src/net/third_party/nss/ssl/ssl3gthr.c - cobalt - Git at Google

 /*
  * 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/. */
 /* $Id: ssl3gthr.c,v 1.14 2012/04/25 14:50:12 gerv%gerv.net Exp $ */

 #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         canFalseStart = PR_FALSE;

     SSL_TRC(30, ("ssl3_GatherCompleteHandshake"));

     PORT_Assert( ss->opt.noLocks || ssl_HaveRecvBufLock(ss) );
     do {
 	/* 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.
 	 */
 	ssl_GetSSL3HandshakeLock(ss);
 	rv = ss->ssl3.hs.restartTarget == NULL ? SECSuccess : SECFailure;
 	ssl_ReleaseSSL3HandshakeLock(ss);
 	if (rv != SECSuccess) {
 	    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 != NULL) {
 	    if (ss->ssl3.hs.msgState.len == 0) {
 		ss->ssl3.hs.msgState.buf = NULL;
 	    }
 	}

 	if (ss->ssl3.hs.msgState.buf != NULL) {
 	    /* 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 (!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 we kicked off a false start in ssl3_HandleServerHelloDone, break
 	 * out of this loop early without finishing the handshake.
 	 */
 	if (ss->opt.enableFalseStart) {
 	    ssl_GetSSL3HandshakeLock(ss);
 	    canFalseStart = (ss->ssl3.hs.ws == wait_change_cipher ||
 			     ss->ssl3.hs.ws == wait_new_session_ticket) &&
 		            ssl3_CanFalseStart(ss);
 	    ssl_ReleaseSSL3HandshakeLock(ss);
 	}
     } while (ss->ssl3.hs.ws != idle_handshake &&
              !canFalseStart &&
              ss->gs.buf.len == 0);

     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;

     PORT_Assert( ss->opt.noLocks || ssl_HaveRecvBufLock(ss) );
     do {
 	rv = ssl3_GatherCompleteHandshake(ss, flags);
     } while (rv > 0 && ss->gs.buf.len == 0);

     return rv;
 }
	/*
	* 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/. */
	/* $Id: ssl3gthr.c,v 1.14 2012/04/25 14:50:12 gerv%gerv.net Exp $ */

	#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 canFalseStart = PR_FALSE;

	SSL_TRC(30, ("ssl3_GatherCompleteHandshake"));

	PORT_Assert( ss->opt.noLocks \|\| ssl_HaveRecvBufLock(ss) );
	do {
	/* 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.
	*/
	ssl_GetSSL3HandshakeLock(ss);
	rv = ss->ssl3.hs.restartTarget == NULL ? SECSuccess : SECFailure;
	ssl_ReleaseSSL3HandshakeLock(ss);
	if (rv != SECSuccess) {
	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 != NULL) {
	if (ss->ssl3.hs.msgState.len == 0) {
	ss->ssl3.hs.msgState.buf = NULL;
	}
	}

	if (ss->ssl3.hs.msgState.buf != NULL) {
	/* 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 (!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 we kicked off a false start in ssl3_HandleServerHelloDone, break
	* out of this loop early without finishing the handshake.
	*/
	if (ss->opt.enableFalseStart) {
	ssl_GetSSL3HandshakeLock(ss);
	canFalseStart = (ss->ssl3.hs.ws == wait_change_cipher \|\|
	ss->ssl3.hs.ws == wait_new_session_ticket) &&
	ssl3_CanFalseStart(ss);
	ssl_ReleaseSSL3HandshakeLock(ss);
	}
	} while (ss->ssl3.hs.ws != idle_handshake &&
	!canFalseStart &&
	ss->gs.buf.len == 0);

	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;

	PORT_Assert( ss->opt.noLocks \|\| ssl_HaveRecvBufLock(ss) );
	do {
	rv = ssl3_GatherCompleteHandshake(ss, flags);
	} while (rv > 0 && ss->gs.buf.len == 0);

	return rv;
	}