gecko-dev/security/nss/lib/ssl/ssl3gthr.c

239 строки
7.2 KiB
C

/*
* Gather (Read) entire SSL3 records from socket into buffer.
*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is the Netscape security libraries.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1994-2000 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License Version 2 or later (the
* "GPL"), in which case the provisions of the GPL are applicable
* instead of those above. If you wish to allow use of your
* version of this file only under the terms of the GPL and not to
* allow others to use your version of this file under the MPL,
* indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by
* the GPL. If you do not delete the provisions above, a recipient
* may use your version of this file under either the MPL or the
* GPL.
*
* $Id: ssl3gthr.c,v 1.3 2000/12/02 00:53:59 nelsonb%netscape.com 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( 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;
}
/* 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)
{
sslGather * gs = ss->gather;
SSL3Ciphertext cText;
int rv;
PORT_Assert( ssl_HaveRecvBufLock(ss) );
do {
/* bring in the next sslv3 record. */
rv = ssl3_GatherData(ss, gs, flags);
if (rv <= 0) {
return rv;
}
/* decipher it, and handle it if it's a handshake.
* If it's application data, gs->buf will not be empty upon return.
*/
cText.type = (SSL3ContentType)gs->hdr[0];
cText.version = (gs->hdr[1] << 8) | gs->hdr[2];
cText.buf = &gs->inbuf;
rv = ssl3_HandleRecord(ss, &cText, &gs->buf);
if (rv < 0) {
return ss->recvdCloseNotify ? 0 : rv;
}
} while (ss->ssl3->hs.ws != idle_handshake && gs->buf.len == 0);
gs->readOffset = 0;
gs->writeOffset = 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)
{
sslGather * gs = ss->gather;
int rv;
PORT_Assert( ssl_HaveRecvBufLock(ss) );
do {
rv = ssl3_GatherCompleteHandshake(ss, flags);
} while (rv > 0 && gs->buf.len == 0);
return rv;
}