hash[33], response[33];
struct AVMD5 *md5ctx;
uint8_t hash[16];
char *authstr;
digest->nc++;
snprintf(nc, sizeof(nc), "%08x", digest->nc);
/* Generate a client nonce. */
for (i = 0; i < 2; i++)
cnonce_buf[i] = av_get_random_seed();
ff_data_to_hex(cnonce, (const uint8_t*) cnonce_buf, sizeof(cnonce_buf), 1);
cnonce[2*sizeof(cnonce_buf)] = 0;
md5ctx = av_malloc(av_md5_size);
if (!md5ctx)
return NULL;
av_md5_init(md5ctx);
update_md5_strings(md5ctx, username, ":", state->realm, ":", password, NULL);
av_md5_final(md5ctx, hash);
ff_data_to_hex(A1hash, hash, 16, 1);
A1hash[32] = 0;
if (!strcmp(digest->algorithm, "") || !strcmp(digest->algorithm, "MD5")) {
} else if (!strcmp(digest->algorithm, "MD5-sess")) {
av_md5_init(md5ctx);
update_md5_strings(md5ctx, A1hash, ":", digest->nonce, ":", cnonce, NULL);
av_md5_final(md5ctx, hash);
ff_data_to_hex(A1hash, hash, 16, 1);
A1hash[32] = 0;
} else {
/* Unsupported algorithm */
av_free(md5ctx);
return NULL;
}
av_md5_init(md5ctx);
update_md5_strings(md5ctx, method, ":", uri, NULL);
av_md5_final(md5ctx, hash);
ff_data_to_hex(A2hash, hash, 16, 1);
A2hash[32] = 0;
av_md5_init(md5ctx);
update_md5_strings(md5ctx, A1hash, ":", digest->nonce, NULL);
if (!strcmp(digest->qop, "auth") || !strcmp(digest->qop, "auth-int")) {
update_md5_strings(md5ctx, ":", nc, ":", cnonce, ":", digest->qop, NULL);
}
update_md5_strings(md5ctx, ":", A2hash, NULL);
av_md5_final(md5ctx, hash);
ff_data_to_hex(response, hash, 16, 1);
response[32] = 0;
av_free(md5ctx);
if (!strcmp(digest->qop, "") || !strcmp(digest->qop, "auth")) {
} else if (!strcmp(digest->qop, "auth-int")) {
/* qop=auth-int not supported */
return NULL;
} else {
/* Unsupported qop value. */
return NULL;
}
len = strlen(username) + strlen(state->realm) + strlen(digest->nonce) +
strlen(uri) + strlen(response) + strlen(digest->algorithm) +
strlen(digest->opaque) + strlen(digest->qop) + strlen(cnonce) +
strlen(nc) + 150;
authstr = av_malloc(len);
if (!authstr)
return NULL;
snprintf(authstr, len, "Authorization: Digest ");
/* TODO: Escape the quoted strings properly. */
av_strlcatf(authstr, len, "username=\"%s\"", username);
av_strlcatf(authstr, len, ",realm=\"%s\"", state->realm);
av_strlcatf(authstr, len, ",nonce=\"%s\"", digest->nonce);
av_strlcatf(authstr, len, ",uri=\"%s\"", uri);
av_strlcatf(authstr, len, ",response=\"%s\"", response);
if (digest->algorithm[0])
av_strlcatf(authstr, len, ",algorithm=%s", digest->algorithm);
if (digest->opaque[0])
av_strlcatf(authstr, len, ",opaque=\"%s\"", digest->opaque);
if (digest->qop[0]) {
av_strlcatf(authstr, len, ",qop=\"%s\"", digest->qop);
av_strlcatf(authstr, len, ",cnonce=\"%s\"", cnonce);
av_strlcatf(authstr, len, ",nc=%s", nc);
}
av_strlcatf(authstr, len, "\r\n");
return authstr;
}
char *ff_http_auth_create_response(HTTPAuthState *state, const char *auth,
const char *path, const char *method)
{
char *authstr = NULL;
if (!auth || !strchr(auth, ':'))
return NULL;
if (state->auth_type == HTTP_AUTH_BASIC) {
int auth_b64_len = AV_BASE64_SIZE(strlen(auth));
int len = auth_b64_len + 30;
char *ptr;
authstr = av_malloc(len);
if (!authstr)
return NULL;
snprintf(authstr, len, "Authorization: Basic ");
ptr = authstr + strlen(authstr);
av_base64_encode(ptr, auth_b64_len, auth, strlen(auth));
av_strlcat(ptr, "\r\n", len - (ptr - authstr));
} else if (state->auth_type == HTTP_AUTH_DIGEST) {
char *username = av_strdup(auth), *password;
if (!username)
return NULL;
if ((password = strchr(username, ':'))) {
*password++ = 0;
authstr = make_digest_auth(state, username, password, path, method);
}
av_free(username);
}
return authstr;
}