Boundaries check for DoCertificate .

-- added size in the function parameters;
-- BUFFER_ERROR returned in case of message overflow (piece larger than the hello size);
-- OPAQUE24_LEN used whenever 3 bytes are needed;
-- removed unnecessary variable i;
-- Moved BUFFER_E check outside of the while, check against certSz is not needed, in this case the problem is a malformed packet since certSz can never be bigger than listSz.
This commit is contained in:
Moisés Guimarães 2014-03-13 19:15:26 -03:00
parent 2d2d1341cf
commit 0a5b758de3

View File

@ -3242,9 +3242,10 @@ int CopyDecodedToX509(CYASSL_X509* x509, DecodedCert* dCert)
#endif /* KEEP_PEER_CERT || SESSION_CERTS */
static int DoCertificate(CYASSL* ssl, byte* input, word32* inOutIdx)
static int DoCertificate(CYASSL* ssl, byte* input, word32* inOutIdx,
word32 size)
{
word32 listSz, i = *inOutIdx;
word32 listSz, begin = *inOutIdx;
int ret = 0;
int anyError = 0;
int totalCerts = 0; /* number of certs in certs buffer */
@ -3256,46 +3257,58 @@ static int DoCertificate(CYASSL* ssl, byte* input, word32* inOutIdx)
if (ssl->hsInfoOn) AddPacketName("Certificate", &ssl->handShakeInfo);
if (ssl->toInfoOn) AddLateName("Certificate", &ssl->timeoutInfo);
#endif
c24to32(&input[i], &listSz);
i += CERT_HEADER_SZ;
if ((*inOutIdx - begin) + OPAQUE24_LEN > size)
return BUFFER_ERROR;
c24to32(input + *inOutIdx, &listSz);
*inOutIdx += OPAQUE24_LEN;
#ifdef HAVE_MAX_FRAGMENT
if (listSz > ssl->max_fragment)
return BUFFER_E;
#else
if (listSz > MAX_RECORD_SIZE)
return BUFFER_E;
#endif
if ((*inOutIdx - begin) + listSz != size)
return BUFFER_ERROR;
CYASSL_MSG("Loading peer's cert chain");
/* first put cert chain into buffer so can verify top down
we're sent bottom up */
while (listSz) {
/* cert size */
word32 certSz;
if (totalCerts >= MAX_CHAIN_DEPTH)
return MAX_CHAIN_ERROR;
c24to32(&input[i], &certSz);
i += CERT_HEADER_SZ;
#ifdef HAVE_MAX_FRAGMENT
if (listSz > ssl->max_fragment || certSz > ssl->max_fragment)
return BUFFER_E;
#else
if (listSz > MAX_RECORD_SIZE || certSz > MAX_RECORD_SIZE)
return BUFFER_E;
#endif
if ((*inOutIdx - begin) + OPAQUE24_LEN > size)
return BUFFER_ERROR;
c24to32(input + *inOutIdx, &certSz);
*inOutIdx += OPAQUE24_LEN;
if ((*inOutIdx - begin) + certSz > size)
return BUFFER_ERROR;
certs[totalCerts].length = certSz;
certs[totalCerts].buffer = input + i;
certs[totalCerts].buffer = input + *inOutIdx;
#ifdef SESSION_CERTS
if (ssl->session.chain.count < MAX_CHAIN_DEPTH &&
certSz < MAX_X509_SIZE) {
ssl->session.chain.certs[ssl->session.chain.count].length = certSz;
XMEMCPY(ssl->session.chain.certs[ssl->session.chain.count].buffer,
input + i, certSz);
input + *inOutIdx, certSz);
ssl->session.chain.count++;
} else {
CYASSL_MSG("Couldn't store chain cert for session");
}
#endif
i += certSz;
*inOutIdx += certSz;
listSz -= certSz + CERT_HEADER_SZ;
totalCerts++;
@ -3625,7 +3638,6 @@ static int DoCertificate(CYASSL* ssl, byte* input, word32* inOutIdx)
}
#endif
*inOutIdx = i;
return ret;
}
@ -3816,7 +3828,7 @@ static int DoHandShakeMsgType(CYASSL* ssl, byte* input, word32* inOutIdx,
#ifndef NO_CERTS
case certificate:
CYASSL_MSG("processing certificate");
ret = DoCertificate(ssl, input, inOutIdx);
ret = DoCertificate(ssl, input, inOutIdx, size);
break;
#endif