Ashley Mills
cyassl re-port with cellular comms, PSK test
Dependencies: VodafoneUSBModem_bleedingedge2 mbed-rtos mbed-src
cyassllib/sniffer.c
- Committer:
- ashleymills
- Date:
- 2013-04-26
- Revision:
- 1:b211d97b0068
- Parent:
- 0:e979170e02e7
File content as of revision 1:b211d97b0068:
/* sniffer.c
*
* Copyright (C) 2006-2012 Sawtooth Consulting Ltd.
*
* This file is part of CyaSSL.
*
* CyaSSL is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* CyaSSL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifdef CYASSL_SNIFFER
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <assert.h>
#include <time.h>
#ifndef _WIN32
#include <arpa/inet.h>
#endif
#ifdef _WIN32
#define SNPRINTF _snprintf
#else
#define SNPRINTF snprintf
#endif
#include <cyassl/openssl/ssl.h>
#include <cyassl/internal.h>
#include <cyassl/error.h>
#include <cyassl/sniffer.h>
#include <cyassl/sniffer_error.h>
#ifndef min
static INLINE word32 min(word32 a, word32 b)
{
return a > b ? b : a;
}
#endif
/* Misc constants */
enum {
MAX_SERVER_ADDRESS = 128, /* maximum server address length */
MAX_ERROR_LEN = 80, /* maximum error length */
ETHER_IF_ADDR_LEN = 6, /* ethernet interface address length */
LOCAL_IF_ADDR_LEN = 4, /* localhost interface address length, !windows */
TCP_PROTO = 6, /* TCP_PROTOCOL */
IP_HDR_SZ = 20, /* IP header legnth, min */
TCP_HDR_SZ = 20, /* TCP header legnth, min */
IPV4 = 4, /* IP version 4 */
TCP_PROTOCOL = 6, /* TCP Protocol id */
TRACE_MSG_SZ = 80, /* Trace Message buffer size */
HASH_SIZE = 499, /* Session Hash Table Rows */
PSEUDO_HDR_SZ = 12, /* TCP Pseudo Header size in bytes */
FATAL_ERROR_STATE = 1, /* SnifferSession fatal error state */
SNIFFER_TIMEOUT = 900, /* Cache unclosed Sessions for 15 minutes */
TICKET_HINT_LEN = 4, /* Session Ticket Hint length */
EXT_TYPE_SZ = 2, /* Extension length */
MAX_INPUT_SZ = MAX_RECORD_SIZE + COMP_EXTRA + MAX_MSG_EXTRA +
MTU_EXTRA, /* Max input sz of reassembly */
TICKET_EXT_ID = 0x23 /* Session Ticket Extension ID */
};
#ifdef _WIN32
static HMODULE dllModule; /* for error string resources */
BOOL APIENTRY DllMain( HMODULE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
static int didInit = 0;
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
if (didInit == 0) {
dllModule = hModule;
ssl_InitSniffer();
didInit = 1;
}
break;
case DLL_THREAD_ATTACH:
break;
case DLL_THREAD_DETACH:
break;
case DLL_PROCESS_DETACH:
if (didInit) {
ssl_FreeSniffer();
didInit = 0;
}
break;
}
return TRUE;
}
#endif /* _WIN32 */
static int TraceOn = 0; /* Trace is off by default */
static FILE* TraceFile = 0;
/* windows uses .rc table for this */
#ifndef _WIN32
static const char* const msgTable[] =
{
/* 1 */
"Out of Memory",
"New SSL Sniffer Server Registered",
"Checking IP Header",
"SSL Sniffer Server Not Registered",
"Checking TCP Header",
/* 6 */
"SSL Sniffer Server Port Not Registered",
"RSA Private Decrypt Error",
"RSA Private Decode Error",
"Set Cipher Spec Error",
"Server Hello Input Malformed",
/* 11 */
"Couldn't Resume Session Error",
"Server Did Resumption",
"Client Hello Input Malformed",
"Client Trying to Resume",
"Handshake Input Malformed",
/* 16 */
"Got Hello Verify msg",
"Got Server Hello msg",
"Got Cert Request msg",
"Got Server Key Exchange msg",
"Got Cert msg",
/* 21 */
"Got Server Hello Done msg",
"Got Finished msg",
"Got Client Hello msg",
"Got Client Key Exchange msg",
"Got Cert Verify msg",
/* 26 */
"Got Unknown Handshake msg",
"New SSL Sniffer Session created",
"Couldn't create new SSL",
"Got a Packet to decode",
"No data present",
/* 31 */
"Session Not Found",
"Got an Old Client Hello msg",
"Old Client Hello Input Malformed",
"Old Client Hello OK",
"Bad Old Client Hello",
/* 36 */
"Bad Record Header",
"Record Header Input Malformed",
"Got a HandShake msg",
"Bad HandShake msg",
"Got a Change Cipher Spec msg",
/* 41 */
"Got Application Data msg",
"Bad Application Data",
"Got an Alert msg",
"Another msg to Process",
"Removing Session From Table",
/* 46 */
"Bad Key File",
"Wrong IP Version",
"Wrong Protocol type",
"Packet Short for header processing",
"Got Unknown Record Type",
/* 51 */
"Can't Open Trace File",
"Session in Fatal Error State",
"Partial SSL record received",
"Buffer Error, malformed input",
"Added to Partial Input",
/* 56 */
"Received a Duplicate Packet",
"Received an Out of Order Packet",
"Received an Overlap Duplicate Packet",
"Received an Overlap Reassembly Begin Duplicate Packet",
"Received an Overlap Reassembly End Duplicate Packet",
/* 61 */
"Missed the Client Hello Entirely",
"Got Hello Request msg",
"Got Session Ticket msg",
"Bad Input",
"Bad Decrypt Type",
/* 66 */
"Bad Finished Message Processing",
"Bad Compression Type",
"Bad DeriveKeys Error",
"Saw ACK for Missing Packet Error"
};
/* *nix version uses table above */
static void GetError(int idx, char* str)
{
XSTRNCPY(str, msgTable[idx - 1], MAX_ERROR_LEN);
}
#else /* _WIN32 */
/* Windows version uses .rc table */
static void GetError(int idx, char* buffer)
{
if (!LoadStringA(dllModule, idx, buffer, MAX_ERROR_LEN))
buffer[0] = 0;
}
#endif /* _WIN32 */
/* Packet Buffer for reassembly list and ready list */
typedef struct PacketBuffer {
word32 begin; /* relative sequence begin */
word32 end; /* relative sequence end */
byte* data; /* actual data */
struct PacketBuffer* next; /* next on reassembly list or ready list */
} PacketBuffer;
/* Sniffer Server holds info for each server/port monitored */
typedef struct SnifferServer {
SSL_CTX* ctx; /* SSL context */
char address[MAX_SERVER_ADDRESS]; /* passed in server address */
word32 server; /* netowrk order address */
int port; /* server port */
struct SnifferServer* next; /* for list */
} SnifferServer;
/* Session Flags */
typedef struct Flags {
byte side; /* which end is current packet headed */
byte serverCipherOn; /* indicates whether cipher is active */
byte clientCipherOn; /* indicates whether cipher is active */
byte resuming; /* did this session come from resumption */
byte cached; /* have we cached this session yet */
byte clientHello; /* processed client hello yet, for SSLv2 */
byte finCount; /* get both FINs before removing */
byte fatalError; /* fatal error state */
} Flags;
/* Out of Order FIN caputre */
typedef struct FinCaputre {
word32 cliFinSeq; /* client relative sequence FIN 0 is no */
word32 srvFinSeq; /* server relative sequence FIN, 0 is no */
byte cliCounted; /* did we count yet, detects duplicates */
byte srvCounted; /* did we count yet, detects duplicates */
} FinCaputre;
/* Sniffer Session holds info for each client/server SSL/TLS session */
typedef struct SnifferSession {
SnifferServer* context; /* server context */
SSL* sslServer; /* SSL server side decode */
SSL* sslClient; /* SSL client side decode */
word32 server; /* server address in network byte order */
word32 client; /* client address in network byte order */
word16 srvPort; /* server port */
word16 cliPort; /* client port */
word32 cliSeqStart; /* client start sequence */
word32 srvSeqStart; /* server start sequence */
word32 cliExpected; /* client expected sequence (relative) */
word32 srvExpected; /* server expected sequence (relative) */
FinCaputre finCaputre; /* retain out of order FIN s */
Flags flags; /* session flags */
time_t bornOn; /* born on ticks */
PacketBuffer* cliReassemblyList; /* client out of order packets */
PacketBuffer* srvReassemblyList; /* server out of order packets */
struct SnifferSession* next; /* for hash table list */
byte* ticketID; /* mac ID of session ticket */
} SnifferSession;
/* Sniffer Server List and mutex */
static SnifferServer* ServerList = 0;
static CyaSSL_Mutex ServerListMutex;
/* Session Hash Table, mutex, and count */
static SnifferSession* SessionTable[HASH_SIZE];
static CyaSSL_Mutex SessionMutex;
static int SessionCount = 0;
/* Initialize overall Sniffer */
void ssl_InitSniffer(void)
{
CyaSSL_Init();
InitMutex(&ServerListMutex);
InitMutex(&SessionMutex);
}
/* Free Sniffer Server's resources/self */
static void FreeSnifferServer(SnifferServer* srv)
{
if (srv)
SSL_CTX_free(srv->ctx);
free(srv);
}
/* free PacketBuffer's resources/self */
static void FreePacketBuffer(PacketBuffer* del)
{
if (del) {
free(del->data);
free(del);
}
}
/* remove PacketBuffer List */
static void FreePacketList(PacketBuffer* in)
{
if (in) {
PacketBuffer* del;
PacketBuffer* packet = in;
while (packet) {
del = packet;
packet = packet->next;
FreePacketBuffer(del);
}
}
}
/* Free Sniffer Session's resources/self */
static void FreeSnifferSession(SnifferSession* session)
{
if (session) {
SSL_free(session->sslClient);
SSL_free(session->sslServer);
FreePacketList(session->cliReassemblyList);
FreePacketList(session->srvReassemblyList);
free(session->ticketID);
}
free(session);
}
/* Free overall Sniffer */
void ssl_FreeSniffer(void)
{
SnifferServer* srv;
SnifferServer* removeServer;
SnifferSession* session;
SnifferSession* removeSession;
int i;
LockMutex(&ServerListMutex);
LockMutex(&SessionMutex);
srv = ServerList;
while (srv) {
removeServer = srv;
srv = srv->next;
FreeSnifferServer(removeServer);
}
for (i = 0; i < HASH_SIZE; i++) {
session = SessionTable[i];
while (session) {
removeSession = session;
session = session->next;
FreeSnifferSession(removeSession);
}
}
UnLockMutex(&SessionMutex);
UnLockMutex(&ServerListMutex);
FreeMutex(&SessionMutex);
FreeMutex(&ServerListMutex);
CyaSSL_Cleanup();
}
/* Initialize a SnifferServer */
static void InitSnifferServer(SnifferServer* sniffer)
{
sniffer->ctx = 0;
XMEMSET(sniffer->address, 0, MAX_SERVER_ADDRESS);
sniffer->server = 0;
sniffer->port = 0;
sniffer->next = 0;
}
/* Initialize session flags */
static void InitFlags(Flags* flags)
{
flags->side = 0;
flags->serverCipherOn = 0;
flags->clientCipherOn = 0;
flags->resuming = 0;
flags->cached = 0;
flags->clientHello = 0;
flags->finCount = 0;
flags->fatalError = 0;
}
/* Initialize FIN Capture */
static void InitFinCapture(FinCaputre* cap)
{
cap->cliFinSeq = 0;
cap->srvFinSeq = 0;
cap->cliCounted = 0;
cap->srvCounted = 0;
}
/* Initialize a Sniffer Session */
static void InitSession(SnifferSession* session)
{
session->context = 0;
session->sslServer = 0;
session->sslClient = 0;
session->server = 0;
session->client = 0;
session->srvPort = 0;
session->cliPort = 0;
session->cliSeqStart = 0;
session->srvSeqStart = 0;
session->cliExpected = 0;
session->srvExpected = 0;
session->bornOn = 0;
session->cliReassemblyList = 0;
session->srvReassemblyList = 0;
session->next = 0;
session->ticketID = 0;
InitFlags(&session->flags);
InitFinCapture(&session->finCaputre);
}
/* IP Info from IP Header */
typedef struct IpInfo {
int length; /* length of this header */
int total; /* total length of fragment */
word32 src; /* network order source address */
word32 dst; /* network order destination address */
} IpInfo;
/* TCP Info from TCP Header */
typedef struct TcpInfo {
int srcPort; /* source port */
int dstPort; /* source port */
int length; /* length of this header */
word32 sequence; /* sequence number */
word32 ackNumber; /* ack number */
byte fin; /* FIN set */
byte rst; /* RST set */
byte syn; /* SYN set */
byte ack; /* ACK set */
} TcpInfo;
/* Tcp Pseudo Header for Checksum calculation */
typedef struct TcpPseudoHdr {
word32 src; /* source address */
word32 dst; /* destination address */
byte rsv; /* reserved, always 0 */
byte protocol; /* IP protocol */
word16 legnth; /* tcp header length + data length (doesn't include */
/* pseudo header length) network order */
} TcpPseudoHdr;
/* Password Setting Callback */
static int SetPassword(char* passwd, int sz, int rw, void* userdata)
{
(void)rw;
XSTRNCPY(passwd, userdata, sz);
return (int)XSTRLEN(userdata);
}
/* Ethernet Header */
typedef struct EthernetHdr {
byte dst[ETHER_IF_ADDR_LEN]; /* destination host address */
byte src[ETHER_IF_ADDR_LEN]; /* source host address */
word16 type; /* IP, ARP, etc */
} EthernetHdr;
/* IP Header */
typedef struct IpHdr {
byte ver_hl; /* version/header length */
byte tos; /* type of service */
word16 length; /* total length */
word16 id; /* identification */
word16 offset; /* fragment offset field */
byte ttl; /* time to live */
byte protocol; /* protocol */
word16 sum; /* checksum */
word32 src; /* source address */
word32 dst; /* destination address */
} IpHdr;
#define IP_HL(ip) ( (((ip)->ver_hl) & 0x0f) * 4)
#define IP_V(ip) ( ((ip)->ver_hl) >> 4)
/* TCP Header */
typedef struct TcpHdr {
word16 srcPort; /* source port */
word16 dstPort; /* destination port */
word32 sequence; /* sequence number */
word32 ack; /* acknoledgment number */
byte offset; /* data offset, reserved */
byte flags; /* option flags */
word16 window; /* window */
word16 sum; /* checksum */
word16 urgent; /* urgent pointer */
} TcpHdr;
#define TCP_LEN(tcp) ( (((tcp)->offset & 0xf0) >> 4) * 4)
#define TCP_FIN 0x01
#define TCP_SYN 0x02
#define TCP_RST 0x04
#define TCP_ACK 0x10
/* Use platform specific GetError to write to tracfile if tracing */
static void Trace(int idx)
{
if (TraceOn) {
char myBuffer[MAX_ERROR_LEN];
GetError(idx, myBuffer);
fprintf(TraceFile, "\t%s\n", myBuffer);
#ifdef DEBUG_SNIFFER
fprintf(stderr, "\t%s\n", myBuffer);
#endif
}
}
/* Show TimeStamp for beginning of packet Trace */
static void TraceHeader(void)
{
if (TraceOn) {
time_t ticks = time(NULL);
fprintf(TraceFile, "\n%s", ctime(&ticks));
}
}
/* Show Set Server info for Trace */
static void TraceSetServer(const char* srv, int port, const char* keyFile)
{
if (TraceOn) {
fprintf(TraceFile, "\tTrying to install a new Sniffer Server with\n");
fprintf(TraceFile, "\tserver: %s, port: %d, keyFile: %s\n", srv, port,
keyFile);
}
}
/* Trace got packet number */
static void TracePacket(void)
{
if (TraceOn) {
static word32 packetNumber = 0;
fprintf(TraceFile, "\tGot a Packet to decode, packet %u\n",
++packetNumber);
}
}
/* Convert network byte order address into human readable */
static char* IpToS(word32 addr, char* str)
{
byte* p = (byte*)&addr;
SNPRINTF(str, TRACE_MSG_SZ, "%d.%d.%d.%d", p[0], p[1], p[2], p[3]);
return str;
}
/* Show destination and source address from Ip Hdr for packet Trace */
static void TraceIP(IpHdr* iphdr)
{
if (TraceOn) {
char src[TRACE_MSG_SZ];
char dst[TRACE_MSG_SZ];
fprintf(TraceFile, "\tdst:%s src:%s\n", IpToS(iphdr->dst, dst),
IpToS(iphdr->src, src));
}
}
/* Show destination and source port from Tcp Hdr for packet Trace */
static void TraceTcp(TcpHdr* tcphdr)
{
if (TraceOn) {
fprintf(TraceFile, "\tdstPort:%u srcPort:%u\n", ntohs(tcphdr->dstPort),
ntohs(tcphdr->srcPort));
}
}
/* Show sequence and payload length for Trace */
static void TraceSequence(word32 seq, int len)
{
if (TraceOn) {
fprintf(TraceFile, "\tSequence:%u, payload length:%d\n", seq, len);
}
}
/* Show sequence and payload length for Trace */
static void TraceAck(word32 ack, word32 expected)
{
if (TraceOn) {
fprintf(TraceFile, "\tAck:%u Expected:%u\n", ack, expected);
}
}
/* Show relative expected and relative received sequences */
static void TraceRelativeSequence(word32 expected, word32 got)
{
if (TraceOn) {
fprintf(TraceFile, "\tExpected sequence:%u, received sequence:%u\n",
expected, got);
}
}
/* Show server sequence startup from SYN */
static void TraceServerSyn(word32 seq)
{
if (TraceOn) {
fprintf(TraceFile, "\tServer SYN, Sequence Start:%u\n", seq);
}
}
/* Show client sequence startup from SYN */
static void TraceClientSyn(word32 seq)
{
if (TraceOn) {
fprintf(TraceFile, "\tClient SYN, Sequence Start:%u\n", seq);
}
}
/* Show client FIN capture */
static void TraceClientFin(word32 finSeq, word32 relSeq)
{
if (TraceOn) {
fprintf(TraceFile, "\tClient FIN capture:%u, current SEQ:%u\n",
finSeq, relSeq);
}
}
/* Show server FIN capture */
static void TraceServerFin(word32 finSeq, word32 relSeq)
{
if (TraceOn) {
fprintf(TraceFile, "\tServer FIN capture:%u, current SEQ:%u\n",
finSeq, relSeq);
}
}
/* Show number of SSL data bytes decoded, could be 0 (ok) */
static void TraceGotData(int bytes)
{
if (TraceOn) {
fprintf(TraceFile, "\t%d bytes of SSL App data processed\n", bytes);
}
}
/* Show bytes added to old SSL App data */
static void TraceAddedData(int newBytes, int existingBytes)
{
if (TraceOn) {
fprintf(TraceFile,
"\t%d bytes added to %d exisiting bytes in User Buffer\n",
newBytes, existingBytes);
}
}
/* Show Stale Session */
static void TraceStaleSession(void)
{
if (TraceOn) {
fprintf(TraceFile, "\tFound a stale session\n");
}
}
/* Show Finding Stale Sessions */
static void TraceFindingStale(void)
{
if (TraceOn) {
fprintf(TraceFile, "\tTrying to find Stale Sessions\n");
}
}
/* Show Removed Session */
static void TraceRemovedSession(void)
{
if (TraceOn) {
fprintf(TraceFile, "\tRemoved it\n");
}
}
/* Set user error string */
static void SetError(int idx, char* error, SnifferSession* session, int fatal)
{
GetError(idx, error);
Trace(idx);
if (session && fatal == FATAL_ERROR_STATE)
session->flags.fatalError = 1;
}
/* See if this IPV4 network order address has been registered */
/* return 1 is true, 0 is false */
static int IsServerRegistered(word32 addr)
{
int ret = 0; /* false */
SnifferServer* sniffer;
LockMutex(&ServerListMutex);
sniffer = ServerList;
while (sniffer) {
if (sniffer->server == addr) {
ret = 1;
break;
}
sniffer = sniffer->next;
}
UnLockMutex(&ServerListMutex);
return ret;
}
/* See if this port has been registered to watch */
/* return 1 is true, 0 is false */
static int IsPortRegistered(word32 port)
{
int ret = 0; /* false */
SnifferServer* sniffer;
LockMutex(&ServerListMutex);
sniffer = ServerList;
while (sniffer) {
if (sniffer->port == (int)port) {
ret = 1;
break;
}
sniffer = sniffer->next;
}
UnLockMutex(&ServerListMutex);
return ret;
}
/* Get SnifferServer from IP and Port */
static SnifferServer* GetSnifferServer(IpInfo* ipInfo, TcpInfo* tcpInfo)
{
SnifferServer* sniffer;
LockMutex(&ServerListMutex);
sniffer = ServerList;
while (sniffer) {
if (sniffer->port == tcpInfo->srcPort && sniffer->server == ipInfo->src)
break;
if (sniffer->port == tcpInfo->dstPort && sniffer->server == ipInfo->dst)
break;
sniffer = sniffer->next;
}
UnLockMutex(&ServerListMutex);
return sniffer;
}
/* Hash the Session Info, return hash row */
static word32 SessionHash(IpInfo* ipInfo, TcpInfo* tcpInfo)
{
word32 hash = ipInfo->src * ipInfo->dst;
hash *= tcpInfo->srcPort * tcpInfo->dstPort;
return hash % HASH_SIZE;
}
/* Get Exisiting SnifferSession from IP and Port */
static SnifferSession* GetSnifferSession(IpInfo* ipInfo, TcpInfo* tcpInfo)
{
SnifferSession* session;
word32 row = SessionHash(ipInfo, tcpInfo);
assert(row <= HASH_SIZE);
LockMutex(&SessionMutex);
session = SessionTable[row];
while (session) {
if (session->server == ipInfo->src && session->client == ipInfo->dst &&
session->srvPort == tcpInfo->srcPort &&
session->cliPort == tcpInfo->dstPort)
break;
if (session->client == ipInfo->src && session->server == ipInfo->dst &&
session->cliPort == tcpInfo->srcPort &&
session->srvPort == tcpInfo->dstPort)
break;
session = session->next;
}
UnLockMutex(&SessionMutex);
/* determine side */
if (session) {
if (ipInfo->dst == session->context->server &&
tcpInfo->dstPort == session->context->port)
session->flags.side = SERVER_END;
else
session->flags.side = CLIENT_END;
}
return session;
}
/* Sets the private key for a specific server and port */
/* returns 0 on success, -1 on error */
int ssl_SetPrivateKey(const char* serverAddress, int port, const char* keyFile,
int typeKey, const char* password, char* error)
{
int ret;
int type = (typeKey == FILETYPE_PEM) ? SSL_FILETYPE_PEM :
SSL_FILETYPE_ASN1;
SnifferServer* sniffer;
TraceHeader();
TraceSetServer(serverAddress, port, keyFile);
sniffer = (SnifferServer*)malloc(sizeof(SnifferServer));
if (sniffer == NULL) {
SetError(MEMORY_STR, error, NULL, 0);
return -1;
}
InitSnifferServer(sniffer);
XSTRNCPY(sniffer->address, serverAddress, MAX_SERVER_ADDRESS);
sniffer->server = inet_addr(sniffer->address);
sniffer->port = port;
/* start in client mode since SSL_new needs a cert for server */
sniffer->ctx = SSL_CTX_new(SSLv3_client_method());
if (!sniffer->ctx) {
SetError(MEMORY_STR, error, NULL, 0);
FreeSnifferServer(sniffer);
return -1;
}
if (password){
SSL_CTX_set_default_passwd_cb(sniffer->ctx, SetPassword);
SSL_CTX_set_default_passwd_cb_userdata(sniffer->ctx, (void*)password);
}
ret = SSL_CTX_use_PrivateKey_file(sniffer->ctx, keyFile, type);
if (ret != SSL_SUCCESS) {
SetError(KEY_FILE_STR, error, NULL, 0);
FreeSnifferServer(sniffer);
return -1;
}
Trace(NEW_SERVER_STR);
LockMutex(&ServerListMutex);
sniffer->next = ServerList;
ServerList = sniffer;
UnLockMutex(&ServerListMutex);
return 0;
}
/* Check IP Header for IPV4, TCP, and a registered server address */
/* returns 0 on success, -1 on error */
static int CheckIpHdr(IpHdr* iphdr, IpInfo* info, char* error)
{
int version = IP_V(iphdr);
TraceIP(iphdr);
Trace(IP_CHECK_STR);
if (version != IPV4) {
SetError(BAD_IPVER_STR, error, NULL, 0);
return -1;
}
if (iphdr->protocol != TCP_PROTOCOL) {
SetError(BAD_PROTO_STR, error, NULL, 0);
return -1;
}
if (!IsServerRegistered(iphdr->src) && !IsServerRegistered(iphdr->dst)) {
SetError(SERVER_NOT_REG_STR, error, NULL, 0);
return -1;
}
info->length = IP_HL(iphdr);
info->total = ntohs(iphdr->length);
info->src = iphdr->src;
info->dst = iphdr->dst;
return 0;
}
/* Check TCP Header for a registered port */
/* returns 0 on success, -1 on error */
static int CheckTcpHdr(TcpHdr* tcphdr, TcpInfo* info, char* error)
{
TraceTcp(tcphdr);
Trace(TCP_CHECK_STR);
info->srcPort = ntohs(tcphdr->srcPort);
info->dstPort = ntohs(tcphdr->dstPort);
info->length = TCP_LEN(tcphdr);
info->sequence = ntohl(tcphdr->sequence);
info->fin = tcphdr->flags & TCP_FIN;
info->rst = tcphdr->flags & TCP_RST;
info->syn = tcphdr->flags & TCP_SYN;
info->ack = tcphdr->flags & TCP_ACK;
if (info->ack)
info->ackNumber = ntohl(tcphdr->ack);
if (!IsPortRegistered(info->srcPort) && !IsPortRegistered(info->dstPort)) {
SetError(SERVER_PORT_NOT_REG_STR, error, NULL, 0);
return -1;
}
return 0;
}
/* Decode Record Layer Header */
static int GetRecordHeader(const byte* input, RecordLayerHeader* rh, int* size)
{
XMEMCPY(rh, input, RECORD_HEADER_SZ);
*size = (rh->length[0] << 8) | rh->length[1];
if (*size > (MAX_RECORD_SIZE + COMP_EXTRA + MAX_MSG_EXTRA))
return LENGTH_ERROR;
return 0;
}
/* Process Client Key Exchange, RSA only */
static int ProcessClientKeyExchange(const byte* input, int* sslBytes,
SnifferSession* session, char* error)
{
word32 idx = 0;
RsaKey key;
int ret;
InitRsaKey(&key, 0);
ret = RsaPrivateKeyDecode(session->context->ctx->privateKey.buffer,
&idx, &key, session->context->ctx->privateKey.length);
if (ret == 0) {
int length = RsaEncryptSize(&key);
if (IsTLS(session->sslServer))
input += 2; /* tls pre length */
if (length > *sslBytes) {
SetError(PARTIAL_INPUT_STR, error, session, FATAL_ERROR_STATE);
FreeRsaKey(&key);
return -1;
}
ret = RsaPrivateDecrypt(input, length,
session->sslServer->arrays->preMasterSecret,SECRET_LEN, &key);
if (ret != SECRET_LEN) {
SetError(RSA_DECRYPT_STR, error, session, FATAL_ERROR_STATE);
FreeRsaKey(&key);
return -1;
}
ret = 0; /* not in error state */
session->sslServer->arrays->preMasterSz = SECRET_LEN;
/* store for client side as well */
XMEMCPY(session->sslClient->arrays->preMasterSecret,
session->sslServer->arrays->preMasterSecret, SECRET_LEN);
session->sslClient->arrays->preMasterSz = SECRET_LEN;
#ifdef SHOW_SECRETS
{
int i;
printf("pre master secret: ");
for (i = 0; i < SECRET_LEN; i++)
printf("%02x", session->sslServer->arrays->preMasterSecret[i]);
printf("\n");
}
#endif
}
else {
SetError(RSA_DECODE_STR, error, session, FATAL_ERROR_STATE);
FreeRsaKey(&key);
return -1;
}
if (SetCipherSpecs(session->sslServer) != 0) {
SetError(BAD_CIPHER_SPEC_STR, error, session, FATAL_ERROR_STATE);
FreeRsaKey(&key);
return -1;
}
if (SetCipherSpecs(session->sslClient) != 0) {
SetError(BAD_CIPHER_SPEC_STR, error, session, FATAL_ERROR_STATE);
FreeRsaKey(&key);
return -1;
}
MakeMasterSecret(session->sslServer);
MakeMasterSecret(session->sslClient);
#ifdef SHOW_SECRETS
{
int i;
printf("server master secret: ");
for (i = 0; i < SECRET_LEN; i++)
printf("%02x", session->sslServer->arrays->masterSecret[i]);
printf("\n");
printf("client master secret: ");
for (i = 0; i < SECRET_LEN; i++)
printf("%02x", session->sslClient->arrays->masterSecret[i]);
printf("\n");
printf("server suite = %d\n", session->sslServer->options.cipherSuite);
printf("client suite = %d\n", session->sslClient->options.cipherSuite);
}
#endif
FreeRsaKey(&key);
return ret;
}
/* Process Session Ticket */
static int ProcessSessionTicket(const byte* input, int* sslBytes,
SnifferSession* session, char* error)
{
word16 len;
/* make sure can read through hint and len */
if (TICKET_HINT_LEN + LENGTH_SZ > *sslBytes) {
SetError(BAD_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
input += TICKET_HINT_LEN; /* skip over hint */
*sslBytes -= TICKET_HINT_LEN;
len = (input[0] << 8) | input[1];
input += LENGTH_SZ;
*sslBytes -= LENGTH_SZ;
/* make sure can read through ticket */
if (len > *sslBytes || len < ID_LEN) {
SetError(BAD_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
/* store session with macID as sessionID */
session->sslServer->options.haveSessionId = 1;
XMEMCPY(session->sslServer->arrays->sessionID, input + len - ID_LEN,ID_LEN);
return 0;
}
/* Process Server Hello */
static int ProcessServerHello(const byte* input, int* sslBytes,
SnifferSession* session, char* error)
{
ProtocolVersion pv;
byte b;
int toRead = VERSION_SZ + RAN_LEN + ENUM_LEN;
int doResume = 0;
/* make sure we didn't miss ClientHello */
if (session->flags.clientHello == 0) {
SetError(MISSED_CLIENT_HELLO_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
/* make sure can read through session len */
if (toRead > *sslBytes) {
SetError(SERVER_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
XMEMCPY(&pv, input, VERSION_SZ);
input += VERSION_SZ;
*sslBytes -= VERSION_SZ;
session->sslServer->version = pv;
session->sslClient->version = pv;
XMEMCPY(session->sslServer->arrays->serverRandom, input, RAN_LEN);
XMEMCPY(session->sslClient->arrays->serverRandom, input, RAN_LEN);
input += RAN_LEN;
*sslBytes -= RAN_LEN;
b = *input++;
*sslBytes -= 1;
/* make sure can read through compression */
if ( (b + SUITE_LEN + ENUM_LEN) > *sslBytes) {
SetError(SERVER_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
if (b) {
XMEMCPY(session->sslServer->arrays->sessionID, input, ID_LEN);
session->sslServer->options.haveSessionId = 1;
}
input += b;
*sslBytes -= b;
/* cipher suite */
(void)*input++; /* eat first byte, always 0 */
b = *input++;
session->sslServer->options.cipherSuite = b;
session->sslClient->options.cipherSuite = b;
*sslBytes -= SUITE_LEN;
/* compression */
b = *input++;
*sslBytes -= ENUM_LEN;
if (b) {
SetError(BAD_COMPRESSION_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
if (session->sslServer->options.haveSessionId &&
XMEMCMP(session->sslServer->arrays->sessionID,
session->sslClient->arrays->sessionID, ID_LEN) == 0)
doResume = 1;
else if (session->sslClient->options.haveSessionId == 0 &&
session->sslServer->options.haveSessionId == 0 &&
session->ticketID)
doResume = 1;
if (session->ticketID && doResume) {
/* use ticketID to retrieve from session */
XMEMCPY(session->sslServer->arrays->sessionID,session->ticketID,ID_LEN);
}
if (doResume ) {
int ret = 0;
SSL_SESSION* resume = GetSession(session->sslServer,
session->sslServer->arrays->masterSecret);
if (resume == NULL) {
SetError(BAD_SESSION_RESUME_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
/* make sure client has master secret too */
XMEMCPY(session->sslClient->arrays->masterSecret,
session->sslServer->arrays->masterSecret, SECRET_LEN);
session->flags.resuming = 1;
Trace(SERVER_DID_RESUMPTION_STR);
if (SetCipherSpecs(session->sslServer) != 0) {
SetError(BAD_CIPHER_SPEC_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
if (SetCipherSpecs(session->sslClient) != 0) {
SetError(BAD_CIPHER_SPEC_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
if (session->sslServer->options.tls) {
ret = DeriveTlsKeys(session->sslServer);
ret += DeriveTlsKeys(session->sslClient);
}
else {
ret = DeriveKeys(session->sslServer);
ret += DeriveKeys(session->sslClient);
}
if (ret != 0) {
SetError(BAD_DERIVE_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
}
#ifdef SHOW_SECRETS
{
int i;
printf("cipher suite = 0x%02x\n",
session->sslServer->options.cipherSuite);
printf("server random: ");
for (i = 0; i < RAN_LEN; i++)
printf("%02x", session->sslServer->arrays->serverRandom[i]);
printf("\n");
}
#endif
return 0;
}
/* Process normal Client Hello */
static int ProcessClientHello(const byte* input, int* sslBytes,
SnifferSession* session, char* error)
{
byte bLen;
word16 len;
int toRead = VERSION_SZ + RAN_LEN + ENUM_LEN;
session->flags.clientHello = 1; /* don't process again */
/* make sure can read up to session len */
if (toRead > *sslBytes) {
SetError(CLIENT_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
/* skip, get negotiated one from server hello */
input += VERSION_SZ;
*sslBytes -= VERSION_SZ;
XMEMCPY(session->sslServer->arrays->clientRandom, input, RAN_LEN);
XMEMCPY(session->sslClient->arrays->clientRandom, input, RAN_LEN);
input += RAN_LEN;
*sslBytes -= RAN_LEN;
/* store session in case trying to resume */
bLen = *input++;
*sslBytes -= ENUM_LEN;
if (bLen) {
if (ID_LEN > *sslBytes) {
SetError(CLIENT_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
Trace(CLIENT_RESUME_TRY_STR);
XMEMCPY(session->sslClient->arrays->sessionID, input, ID_LEN);
session->sslClient->options.haveSessionId = 1;
}
#ifdef SHOW_SECRETS
{
int i;
printf("client random: ");
for (i = 0; i < RAN_LEN; i++)
printf("%02x", session->sslServer->arrays->clientRandom[i]);
printf("\n");
}
#endif
input += bLen;
*sslBytes -= bLen;
/* skip cipher suites */
/* make sure can read len */
if (SUITE_LEN > *sslBytes) {
SetError(CLIENT_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
len = (input[0] << 8) | input[1];
input += SUITE_LEN;
*sslBytes -= SUITE_LEN;
/* make sure can read suites + comp len */
if (len + ENUM_LEN > *sslBytes) {
SetError(CLIENT_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
input += len;
*sslBytes -= len;
/* skip compression */
bLen = *input++;
*sslBytes -= ENUM_LEN;
/* make sure can read len */
if (bLen > *sslBytes) {
SetError(CLIENT_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
input += bLen;
*sslBytes -= bLen;
if (*sslBytes == 0) {
/* no extensions */
return 0;
}
/* skip extensions until session ticket */
/* make sure can read len */
if (SUITE_LEN > *sslBytes) {
SetError(CLIENT_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
len = (input[0] << 8) | input[1];
input += SUITE_LEN;
*sslBytes -= SUITE_LEN;
/* make sure can read through all extensions */
if (len > *sslBytes) {
SetError(CLIENT_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
while (len > EXT_TYPE_SZ + LENGTH_SZ) {
byte extType[EXT_TYPE_SZ];
word16 extLen;
extType[0] = input[0];
extType[1] = input[1];
input += EXT_TYPE_SZ;
*sslBytes -= EXT_TYPE_SZ;
extLen = (input[0] << 8) | input[1];
input += LENGTH_SZ;
*sslBytes -= LENGTH_SZ;
/* make sure can read through individual extension */
if (extLen > *sslBytes) {
SetError(CLIENT_HELLO_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
if (extType[0] == 0x00 && extType[1] == TICKET_EXT_ID) {
/* make sure can read through ticket if there is a non blank one */
if (extLen && extLen < ID_LEN) {
SetError(CLIENT_HELLO_INPUT_STR, error, session,
FATAL_ERROR_STATE);
return -1;
}
if (extLen) {
if (session->ticketID == 0) {
session->ticketID = (byte*)malloc(ID_LEN);
if (session->ticketID == 0) {
SetError(MEMORY_STR, error, session,
FATAL_ERROR_STATE);
return -1;
}
}
XMEMCPY(session->ticketID, input + extLen - ID_LEN, ID_LEN);
}
}
input += extLen;
*sslBytes -= extLen;
len -= extLen + EXT_TYPE_SZ + LENGTH_SZ;
}
return 0;
}
/* Process Finished */
static int ProcessFinished(const byte* input, int* sslBytes,
SnifferSession* session, char* error)
{
SSL* ssl;
word32 inOutIdx = 0;
int ret;
if (session->flags.side == SERVER_END)
ssl = session->sslServer;
else
ssl = session->sslClient;
ret = DoFinished(ssl, input, &inOutIdx, SNIFF);
*sslBytes -= (int)inOutIdx;
if (ret < 0) {
SetError(BAD_FINISHED_MSG, error, session, FATAL_ERROR_STATE);
return ret;
}
if (ret == 0 && session->flags.cached == 0) {
if (session->sslServer->options.haveSessionId) {
CYASSL_SESSION* sess = GetSession(session->sslServer, NULL);
if (sess == NULL)
AddSession(session->sslServer); /* don't re add */
session->flags.cached = 1;
}
}
FreeHandshakeResources(ssl);
return ret;
}
/* Process HandShake input */
static int DoHandShake(const byte* input, int* sslBytes,
SnifferSession* session, char* error)
{
byte type;
int size;
int ret = 0;
if (*sslBytes < HANDSHAKE_HEADER_SZ) {
SetError(HANDSHAKE_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
type = input[0];
size = (input[1] << 16) | (input[2] << 8) | input[3];
input += HANDSHAKE_HEADER_SZ;
*sslBytes -= HANDSHAKE_HEADER_SZ;
if (*sslBytes < size) {
SetError(HANDSHAKE_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
switch (type) {
case hello_verify_request:
Trace(GOT_HELLO_VERIFY_STR);
break;
case hello_request:
Trace(GOT_HELLO_REQUEST_STR);
break;
case session_ticket:
Trace(GOT_SESSION_TICKET_STR);
ret = ProcessSessionTicket(input, sslBytes, session, error);
break;
case server_hello:
Trace(GOT_SERVER_HELLO_STR);
ret = ProcessServerHello(input, sslBytes, session, error);
break;
case certificate_request:
Trace(GOT_CERT_REQ_STR);
break;
case server_key_exchange:
Trace(GOT_SERVER_KEY_EX_STR);
/* can't know temp key passively */
SetError(BAD_CIPHER_SPEC_STR, error, session, FATAL_ERROR_STATE);
ret = -1;
break;
case certificate:
Trace(GOT_CERT_STR);
break;
case server_hello_done:
Trace(GOT_SERVER_HELLO_DONE_STR);
break;
case finished:
Trace(GOT_FINISHED_STR);
ret = ProcessFinished(input, sslBytes, session, error);
break;
case client_hello:
Trace(GOT_CLIENT_HELLO_STR);
ret = ProcessClientHello(input, sslBytes, session, error);
break;
case client_key_exchange:
Trace(GOT_CLIENT_KEY_EX_STR);
ret = ProcessClientKeyExchange(input, sslBytes, session, error);
break;
case certificate_verify:
Trace(GOT_CERT_VER_STR);
break;
default:
SetError(GOT_UNKNOWN_HANDSHAKE_STR, error, session, 0);
return -1;
}
return ret;
}
/* Decrypt input into plain output */
static void Decrypt(SSL* ssl, byte* output, const byte* input, word32 sz)
{
switch (ssl->specs.bulk_cipher_algorithm) {
#ifdef BUILD_ARC4
case rc4:
Arc4Process(ssl->decrypt.arc4, output, input, sz);
break;
#endif
#ifdef BUILD_DES3
case triple_des:
Des3_CbcDecrypt(ssl->decrypt.des3, output, input, sz);
break;
#endif
#ifdef BUILD_AES
case aes:
AesCbcDecrypt(ssl->decrypt.aes, output, input, sz);
break;
#endif
#ifdef HAVE_HC128
case hc128:
Hc128_Process(ssl->decrypt.hc128, output, input, sz);
break;
#endif
#ifdef BUILD_RABBIT
case rabbit:
RabbitProcess(ssl->decrypt.rabbit, output, input, sz);
break;
#endif
default:
Trace(BAD_DECRYPT_TYPE);
break;
}
}
/* Decrypt input message into output, adjust output steam if needed */
static const byte* DecryptMessage(SSL* ssl, const byte* input, word32 sz,
byte* output)
{
Decrypt(ssl, output, input, sz);
ssl->keys.encryptSz = sz;
if (ssl->options.tls1_1 && ssl->specs.cipher_type == block)
return output + ssl->specs.block_size; /* go past TLSv1.1 IV */
return output;
}
/* remove session from table, use rowHint if no info (means we have a lock) */
static void RemoveSession(SnifferSession* session, IpInfo* ipInfo,
TcpInfo* tcpInfo, word32 rowHint)
{
SnifferSession* previous = 0;
SnifferSession* current;
word32 row = rowHint;
int haveLock = 0;
if (ipInfo && tcpInfo)
row = SessionHash(ipInfo, tcpInfo);
else
haveLock = 1;
assert(row <= HASH_SIZE);
Trace(REMOVE_SESSION_STR);
if (!haveLock)
LockMutex(&SessionMutex);
current = SessionTable[row];
while (current) {
if (current == session) {
if (previous)
previous->next = current->next;
else
SessionTable[row] = current->next;
FreeSnifferSession(session);
TraceRemovedSession();
break;
}
previous = current;
current = current->next;
}
if (!haveLock)
UnLockMutex(&SessionMutex);
}
/* Remove stale sessions from the Session Table, have a lock */
static void RemoveStaleSessions(void)
{
word32 i;
SnifferSession* session;
for (i = 0; i < HASH_SIZE; i++) {
session = SessionTable[i];
while (session) {
SnifferSession* next = session->next;
if (time(NULL) >= session->bornOn + SNIFFER_TIMEOUT) {
TraceStaleSession();
RemoveSession(session, NULL, NULL, i);
}
session = next;
}
}
}
/* Create a new Sniffer Session */
static SnifferSession* CreateSession(IpInfo* ipInfo, TcpInfo* tcpInfo,
char* error)
{
SnifferSession* session = 0;
int row;
Trace(NEW_SESSION_STR);
/* create a new one */
session = (SnifferSession*)malloc(sizeof(SnifferSession));
if (session == NULL) {
SetError(MEMORY_STR, error, NULL, 0);
return 0;
}
InitSession(session);
session->server = ipInfo->dst;
session->client = ipInfo->src;
session->srvPort = tcpInfo->dstPort;
session->cliPort = tcpInfo->srcPort;
session->cliSeqStart = tcpInfo->sequence;
session->cliExpected = 1; /* relative */
session->bornOn = time(NULL);
session->context = GetSnifferServer(ipInfo, tcpInfo);
if (session->context == NULL) {
SetError(SERVER_NOT_REG_STR, error, NULL, 0);
free(session);
return 0;
}
session->sslServer = SSL_new(session->context->ctx);
if (session->sslServer == NULL) {
SetError(BAD_NEW_SSL_STR, error, session, FATAL_ERROR_STATE);
free(session);
return 0;
}
session->sslClient = SSL_new(session->context->ctx);
if (session->sslClient == NULL) {
SSL_free(session->sslServer);
session->sslServer = 0;
SetError(BAD_NEW_SSL_STR, error, session, FATAL_ERROR_STATE);
free(session);
return 0;
}
/* put server back into server mode */
session->sslServer->options.side = SERVER_END;
row = SessionHash(ipInfo, tcpInfo);
/* add it to the session table */
LockMutex(&SessionMutex);
session->next = SessionTable[row];
SessionTable[row] = session;
SessionCount++;
if ( (SessionCount % HASH_SIZE) == 0) {
TraceFindingStale();
RemoveStaleSessions();
}
UnLockMutex(&SessionMutex);
/* determine headed side */
if (ipInfo->dst == session->context->server &&
tcpInfo->dstPort == session->context->port)
session->flags.side = SERVER_END;
else
session->flags.side = CLIENT_END;
return session;
}
/* Process Old Client Hello Input */
static int DoOldHello(SnifferSession* session, const byte* sslFrame,
int* rhSize, int* sslBytes, char* error)
{
const byte* input = sslFrame;
byte b0, b1;
word32 idx = 0;
int ret;
Trace(GOT_OLD_CLIENT_HELLO_STR);
session->flags.clientHello = 1; /* don't process again */
b0 = *input++;
b1 = *input++;
*sslBytes -= 2;
*rhSize = ((b0 & 0x7f) << 8) | b1;
if (*rhSize > *sslBytes) {
SetError(OLD_CLIENT_INPUT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
ret = ProcessOldClientHello(session->sslServer, input, &idx, *sslBytes,
*rhSize);
if (ret < 0) {
SetError(BAD_OLD_CLIENT_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
Trace(OLD_CLIENT_OK_STR);
XMEMCPY(session->sslClient->arrays->clientRandom,
session->sslServer->arrays->clientRandom, RAN_LEN);
*sslBytes -= *rhSize;
return 0;
}
#if 0
/* Calculate the TCP checksum, see RFC 1071 */
/* return 0 for success, -1 on error */
/* can be called from decode() with
TcpChecksum(&ipInfo, &tcpInfo, sslBytes, packet + ipInfo.length);
could also add a 64bit version if type available and using this
*/
int TcpChecksum(IpInfo* ipInfo, TcpInfo* tcpInfo, int dataLen,
const byte* packet)
{
TcpPseudoHdr pseudo;
int count = PSEUDO_HDR_SZ;
const word16* data = (word16*)&pseudo;
word32 sum = 0;
word16 checksum;
pseudo.src = ipInfo->src;
pseudo.dst = ipInfo->dst;
pseudo.rsv = 0;
pseudo.protocol = TCP_PROTO;
pseudo.legnth = htons(tcpInfo->length + dataLen);
/* pseudo header sum */
while (count >= 2) {
sum += *data++;
count -= 2;
}
count = tcpInfo->length + dataLen;
data = (word16*)packet;
/* main sum */
while (count > 1) {
sum += *data++;
count -=2;
}
/* get left-over, if any */
packet = (byte*)data;
if (count > 0) {
sum += *packet;
}
/* fold 32bit sum into 16 bits */
while (sum >> 16)
sum = (sum & 0xffff) + (sum >> 16);
checksum = (word16)~sum;
/* checksum should now equal 0, since included already calcd checksum */
/* field, but tcp checksum offloading could negate calculation */
if (checksum == 0)
return 0;
return -1;
}
#endif
/* Check IP and TCP headers, set payload */
/* returns 0 on success, -1 on error */
static int CheckHeaders(IpInfo* ipInfo, TcpInfo* tcpInfo, const byte* packet,
int length, const byte** sslFrame, int* sslBytes, char* error)
{
TraceHeader();
TracePacket();
if (length < IP_HDR_SZ) {
SetError(PACKET_HDR_SHORT_STR, error, NULL, 0);
return -1;
}
if (CheckIpHdr((IpHdr*)packet, ipInfo, error) != 0)
return -1;
if (length < (ipInfo->length + TCP_HDR_SZ)) {
SetError(PACKET_HDR_SHORT_STR, error, NULL, 0);
return -1;
}
if (CheckTcpHdr((TcpHdr*)(packet + ipInfo->length), tcpInfo, error) != 0)
return -1;
*sslFrame = packet + ipInfo->length + tcpInfo->length;
if (*sslFrame > packet + length) {
SetError(PACKET_HDR_SHORT_STR, error, NULL, 0);
return -1;
}
*sslBytes = (int)(packet + length - *sslFrame);
return 0;
}
/* Create or Find existing session */
/* returns 0 on success (continue), -1 on error, 1 on success (end) */
static int CheckSession(IpInfo* ipInfo, TcpInfo* tcpInfo, int sslBytes,
SnifferSession** session, char* error)
{
/* create a new SnifferSession on client SYN */
if (tcpInfo->syn && !tcpInfo->ack) {
TraceClientSyn(tcpInfo->sequence);
*session = CreateSession(ipInfo, tcpInfo, error);
if (*session == NULL) {
*session = GetSnifferSession(ipInfo, tcpInfo);
/* already had exisiting, so OK */
if (*session)
return 1;
SetError(MEMORY_STR, error, NULL, 0);
return -1;
}
return 1;
}
/* get existing sniffer session */
else {
*session = GetSnifferSession(ipInfo, tcpInfo);
if (*session == NULL) {
/* don't worry about extraneous RST or duplicate FINs */
if (tcpInfo->fin || tcpInfo->rst)
return 1;
/* don't worry about duplicate ACKs either */
if (sslBytes == 0 && tcpInfo->ack)
return 1;
SetError(BAD_SESSION_STR, error, NULL, 0);
return -1;
}
}
return 0;
}
/* Create a Packet Buffer from *begin - end, adjust new *begin and bytesLeft */
static PacketBuffer* CreateBuffer(word32* begin, word32 end, const byte* data,
int* bytesLeft)
{
PacketBuffer* pb;
int added = end - *begin + 1;
assert(*begin <= end);
pb = (PacketBuffer*)malloc(sizeof(PacketBuffer));
if (pb == NULL) return NULL;
pb->next = 0;
pb->begin = *begin;
pb->end = end;
pb->data = (byte*)malloc(added);
if (pb->data == NULL) {
free(pb);
return NULL;
}
XMEMCPY(pb->data, data, added);
*bytesLeft -= added;
*begin = pb->end + 1;
return pb;
}
/* Add sslFrame to Reassembly List */
/* returns 1 (end) on success, -1, on error */
static int AddToReassembly(byte from, word32 seq, const byte* sslFrame,
int sslBytes, SnifferSession* session, char* error)
{
PacketBuffer* add;
PacketBuffer** front = (from == SERVER_END) ? &session->cliReassemblyList:
&session->srvReassemblyList;
PacketBuffer* curr = *front;
PacketBuffer* prev = curr;
word32 startSeq = seq;
word32 added;
int bytesLeft = sslBytes; /* could be overlapping fragment */
/* if list is empty add full frame to front */
if (!curr) {
add = CreateBuffer(&seq, seq + sslBytes - 1, sslFrame, &bytesLeft);
if (add == NULL) {
SetError(MEMORY_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
*front = add;
return 1;
}
/* add to front if before current front, up to next->begin */
if (seq < curr->begin) {
word32 end = seq + sslBytes - 1;
if (end >= curr->begin)
end = curr->begin - 1;
add = CreateBuffer(&seq, end, sslFrame, &bytesLeft);
if (add == NULL) {
SetError(MEMORY_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
add->next = curr;
*front = add;
}
/* while we have bytes left, try to find a gap to fill */
while (bytesLeft > 0) {
/* get previous packet in list */
while (curr && (seq >= curr->begin)) {
prev = curr;
curr = curr->next;
}
/* don't add duplicate data */
if (prev->end >= seq) {
if ( (seq + bytesLeft - 1) <= prev->end)
return 1;
seq = prev->end + 1;
bytesLeft = startSeq + sslBytes - seq;
}
if (!curr)
/* we're at the end */
added = bytesLeft;
else
/* we're in between two frames */
added = min((word32)bytesLeft, curr->begin - seq);
/* data already there */
if (added == 0)
continue;
add = CreateBuffer(&seq, seq + added - 1, &sslFrame[seq - startSeq],
&bytesLeft);
if (add == NULL) {
SetError(MEMORY_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
add->next = prev->next;
prev->next = add;
}
return 1;
}
/* Add out of order FIN capture */
/* returns 1 for success (end) */
static int AddFinCapture(SnifferSession* session, word32 sequence)
{
if (session->flags.side == SERVER_END) {
if (session->finCaputre.cliCounted == 0)
session->finCaputre.cliFinSeq = sequence;
}
else {
if (session->finCaputre.srvCounted == 0)
session->finCaputre.srvFinSeq = sequence;
}
return 1;
}
/* Adjust incoming sequence based on side */
/* returns 0 on success (continue), -1 on error, 1 on success (end) */
static int AdjustSequence(TcpInfo* tcpInfo, SnifferSession* session,
int* sslBytes, const byte** sslFrame, char* error)
{
word32 seqStart = (session->flags.side == SERVER_END) ?
session->cliSeqStart :session->srvSeqStart;
word32 real = tcpInfo->sequence - seqStart;
word32* expected = (session->flags.side == SERVER_END) ?
&session->cliExpected : &session->srvExpected;
PacketBuffer* reassemblyList = (session->flags.side == SERVER_END) ?
session->cliReassemblyList : session->srvReassemblyList;
/* handle rollover of sequence */
if (tcpInfo->sequence < seqStart)
real = 0xffffffffU - seqStart + tcpInfo->sequence;
TraceRelativeSequence(*expected, real);
if (real < *expected) {
Trace(DUPLICATE_STR);
if (real + *sslBytes > *expected) {
int overlap = *expected - real;
Trace(OVERLAP_DUPLICATE_STR);
/* adjust to expected, remove duplicate */
*sslFrame += overlap;
*sslBytes -= overlap;
if (reassemblyList) {
word32 newEnd = *expected + *sslBytes;
if (newEnd > reassemblyList->begin) {
Trace(OVERLAP_REASSEMBLY_BEGIN_STR);
/* remove bytes already on reassembly list */
*sslBytes -= newEnd - reassemblyList->begin;
}
if (newEnd > reassemblyList->end) {
Trace(OVERLAP_REASSEMBLY_END_STR);
/* may be past reassembly list end (could have more on list)
so try to add what's past the front->end */
AddToReassembly(session->flags.side, reassemblyList->end +1,
*sslFrame + reassemblyList->end - *expected + 1,
newEnd - reassemblyList->end, session, error);
}
}
}
else
return 1;
}
else if (real > *expected) {
Trace(OUT_OF_ORDER_STR);
if (*sslBytes > 0)
return AddToReassembly(session->flags.side, real, *sslFrame,
*sslBytes, session, error);
else if (tcpInfo->fin)
return AddFinCapture(session, real);
}
/* got expected sequence */
*expected += *sslBytes;
if (tcpInfo->fin)
*expected += 1;
return 0;
}
/* Check latest ack number for missing packets
return 0 ok, <0 on error */
static int CheckAck(TcpInfo* tcpInfo, SnifferSession* session)
{
if (tcpInfo->ack) {
word32 seqStart = (session->flags.side == SERVER_END) ?
session->srvSeqStart :session->cliSeqStart;
word32 real = tcpInfo->ackNumber - seqStart;
word32 expected = (session->flags.side == SERVER_END) ?
session->srvExpected : session->cliExpected;
/* handle rollover of sequence */
if (tcpInfo->ackNumber < seqStart)
real = 0xffffffffU - seqStart + tcpInfo->ackNumber;
TraceAck(real, expected);
if (real > expected)
return -1; /* we missed a packet, ACKing data we never saw */
}
return 0;
}
/* Check TCP Sequence status */
/* returns 0 on success (continue), -1 on error, 1 on success (end) */
static int CheckSequence(IpInfo* ipInfo, TcpInfo* tcpInfo,
SnifferSession* session, int* sslBytes,
const byte** sslFrame, char* error)
{
int actualLen;
/* init SEQ from server to client */
if (tcpInfo->syn && tcpInfo->ack) {
session->srvSeqStart = tcpInfo->sequence;
session->srvExpected = 1;
TraceServerSyn(tcpInfo->sequence);
return 1;
}
/* adjust potential ethernet trailer */
actualLen = ipInfo->total - ipInfo->length - tcpInfo->length;
if (*sslBytes > actualLen) {
*sslBytes = actualLen;
}
TraceSequence(tcpInfo->sequence, *sslBytes);
if (CheckAck(tcpInfo, session) < 0) {
SetError(ACK_MISSED_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
return AdjustSequence(tcpInfo, session, sslBytes, sslFrame, error);
}
/* Check Status before record processing */
/* returns 0 on success (continue), -1 on error, 1 on success (end) */
static int CheckPreRecord(IpInfo* ipInfo, TcpInfo* tcpInfo,
const byte** sslFrame, SnifferSession** session,
int* sslBytes, const byte** end, char* error)
{
word32 length;
SSL* ssl = ((*session)->flags.side == SERVER_END) ? (*session)->sslServer :
(*session)->sslClient;
/* remove SnifferSession on 2nd FIN or RST */
if (tcpInfo->fin || tcpInfo->rst) {
/* flag FIN and RST */
if (tcpInfo->fin)
(*session)->flags.finCount += 1;
else if (tcpInfo->rst)
(*session)->flags.finCount += 2;
if ((*session)->flags.finCount >= 2) {
RemoveSession(*session, ipInfo, tcpInfo, 0);
*session = NULL;
return 1;
}
}
if ((*session)->flags.fatalError == FATAL_ERROR_STATE) {
SetError(FATAL_ERROR_STR, error, NULL, 0);
return -1;
}
if (*sslBytes == 0) {
Trace(NO_DATA_STR);
return 1;
}
/* if current partial data, add to end of partial */
if ( (length = ssl->buffers.inputBuffer.length) ) {
Trace(PARTIAL_ADD_STR);
if ( (*sslBytes + length) > ssl->buffers.inputBuffer.bufferSize) {
if (GrowInputBuffer(ssl, *sslBytes, length) < 0) {
SetError(MEMORY_STR, error, *session, FATAL_ERROR_STATE);
return -1;
}
}
XMEMCPY(&ssl->buffers.inputBuffer.buffer[length], *sslFrame, *sslBytes);
*sslBytes += length;
ssl->buffers.inputBuffer.length = *sslBytes;
*sslFrame = ssl->buffers.inputBuffer.buffer;
*end = *sslFrame + *sslBytes;
}
if ((*session)->flags.clientHello == 0 && **sslFrame != handshake) {
int rhSize;
int ret = DoOldHello(*session, *sslFrame, &rhSize, sslBytes, error);
if (ret < 0)
return -1; /* error already set */
if (*sslBytes <= 0)
return 1;
}
return 0;
}
/* See if input on the reassembly list is ready for consuming */
/* returns 1 for TRUE, 0 for FALSE */
static int HaveMoreInput(SnifferSession* session, const byte** sslFrame,
int* sslBytes, const byte** end, char* error)
{
/* sequence and reassembly based on from, not to */
int moreInput = 0;
PacketBuffer** front = (session->flags.side == SERVER_END) ?
&session->cliReassemblyList : &session->srvReassemblyList;
word32* expected = (session->flags.side == SERVER_END) ?
&session->cliExpected : &session->srvExpected;
/* buffer is on receiving end */
word32* length = (session->flags.side == SERVER_END) ?
&session->sslServer->buffers.inputBuffer.length :
&session->sslClient->buffers.inputBuffer.length;
byte* myBuffer = (session->flags.side == SERVER_END) ?
session->sslServer->buffers.inputBuffer.buffer :
session->sslClient->buffers.inputBuffer.buffer;
word32 bufferSize = (session->flags.side == SERVER_END) ?
session->sslServer->buffers.inputBuffer.bufferSize :
session->sslClient->buffers.inputBuffer.bufferSize;
SSL* ssl = (session->flags.side == SERVER_END) ?
session->sslServer : session->sslClient;
while (*front && ((*front)->begin == *expected) ) {
word32 room = bufferSize - *length;
word32 packetLen = (*front)->end - (*front)->begin + 1;
if (packetLen > room && bufferSize < MAX_INPUT_SZ) {
if (GrowInputBuffer(ssl, packetLen, *length) < 0) {
SetError(MEMORY_STR, error, session, FATAL_ERROR_STATE);
return 0;
}
}
if (packetLen <= room) {
PacketBuffer* del = *front;
XMEMCPY(&myBuffer[*length], (*front)->data, packetLen);
*length += packetLen;
*expected += packetLen;
/* remove used packet */
*front = (*front)->next;
FreePacketBuffer(del);
moreInput = 1;
}
else
break;
}
if (moreInput) {
*sslFrame = myBuffer;
*sslBytes = *length;
*end = myBuffer + *length;
}
return moreInput;
}
/* Process Message(s) from sslFrame */
/* return Number of bytes on success, 0 for no data yet, and -1 on error */
static int ProcessMessage(const byte* sslFrame, SnifferSession* session,
int sslBytes, byte* data, const byte* end,char* error)
{
const byte* sslBegin = sslFrame;
const byte* tmp;
RecordLayerHeader rh;
int rhSize = 0;
int ret;
int decoded = 0; /* bytes stored for user in data */
int notEnough; /* notEnough bytes yet flag */
SSL* ssl = (session->flags.side == SERVER_END) ?
session->sslServer : session->sslClient;
doMessage:
notEnough = 0;
if (sslBytes >= RECORD_HEADER_SZ) {
if (GetRecordHeader(sslFrame, &rh, &rhSize) != 0) {
SetError(BAD_RECORD_HDR_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
}
else
notEnough = 1;
if (notEnough || rhSize > (sslBytes - RECORD_HEADER_SZ)) {
/* don't have enough input yet to process full SSL record */
Trace(PARTIAL_INPUT_STR);
/* store partial if not there already or we advanced */
if (ssl->buffers.inputBuffer.length == 0 || sslBegin != sslFrame) {
if (sslBytes > (int)ssl->buffers.inputBuffer.bufferSize) {
if (GrowInputBuffer(ssl, sslBytes, 0) < 0) {
SetError(MEMORY_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
}
XMEMCPY(ssl->buffers.inputBuffer.buffer, sslFrame, sslBytes);
ssl->buffers.inputBuffer.length = sslBytes;
}
if (HaveMoreInput(session, &sslFrame, &sslBytes, &end, error))
goto doMessage;
return decoded;
}
sslFrame += RECORD_HEADER_SZ;
sslBytes -= RECORD_HEADER_SZ;
tmp = sslFrame + rhSize; /* may have more than one record to process */
/* decrypt if needed */
if ((session->flags.side == SERVER_END && session->flags.serverCipherOn)
|| (session->flags.side == CLIENT_END && session->flags.clientCipherOn)) {
if (CheckAvalaibleSize(ssl, rhSize) < 0) {
SetError(MEMORY_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
sslFrame = DecryptMessage(ssl, sslFrame, rhSize,
ssl->buffers.outputBuffer.buffer);
}
switch ((enum ContentType)rh.type) {
case handshake:
Trace(GOT_HANDSHAKE_STR);
ret = DoHandShake(sslFrame, &sslBytes, session, error);
if (ret != 0) {
if (session->flags.fatalError == 0)
SetError(BAD_HANDSHAKE_STR,error,session,FATAL_ERROR_STATE);
return -1;
}
break;
case change_cipher_spec:
if (session->flags.side == SERVER_END)
session->flags.serverCipherOn = 1;
else
session->flags.clientCipherOn = 1;
Trace(GOT_CHANGE_CIPHER_STR);
ssl->options.handShakeState = HANDSHAKE_DONE;
break;
case application_data:
Trace(GOT_APP_DATA_STR);
{
word32 inOutIdx = 0;
ret = DoApplicationData(ssl, (byte*)sslFrame, &inOutIdx);
if (ret == 0) {
ret = ssl->buffers.clearOutputBuffer.length;
TraceGotData(ret);
if (ret) { /* may be blank message */
XMEMCPY(&data[decoded],
ssl->buffers.clearOutputBuffer.buffer, ret);
TraceAddedData(ret, decoded);
decoded += ret;
ssl->buffers.clearOutputBuffer.length = 0;
}
}
else {
SetError(BAD_APP_DATA_STR, error,session,FATAL_ERROR_STATE);
return -1;
}
if (ssl->buffers.outputBuffer.dynamicFlag)
ShrinkOutputBuffer(ssl);
}
break;
case alert:
Trace(GOT_ALERT_STR);
break;
case no_type:
default:
SetError(GOT_UNKNOWN_RECORD_STR, error, session, FATAL_ERROR_STATE);
return -1;
}
if (tmp < end) {
Trace(ANOTHER_MSG_STR);
sslFrame = tmp;
sslBytes = (int)(end - tmp);
goto doMessage;
}
/* clear used input */
ssl->buffers.inputBuffer.length = 0;
/* could have more input ready now */
if (HaveMoreInput(session, &sslFrame, &sslBytes, &end, error))
goto doMessage;
if (ssl->buffers.inputBuffer.dynamicFlag)
ShrinkInputBuffer(ssl, NO_FORCED_FREE);
return decoded;
}
/* See if we need to process any pending FIN captures */
static void CheckFinCapture(IpInfo* ipInfo, TcpInfo* tcpInfo,
SnifferSession* session)
{
if (session->finCaputre.cliFinSeq && session->finCaputre.cliFinSeq <=
session->cliExpected) {
if (session->finCaputre.cliCounted == 0) {
session->flags.finCount += 1;
session->finCaputre.cliCounted = 1;
TraceClientFin(session->finCaputre.cliFinSeq, session->cliExpected);
}
}
if (session->finCaputre.srvFinSeq && session->finCaputre.srvFinSeq <=
session->srvExpected) {
if (session->finCaputre.srvCounted == 0) {
session->flags.finCount += 1;
session->finCaputre.srvCounted = 1;
TraceServerFin(session->finCaputre.srvFinSeq, session->srvExpected);
}
}
if (session->flags.finCount >= 2)
RemoveSession(session, ipInfo, tcpInfo, 0);
}
/* If session is in fatal error state free resources now
return true if removed, 0 otherwise */
static int RemoveFatalSession(IpInfo* ipInfo, TcpInfo* tcpInfo,
SnifferSession* session, char* error)
{
if (session && session->flags.fatalError == FATAL_ERROR_STATE) {
RemoveSession(session, ipInfo, tcpInfo, 0);
SetError(FATAL_ERROR_STR, error, NULL, 0);
return 1;
}
return 0;
}
/* Passes in an IP/TCP packet for decoding (ethernet/localhost frame) removed */
/* returns Number of bytes on success, 0 for no data yet, and -1 on error */
int ssl_DecodePacket(const byte* packet, int length, byte* data, char* error)
{
TcpInfo tcpInfo;
IpInfo ipInfo;
const byte* sslFrame;
const byte* end = packet + length;
int sslBytes; /* ssl bytes unconsumed */
int ret;
SnifferSession* session = 0;
if (CheckHeaders(&ipInfo, &tcpInfo, packet, length, &sslFrame, &sslBytes,
error) != 0)
return -1;
ret = CheckSession(&ipInfo, &tcpInfo, sslBytes, &session, error);
if (RemoveFatalSession(&ipInfo, &tcpInfo, session, error)) return -1;
else if (ret == -1) return -1;
else if (ret == 1) return 0; /* done for now */
ret = CheckSequence(&ipInfo, &tcpInfo, session, &sslBytes, &sslFrame,error);
if (RemoveFatalSession(&ipInfo, &tcpInfo, session, error)) return -1;
else if (ret == -1) return -1;
else if (ret == 1) return 0; /* done for now */
ret = CheckPreRecord(&ipInfo, &tcpInfo, &sslFrame, &session, &sslBytes,
&end, error);
if (RemoveFatalSession(&ipInfo, &tcpInfo, session, error)) return -1;
else if (ret == -1) return -1;
else if (ret == 1) return 0; /* done for now */
ret = ProcessMessage(sslFrame, session, sslBytes, data, end, error);
if (RemoveFatalSession(&ipInfo, &tcpInfo, session, error)) return -1;
CheckFinCapture(&ipInfo, &tcpInfo, session);
return ret;
}
/* Enables (if traceFile)/ Disables debug tracing */
/* returns 0 on success, -1 on error */
int ssl_Trace(const char* traceFile, char* error)
{
if (traceFile) {
TraceFile = fopen(traceFile, "a");
if (!TraceFile) {
SetError(BAD_TRACE_FILE_STR, error, NULL, 0);
return -1;
}
TraceOn = 1;
}
else
TraceOn = 0;
return 0;
}
#endif /* CYASSL_SNIFFER */