history purge

tpws/protocol.c

@@ -0,0 +1,132 @@
+#define _GNU_SOURCE
+
+#include "protocol.h"
+#include "helpers.h"
+#include <string.h>
+#include <ctype.h>
+#include <arpa/inet.h>
+#include <string.h>
+
+const char *http_methods[] = { "GET /","POST /","HEAD /","OPTIONS /","PUT /","DELETE /","CONNECT /","TRACE /",NULL };
+bool IsHttp(const uint8_t *data, size_t len)
+{
+	const char **method;
+	size_t method_len;
+	for (method = http_methods; *method; method++)
+	{
+		method_len = strlen(*method);
+		if (method_len <= len && !memcmp(data, *method, method_len))
+			return true;
+	}
+	return false;
+}
+bool HttpExtractHost(const uint8_t *data, size_t len, char *host, size_t len_host)
+{
+	const uint8_t *p, *s, *e=data+len;
+
+	p = (uint8_t*)strncasestr((char*)data, "\nHost:", len);
+	if (!p) return false;
+	p+=6;
+	while(p<e && (*p==' ' || *p=='\t')) p++;
+	s=p;
+	while(s<e && (*s!='\r' && *s!='\n' && *s!=' ' && *s!='\t')) s++;
+	if (s>p)
+	{
+		size_t slen = s-p;
+		if (host && len_host)
+		{
+			if (slen>=len_host) slen=len_host-1;
+			for(size_t i=0;i<slen;i++) host[i]=tolower(p[i]);
+			host[slen]=0;
+		}
+		return true;
+	}
+	return false;
+}
+bool IsTLSClientHello(const uint8_t *data, size_t len)
+{
+	return len>=6 && data[0]==0x16 && data[1]==0x03 && data[2]==0x01 && data[5]==0x01 && (ntohs(*(uint16_t*)(data+3))+5)<=len;
+}
+bool TLSFindExt(const uint8_t *data, size_t len, uint16_t type, const uint8_t **ext, size_t *len_ext)
+{
+	// +0
+	// u8	ContentType: Handshake
+	// u16	Version: TLS1.0
+	// u16	Length
+	// +5 
+	// u8	HandshakeType: ClientHello
+	// u24	Length
+	// u16	Version
+	// c[32] random
+	// u8	SessionIDLength
+	//	<SessionID>
+	// u16	CipherSuitesLength
+	//	<CipherSuites>
+	// u8	CompressionMethodsLength
+	//	<CompressionMethods>
+	// u16	ExtensionsLength
+
+	size_t l,ll;
+
+	l = 1+2+2+1+3+2+32;
+	// SessionIDLength
+	if (len<(l+1)) return false;
+	ll = data[6]<<16 | data[7]<<8 | data[8]; // HandshakeProtocol length
+	if (len<(ll+9)) return false;
+	l += data[l]+1;
+	// CipherSuitesLength
+	if (len<(l+2)) return false;
+	l += ntohs(*(uint16_t*)(data+l))+2;
+	// CompressionMethodsLength
+	if (len<(l+1)) return false;
+	l += data[l]+1;
+	// ExtensionsLength
+	if (len<(l+2)) return false;
+
+	data+=l; len-=l;
+	l=ntohs(*(uint16_t*)data);
+	data+=2; len-=2;
+	if (l<len) return false;
+
+	uint16_t ntype=htons(type);
+	while(l>=4)
+	{
+		uint16_t etype=*(uint16_t*)data;
+		size_t elen=ntohs(*(uint16_t*)(data+2));
+		data+=4; l-=4;
+		if (l<elen) break;
+		if (etype==ntype)
+		{
+			if (ext && len_ext)
+			{
+				*ext = data;
+				*len_ext = elen;
+			}
+			return true;
+		}
+		data+=elen; l-=elen;
+	}
+
+	return false;
+}
+bool TLSHelloExtractHost(const uint8_t *data, size_t len, char *host, size_t len_host)
+{
+	const uint8_t *ext;
+	size_t elen;
+
+	if (!TLSFindExt(data,len,0,&ext,&elen)) return false;
+	// u16	data+0 - name list length
+	// u8	data+2 - server name type. 0=host_name
+	// u16	data+3 - server name length
+	if (elen<5 || ext[2]!=0) return false;
+	size_t slen = ntohs(*(uint16_t*)(ext+3));
+	ext+=5; elen-=5;
+	if (slen<elen) return false;
+	if (ext && len_host)
+	{
+		if (slen>=len_host) slen=len_host-1;
+		for(size_t i=0;i<slen;i++) host[i]=tolower(ext[i]);
+		host[slen]=0;
+	}
+	return true;
+}