mirror of
https://github.com/hufrea/byedpi.git
synced 2024-12-22 06:15:14 +00:00
421 lines
10 KiB
C
421 lines
10 KiB
C
#define _GNU_SOURCE
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#include <packets.h>
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#include <ctype.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <string.h>
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#ifdef _WIN32
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#include <winsock2.h>
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#else
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#include <arpa/inet.h>
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#endif
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#define ANTOHS(data, i) \
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(uint16_t)((data[i] << 8) + (uint8_t)data[i + 1])
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#define SHTONA(data, i, x) \
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data[i] = (uint8_t)(x >> 8); \
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data[i + 1] = x & 0xff;
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char tls_data[517] = {
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"\x16\x03\x01\x02\x00\x01\x00\x01\xfc\x03\x03\x03\x5f"
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"\x6f\x2c\xed\x13\x22\xf8\xdc\xb2\xf2\x60\x48\x2d\x72"
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"\x66\x6f\x57\xdd\x13\x9d\x1b\x37\xdc\xfa\x36\x2e\xba"
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"\xf9\x92\x99\x3a\x20\xf9\xdf\x0c\x2e\x8a\x55\x89\x82"
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"\x31\x63\x1a\xef\xa8\xbe\x08\x58\xa7\xa3\x5a\x18\xd3"
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"\x96\x5f\x04\x5c\xb4\x62\xaf\x89\xd7\x0f\x8b\x00\x3e"
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"\x13\x02\x13\x03\x13\x01\xc0\x2c\xc0\x30\x00\x9f\xcc"
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"\xa9\xcc\xa8\xcc\xaa\xc0\x2b\xc0\x2f\x00\x9e\xc0\x24"
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"\xc0\x28\x00\x6b\xc0\x23\xc0\x27\x00\x67\xc0\x0a\xc0"
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"\x14\x00\x39\xc0\x09\xc0\x13\x00\x33\x00\x9d\x00\x9c"
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"\x00\x3d\x00\x3c\x00\x35\x00\x2f\x00\xff\x01\x00\x01"
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"\x75\x00\x00\x00\x16\x00\x14\x00\x00\x11\x77\x77\x77"
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"\x2e\x77\x69\x6b\x69\x70\x65\x64\x69\x61\x2e\x6f\x72"
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"\x67\x00\x0b\x00\x04\x03\x00\x01\x02\x00\x0a\x00\x16"
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"\x00\x14\x00\x1d\x00\x17\x00\x1e\x00\x19\x00\x18\x01"
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"\x00\x01\x01\x01\x02\x01\x03\x01\x04\x00\x10\x00\x0e"
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"\x00\x0c\x02\x68\x32\x08\x68\x74\x74\x70\x2f\x31\x2e"
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"\x31\x00\x16\x00\x00\x00\x17\x00\x00\x00\x31\x00\x00"
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"\x00\x0d\x00\x2a\x00\x28\x04\x03\x05\x03\x06\x03\x08"
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"\x07\x08\x08\x08\x09\x08\x0a\x08\x0b\x08\x04\x08\x05"
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"\x08\x06\x04\x01\x05\x01\x06\x01\x03\x03\x03\x01\x03"
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"\x02\x04\x02\x05\x02\x06\x02\x00\x2b\x00\x09\x08\x03"
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"\x04\x03\x03\x03\x02\x03\x01\x00\x2d\x00\x02\x01\x01"
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"\x00\x33\x00\x26\x00\x24\x00\x1d\x00\x20\x11\x8c\xb8"
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"\x8c\xe8\x8a\x08\x90\x1e\xee\x19\xd9\xdd\xe8\xd4\x06"
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"\xb1\xd1\xe2\xab\xe0\x16\x63\xd6\xdc\xda\x84\xa4\xb8"
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"\x4b\xfb\x0e\x00\x15\x00\xac\x00\x00\x00\x00\x00\x00"
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};
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char http_data[43] = {
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"GET / HTTP/1.1\r\n"
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"Host: www.wikipedia.org\r\n\r\n"
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};
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char udp_data[64] = { 0 };
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char *strncasestr(char *a, size_t as, char *b, size_t bs)
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{
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for (char *p = a; ; p++) {
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p = memchr(p, *b, as - (p - a));
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if (!p) {
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return 0;
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}
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if ((p + bs) > (a + as)) {
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return 0;
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}
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if (!strncasecmp(p, b, bs)) {
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return p;
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}
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}
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return 0;
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}
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size_t find_tls_ext_offset(uint16_t type,
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char *data, size_t size, size_t skip)
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{
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if (size <= (skip + 2)) {
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return 0;
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}
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uint16_t ext_len = ANTOHS(data, skip);
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skip += 2;
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if (ext_len < (size - skip)) {
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size = ext_len + skip;
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}
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while ((skip + 4) < size) {
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uint16_t epyt = ANTOHS(data, skip);
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if (type == epyt) {
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return skip;
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}
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uint16_t len = ANTOHS(data, skip + 2);
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skip += (len + 4);
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}
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return 0;
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}
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size_t chello_ext_offset(uint16_t type, char *data, size_t size)
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{
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if (size < 44) {
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return 0;
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}
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uint8_t sid_len = data[43];
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if (size < 44 + sid_len + 2) {
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return 0;
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}
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uint16_t cip_len = ANTOHS(data, 44 + sid_len);
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size_t skip = 44 + sid_len + 2 + cip_len + 2;
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return find_tls_ext_offset(type, data, size, skip);
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}
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int change_tls_sni(const char *host, char *buffer, size_t bsize)
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{
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size_t sni_offs, pad_offs;
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if (!(sni_offs = chello_ext_offset(0x00, buffer, bsize))) {
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return -1;
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}
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if (!(pad_offs = chello_ext_offset(0x15, buffer, bsize))) {
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return -1;
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}
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char *sni = &buffer[sni_offs];
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char *pad = &buffer[pad_offs];
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uint16_t old_sz = ANTOHS(buffer, sni_offs + 2) - 5;
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uint16_t free_sz = ANTOHS(buffer, pad_offs + 2);
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uint16_t new_sz = strlen(host);
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ssize_t diff = new_sz - old_sz;
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if ((free_sz != (bsize - pad_offs - 4))
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|| free_sz < diff) {
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return -1;
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}
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SHTONA(sni, 2, old_sz + diff + 5);
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SHTONA(sni, 4, old_sz + diff + 3);
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SHTONA(sni, 7, old_sz + diff);
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SHTONA(pad, 2, free_sz - diff);
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char *host_end = sni + 9 + old_sz;
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int oth_sz = bsize - (sni_offs + 9 + old_sz);
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memmove(host_end + diff, host_end, oth_sz);
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memcpy(sni + 9, host, new_sz);
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return 0;
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}
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bool is_tls_chello(char *buffer, size_t bsize)
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{
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return (bsize > 5 &&
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ANTOHS(buffer, 0) == 0x1603 &&
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buffer[5] == 0x01);
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}
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int parse_tls(char *buffer, size_t bsize, char **hs)
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{
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if (!is_tls_chello(buffer, bsize)) {
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return 0;
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}
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size_t sni_offs = chello_ext_offset(0x00, buffer, bsize);
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if (!sni_offs || (sni_offs + 12) >= bsize) {
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return 0;
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}
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uint16_t len = ANTOHS(buffer, sni_offs + 7);
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if ((sni_offs + 9 + len) > bsize) {
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return 0;
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}
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*hs = &buffer[sni_offs + 9];
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return len;
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}
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bool is_http(char *buffer, size_t bsize)
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{
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if (bsize < 16 || *buffer > 'T' || *buffer < 'C') {
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return 0;
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}
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const char *methods[] = {
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"HEAD", "GET", "POST", "PUT", "DELETE",
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"OPTIONS", "CONNECT", "TRACE", "PATCH", 0
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};
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for (const char **m = methods; *m; m++) {
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if (strncmp(buffer, *m, strlen(*m)) == 0) {
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return 1;
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}
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}
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return 0;
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}
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int parse_http(char *buffer, size_t bsize, char **hs, uint16_t *port)
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{
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char *host = buffer, *h_end;
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char *buff_end = buffer + bsize;
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if (!is_http(buffer, bsize)) {
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return 0;
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}
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host = strncasestr(buffer, bsize, "\nHost:", 6);
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if (!host) {
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return 0;
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}
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host += 6;
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while ((buff_end - host) > 0 && isblank(*host)) {
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host++;
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}
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char *l_end = memchr(host, '\n', buff_end - host);
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if (!l_end) {
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return 0;
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}
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for (; isspace(*(l_end - 1)); l_end--) {}
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if (!(isdigit(*(l_end - 1))))
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h_end = 0;
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else {
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char *h = host;
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h_end = 0;
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do {
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h = memchr(h, ':', l_end - h);
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if (h) {
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h_end = h;
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h++;
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}
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} while (h && h < l_end);
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}
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if (!h_end) {
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if (port) *port = 80;
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h_end = l_end;
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}
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else if (port) {
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char *end;
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long i = strtol(h_end + 1, &end, 10);
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if (i <= 0 || end != l_end || i > 0xffff)
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return 0;
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*port = i;
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}
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*hs = host;
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return h_end - host;
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}
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int get_http_code(char *b, size_t n)
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{
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if (n < 13) return 0;
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if (strncmp(b, "HTTP/1.", 7)) {
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return 0;
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}
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if (!memchr(b + 13, '\n', n)) {
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return 0;
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}
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char *e;
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long num = strtol(b + 9, &e, 10);
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if (num < 100 || num > 511 || !isspace(*e)) {
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return 0;
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}
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return (int )num;
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}
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bool is_http_redirect(char *req, size_t qn, char *resp, size_t sn)
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{
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char *host = 0;
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int len = parse_http(req, qn, &host, 0);
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if (len <= 0 || sn < 29) {
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return 0;
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}
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int code = get_http_code(resp, sn);
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if (code > 308 || code < 300) {
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return 0;
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}
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char *location = strncasestr(resp, sn, "\nLocation:", 10);
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if (!location) {
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return 0;
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}
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location += 11;
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if ((location + 8) >= (resp + sn)) {
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return 0;
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}
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char *l_end = memchr(location, '\n', sn - (location - resp));
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if (!l_end) {
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return 0;
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}
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for (; isspace(*(l_end - 1)); l_end--) {}
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if ((l_end - location) > 7) {
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if (!strncmp(location, "http://", 7)) {
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location += 7;
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}
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else if (!strncmp(location, "https://", 8)) {
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location += 8;
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}
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}
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char *e = memchr(location, '/', l_end - location);
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if (!e) e = l_end;
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for (; (e - location) > len; location++) {
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location = memchr(location, '.', e - location);
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if (!location) {
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return 1;
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}
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}
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for (; len > (e - location); host++) {
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char *p = memchr(host, '.', len);
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if (!p) {
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return 1;
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}
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len -= (host - p) + 1;
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host = p;
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}
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return (((e - location) != len)
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|| strncmp(host, location, len));
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}
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bool neq_tls_sid(char *req, size_t qn, char *resp, size_t sn)
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{
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if (qn < 75 || sn < 75) {
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return 0;
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}
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if (!is_tls_chello(req, qn)
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|| ANTOHS(resp, 0) != 0x1603) {
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return 0;
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}
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uint8_t sid_len = req[43];
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size_t skip = 44 + sid_len + 3;
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if (!find_tls_ext_offset(0x2b, resp, sn, skip)) {
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return 0;
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}
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if (req[43] != resp[43]) {
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return 1;
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}
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return memcmp(req + 44, resp + 44, sid_len);
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}
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bool is_tls_alert(char *resp, size_t sn) {
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return (sn >= 7
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&& resp[0] == 0x15 && resp[1] == 0x03
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&& !memcmp(resp + 3, "\x00\x02\x02", 3));
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}
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/*
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bool is_dns_req(char *buffer, size_t n)
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{
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if (n < 12) {
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return 0;
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}
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return !memcmp(buffer + 2, "\1\0\0\1\0\0\0\0\0\0", 10);
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}
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bool is_quic_initial(char *buffer, size_t bsize)
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{
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return (bsize > 64 && (buffer[0] & 0xc0) == 0xc0);
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}
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*/
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int mod_http(char *buffer, size_t bsize, int m)
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{
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char *host = 0, *par;
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int hlen = parse_http(buffer, bsize, &host, 0);
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if (!hlen)
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return -1;
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for (par = host - 1; *par != ':'; par--) {}
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par -= 4;
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if (m & MH_HMIX) {
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par[0] = tolower(par[0]);
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par[1] = toupper(par[1]);
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par[3] = toupper(par[3]);
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}
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if (m & MH_DMIX) {
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for (int i = 0; i < hlen; i += 2) {
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host[i] = toupper(host[i]);
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}
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}
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if (m & MH_SPACE) {
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for (; !isspace(*(host + hlen)); hlen++) {}
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int sc = host - (par + 5);
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memmove(par + 5, host, hlen);
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memset(par + 5 + hlen, '\t', sc);
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}
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return 0;
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}
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int part_tls(char *buffer, size_t bsize, ssize_t n, long pos)
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{
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if ((n < 3) || (bsize - n < 5) ||
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(pos < 0) || (pos + 5 > n)) {
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return 0;
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}
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uint16_t r_sz = ANTOHS(buffer, 3);
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if (r_sz < pos) {
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return n;
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}
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memmove(buffer + 5 + pos + 5, buffer + 5 + pos, n - (5 + pos));
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memcpy(buffer + 5 + pos, buffer, 3);
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SHTONA(buffer, 3, pos);
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SHTONA(buffer, 5 + pos + 3, r_sz - pos);
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return 5;
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}
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