mirror of
https://github.com/bol-van/zapret.git
synced 2024-12-18 22:11:31 +03:00
945 lines
26 KiB
C
945 lines
26 KiB
C
#define _GNU_SOURCE
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#include "protocol.h"
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#include "helpers.h"
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#include <string.h>
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#include <ctype.h>
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#include <arpa/inet.h>
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#include <string.h>
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// find N level domain
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static bool FindNLD(const uint8_t *dom, size_t dlen, int level, const uint8_t **p, size_t *len)
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{
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int i;
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const uint8_t *p1,*p2;
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for (i=1,p2=dom+dlen;i<level;i++)
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{
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for (p2--; p2>dom && *p2!='.'; p2--);
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if (p2<=dom) return false;
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}
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for (p1=p2-1 ; p1>dom && *p1!='.'; p1--);
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if (*p1=='.') p1++;
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if (p) *p = p1;
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if (len) *len = p2-p1;
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return true;
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}
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const char *l7proto_str(t_l7proto l7)
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{
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switch(l7)
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{
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case HTTP: return "http";
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case TLS: return "tls";
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case QUIC: return "quic";
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case WIREGUARD: return "wireguard";
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case DHT: return "dht";
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default: return "unknown";
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}
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}
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bool l7_proto_match(t_l7proto l7proto, uint32_t filter_l7)
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{
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return (l7proto==UNKNOWN && (filter_l7 & L7_PROTO_UNKNOWN)) ||
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(l7proto==HTTP && (filter_l7 & L7_PROTO_HTTP)) ||
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(l7proto==TLS && (filter_l7 & L7_PROTO_TLS)) ||
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(l7proto==QUIC && (filter_l7 & L7_PROTO_QUIC)) ||
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(l7proto==WIREGUARD && (filter_l7 & L7_PROTO_WIREGUARD)) ||
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(l7proto==DHT && (filter_l7 & L7_PROTO_DHT));
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}
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#define PM_ABS 0
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#define PM_HOST 1
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#define PM_HOST_END 2
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#define PM_HOST_SLD 3
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#define PM_HOST_MIDSLD 4
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#define PM_HOST_ENDSLD 5
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#define PM_HTTP_METHOD 6
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#define PM_SNI_EXT 7
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bool IsHostMarker(uint8_t posmarker)
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{
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switch(posmarker)
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{
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case PM_HOST:
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case PM_HOST_END:
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case PM_HOST_SLD:
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case PM_HOST_MIDSLD:
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case PM_HOST_ENDSLD:
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return true;
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default:
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return false;
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}
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}
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const char *posmarker_name(uint8_t posmarker)
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{
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switch(posmarker)
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{
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case PM_ABS: return "abs";
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case PM_HOST: return "host";
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case PM_HOST_END: return "endhost";
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case PM_HOST_SLD: return "sld";
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case PM_HOST_MIDSLD: return "midsld";
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case PM_HOST_ENDSLD: return "endsld";
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case PM_HTTP_METHOD: return "method";
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case PM_SNI_EXT: return "sniext";
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default: return "?";
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}
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}
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static size_t CheckPos(size_t sz, ssize_t offset)
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{
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return (offset>=0 && offset<sz) ? offset : 0;
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}
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size_t AnyProtoPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz)
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{
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ssize_t offset;
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switch(posmarker)
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{
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case PM_ABS:
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offset = (pos<0) ? sz+pos : pos;
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return CheckPos(sz,offset);
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default:
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return 0;
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}
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}
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static size_t HostPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz, size_t offset_host, size_t len_host)
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{
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ssize_t offset;
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const uint8_t *p;
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size_t slen;
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switch(posmarker)
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{
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case PM_HOST:
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offset = offset_host+pos;
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break;
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case PM_HOST_END:
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offset = offset_host+len_host+pos;
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break;
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case PM_HOST_SLD:
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case PM_HOST_MIDSLD:
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case PM_HOST_ENDSLD:
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if (((offset_host+len_host)<=sz) && FindNLD(data+offset_host,len_host,2,&p,&slen))
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offset = (posmarker==PM_HOST_SLD ? p-data : posmarker==PM_HOST_ENDSLD ? p-data+slen : slen==1 ? p+1-data : p+slen/2-data) + pos;
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else
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offset = 0;
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break;
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}
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return CheckPos(sz,offset);
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}
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size_t ResolvePos(const uint8_t *data, size_t sz, t_l7proto l7proto, const struct proto_pos *sp)
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{
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switch(l7proto)
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{
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case HTTP:
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return HttpPos(sp->marker, sp->pos, data, sz);
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case TLS:
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return TLSPos(sp->marker, sp->pos, data, sz);
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default:
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return AnyProtoPos(sp->marker, sp->pos, data, sz);
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}
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}
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void ResolveMultiPos(const uint8_t *data, size_t sz, t_l7proto l7proto, const struct proto_pos *splits, int split_count, size_t *pos, int *pos_count)
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{
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int i,j;
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for(i=j=0;i<split_count;i++)
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{
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pos[j] = ResolvePos(data,sz,l7proto,splits+i);
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if (pos[j]) j++;
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}
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qsort_size_t(pos, j);
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j=unique_size_t(pos, j);
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*pos_count=j;
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}
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const char *http_methods[] = { "GET /","POST /","HEAD /","OPTIONS ","PUT /","DELETE /","CONNECT ","TRACE /",NULL };
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const char *HttpMethod(const uint8_t *data, size_t len)
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{
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const char **method;
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size_t method_len;
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for (method = http_methods; *method; method++)
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{
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method_len = strlen(*method);
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if (method_len <= len && !memcmp(data, *method, method_len))
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return *method;
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}
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return NULL;
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}
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bool IsHttp(const uint8_t *data, size_t len)
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{
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return !!HttpMethod(data,len);
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}
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static bool IsHostAt(const uint8_t *p)
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{
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return \
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p[0]=='\n' &&
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(p[1]=='H' || p[1]=='h') &&
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(p[2]=='o' || p[2]=='O') &&
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(p[3]=='s' || p[3]=='S') &&
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(p[4]=='t' || p[4]=='T') &&
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p[5]==':';
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}
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static uint8_t *FindHostIn(uint8_t *buf, size_t bs)
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{
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size_t pos;
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if (bs<6) return NULL;
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bs-=6;
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for(pos=0;pos<=bs;pos++)
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if (IsHostAt(buf+pos))
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return buf+pos;
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return NULL;
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}
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static const uint8_t *FindHostInConst(const uint8_t *buf, size_t bs)
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{
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size_t pos;
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if (bs<6) return NULL;
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bs-=6;
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for(pos=0;pos<=bs;pos++)
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if (IsHostAt(buf+pos))
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return buf+pos;
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return NULL;
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}
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// pHost points to "Host: ..."
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bool HttpFindHost(uint8_t **pHost,uint8_t *buf,size_t bs)
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{
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if (!*pHost)
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{
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*pHost = FindHostIn(buf, bs);
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if (*pHost) (*pHost)++;
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}
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return !!*pHost;
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}
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bool HttpFindHostConst(const uint8_t **pHost,const uint8_t *buf,size_t bs)
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{
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if (!*pHost)
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{
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*pHost = FindHostInConst(buf, bs);
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if (*pHost) (*pHost)++;
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}
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return !!*pHost;
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}
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bool IsHttpReply(const uint8_t *data, size_t len)
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{
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// HTTP/1.x 200\r\n
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return len>14 && !memcmp(data,"HTTP/1.",7) && (data[7]=='0' || data[7]=='1') && data[8]==' ' &&
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data[9]>='0' && data[9]<='9' &&
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data[10]>='0' && data[10]<='9' &&
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data[11]>='0' && data[11]<='9';
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}
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int HttpReplyCode(const uint8_t *data, size_t len)
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{
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return (data[9]-'0')*100 + (data[10]-'0')*10 + (data[11]-'0');
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}
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bool HttpExtractHeader(const uint8_t *data, size_t len, const char *header, char *buf, size_t len_buf)
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{
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const uint8_t *p, *s, *e = data + len;
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p = (uint8_t*)strncasestr((char*)data, header, len);
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if (!p) return false;
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p += strlen(header);
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while (p < e && (*p == ' ' || *p == '\t')) p++;
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s = p;
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while (s < e && (*s != '\r' && *s != '\n' && *s != ' ' && *s != '\t')) s++;
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if (s > p)
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{
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size_t slen = s - p;
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if (buf && len_buf)
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{
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if (slen >= len_buf) slen = len_buf - 1;
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for (size_t i = 0; i < slen; i++) buf[i] = tolower(p[i]);
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buf[slen] = 0;
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}
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return true;
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}
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return false;
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}
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bool HttpExtractHost(const uint8_t *data, size_t len, char *host, size_t len_host)
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{
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return HttpExtractHeader(data, len, "\nHost:", host, len_host);
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}
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// DPI redirects are global redirects to another domain
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bool HttpReplyLooksLikeDPIRedirect(const uint8_t *data, size_t len, const char *host)
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{
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char loc[256],*redirect_host, *p;
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int code;
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if (!host || !*host) return false;
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code = HttpReplyCode(data,len);
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if ((code!=302 && code!=307) || !HttpExtractHeader(data,len,"\nLocation:",loc,sizeof(loc))) return false;
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// something like : https://censor.net/badpage.php?reason=denied&source=RKN
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if (!strncmp(loc,"http://",7))
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redirect_host=loc+7;
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else if (!strncmp(loc,"https://",8))
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redirect_host=loc+8;
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else
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return false;
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// somethinkg like : censor.net/badpage.php?reason=denied&source=RKN
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for(p=redirect_host; *p && *p!='/' ; p++);
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*p=0;
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if (!*redirect_host) return false;
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// somethinkg like : censor.net
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// extract 2nd level domains
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const char *dhost, *drhost;
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if (!FindNLD((uint8_t*)host,strlen(host),2,(const uint8_t**)&dhost,NULL) || !FindNLD((uint8_t*)redirect_host,strlen(redirect_host),2,(const uint8_t**)&drhost,NULL))
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return false;
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// compare 2nd level domains
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return strcasecmp(dhost, drhost)!=0;
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}
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size_t HttpPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz)
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{
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const uint8_t *method, *host=NULL, *p;
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size_t offset_host,len_host;
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ssize_t offset;
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int i;
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switch(posmarker)
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{
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case PM_HTTP_METHOD:
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// recognize some tpws pre-applied hacks
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method=data;
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if (sz<10) break;
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if (*method=='\n' || *method=='\r') method++;
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if (*method=='\n' || *method=='\r') method++;
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for (p=method,i=0;i<7;i++) if (*p>='A' && *p<='Z') p++;
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if (i<3 || *p!=' ') break;
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return CheckPos(sz,method-data+pos);
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case PM_HOST:
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case PM_HOST_END:
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case PM_HOST_SLD:
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case PM_HOST_MIDSLD:
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case PM_HOST_ENDSLD:
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if (HttpFindHostConst(&host,data,sz) && (host-data+7)<sz)
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{
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host+=5;
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if (*host==' ' || *host=='\t') host++;
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offset_host = host-data;
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if (posmarker!=PM_HOST)
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for (len_host=0; (offset_host+len_host)<sz && data[offset_host+len_host]!='\r' && data[offset_host+len_host]!='\n'; len_host++);
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else
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len_host = 0;
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return HostPos(posmarker,pos,data,sz,offset_host,len_host);
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}
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break;
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default:
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return AnyProtoPos(posmarker,pos,data,sz);
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}
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return 0;
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}
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uint16_t TLSRecordDataLen(const uint8_t *data)
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{
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return pntoh16(data + 3);
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}
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size_t TLSRecordLen(const uint8_t *data)
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{
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return TLSRecordDataLen(data) + 5;
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}
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bool IsTLSRecordFull(const uint8_t *data, size_t len)
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{
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return TLSRecordLen(data)<=len;
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}
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bool IsTLSClientHello(const uint8_t *data, size_t len, bool bPartialIsOK)
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{
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return len >= 6 && data[0] == 0x16 && data[1] == 0x03 && data[2] <= 0x03 && data[5] == 0x01 && (bPartialIsOK || TLSRecordLen(data) <= len);
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}
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size_t TLSHandshakeLen(const uint8_t *data)
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{
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return data[1] << 16 | data[2] << 8 | data[3]; // HandshakeProtocol length
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}
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bool IsTLSHandshakeClientHello(const uint8_t *data, size_t len)
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{
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return len>=4 && data[0]==0x01 && TLSHandshakeLen(data)>0;
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}
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bool IsTLSHandshakeFull(const uint8_t *data, size_t len)
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{
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return (4+TLSHandshakeLen(data))<=len;
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}
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// bPartialIsOK=true - accept partial packets not containing the whole TLS message
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bool TLSFindExtInHandshake(const uint8_t *data, size_t len, uint16_t type, const uint8_t **ext, size_t *len_ext, bool bPartialIsOK)
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{
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// +0
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// u8 HandshakeType: ClientHello
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// u24 Length
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// u16 Version
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// c[32] random
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// u8 SessionIDLength
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// <SessionID>
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// u16 CipherSuitesLength
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// <CipherSuites>
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// u8 CompressionMethodsLength
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// <CompressionMethods>
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// u16 ExtensionsLength
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size_t l;
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if (!bPartialIsOK && !IsTLSHandshakeFull(data,len)) return false;
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l = 1 + 3 + 2 + 32;
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// SessionIDLength
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if (len < (l + 1)) return false;
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l += data[l] + 1;
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// CipherSuitesLength
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if (len < (l + 2)) return false;
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l += pntoh16(data + l) + 2;
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// CompressionMethodsLength
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if (len < (l + 1)) return false;
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l += data[l] + 1;
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// ExtensionsLength
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if (len < (l + 2)) return false;
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data += l; len -= l;
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l = pntoh16(data);
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data += 2; len -= 2;
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if (bPartialIsOK)
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{
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if (len < l) l = len;
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}
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else
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{
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if (len < l) return false;
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}
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while (l >= 4)
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{
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uint16_t etype = pntoh16(data);
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size_t elen = pntoh16(data + 2);
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data += 4; l -= 4;
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if (l < elen) break;
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if (etype == type)
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{
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if (ext && len_ext)
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{
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*ext = data;
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*len_ext = elen;
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}
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return true;
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}
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data += elen; l -= elen;
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}
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return false;
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}
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bool TLSFindExt(const uint8_t *data, size_t len, uint16_t type, const uint8_t **ext, size_t *len_ext, bool bPartialIsOK)
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{
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// +0
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// u8 ContentType: Handshake
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// u16 Version: TLS1.0
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// u16 Length
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size_t reclen;
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if (!IsTLSClientHello(data, len, bPartialIsOK)) return false;
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reclen=TLSRecordLen(data);
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if (reclen<len) len=reclen; // correct len if it has more data than the first tls record has
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return TLSFindExtInHandshake(data + 5, len - 5, type, ext, len_ext, bPartialIsOK);
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}
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static bool TLSAdvanceToHostInSNI(const uint8_t **ext, size_t *elen, size_t *slen)
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{
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// u16 data+0 - name list length
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// u8 data+2 - server name type. 0=host_name
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// u16 data+3 - server name length
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if (*elen < 5 || (*ext)[2] != 0) return false;
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*slen = pntoh16(*ext + 3);
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*ext += 5; *elen -= 5;
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return *slen <= *elen;
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}
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static bool TLSExtractHostFromExt(const uint8_t *ext, size_t elen, char *host, size_t len_host)
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{
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// u16 data+0 - name list length
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// u8 data+2 - server name type. 0=host_name
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// u16 data+3 - server name length
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size_t slen;
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if (!TLSAdvanceToHostInSNI(&ext,&elen,&slen))
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return false;
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if (host && len_host)
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{
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if (slen >= len_host) slen = len_host - 1;
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for (size_t i = 0; i < slen; i++) host[i] = tolower(ext[i]);
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host[slen] = 0;
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}
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return true;
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}
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bool TLSHelloExtractHost(const uint8_t *data, size_t len, char *host, size_t len_host, bool bPartialIsOK)
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{
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const uint8_t *ext;
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size_t elen;
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|
|
|
if (!TLSFindExt(data, len, 0, &ext, &elen, bPartialIsOK)) return false;
|
|
return TLSExtractHostFromExt(ext, elen, host, len_host);
|
|
}
|
|
bool TLSHelloExtractHostFromHandshake(const uint8_t *data, size_t len, char *host, size_t len_host, bool bPartialIsOK)
|
|
{
|
|
const uint8_t *ext;
|
|
size_t elen;
|
|
|
|
if (!TLSFindExtInHandshake(data, len, 0, &ext, &elen, bPartialIsOK)) return false;
|
|
return TLSExtractHostFromExt(ext, elen, host, len_host);
|
|
}
|
|
|
|
size_t TLSPos(uint8_t posmarker, int16_t pos, const uint8_t *data, size_t sz)
|
|
{
|
|
size_t elen;
|
|
const uint8_t *ext, *p;
|
|
size_t offset_host,len_host;
|
|
ssize_t offset;
|
|
|
|
switch(posmarker)
|
|
{
|
|
case PM_HOST:
|
|
case PM_HOST_END:
|
|
case PM_HOST_SLD:
|
|
case PM_HOST_MIDSLD:
|
|
case PM_HOST_ENDSLD:
|
|
case PM_SNI_EXT:
|
|
if (TLSFindExt(data,sz,0,&ext,&elen,false))
|
|
{
|
|
if (posmarker==PM_SNI_EXT)
|
|
{
|
|
return CheckPos(sz,ext-data+pos);
|
|
}
|
|
else
|
|
{
|
|
if (!TLSAdvanceToHostInSNI(&ext,&elen,&len_host))
|
|
return 0;
|
|
offset_host = ext-data;
|
|
return HostPos(posmarker,pos,data,sz,offset_host,len_host);
|
|
}
|
|
}
|
|
return 0;
|
|
default:
|
|
return AnyProtoPos(posmarker,pos,data,sz);
|
|
}
|
|
}
|
|
|
|
|
|
|
|
static uint8_t tvb_get_varint(const uint8_t *tvb, uint64_t *value)
|
|
{
|
|
switch (*tvb >> 6)
|
|
{
|
|
case 0: /* 0b00 => 1 byte length (6 bits Usable) */
|
|
if (value) *value = *tvb & 0x3F;
|
|
return 1;
|
|
case 1: /* 0b01 => 2 bytes length (14 bits Usable) */
|
|
if (value) *value = pntoh16(tvb) & 0x3FFF;
|
|
return 2;
|
|
case 2: /* 0b10 => 4 bytes length (30 bits Usable) */
|
|
if (value) *value = pntoh32(tvb) & 0x3FFFFFFF;
|
|
return 4;
|
|
case 3: /* 0b11 => 8 bytes length (62 bits Usable) */
|
|
if (value) *value = pntoh64(tvb) & 0x3FFFFFFFFFFFFFFF;
|
|
return 8;
|
|
}
|
|
// impossible case
|
|
if (*value) *value = 0;
|
|
return 0;
|
|
}
|
|
static uint8_t tvb_get_size(uint8_t tvb)
|
|
{
|
|
return 1 << (tvb >> 6);
|
|
}
|
|
|
|
bool IsQUICCryptoHello(const uint8_t *data, size_t len, size_t *hello_offset, size_t *hello_len)
|
|
{
|
|
size_t offset = 1;
|
|
uint64_t coff, clen;
|
|
if (len < 3 || *data != 6) return false;
|
|
if ((offset+tvb_get_size(data[offset])) >= len) return false;
|
|
offset += tvb_get_varint(data + offset, &coff);
|
|
// offset must be 0 if it's a full segment, not just a chunk
|
|
if (coff || (offset+tvb_get_size(data[offset])) >= len) return false;
|
|
offset += tvb_get_varint(data + offset, &clen);
|
|
if ((offset + clen) > len || !IsTLSHandshakeClientHello(data+offset,clen)) return false;
|
|
if (hello_offset) *hello_offset = offset;
|
|
if (hello_len) *hello_len = (size_t)clen;
|
|
return true;
|
|
}
|
|
|
|
/* Returns the QUIC draft version or 0 if not applicable. */
|
|
uint8_t QUICDraftVersion(uint32_t version)
|
|
{
|
|
/* IETF Draft versions */
|
|
if ((version >> 8) == 0xff0000) {
|
|
return (uint8_t)version;
|
|
}
|
|
/* Facebook mvfst, based on draft -22. */
|
|
if (version == 0xfaceb001) {
|
|
return 22;
|
|
}
|
|
/* Facebook mvfst, based on draft -27. */
|
|
if (version == 0xfaceb002 || version == 0xfaceb00e) {
|
|
return 27;
|
|
}
|
|
/* GQUIC Q050, T050 and T051: they are not really based on any drafts,
|
|
* but we must return a sensible value */
|
|
if (version == 0x51303530 ||
|
|
version == 0x54303530 ||
|
|
version == 0x54303531) {
|
|
return 27;
|
|
}
|
|
/* https://tools.ietf.org/html/draft-ietf-quic-transport-32#section-15
|
|
"Versions that follow the pattern 0x?a?a?a?a are reserved for use in
|
|
forcing version negotiation to be exercised"
|
|
It is tricky to return a correct draft version: such number is primarily
|
|
used to select a proper salt (which depends on the version itself), but
|
|
we don't have a real version here! Let's hope that we need to handle
|
|
only latest drafts... */
|
|
if ((version & 0x0F0F0F0F) == 0x0a0a0a0a) {
|
|
return 29;
|
|
}
|
|
/* QUIC (final?) constants for v1 are defined in draft-33, but draft-34 is the
|
|
final draft version */
|
|
if (version == 0x00000001) {
|
|
return 34;
|
|
}
|
|
/* QUIC Version 2 */
|
|
/* TODO: for the time being use 100 as a number for V2 and let see how v2 drafts evolve */
|
|
if (version == 0x709A50C4) {
|
|
return 100;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static bool is_quic_draft_max(uint32_t draft_version, uint8_t max_version)
|
|
{
|
|
return draft_version && draft_version <= max_version;
|
|
}
|
|
static bool is_quic_v2(uint32_t version)
|
|
{
|
|
return version == 0x6b3343cf;
|
|
}
|
|
|
|
static bool quic_hkdf_expand_label(const uint8_t *secret, uint8_t secret_len, const char *label, uint8_t *out, size_t out_len)
|
|
{
|
|
uint8_t hkdflabel[64];
|
|
|
|
size_t label_size = strlen(label);
|
|
if (label_size > 255) return false;
|
|
size_t hkdflabel_size = 2 + 1 + label_size + 1;
|
|
if (hkdflabel_size > sizeof(hkdflabel)) return false;
|
|
|
|
phton16(hkdflabel, out_len);
|
|
hkdflabel[2] = (uint8_t)label_size;
|
|
memcpy(hkdflabel + 3, label, label_size);
|
|
hkdflabel[3 + label_size] = 0;
|
|
return !hkdfExpand(SHA256, secret, secret_len, hkdflabel, hkdflabel_size, out, out_len);
|
|
}
|
|
|
|
static bool quic_derive_initial_secret(const quic_cid_t *cid, uint8_t *client_initial_secret, uint32_t version)
|
|
{
|
|
/*
|
|
* https://tools.ietf.org/html/draft-ietf-quic-tls-29#section-5.2
|
|
*
|
|
* initial_salt = 0xafbfec289993d24c9e9786f19c6111e04390a899
|
|
* initial_secret = HKDF-Extract(initial_salt, client_dst_connection_id)
|
|
*
|
|
* client_initial_secret = HKDF-Expand-Label(initial_secret,
|
|
* "client in", "", Hash.length)
|
|
* server_initial_secret = HKDF-Expand-Label(initial_secret,
|
|
* "server in", "", Hash.length)
|
|
*
|
|
* Hash for handshake packets is SHA-256 (output size 32).
|
|
*/
|
|
static const uint8_t handshake_salt_draft_22[20] = {
|
|
0x7f, 0xbc, 0xdb, 0x0e, 0x7c, 0x66, 0xbb, 0xe9, 0x19, 0x3a,
|
|
0x96, 0xcd, 0x21, 0x51, 0x9e, 0xbd, 0x7a, 0x02, 0x64, 0x4a
|
|
};
|
|
static const uint8_t handshake_salt_draft_23[20] = {
|
|
0xc3, 0xee, 0xf7, 0x12, 0xc7, 0x2e, 0xbb, 0x5a, 0x11, 0xa7,
|
|
0xd2, 0x43, 0x2b, 0xb4, 0x63, 0x65, 0xbe, 0xf9, 0xf5, 0x02,
|
|
};
|
|
static const uint8_t handshake_salt_draft_29[20] = {
|
|
0xaf, 0xbf, 0xec, 0x28, 0x99, 0x93, 0xd2, 0x4c, 0x9e, 0x97,
|
|
0x86, 0xf1, 0x9c, 0x61, 0x11, 0xe0, 0x43, 0x90, 0xa8, 0x99
|
|
};
|
|
static const uint8_t handshake_salt_v1[20] = {
|
|
0x38, 0x76, 0x2c, 0xf7, 0xf5, 0x59, 0x34, 0xb3, 0x4d, 0x17,
|
|
0x9a, 0xe6, 0xa4, 0xc8, 0x0c, 0xad, 0xcc, 0xbb, 0x7f, 0x0a
|
|
};
|
|
static const uint8_t hanshake_salt_draft_q50[20] = {
|
|
0x50, 0x45, 0x74, 0xEF, 0xD0, 0x66, 0xFE, 0x2F, 0x9D, 0x94,
|
|
0x5C, 0xFC, 0xDB, 0xD3, 0xA7, 0xF0, 0xD3, 0xB5, 0x6B, 0x45
|
|
};
|
|
static const uint8_t hanshake_salt_draft_t50[20] = {
|
|
0x7f, 0xf5, 0x79, 0xe5, 0xac, 0xd0, 0x72, 0x91, 0x55, 0x80,
|
|
0x30, 0x4c, 0x43, 0xa2, 0x36, 0x7c, 0x60, 0x48, 0x83, 0x10
|
|
};
|
|
static const uint8_t hanshake_salt_draft_t51[20] = {
|
|
0x7a, 0x4e, 0xde, 0xf4, 0xe7, 0xcc, 0xee, 0x5f, 0xa4, 0x50,
|
|
0x6c, 0x19, 0x12, 0x4f, 0xc8, 0xcc, 0xda, 0x6e, 0x03, 0x3d
|
|
};
|
|
static const uint8_t handshake_salt_v2[20] = {
|
|
0x0d, 0xed, 0xe3, 0xde, 0xf7, 0x00, 0xa6, 0xdb, 0x81, 0x93,
|
|
0x81, 0xbe, 0x6e, 0x26, 0x9d, 0xcb, 0xf9, 0xbd, 0x2e, 0xd9
|
|
};
|
|
|
|
int err;
|
|
const uint8_t *salt;
|
|
uint8_t secret[USHAMaxHashSize];
|
|
uint8_t draft_version = QUICDraftVersion(version);
|
|
|
|
if (version == 0x51303530) {
|
|
salt = hanshake_salt_draft_q50;
|
|
}
|
|
else if (version == 0x54303530) {
|
|
salt = hanshake_salt_draft_t50;
|
|
}
|
|
else if (version == 0x54303531) {
|
|
salt = hanshake_salt_draft_t51;
|
|
}
|
|
else if (is_quic_draft_max(draft_version, 22)) {
|
|
salt = handshake_salt_draft_22;
|
|
}
|
|
else if (is_quic_draft_max(draft_version, 28)) {
|
|
salt = handshake_salt_draft_23;
|
|
}
|
|
else if (is_quic_draft_max(draft_version, 32)) {
|
|
salt = handshake_salt_draft_29;
|
|
}
|
|
else if (is_quic_draft_max(draft_version, 34)) {
|
|
salt = handshake_salt_v1;
|
|
}
|
|
else {
|
|
salt = handshake_salt_v2;
|
|
}
|
|
|
|
err = hkdfExtract(SHA256, salt, 20, cid->cid, cid->len, secret);
|
|
if (err) return false;
|
|
|
|
if (client_initial_secret && !quic_hkdf_expand_label(secret, SHA256HashSize, "tls13 client in", client_initial_secret, SHA256HashSize))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
bool QUICIsLongHeader(const uint8_t *data, size_t len)
|
|
{
|
|
return len>=9 && !!(*data & 0x80);
|
|
}
|
|
uint32_t QUICExtractVersion(const uint8_t *data, size_t len)
|
|
{
|
|
// long header, fixed bit, type=initial
|
|
return QUICIsLongHeader(data, len) ? ntohl(*(uint32_t*)(data + 1)) : 0;
|
|
}
|
|
bool QUICExtractDCID(const uint8_t *data, size_t len, quic_cid_t *cid)
|
|
{
|
|
if (!QUICIsLongHeader(data,len) || !data[5] || data[5] > QUIC_MAX_CID_LENGTH || (6+data[5])>len) return false;
|
|
cid->len = data[5];
|
|
memcpy(&cid->cid, data + 6, data[5]);
|
|
return true;
|
|
}
|
|
bool QUICDecryptInitial(const uint8_t *data, size_t data_len, uint8_t *clean, size_t *clean_len)
|
|
{
|
|
uint32_t ver = QUICExtractVersion(data, data_len);
|
|
if (!ver) return false;
|
|
|
|
quic_cid_t dcid;
|
|
if (!QUICExtractDCID(data, data_len, &dcid)) return false;
|
|
|
|
uint8_t client_initial_secret[SHA256HashSize];
|
|
if (!quic_derive_initial_secret(&dcid, client_initial_secret, ver)) return false;
|
|
|
|
uint8_t aeskey[16], aesiv[12], aeshp[16];
|
|
bool v1_label = !is_quic_v2(ver);
|
|
if (!quic_hkdf_expand_label(client_initial_secret, SHA256HashSize, v1_label ? "tls13 quic key" : "tls13 quicv2 key", aeskey, sizeof(aeskey)) ||
|
|
!quic_hkdf_expand_label(client_initial_secret, SHA256HashSize, v1_label ? "tls13 quic iv" : "tls13 quicv2 iv", aesiv, sizeof(aesiv)) ||
|
|
!quic_hkdf_expand_label(client_initial_secret, SHA256HashSize, v1_label ? "tls13 quic hp" : "tls13 quicv2 hp", aeshp, sizeof(aeshp)))
|
|
{
|
|
return false;
|
|
}
|
|
|
|
uint64_t payload_len,token_len;
|
|
size_t pn_offset;
|
|
pn_offset = 1 + 4 + 1 + data[5];
|
|
if (pn_offset >= data_len) return false;
|
|
pn_offset += 1 + data[pn_offset];
|
|
if ((pn_offset + tvb_get_size(data[pn_offset])) >= data_len) return false;
|
|
pn_offset += tvb_get_varint(data + pn_offset, &token_len);
|
|
pn_offset += token_len;
|
|
if ((pn_offset + tvb_get_size(data[pn_offset])) >= data_len) return false;
|
|
pn_offset += tvb_get_varint(data + pn_offset, &payload_len);
|
|
if (payload_len<20 || (pn_offset + payload_len)>data_len) return false;
|
|
|
|
aes_init_keygen_tables();
|
|
|
|
uint8_t sample_enc[16];
|
|
aes_context ctx;
|
|
if (aes_setkey(&ctx, 1, aeshp, sizeof(aeshp)) || aes_cipher(&ctx, data + pn_offset + 4, sample_enc)) return false;
|
|
|
|
uint8_t mask[5];
|
|
memcpy(mask, sample_enc, sizeof(mask));
|
|
|
|
uint8_t packet0 = data[0] ^ (mask[0] & 0x0f);
|
|
uint8_t pkn_len = (packet0 & 0x03) + 1;
|
|
|
|
uint8_t pkn_bytes[4];
|
|
memcpy(pkn_bytes, data + pn_offset, pkn_len);
|
|
uint32_t pkn = 0;
|
|
for (uint8_t i = 0; i < pkn_len; i++) pkn |= (uint32_t)(pkn_bytes[i] ^ mask[1 + i]) << (8 * (pkn_len - 1 - i));
|
|
|
|
phton64(aesiv + sizeof(aesiv) - 8, pntoh64(aesiv + sizeof(aesiv) - 8) ^ pkn);
|
|
|
|
size_t cryptlen = payload_len - pkn_len - 16;
|
|
if (cryptlen > *clean_len) return false;
|
|
*clean_len = cryptlen;
|
|
const uint8_t *decrypt_begin = data + pn_offset + pkn_len;
|
|
|
|
uint8_t atag[16],header[256];
|
|
size_t header_len = pn_offset + pkn_len;
|
|
if (header_len > sizeof(header)) return false; // not likely header will be so large
|
|
memcpy(header, data, header_len);
|
|
header[0] = packet0;
|
|
for(uint8_t i = 0; i < pkn_len; i++) header[header_len - 1 - i] = (uint8_t)(pkn >> (8 * i));
|
|
|
|
if (aes_gcm_crypt(AES_DECRYPT, clean, decrypt_begin, cryptlen, aeskey, sizeof(aeskey), aesiv, sizeof(aesiv), header, header_len, atag, sizeof(atag)))
|
|
return false;
|
|
|
|
// check if message was decrypted correctly : good keys , no data corruption
|
|
return !memcmp(data + pn_offset + pkn_len + cryptlen, atag, 16);
|
|
}
|
|
|
|
bool QUICDefragCrypto(const uint8_t *clean,size_t clean_len, uint8_t *defrag,size_t *defrag_len)
|
|
{
|
|
// Crypto frame can be split into multiple chunks
|
|
// chromium randomly splits it and pads with zero/one bytes to force support the standard
|
|
// mozilla does not split
|
|
|
|
if (*defrag_len<10) return false;
|
|
uint8_t *defrag_data = defrag+10;
|
|
size_t defrag_data_len = *defrag_len-10;
|
|
|
|
uint8_t ft;
|
|
uint64_t offset,sz,szmax=0,zeropos=0,pos=0;
|
|
bool found=false;
|
|
|
|
while(pos<clean_len)
|
|
{
|
|
ft = clean[pos];
|
|
pos++;
|
|
if (ft>1) // 00 - padding, 01 - ping
|
|
{
|
|
if (ft!=6) return false; // dont want to know all possible frame type formats
|
|
|
|
if (pos>=clean_len) return false;
|
|
|
|
if ((pos+tvb_get_size(clean[pos])>=clean_len)) return false;
|
|
pos += tvb_get_varint(clean+pos, &offset);
|
|
|
|
if ((pos+tvb_get_size(clean[pos])>clean_len)) return false;
|
|
pos += tvb_get_varint(clean+pos, &sz);
|
|
if ((pos+sz)>clean_len) return false;
|
|
|
|
if ((offset+sz)>defrag_data_len) return false;
|
|
if (zeropos < offset)
|
|
// make sure no uninitialized gaps exist in case of not full fragment coverage
|
|
memset(defrag_data+zeropos,0,offset-zeropos);
|
|
if ((offset+sz) > zeropos)
|
|
zeropos=offset+sz;
|
|
memcpy(defrag_data+offset,clean+pos,sz);
|
|
if ((offset+sz) > szmax) szmax = offset+sz;
|
|
|
|
found=true;
|
|
pos+=sz;
|
|
}
|
|
}
|
|
if (found)
|
|
{
|
|
defrag[0] = 6;
|
|
defrag[1] = 0; // offset
|
|
// 2..9 - length 64 bit
|
|
// +10 - data start
|
|
phton64(defrag+2,szmax);
|
|
defrag[2] |= 0xC0; // 64 bit value
|
|
*defrag_len = (size_t)(szmax+10);
|
|
}
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
bool QUICExtractHostFromInitial(const uint8_t *data, size_t data_len, char *host, size_t len_host, bool *bDecryptOK, bool *bIsCryptoHello)
|
|
{
|
|
if (bIsCryptoHello) *bIsCryptoHello=false;
|
|
if (bDecryptOK) *bDecryptOK=false;
|
|
|
|
uint8_t clean[1500];
|
|
size_t clean_len = sizeof(clean);
|
|
if (!QUICDecryptInitial(data,data_len,clean,&clean_len)) return false;
|
|
|
|
if (bDecryptOK) *bDecryptOK=true;
|
|
|
|
uint8_t defrag[1500];
|
|
size_t defrag_len = sizeof(defrag);
|
|
if (!QUICDefragCrypto(clean,clean_len,defrag,&defrag_len)) return false;
|
|
|
|
size_t hello_offset, hello_len;
|
|
if (!IsQUICCryptoHello(defrag, defrag_len, &hello_offset, &hello_len)) return false;
|
|
if (bIsCryptoHello) *bIsCryptoHello=true;
|
|
|
|
return TLSHelloExtractHostFromHandshake(defrag + hello_offset, hello_len, host, len_host, NULL, true);
|
|
}
|
|
*/
|
|
|
|
bool IsQUICInitial(const uint8_t *data, size_t len)
|
|
{
|
|
// too small packets are not likely to be initials with client hello
|
|
// long header, fixed bit
|
|
if (len < 256 || (data[0] & 0xC0)!=0xC0) return false;
|
|
|
|
uint32_t ver = QUICExtractVersion(data,len);
|
|
if (QUICDraftVersion(ver) < 11) return false;
|
|
|
|
// quic v1 : initial packets are 00b
|
|
// quic v2 : initial packets are 01b
|
|
if ((data[0] & 0x30) != (is_quic_v2(ver) ? 0x10 : 0x00)) return false;
|
|
|
|
uint64_t offset=5, sz;
|
|
|
|
// DCID. must be present
|
|
if (!data[offset] || data[offset] > QUIC_MAX_CID_LENGTH) return false;
|
|
offset += 1 + data[offset];
|
|
|
|
// SCID
|
|
if (data[offset] > QUIC_MAX_CID_LENGTH) return false;
|
|
offset += 1 + data[offset];
|
|
|
|
// token length
|
|
offset += tvb_get_varint(data + offset, &sz);
|
|
offset += sz;
|
|
if (offset >= len) return false;
|
|
|
|
// payload length
|
|
if ((offset + tvb_get_size(data[offset])) > len) return false;
|
|
tvb_get_varint(data + offset, &sz);
|
|
offset += sz;
|
|
if (offset > len) return false;
|
|
|
|
// client hello cannot be too small. likely ACK
|
|
return sz>=96;
|
|
}
|
|
|
|
|
|
|
|
bool IsWireguardHandshakeInitiation(const uint8_t *data, size_t len)
|
|
{
|
|
return len==148 && data[0]==1 && data[1]==0 && data[2]==0 && data[3]==0;
|
|
}
|
|
bool IsDhtD1(const uint8_t *data, size_t len)
|
|
{
|
|
return len>=7 && data[0]=='d' && data[1]=='1' && data[len-1]=='e';
|
|
}
|