/*
* Gather (Read) entire SSL3 records from socket into buffer.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "cert.h"
#include "ssl.h"
#include "sslimpl.h"
#include "ssl3prot.h"
/*
* Attempt to read in an entire SSL3 record.
* Blocks here for blocking sockets, otherwise returns -1 with
* PR_WOULD_BLOCK_ERROR when socket would block.
*
* returns 1 if received a complete SSL3 record.
* returns 0 if recv returns EOF
* returns -1 if recv returns < 0
* (The error value may have already been set to PR_WOULD_BLOCK_ERROR)
*
* Caller must hold the recv buf lock.
*
* The Gather state machine has 3 states: GS_INIT, GS_HEADER, GS_DATA.
* GS_HEADER: waiting for the 5-byte SSL3 record header to come in.
* GS_DATA: waiting for the body of the SSL3 record to come in.
*
* This loop returns when either
* (a) an error or EOF occurs,
* (b) PR_WOULD_BLOCK_ERROR,
* (c) data (entire SSL3 record) has been received.
*/
static int
ssl3_GatherData(sslSocket *ss, sslGather *gs, int flags)
{
unsigned char *bp;
unsigned char *lbp;
int nb;
int err;
int rv = 1;
PORT_Assert( ss->opt.noLocks || ssl_HaveRecvBufLock(ss) );
if (gs->state == GS_INIT) {
gs->state = GS_HEADER;
gs->remainder = 5;
gs->offset = 0;
gs->writeOffset = 0;
gs->readOffset = 0;
gs->inbuf.len = 0;
}
lbp = gs->inbuf.buf;
for(;;) {
SSL_TRC(30, ("%d: SSL3[%d]: gather state %d (need %d more)",
SSL_GETPID(), ss->fd, gs->state, gs->remainder));
bp = ((gs->state != GS_HEADER) ? lbp : gs->hdr) + gs->offset;
nb = ssl_DefRecv(ss, bp, gs->remainder, flags);
if (nb > 0) {
PRINT_BUF(60, (ss, "raw gather data:", bp, nb));
} else if (nb == 0) {
/* EOF */
SSL_TRC(30, ("%d: SSL3[%d]: EOF", SSL_GETPID(), ss->fd));
rv = 0;
break;
} else /* if (nb < 0) */ {
SSL_DBG(("%d: SSL3[%d]: recv error %d", SSL_GETPID(), ss->fd,
PR_GetError()));
rv = SECFailure;
break;
}
PORT_Assert( nb <= gs->remainder );
if (nb > gs->remainder) {
/* ssl_DefRecv is misbehaving! this error is fatal to SSL. */
gs->state = GS_INIT; /* so we don't crash next time */
rv = SECFailure;
break;
}
gs->offset += nb;
gs->remainder -= nb;
if (gs->state == GS_DATA)
gs->inbuf.len += nb;
/* if there's more to go, read some more. */
if (gs->remainder > 0) {
continue;
}
/* have received entire record header, or entire record. */
switch (gs->state) {
case GS_HEADER:
/*
** Have received SSL3 record header in gs->hdr.
** Now extract the length of the following encrypted data,
** and then read in the rest of the SSL3 record into gs->inbuf.
*/
gs->remainder = (gs->hdr[3] << 8) | gs->hdr[4];
/* This is the max fragment length for an encrypted fragment
** plus the size of the record header.
*/
if(gs->remainder > (MAX_FRAGMENT_LENGTH + 2048 + 5)) {
SSL3_SendAlert(ss, alert_fatal, unexpected_message);
gs->state = GS_INIT;
PORT_SetError(SSL_ERROR_RX_RECORD_TOO_LONG);
return SECFailure;
}
gs->state = GS_DATA;
gs->offset = 0;
gs->inbuf.len = 0;
if (gs->remainder > gs->inbuf.space) {
err = sslBuffer_Grow(&gs->inbuf, gs->remainder);
if (err) { /* realloc has set error code to no mem. */
return err;
}
lbp = gs->inbuf.buf;
}
break; /* End this case. Continue around the loop. */
case GS_DATA:
/*
** SSL3 record has been completely received.
*/
gs->state = GS_INIT;
return 1;
}
}
return rv;
}
/*
* Read in an entire DTLS record.
*
* Blocks here for blocking sockets, otherwise returns -1 with
* PR_WOULD_BLOCK_ERROR when socket would block.
*
* This is simpler than SSL because we are reading on a datagram socket
* and datagrams must contain >=1 complete records.
*
* returns 1 if received a complete DTLS record.
* returns 0 if recv returns EOF
* returns -1 if recv returns < 0
* (The error value may have already been set to PR_WOULD_BLOCK_ERROR)
*
* Caller must hold the recv buf lock.
*
* This loop returns when either
* (a) an error or EOF occurs,
* (b) PR_WOULD_BLOCK_ERROR,
* (c) data (entire DTLS record) has been received.
*/
static int
dtls_GatherData(sslSocket *ss, sslGather *gs, int flags)
{
int nb;
int err;
int rv = 1;
SSL_TRC(30, ("dtls_GatherData"));
PORT_Assert( ss->opt.noLocks || ssl_HaveRecvBufLock(ss) );
gs->state = GS_HEADER;
gs->offset = 0;
if (gs->dtlsPacketOffset == gs->dtlsPacket.len) { /* No data left */
gs->dtlsPacketOffset = 0;
gs->dtlsPacket.len = 0;
/* Resize to the maximum possible size so we can fit a full datagram */
/* This is the max fragment length for an encrypted fragment
** plus the size of the record header.
** This magic constant is copied from ssl3_GatherData, with 5 changed
** to 13 (the size of the record header).
*/
if (gs->dtlsPacket.space < MAX_FRAGMENT_LENGTH + 2048 + 13) {
err = sslBuffer_Grow(&gs->dtlsPacket,
MAX_FRAGMENT_LENGTH + 2048 + 13);
if (err) { /* realloc has set error code to no mem. */
return err;
}
}
/* recv() needs to read a full datagram at a time */
nb = ssl_DefRecv(ss, gs->dtlsPacket.buf, gs->dtlsPacket.space, flags);
if (nb > 0) {
PRINT_BUF(60, (ss, "raw gather data:", gs->dtlsPacket.buf, nb));
} else if (nb == 0) {
/* EOF */
SSL_TRC(30, ("%d: SSL3[%d]: EOF", SSL_GETPID(), ss->fd));
rv = 0;
return rv;
} else /* if (nb < 0) */ {
SSL_DBG(("%d: SSL3[%d]: recv error %d", SSL_GETPID(), ss->fd,
PR_GetError()));
rv = SECFailure;
return rv;
}
gs->dtlsPacket.len = nb;
}
/* At this point we should have >=1 complete records lined up in
* dtlsPacket. Read off the header.
*/
if ((gs->dtlsPacket.len - gs->dtlsPacketOffset) < 13) {
SSL_DBG(("%d: SSL3[%d]: rest of DTLS packet "
"too short to contain header", SSL_GETPID(), ss->fd));
PR_SetError(PR_WOULD_BLOCK_ERROR, 0);
gs->dtlsPacketOffset = 0;
gs->dtlsPacket.len = 0;
rv = SECFailure;
return rv;
}
memcpy(gs->hdr, gs->dtlsPacket.buf + gs->dtlsPacketOffset, 13);
gs->dtlsPacketOffset += 13;
/* Have received SSL3 record header in gs->hdr. */
gs->remainder = (gs->hdr[11] << 8) | gs->hdr[12];
if ((gs->dtlsPacket.len - gs->dtlsPacketOffset) < gs->remainder) {
SSL_DBG(("%d: SSL3[%d]: rest of DTLS packet too short "
"to contain rest of body", SSL_GETPID(), ss->fd));
PR_SetError(PR_WOULD_BLOCK_ERROR, 0);
gs->dtlsPacketOffset = 0;
gs->dtlsPacket.len = 0;
rv = SECFailure;
return rv;
}
/* OK, we have at least one complete packet, copy into inbuf */
if (gs->remainder > gs->inbuf.space) {
err = sslBuffer_Grow(&gs->inbuf, gs->remainder);
if (err) { /* realloc has set error code to no mem. */
return err;
}
}
memcpy(gs->inbuf.buf, gs->dtlsPacket.buf + gs->dtlsPacketOffset,
gs->remainder);
gs->inbuf.len = gs->remainder;
gs->offset = gs->remainder;
gs->dtlsPacketOffset += gs->remainder;
gs->state = GS_INIT;
return 1;
}
/* Gather in a record and when complete, Handle that record.
* Repeat this until the handshake is complete,
* or until application data is available.
*
* Returns 1 when the handshake is completed without error, or
* application data is available.
* Returns 0 if ssl3_GatherData hits EOF.
* Returns -1 on read error, or PR_WOULD_BLOCK_ERROR, or handleRecord error.
* Returns -2 on SECWouldBlock return from ssl3_HandleRecord.
*
* Called from ssl_GatherRecord1stHandshake in sslcon.c,
* and from SSL_ForceHandshake in sslsecur.c
* and from ssl3_GatherAppDataRecord below (<- DoRecv in sslsecur.c).
*
* Caller must hold the recv buf lock.
*/
int
ssl3_GatherCompleteHandshake(sslSocket *ss, int flags)
{
SSL3Ciphertext cText;
int rv;
PRBool keepGoing = PR_TRUE;
SSL_TRC(30, ("ssl3_GatherCompleteHandshake"));
/* ssl3_HandleRecord may end up eventually calling ssl_FinishHandshake,
* which requires the 1stHandshakeLock, which must be acquired before the
* RecvBufLock.
*/
PORT_Assert( ss->opt.noLocks || ssl_Have1stHandshakeLock(ss) );
PORT_Assert( ss->opt.noLocks || ssl_HaveRecvBufLock(ss) );
do {
PRBool handleRecordNow = PR_FALSE;
ssl_GetSSL3HandshakeLock(ss);
/* Without this, we may end up wrongly reporting
* SSL_ERROR_RX_UNEXPECTED_* errors if we receive any records from the
* peer while we are waiting to be restarted.
*/
if (ss->ssl3.hs.restartTarget) {
ssl_ReleaseSSL3HandshakeLock(ss);
PORT_SetError(PR_WOULD_BLOCK_ERROR);
return (int) SECFailure;
}
/* Treat an empty msgState like a NULL msgState. (Most of the time
* when ssl3_HandleHandshake returns SECWouldBlock, it leaves
* behind a non-NULL but zero-length msgState).
* Test: async_cert_restart_server_sends_hello_request_first_in_separate_record
*/
if (ss->ssl3.hs.msgState.buf) {
if (ss->ssl3.hs.msgState.len == 0) {
ss->ssl3.hs.msgState.buf = NULL;
} else {
handleRecordNow = PR_TRUE;
}
}
ssl_ReleaseSSL3HandshakeLock(ss);
if (handleRecordNow) {
/* ssl3_HandleHandshake previously returned SECWouldBlock and the
* as-yet-unprocessed plaintext of that previous handshake record.
* We need to process it now before we overwrite it with the next
* handshake record.
*/
rv = ssl3_HandleRecord(ss, NULL, &ss->gs.buf);
} else {
/* bring in the next sslv3 record. */
if (ss->recvdCloseNotify) {
/* RFC 5246 Section 7.2.1:
* Any data received after a closure alert is ignored.
*/
return 0;
}
if (!IS_DTLS(ss)) {
rv = ssl3_GatherData(ss, &ss->gs, flags);
} else {
rv = dtls_GatherData(ss, &ss->gs, flags);
/* If we got a would block error, that means that no data was
* available, so we check the timer to see if it's time to
* retransmit */
if (rv == SECFailure &&
(PORT_GetError() == PR_WOULD_BLOCK_ERROR)) {
ssl_GetSSL3HandshakeLock(ss);
dtls_CheckTimer(ss);
ssl_ReleaseSSL3HandshakeLock(ss);
/* Restore the error in case something succeeded */
PORT_SetError(PR_WOULD_BLOCK_ERROR);
}
}
if (rv <= 0) {
return rv;
}
/* decipher it, and handle it if it's a handshake.
* If it's application data, ss->gs.buf will not be empty upon return.
* If it's a change cipher spec, alert, or handshake message,
* ss->gs.buf.len will be 0 when ssl3_HandleRecord returns SECSuccess.
*/
cText.type = (SSL3ContentType)ss->gs.hdr[0];
cText.version = (ss->gs.hdr[1] << 8) | ss->gs.hdr[2];
if (IS_DTLS(ss)) {
int i;
cText.version = dtls_DTLSVersionToTLSVersion(cText.version);
/* DTLS sequence number */
cText.seq_num.high = 0; cText.seq_num.low = 0;
for (i = 0; i < 4; i++) {
cText.seq_num.high <<= 8; cText.seq_num.low <<= 8;
cText.seq_num.high |= ss->gs.hdr[3 + i];
cText.seq_num.low |= ss->gs.hdr[7 + i];
}
}
cText.buf = &ss->gs.inbuf;
rv = ssl3_HandleRecord(ss, &cText, &ss->gs.buf);
}
if (rv < 0) {
return ss->recvdCloseNotify ? 0 : rv;
}
if (ss->gs.buf.len > 0) {
/* We have application data to return to the application. This
* prioritizes returning application data to the application over
* completing any renegotiation handshake we may be doing.
*/
PORT_Assert(ss->firstHsDone);
PORT_Assert(cText.type == content_application_data);
break;
}
PORT_Assert(keepGoing);
ssl_GetSSL3HandshakeLock(ss);
if (ss->ssl3.hs.ws == idle_handshake) {
/* We are done with the current handshake so stop trying to
* handshake. Note that it would be safe to test ss->firstHsDone
* instead of ss->ssl3.hs.ws. By testing ss->ssl3.hs.ws instead,
* we prioritize completing a renegotiation handshake over sending
* application data.
*/
PORT_Assert(ss->firstHsDone);
PORT_Assert(!ss->ssl3.hs.canFalseStart);
keepGoing = PR_FALSE;
} else if (ss->ssl3.hs.canFalseStart) {
/* Prioritize sending application data over trying to complete
* the handshake if we're false starting.
*
* If we were to do this check at the beginning of the loop instead
* of here, then this function would become be a no-op after
* receiving the ServerHelloDone in the false start case, and we
* would never complete the handshake.
*/
PORT_Assert(!ss->firstHsDone);
if (ssl3_WaitingForStartOfServerSecondRound(ss)) {
keepGoing = PR_FALSE;
} else {
ss->ssl3.hs.canFalseStart = PR_FALSE;
}
}
ssl_ReleaseSSL3HandshakeLock(ss);
} while (keepGoing);
ss->gs.readOffset = 0;
ss->gs.writeOffset = ss->gs.buf.len;
return 1;
}
/* Repeatedly gather in a record and when complete, Handle that record.
* Repeat this until some application data is received.
*
* Returns 1 when application data is available.
* Returns 0 if ssl3_GatherData hits EOF.
* Returns -1 on read error, or PR_WOULD_BLOCK_ERROR, or handleRecord error.
* Returns -2 on SECWouldBlock return from ssl3_HandleRecord.
*
* Called from DoRecv in sslsecur.c
* Caller must hold the recv buf lock.
*/
int
ssl3_GatherAppDataRecord(sslSocket *ss, int flags)
{
int rv;
/* ssl3_GatherCompleteHandshake requires both of these locks. */
PORT_Assert( ss->opt.noLocks || ssl_Have1stHandshakeLock(ss) );
PORT_Assert( ss->opt.noLocks || ssl_HaveRecvBufLock(ss) );
do {
rv = ssl3_GatherCompleteHandshake(ss, flags);
} while (rv > 0 && ss->gs.buf.len == 0);
return rv;
}