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Added new sniffer API for callback for key use ssl_SetKeyCallback. Support indicated by WOLFSSL_SNIFFER_KEY_CALLBACK. Trace cleanup for custom error.

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This commit is contained in:
David Garske
2021-06-30 15:19:48 -07:00
parent 197b959916
commit 2dd169f9a1
3 changed files with 140 additions and 24 deletions
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107
src/sniffer.c
View File

@ -349,6 +349,9 @@ static const char* const msgTable[] =
/* *nix version uses table above */
static void GetError(int idx, char* str)
{
if (str == NULL ||
idx < 0 || idx > (int)(sizeof(msgTable)/sizeof(const char* const)))
return;
XSTRNCPY(str, msgTable[idx - 1], MAX_ERROR_LEN-1);
str[MAX_ERROR_LEN-1] = '\0';
}
@ -360,6 +363,8 @@ static void GetError(int idx, char* str)
/* Windows version uses .rc table */
static void GetError(int idx, char* buffer)
{
if (buffer == NULL)
return;
if (!LoadStringA(dllModule, idx, buffer, MAX_ERROR_LEN))
buffer[0] = 0;
}
@ -517,10 +522,9 @@ typedef struct SnifferSession {
/* Sniffer Server List and mutex */
static WOLFSSL_GLOBAL SnifferServer* ServerList = 0;
static WOLFSSL_GLOBAL SnifferServer* ServerList = NULL;
static WOLFSSL_GLOBAL wolfSSL_Mutex ServerListMutex;
/* Session Hash Table, mutex, and count */
static WOLFSSL_GLOBAL SnifferSession* SessionTable[HASH_SIZE];
static WOLFSSL_GLOBAL wolfSSL_Mutex SessionMutex;
@ -536,7 +540,7 @@ static WOLFSSL_GLOBAL word32 MissedDataSessions = 0;
/* Connection Info Callback */
static WOLFSSL_GLOBAL SSLConnCb ConnectionCb;
static WOLFSSL_GLOBAL void* ConnectionCbCtx = NULL;
static WOLFSSL_GLOBAL void* ConnectionCbCtx = NULL;
#ifdef WOLFSSL_SNIFFER_STATS
/* Sessions Statistics */
@ -544,10 +548,15 @@ static WOLFSSL_GLOBAL SSLStats SnifferStats;
static WOLFSSL_GLOBAL wolfSSL_Mutex StatsMutex;
#endif
#ifdef WOLFSSL_SNIFFER_KEY_CALLBACK
static WOLFSSL_GLOBAL SSLKeyCb KeyCb;
static WOLFSSL_GLOBAL void* KeyCbCtx = NULL;
#endif
#ifdef WOLFSSL_SNIFFER_WATCH
/* Watch Key Callback */
static WOLFSSL_GLOBAL SSLWatchCb WatchCb;
static WOLFSSL_GLOBAL void* WatchCbCtx = NULL;
static WOLFSSL_GLOBAL void* WatchCbCtx = NULL;
#endif
#ifdef WOLFSSL_SNIFFER_STORE_DATA_CB
@ -993,18 +1002,26 @@ typedef struct TcpHdr {
/* Use platform specific GetError to write to trace file if tracing */
static void Trace(int idx)
static void TraceError(int idx, char* error)
{
if (TraceOn) {
char myBuffer[MAX_ERROR_LEN];
GetError(idx, myBuffer);
XFPRINTF(TraceFile, "\t%s\n", myBuffer);
if (error == NULL) {
error = myBuffer;
GetError(idx, myBuffer);
}
XFPRINTF(TraceFile, "\t%s\n", error);
#ifdef DEBUG_SNIFFER
XFPRINTF(stderr, "\t%s\n", myBuffer);
XFPRINTF(stderr, "\t%s\n", error);
#endif
}
}
static void Trace(int idx)
{
TraceError(idx, NULL);
}
/* Show TimeStamp for beginning of packet Trace */
static void TraceHeader(void)
@ -1255,7 +1272,7 @@ static void TraceStat(const char* name, int add)
static void SetError(int idx, char* error, SnifferSession* session, int fatal)
{
GetError(idx, error);
Trace(idx);
TraceError(idx, error);
if (session && fatal == FATAL_ERROR_STATE)
session->flags.fatalError = 1;
}
@ -1563,7 +1580,7 @@ static int CreateWatchSnifferServer(char* error)
return -1;
}
InitSnifferServer(sniffer);
sniffer->ctx = wolfSSL_CTX_new(SSLv23_client_method());
sniffer->ctx = wolfSSL_CTX_new(wolfSSLv23_client_method());
if (!sniffer->ctx) {
SetError(MEMORY_STR, error, NULL, 0);
FreeSnifferServer(sniffer);
@ -1573,7 +1590,12 @@ static int CreateWatchSnifferServer(char* error)
if (CryptoDeviceId != INVALID_DEVID)
wolfSSL_CTX_SetDevId(sniffer->ctx, CryptoDeviceId);
#endif
/* add to server list */
wc_LockMutex(&ServerListMutex);
sniffer->next = ServerList;
ServerList = sniffer;
wc_UnLockMutex(&ServerListMutex);
return 0;
}
@ -1659,7 +1681,7 @@ static int SetNamedPrivateKey(const char* name, const char* address, int port,
sniffer->server = serverIp;
sniffer->port = port;
sniffer->ctx = wolfSSL_CTX_new(SSLv23_client_method());
sniffer->ctx = wolfSSL_CTX_new(wolfSSLv23_client_method());
if (!sniffer->ctx) {
SetError(MEMORY_STR, error, NULL, 0);
#ifdef HAVE_SNI
@ -2140,6 +2162,10 @@ static int SetupKeys(const byte* input, int* sslBytes, SnifferSession* session,
if (ksInfo && ksInfo->curve_id != 0)
useEccCurveId = ksInfo->curve_id;
#endif
int devId = INVALID_DEVID;
#ifdef WOLF_CRYPTO_CB
devId = CryptoDeviceId;
#endif
#ifndef NO_RSA
/* Static RSA */
@ -2149,7 +2175,7 @@ static int SetupKeys(const byte* input, int* sslBytes, SnifferSession* session,
keyBuf = keys->rsaKey;
ret = wc_InitRsaKey(&key, 0);
ret = wc_InitRsaKey_ex(&key, NULL, devId);
if (ret == 0) {
ret = wc_RsaPrivateKeyDecode(keyBuf->buffer, &idx, &key, keyBuf->length);
if (ret != 0) {
@ -2227,6 +2253,19 @@ static int SetupKeys(const byte* input, int* sslBytes, SnifferSession* session,
keyBuf = keys->dhKey;
#ifdef WOLFSSL_SNIFFER_KEY_CALLBACK
if (KeyCb != NULL) {
ret = KeyCb(session, ksInfo->named_group,
session->srvKs.key, session->srvKs.key_len,
session->cliKs.key, session->cliKs.key_len,
keyBuf, KeyCbCtx, error);
if (ret != 0) {
SetError(-1, error, session, FATAL_ERROR_STATE);
return ret;
}
}
#endif
/* get DH params */
switch (ksInfo->named_group) {
#ifdef HAVE_FFDHE_2048
@ -2263,7 +2302,7 @@ static int SetupKeys(const byte* input, int* sslBytes, SnifferSession* session,
return BAD_FUNC_ARG;
}
ret = wc_InitDhKey(&dhKey);
ret = wc_InitDhKey_ex(&dhKey, NULL, devId);
if (ret == 0) {
ret = wc_DhSetKey(&dhKey,
(byte*)params->p, params->p_len,
@ -2315,8 +2354,22 @@ static int SetupKeys(const byte* input, int* sslBytes, SnifferSession* session,
int length, keyInit = 0, pubKeyInit = 0;
keyBuf = keys->ecKey;
#ifdef WOLFSSL_SNIFFER_KEY_CALLBACK
if (KeyCb != NULL && ksInfo) {
ret = KeyCb(session, ksInfo->named_group,
session->srvKs.key, session->srvKs.key_len,
session->cliKs.key, session->cliKs.key_len,
keyBuf, KeyCbCtx, error);
if (ret != 0) {
SetError(-1, error, session, FATAL_ERROR_STATE);
return ret;
}
}
#endif
idx = 0;
ret = wc_ecc_init(&key);
ret = wc_ecc_init_ex(&key, NULL, devId);
if (ret == 0) {
keyInit = 1;
ret = wc_ecc_init(&pubKey);
@ -3100,6 +3153,7 @@ static int ProcessServerHello(int msgSz, const byte* input, int* sslBytes,
keys.ecKey = session->sslServer->staticKE.ecKey;
#endif
#endif
ret = SetupKeys(session->cliKs.key, &session->cliKs.key_len,
session, error, &session->cliKs, &keys);
if (ret != 0) {
@ -3507,7 +3561,7 @@ static int ProcessCertificate(const byte* input, int* sslBytes,
return KeyWatchCall(session, input, certSz, error);
}
#endif
#endif /* WOLFSSL_SNIFFER_WATCH */
/* Process Finished */
@ -3813,8 +3867,11 @@ static int DoHandShake(const byte* input, int* sslBytes,
session->sslClient->options.haveEMS = 0;
}
#endif
if (ret == 0)
if (ret == 0) {
ret = ProcessClientKeyExchange(input, sslBytes, session, error);
if (ret != 0)
SetError(GOT_CLIENT_KEY_EX_STR, error, session, FATAL_ERROR_STATE);
}
break;
case certificate_verify:
Trace(GOT_CERT_VER_STR);
@ -5676,19 +5733,22 @@ int ssl_ReadResetStatistics(SSLStats* stats)
int ssl_SetWatchKeyCallback_ex(SSLWatchCb cb, int devId, char* error)
{
#ifdef WOLF_CRYPTO_CB
if (CryptoDeviceId == INVALID_DEVID)
CryptoDeviceId = devId;
#else
(void)devId;
#endif
WatchCb = cb;
return CreateWatchSnifferServer(error);
}
int ssl_SetWatchKeyCallback(SSLWatchCb cb, char* error)
{
WatchCb = cb;
return CreateWatchSnifferServer(error);
}
int ssl_SetWatchKeyCtx(void* ctx, char* error)
{
(void)error;
@ -5696,7 +5756,6 @@ int ssl_SetWatchKeyCtx(void* ctx, char* error)
return 0;
}
int ssl_SetWatchKey_buffer(void* vSniffer, const byte* key, word32 keySz,
int keyType, char* error)
{
@ -5739,7 +5798,6 @@ int ssl_SetWatchKey_buffer(void* vSniffer, const byte* key, word32 keySz,
return 0;
}
int ssl_SetWatchKey_file(void* vSniffer, const char* keyFile, int keyType,
const char* password, char* error)
{
@ -5786,5 +5844,14 @@ int ssl_SetStoreDataCallback(SSLStoreDataCb cb)
#endif /* WOLFSSL_SNIFFER_STORE_DATA_CB */
#ifdef WOLFSSL_SNIFFER_KEY_CALLBACK
int ssl_SetKeyCallback(SSLKeyCb cb, void* cbCtx)
{
KeyCb = cb;
KeyCbCtx = cbCtx;
return 0;
}
#endif
#endif /* WOLFSSL_SNIFFER */
#endif /* WOLFCRYPT_ONLY */

28
sslSniffer/README.md
View File

@ -369,6 +369,32 @@ Return Values:
* -1 if a problem occurred
### ssl_SetKeyCallback
This feature is enabled by default and will be called when a key is required for a session using static ephemeral keys with TLS v1.3.
The public key being used will be provided allowing lookup of the corresponding private key.
The `privKey` buffer is a dynamic buffer assigned via a call to setup a static ephemeral key via `ssl_SetNamedEphemeralKey` or `ssl_SetEphemeralKey`.
```c
typedef int (*SSLKeyCb)(void* vSniffer, int namedGroup,
const unsigned char* srvPub, unsigned int srvPubSz,
const unsigned char* cliPub, unsigned int cliPubSz,
unsigned char* privKey, unsigned int* privKeySz,
void* ctx, char* error);
int ssl_SetKeyCallback(SSLKeyCb cb, void* ctx, char* error);
```
The parameter `vSniffer` is a typeless pointer to the current sniffer session (`SnifferSession`). The `namedGroup` is the TLS defined named groups like `WOLFSSL_ECC_SECP256R1` or `WOLFSSL_FFDHE_2048`. The server and client public key information are provided to lookup the private key to be used for this session. The loaded private key to be used will be passed in `key`. If a different key should be used it can optionally be returned in `privKey` and `privKeySz`.
Return Values:
* 0 on success
* -1 if a problem occurred, the string error will hold a message describing the problem
## API Usage: SSL Statistics options
For an example on the use of the sniffer stats option, search the source `snifftest.c` for `WOLFSSL_SNIFFER_STATS`.
@ -460,7 +486,7 @@ typedef int (*SSLWatchCb)(void* vSniffer,
void* ctx, char* error);
```
The parameter `vSniffer` is a typeless pointer to the current sniffer session and is meant to be passed directly to the function `ssl_SetWatchKey`. `certHash` is a SHA-256 hash of the certificate sent by the server, and its size is `certHashSz`. A pointer to certificate message’s payload is provided in the parameter `certChain`, and the certificate chain’s size in `certChainSz`. This will be a list of pairs of 24-bit certificate sizes and raw DER certificates in network order from the wire. The application space callback context data is provided in parameter ctx and is set by the function `ssl_SetWatchKeyCtx`. Any error string is copied into parameter error. Your callback function can use these values to locate the appropriate private key and load it into the sniffer session with the function `ssl_SetWatchKey`.
The parameter `vSniffer` is a typeless pointer to the current sniffer session and is meant to be passed directly to the function `ssl_SetWatchKey_file` or `ssl_SetWatchKey_buffer`. The `certHash` is a SHA-256 hash of the certificate sent by the server, and its size is `certHashSz`. A pointer to certificate message’s payload is provided in the parameter `certChain`, and the certificate chain’s size in `certChainSz`. This will be a list of pairs of 24-bit certificate sizes and raw DER certificates in network order from the wire. The application space callback context data is provided in parameter ctx and is set by the function `ssl_SetWatchKeyCtx`. Any error string is copied into parameter error. Your callback function can use these values to locate the appropriate private key and load it into the sniffer session with the function `ssl_SetWatchKey_file` or `ssl_SetWatchKey_buffer`.
Return Values:

29
wolfssl/sniffer.h
View File

@ -25,6 +25,7 @@
#define WOLFSSL_SNIFFER_H
#include <wolfssl/wolfcrypt/settings.h>
#include <wolfssl/wolfcrypt/asn_public.h>
#ifdef _WIN32
#ifdef SSL_SNIFFER_EXPORTS
@ -199,7 +200,21 @@ SSL_SNIFFER_API int ssl_ReadStatistics(SSLStats* stats);
WOLFSSL_API
SSL_SNIFFER_API int ssl_ReadResetStatistics(SSLStats* stats);
typedef int (*SSLKeyCb)(void* vSniffer, int namedGroup,
const unsigned char* srvPub, unsigned int srvPubSz,
const unsigned char* cliPub, unsigned int cliPubSz,
DerBuffer* privKey, void* cbCtx, char* error);
#if defined(WOLFSSL_STATIC_EPHEMERAL) && defined(WOLFSSL_TLS13)
/* macro indicating support for key callback */
#undef WOLFSSL_SNIFFER_KEY_CALLBACK
#define WOLFSSL_SNIFFER_KEY_CALLBACK
WOLFSSL_API
SSL_SNIFFER_API int ssl_SetKeyCallback(SSLKeyCb cb, void* cbCtx);
#endif
#ifdef WOLFSSL_SNIFFER_WATCH
typedef int (*SSLWatchCb)(void* vSniffer,
const unsigned char* certHash,
unsigned int certHashSz,
@ -226,29 +241,37 @@ WOLFSSL_API
SSL_SNIFFER_API int ssl_SetWatchKey_file(void* vSniffer,
const char* keyFile, int keyType,
const char* password, char* error);
#endif
#ifdef WOLFSSL_SNIFFER_STORE_DATA_CB
typedef int (*SSLStoreDataCb)(const unsigned char* decryptBuf,
unsigned int decryptBufSz, unsigned int decryptBufOffset, void* ctx);
WOLFSSL_API
SSL_SNIFFER_API int ssl_SetStoreDataCallback(SSLStoreDataCb cb);
#endif
#ifdef WOLFSSL_SNIFFER_STORE_DATA_CB
WOLFSSL_API
SSL_SNIFFER_API int ssl_DecodePacketWithSessionInfoStoreData(
const unsigned char* packet, int length, void* ctx,
SSLInfo* sslInfo, char* error);
#endif
#ifdef WOLFSSL_SNIFFER_CHAIN_INPUT
WOLFSSL_API
SSL_SNIFFER_API int ssl_DecodePacketWithChain(void* vChain,
unsigned int chainSz, unsigned char** data, char* error);
#endif
#if defined(WOLFSSL_SNIFFER_CHAIN_INPUT) && \
defined(WOLFSSL_SNIFFER_STORE_DATA_CB)
WOLFSSL_API
SSL_SNIFFER_API int ssl_DecodePacketWithChainSessionInfoStoreData(
void* vChain, unsigned int chainSz, void* ctx, SSLInfo* sslInfo,
char* error);
#endif
#ifdef __cplusplus
} /* extern "C" */