mirror of
https://github.com/Waujito/youtubeUnblock.git
synced 2024-12-22 06:15:31 +00:00
3ee979f7d1
Instead of real middle sni we use targetted middle sni for explicit (not all) sni domain list
339 lines
7.8 KiB
C
339 lines
7.8 KiB
C
#include "types.h"
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#include "tls.h"
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#include "config.h"
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#include "logging.h"
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#include "utils.h"
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#ifndef KERNEL_SPACE
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#include <stdlib.h>
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#include <sys/random.h>
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#endif
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#define TLS_CONTENT_TYPE_HANDSHAKE 0x16
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#define TLS_HANDSHAKE_TYPE_CLIENT_HELLO 0x01
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#define TLS_EXTENSION_SNI 0x0000
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#define TLS_EXTENSION_CLIENT_HELLO_ENCRYPTED 0xfe0d
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/**
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* Processes tls payload of the tcp request.
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*
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* data Payload data of TCP.
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* dlen Length of `data`.
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*/
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struct tls_verdict analyze_tls_data(
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const uint8_t *data,
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uint32_t dlen)
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{
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struct tls_verdict vrd = {0};
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size_t i = 0;
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const uint8_t *data_end = data + dlen;
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while (i + 4 < dlen) {
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const uint8_t *msgData = data + i;
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uint8_t tls_content_type = *msgData;
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uint8_t tls_vmajor = *(msgData + 1);
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uint16_t message_length = ntohs(*(uint16_t *)(msgData + 3));
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if (tls_vmajor != 0x03) goto nextMessage;
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if (i + 5 > dlen) break;
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if (tls_content_type != TLS_CONTENT_TYPE_HANDSHAKE)
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goto nextMessage;
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if (config.sni_detection == SNI_DETECTION_BRUTE) {
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goto brute;
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}
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const uint8_t *handshakeProto = msgData + 5;
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if (handshakeProto + 1 >= data_end) break;
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uint8_t handshakeType = *handshakeProto;
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if (handshakeType != TLS_HANDSHAKE_TYPE_CLIENT_HELLO)
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goto nextMessage;
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const uint8_t *msgPtr = handshakeProto;
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msgPtr += 1;
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msgPtr += 3 + 2 + 32;
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if (msgPtr + 1 >= data_end) break;
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uint8_t sessionIdLength = *msgPtr;
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msgPtr++;
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msgPtr += sessionIdLength;
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if (msgPtr + 2 >= data_end) break;
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uint16_t ciphersLength = ntohs(*(uint16_t *)msgPtr);
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msgPtr += 2;
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msgPtr += ciphersLength;
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if (msgPtr + 1 >= data_end) break;
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uint8_t compMethodsLen = *msgPtr;
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msgPtr++;
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msgPtr += compMethodsLen;
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if (msgPtr + 2 >= data_end) break;
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uint16_t extensionsLen = ntohs(*(uint16_t *)msgPtr);
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msgPtr += 2;
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const uint8_t *extensionsPtr = msgPtr;
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const uint8_t *extensions_end = extensionsPtr + extensionsLen;
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if (extensions_end > data_end) extensions_end = data_end;
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while (extensionsPtr < extensions_end) {
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const uint8_t *extensionPtr = extensionsPtr;
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if (extensionPtr + 4 >= extensions_end) break;
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uint16_t extensionType =
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ntohs(*(uint16_t *)extensionPtr);
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extensionPtr += 2;
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uint16_t extensionLen =
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ntohs(*(uint16_t *)extensionPtr);
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extensionPtr += 2;
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if (extensionPtr + extensionLen > extensions_end)
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break;
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if (extensionType != TLS_EXTENSION_SNI)
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goto nextExtension;
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const uint8_t *sni_ext_ptr = extensionPtr;
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if (sni_ext_ptr + 2 >= extensions_end) break;
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uint16_t sni_ext_dlen = ntohs(*(uint16_t *)sni_ext_ptr);
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sni_ext_ptr += 2;
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const uint8_t *sni_ext_end = sni_ext_ptr + sni_ext_dlen;
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if (sni_ext_end >= extensions_end) break;
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if (sni_ext_ptr + 3 >= sni_ext_end) break;
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sni_ext_ptr++;
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uint16_t sni_len = ntohs(*(uint16_t *)sni_ext_ptr);
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sni_ext_ptr += 2;
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if (sni_ext_ptr + sni_len > sni_ext_end) break;
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char *sni_name = (char *)sni_ext_ptr;
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vrd.sni_offset = (uint8_t *)sni_name - data;
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vrd.sni_target_offset = vrd.sni_offset;
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vrd.sni_len = sni_len;
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if (config.all_domains) {
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vrd.target_sni = 1;
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goto check_domain;
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}
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unsigned int j = 0;
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for (unsigned int i = 0; i <= config.domains_strlen; i++) {
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if ( i > j &&
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(i == config.domains_strlen ||
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config.domains_str[i] == '\0' ||
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config.domains_str[i] == ',' ||
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config.domains_str[i] == '\n' )) {
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unsigned int domain_len = (i - j);
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const char *sni_startp = sni_name + sni_len - domain_len;
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const char *domain_startp = config.domains_str + j;
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if (sni_len >= domain_len &&
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sni_len < 128 &&
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!strncmp(sni_startp,
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domain_startp,
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domain_len)) {
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vrd.target_sni = 1;
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vrd.sni_target_offset = (const uint8_t *)sni_startp - data;
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goto check_domain;
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}
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j = i + 1;
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}
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}
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check_domain:
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if (vrd.target_sni == 1 && config.exclude_domains_strlen != 0) {
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unsigned int j = 0;
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for (unsigned int i = 0; i <= config.exclude_domains_strlen; i++) {
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if ( i > j &&
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(i == config.exclude_domains_strlen ||
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config.exclude_domains_str[i] == '\0' ||
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config.exclude_domains_str[i] == ',' ||
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config.exclude_domains_str[i] == '\n' )) {
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unsigned int domain_len = (i - j);
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const char *sni_startp = sni_name + sni_len - domain_len;
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const char *domain_startp = config.exclude_domains_str + j;
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if (sni_len >= domain_len &&
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sni_len < 128 &&
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!strncmp(sni_startp,
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domain_startp,
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domain_len)) {
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vrd.target_sni = 0;
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lgdebugmsg("Excluded SNI: %.*s",
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vrd.sni_len, data + vrd.sni_offset);
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goto out;
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}
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j = i + 1;
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}
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}
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}
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goto out;
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nextExtension:
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extensionsPtr += 2 + 2 + extensionLen;
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}
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nextMessage:
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i += 5 + message_length;
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}
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out:
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return vrd;
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brute:
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if (config.all_domains) {
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vrd.target_sni = 1;
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vrd.sni_len = 0;
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vrd.sni_offset = dlen / 2;
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goto out;
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}
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unsigned int j = 0;
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for (unsigned int i = 0; i <= config.domains_strlen; i++) {
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if ( i > j &&
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(i == config.domains_strlen ||
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config.domains_str[i] == '\0' ||
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config.domains_str[i] == ',' ||
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config.domains_str[i] == '\n' )) {
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unsigned int domain_len = (i - j);
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const char *domain_startp = config.domains_str + j;
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if (domain_len + dlen + 1> MAX_PACKET_SIZE) {
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continue;
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}
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NETBUF_ALLOC(buf, MAX_PACKET_SIZE);
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if (!NETBUF_CHECK(buf)) {
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lgerror("Allocation error", -ENOMEM);
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goto out;
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}
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NETBUF_ALLOC(nzbuf, MAX_PACKET_SIZE * sizeof(int));
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if (!NETBUF_CHECK(nzbuf)) {
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lgerror("Allocation error", -ENOMEM);
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NETBUF_FREE(buf);
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goto out;
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}
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int *zbuf = (void *)nzbuf;
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memcpy(buf, domain_startp, domain_len);
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memcpy(buf + domain_len, "#", 1);
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memcpy(buf + domain_len + 1, data, dlen);
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z_function((char *)buf, zbuf, domain_len + 1 + dlen);
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for (unsigned int k = 0; k < dlen; k++) {
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if (zbuf[k] == domain_len) {
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vrd.target_sni = 1;
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vrd.sni_len = domain_len;
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vrd.sni_offset = (k - domain_len - 1);
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vrd.sni_target_offset = vrd.sni_offset
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NETBUF_FREE(buf);
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NETBUF_FREE(nzbuf);
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goto out;
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}
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}
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j = i + 1;
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NETBUF_FREE(buf);
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NETBUF_FREE(nzbuf);
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}
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}
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goto out;
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}
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int gen_fake_sni(struct fake_type type,
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const void *ipxh, uint32_t iph_len,
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const struct tcphdr *tcph, uint32_t tcph_len,
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uint8_t *buf, uint32_t *buflen) {
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uint32_t data_len = type.fake_len;
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if (type.type == FAKE_PAYLOAD_RANDOM && data_len == 0) {
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data_len = random() % 1200;
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} else if (type.type == FAKE_PAYLOAD_DEFAULT) {
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data_len = config.fake_sni_pkt_sz;
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}
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if (!ipxh || !tcph || !buf || !buflen)
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return -EINVAL;
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int ipxv = netproto_version(ipxh, iph_len);
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if (ipxv == IP4VERSION) {
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const struct iphdr *iph = ipxh;
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memcpy(buf, iph, iph_len);
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struct iphdr *niph = (struct iphdr *)buf;
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niph->protocol = IPPROTO_TCP;
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} else if (ipxv == IP6VERSION) {
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const struct ip6_hdr *iph = ipxh;
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iph_len = sizeof(struct ip6_hdr);
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memcpy(buf, iph, iph_len);
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struct ip6_hdr *niph = (struct ip6_hdr *)buf;
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niph->ip6_nxt = IPPROTO_TCP;
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} else {
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return -EINVAL;
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}
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uint32_t dlen = iph_len + tcph_len + data_len;
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if (*buflen < dlen)
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return -ENOMEM;
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memcpy(buf + iph_len, tcph, tcph_len);
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uint8_t *bfdptr = buf + iph_len + tcph_len;
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switch (type.type) {
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case FAKE_PAYLOAD_DEFAULT:
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memcpy(bfdptr, config.fake_sni_pkt, data_len);
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break;
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case FAKE_PAYLOAD_DATA:
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memcpy(bfdptr, type.fake_data, data_len);
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break;
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default: // FAKE_PAYLOAD_RANDOM
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getrandom(bfdptr, data_len, 0);
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}
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if (ipxv == IP4VERSION) {
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struct iphdr *niph = (struct iphdr *)buf;
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niph->tot_len = htons(dlen);
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} else if (ipxv == IP6VERSION) {
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struct ip6_hdr *niph = (struct ip6_hdr *)buf;
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niph->ip6_plen = htons(dlen - iph_len);
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}
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fail_packet(type.strategy, buf, &dlen, *buflen);
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*buflen = dlen;
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return 0;
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}
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