Boundaries check for client hello parsing.
-- INCOMPLETE DATA checked only once with hello size against buffer size -- BUFFER_ERROR returned in case of message overflow (piece larger than the hello size) -- OPAQUE16_LEN used whenever 2 bytes are needed. -- Session id checking improved. TLS extensions return codes fixed.
This commit is contained in:
Moisés Guimarães
parent
1cf884dccc
commit
2ff78b7fda
129
src/internal.c
129
src/internal.c
@ -9988,30 +9988,39 @@ static void PickHashSigAlgo(CYASSL* ssl,
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static int DoClientHello(CYASSL* ssl, const byte* input, word32* inOutIdx,
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word32 totalSz, word32 helloSz)
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{
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byte b;
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byte b;
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ProtocolVersion pv;
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Suites clSuites;
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word32 i = *inOutIdx;
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word32 begin = i;
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word32 i = *inOutIdx;
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word32 begin = i;
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#ifdef CYASSL_CALLBACKS
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if (ssl->hsInfoOn) AddPacketName("ClientHello", &ssl->handShakeInfo);
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if (ssl->toInfoOn) AddLateName("ClientHello", &ssl->timeoutInfo);
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#endif
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/* make sure can read up to session */
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if (i + sizeof(pv) + RAN_LEN + ENUM_LEN > totalSz)
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/* make sure can read the client hello */
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if (begin + helloSz > totalSz)
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return INCOMPLETE_DATA;
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XMEMCPY(&pv, input + i, sizeof(pv));
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/* protocol version, random and session id length check */
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if ((i - begin) + OPAQUE16_LEN + RAN_LEN + ENUM_LEN > helloSz)
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return BUFFER_ERROR;
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/* protocol version */
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XMEMCPY(&pv, input + i, OPAQUE16_LEN);
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ssl->chVersion = pv; /* store */
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i += (word32)sizeof(pv);
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i += OPAQUE16_LEN;
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if (ssl->version.minor > pv.minor) {
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byte haveRSA = 0;
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byte havePSK = 0;
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if (!ssl->options.downgrade) {
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CYASSL_MSG("Client trying to connect with lesser version");
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return VERSION_ERROR;
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}
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if (pv.minor == SSLv3_MINOR) {
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/* turn off tls */
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CYASSL_MSG(" downgrading to SSLv3");
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@ -10040,6 +10049,7 @@ static void PickHashSigAlgo(CYASSL* ssl,
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ssl->options.haveECDSAsig, ssl->options.haveStaticECC,
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ssl->options.side);
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}
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/* random */
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XMEMCPY(ssl->arrays->clientRandom, input + i, RAN_LEN);
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i += RAN_LEN;
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@ -10053,79 +10063,103 @@ static void PickHashSigAlgo(CYASSL* ssl,
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printf("\n");
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}
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#endif
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/* session id */
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b = input[i++];
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if (b) {
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if (i + ID_LEN > totalSz)
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return INCOMPLETE_DATA;
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if (b == ID_LEN) {
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if ((i - begin) + ID_LEN > helloSz)
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return BUFFER_ERROR;
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XMEMCPY(ssl->arrays->sessionID, input + i, ID_LEN);
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i += b;
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ssl->options.resuming= 1; /* client wants to resume */
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i += ID_LEN;
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ssl->options.resuming = 1; /* client wants to resume */
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CYASSL_MSG("Client wants to resume session");
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}
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else if (b)
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return BUFFER_ERROR; /* session ID nor 0 neither 32 bytes long */
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#ifdef CYASSL_DTLS
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/* cookie */
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if (ssl->options.dtls) {
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if ((i - begin) + ENUM_LEN > helloSz)
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return BUFFER_ERROR;
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b = input[i++];
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if (b) {
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byte cookie[MAX_COOKIE_LEN];
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if (b > MAX_COOKIE_LEN)
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return BUFFER_ERROR;
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if (i + b > totalSz)
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return INCOMPLETE_DATA;
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if ((i - begin) + b > helloSz)
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return BUFFER_ERROR;
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if (ssl->ctx->CBIOCookie == NULL) {
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CYASSL_MSG("Your Cookie callback is null, please set");
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return COOKIE_ERROR;
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}
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if ((ssl->ctx->CBIOCookie(ssl, cookie, COOKIE_SZ,
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ssl->IOCB_CookieCtx) != COOKIE_SZ)
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|| (b != COOKIE_SZ)
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|| (XMEMCMP(cookie, input + i, b) != 0)) {
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return COOKIE_ERROR;
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}
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i += b;
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}
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}
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#endif
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if (i + LENGTH_SZ > totalSz)
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return INCOMPLETE_DATA;
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/* suites */
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ato16(&input[i], &clSuites.suiteSz);
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i += 2;
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if ((i - begin) + OPAQUE16_LEN > helloSz)
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return BUFFER_ERROR;
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ato16(&input[i], &clSuites.suiteSz);
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i += OPAQUE16_LEN;
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/* suites and compression length check */
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if ((i - begin) + clSuites.suiteSz + ENUM_LEN > helloSz)
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return BUFFER_ERROR;
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/* suites and comp len */
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if (i + clSuites.suiteSz + ENUM_LEN > totalSz)
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return INCOMPLETE_DATA;
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if (clSuites.suiteSz > MAX_SUITE_SZ)
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return BUFFER_ERROR;
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XMEMCPY(clSuites.suites, input + i, clSuites.suiteSz);
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i += clSuites.suiteSz;
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clSuites.hashSigAlgoSz = 0;
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b = input[i++]; /* comp len */
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if (i + b > totalSz)
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return INCOMPLETE_DATA;
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/* compression length */
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b = input[i++];
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if ((i - begin) + b > helloSz)
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return BUFFER_ERROR;
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if (ssl->options.usingCompression) {
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int match = 0;
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while (b--) {
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byte comp = input[i++];
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if (comp == ZLIB_COMPRESSION)
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match = 1;
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}
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if (!match) {
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CYASSL_MSG("Not matching compression, turning off");
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ssl->options.usingCompression = 0; /* turn off */
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}
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}
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else
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i += b; /* ignore, since we're not on */
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i += b; /* ignore, since we're not on */
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*inOutIdx = i;
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if ( (i - begin) < helloSz) {
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/* tls extensions */
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if ((i - begin) < helloSz) {
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#ifdef HAVE_TLS_EXTENSIONS
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if (IsTLS(ssl)) {
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int ret = 0;
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@ -10135,10 +10169,14 @@ static void PickHashSigAlgo(CYASSL* ssl,
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/* Process the hello extension. Skip unsupported. */
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word16 totalExtSz;
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if ((i - begin) + OPAQUE16_LEN > helloSz)
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return BUFFER_ERROR;
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ato16(&input[i], &totalExtSz);
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i += LENGTH_SZ;
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if (totalExtSz > helloSz + begin - i)
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return INCOMPLETE_DATA;
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i += OPAQUE16_LEN;
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if ((i - begin) + totalExtSz > helloSz)
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return BUFFER_ERROR;
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#ifdef HAVE_TLS_EXTENSIONS
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if ((ret = TLSX_Parse(ssl, (byte *) input + i,
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@ -10149,19 +10187,24 @@ static void PickHashSigAlgo(CYASSL* ssl,
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#else
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while (totalExtSz) {
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word16 extId, extSz;
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if (OPAQUE16_LEN + OPAQUE16_LEN > totalExtSz)
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return BUFFER_ERROR;
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ato16(&input[i], &extId);
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i += LENGTH_SZ;
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i += OPAQUE16_LEN;
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ato16(&input[i], &extSz);
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i += EXT_ID_SZ;
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if (extSz > totalExtSz - LENGTH_SZ - EXT_ID_SZ)
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return INCOMPLETE_DATA;
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i += OPAQUE16_LEN;
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if (OPAQUE16_LEN + OPAQUE16_LEN + extSz > totalExtSz)
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return BUFFER_ERROR;
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if (extId == HELLO_EXT_SIG_ALGO) {
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ato16(&input[i], &clSuites.hashSigAlgoSz);
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i += LENGTH_SZ;
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if (clSuites.hashSigAlgoSz > extSz - LENGTH_SZ)
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return INCOMPLETE_DATA;
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i += OPAQUE16_LEN;
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if (OPAQUE16_LEN + clSuites.hashSigAlgoSz > extSz)
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return BUFFER_ERROR;
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XMEMCPY(clSuites.hashSigAlgo, &input[i],
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min(clSuites.hashSigAlgoSz, HELLO_EXT_SIGALGO_MAX));
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@ -10170,27 +10213,29 @@ static void PickHashSigAlgo(CYASSL* ssl,
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else
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i += extSz;
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totalExtSz -= LENGTH_SZ + EXT_ID_SZ + extSz;
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totalExtSz -= OPAQUE16_LEN + OPAQUE16_LEN + extSz;
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}
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#endif
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*inOutIdx = i;
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}
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else
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*inOutIdx = begin + helloSz; /* skip extensions */
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*inOutIdx = begin + helloSz; /* skip extensions */
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}
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ssl->options.clientState = CLIENT_HELLO_COMPLETE;
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ssl->options.clientState = CLIENT_HELLO_COMPLETE;
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ssl->options.haveSessionId = 1;
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/* ProcessOld uses same resume code */
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if (ssl->options.resuming && (!ssl->options.dtls ||
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ssl->options.acceptState == HELLO_VERIFY_SENT)) { /* let's try */
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ssl->options.acceptState == HELLO_VERIFY_SENT)) { /* let's try */
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int ret = -1;
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CYASSL_SESSION* session = GetSession(ssl,ssl->arrays->masterSecret);
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if (!session) {
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CYASSL_MSG("Session lookup for resume failed");
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ssl->options.resuming = 0;
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} else {
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}
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else {
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if (MatchSuite(ssl, &clSuites) < 0) {
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CYASSL_MSG("Unsupported cipher suite, ClientHello");
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return UNSUPPORTED_SUITE;
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62
src/tls.c
62
src/tls.c
@ -721,46 +721,38 @@ static int TLSX_SNI_Parse(CYASSL* ssl, byte* input, word16 length,
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if (!extension)
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extension = TLSX_Find(ssl->ctx->extensions, SERVER_NAME_INDICATION);
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if (!extension || !extension->data) {
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if (!isRequest) {
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CYASSL_MSG("Unexpected SNI response from server");
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}
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if (!extension || !extension->data)
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return isRequest ? 0 : BUFFER_ERROR; /* not using SNI OR unexpected
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SNI response from server. */
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return 0; /* not using SNI */
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}
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if (!isRequest) {
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if (length) {
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CYASSL_MSG("SNI response should be empty!");
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}
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return 0; /* nothing to do */
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}
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if (!isRequest)
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return length ? BUFFER_ERROR : 0; /* SNI response must be empty!
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Nothing else to do. */
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#ifndef NO_CYASSL_SERVER
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if (OPAQUE16_LEN > length)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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ato16(input, &size);
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offset += OPAQUE16_LEN;
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/* validating sni list length */
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if (length != OPAQUE16_LEN + size)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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for (size = 0; offset < length; offset += size) {
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SNI *sni;
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byte type = input[offset++];
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if (offset + OPAQUE16_LEN > length)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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ato16(input + offset, &size);
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offset += OPAQUE16_LEN;
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if (offset + size > length)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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if (!(sni = TLSX_SNI_Find((SNI *) extension->data, type))) {
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continue; /* not using this SNI type */
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@ -905,34 +897,34 @@ int TLSX_SNI_GetFromBuffer(const byte* clientHello, word32 helloSz,
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offset += HANDSHAKE_HEADER_SZ;
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if (offset + len32 > helloSz)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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/* client hello */
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offset += VERSION_SZ + RAN_LEN; /* version, random */
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if (helloSz < offset + clientHello[offset])
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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offset += ENUM_LEN + clientHello[offset]; /* skip session id */
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/* cypher suites */
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if (helloSz < offset + OPAQUE16_LEN)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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ato16(clientHello + offset, &len16);
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offset += OPAQUE16_LEN;
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if (helloSz < offset + len16)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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offset += len16; /* skip cypher suites */
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/* compression methods */
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if (helloSz < offset + 1)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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if (helloSz < offset + clientHello[offset])
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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offset += ENUM_LEN + clientHello[offset]; /* skip compression methods */
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@ -944,7 +936,7 @@ int TLSX_SNI_GetFromBuffer(const byte* clientHello, word32 helloSz,
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offset += OPAQUE16_LEN;
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if (helloSz < offset + len16)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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while (len16 > OPAQUE16_LEN + OPAQUE16_LEN) {
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word16 extType;
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@ -957,7 +949,7 @@ int TLSX_SNI_GetFromBuffer(const byte* clientHello, word32 helloSz,
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offset += OPAQUE16_LEN;
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if (helloSz < offset + extLen)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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if (extType != SERVER_NAME_INDICATION) {
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offset += extLen; /* skip extension */
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@ -968,7 +960,7 @@ int TLSX_SNI_GetFromBuffer(const byte* clientHello, word32 helloSz,
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offset += OPAQUE16_LEN;
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if (helloSz < offset + listLen)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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while (listLen > ENUM_LEN + OPAQUE16_LEN) {
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byte sniType = clientHello[offset++];
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@ -978,7 +970,7 @@ int TLSX_SNI_GetFromBuffer(const byte* clientHello, word32 helloSz,
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offset += OPAQUE16_LEN;
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if (helloSz < offset + sniLen)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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if (sniType != type) {
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offset += sniLen;
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@ -1028,7 +1020,7 @@ static int TLSX_MFL_Parse(CYASSL* ssl, byte* input, word16 length,
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byte isRequest)
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{
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if (length != ENUM_LEN)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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switch (*input) {
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case CYASSL_MFL_2_9 : ssl->max_fragment = 512; break;
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@ -1135,7 +1127,7 @@ static int TLSX_THM_Parse(CYASSL* ssl, byte* input, word16 length,
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byte isRequest)
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{
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if (length != 0 || input == NULL)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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#ifndef NO_CYASSL_SERVER
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if (isRequest) {
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@ -1258,13 +1250,13 @@ static int TLSX_EllipticCurve_Parse(CYASSL* ssl, byte* input, word16 length,
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(void) isRequest; /* shut up compiler! */
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if (OPAQUE16_LEN > length || length % OPAQUE16_LEN)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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ato16(input, &offset);
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/* validating curve list length */
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if (length != OPAQUE16_LEN + offset)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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while (offset) {
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ato16(input + offset, &name);
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@ -1705,7 +1697,7 @@ int TLSX_Parse(CYASSL* ssl, byte* input, word16 length, byte isRequest,
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word16 size;
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if (length - offset < HELLO_EXT_TYPE_SZ + OPAQUE16_LEN)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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ato16(input + offset, &type);
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offset += HELLO_EXT_TYPE_SZ;
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@ -1714,7 +1706,7 @@ int TLSX_Parse(CYASSL* ssl, byte* input, word16 length, byte isRequest,
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offset += OPAQUE16_LEN;
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if (offset + size > length)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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switch (type) {
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case SERVER_NAME_INDICATION:
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@ -1748,7 +1740,7 @@ int TLSX_Parse(CYASSL* ssl, byte* input, word16 length, byte isRequest,
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ato16(input + offset, &suites->hashSigAlgoSz);
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if (suites->hashSigAlgoSz > size - OPAQUE16_LEN)
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return INCOMPLETE_DATA;
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return BUFFER_ERROR;
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XMEMCPY(suites->hashSigAlgo,
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input + offset + OPAQUE16_LEN,
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