/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* * 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 "sslproto.h" #include "ssl3prot.h" struct ssl2GatherStr { /* true when ssl3_GatherData encounters an SSLv2 handshake */ PRBool isV2; /* number of bytes of padding appended to the message content */ PRUint8 padding; }; typedef struct ssl2GatherStr ssl2Gather; /* Caller should hold RecvBufLock. */ SECStatus ssl3_InitGather(sslGather *gs) { SECStatus status; gs->state = GS_INIT; gs->writeOffset = 0; gs->readOffset = 0; gs->dtlsPacketOffset = 0; gs->dtlsPacket.len = 0; gs->rejectV2Records = PR_FALSE; status = sslBuffer_Grow(&gs->buf, 4096); return status; } /* Caller must hold RecvBufLock. */ void ssl3_DestroyGather(sslGather *gs) { if (gs) { /* the PORT_*Free functions check for NULL pointers. */ PORT_ZFree(gs->buf.buf, gs->buf.space); PORT_Free(gs->inbuf.buf); PORT_Free(gs->dtlsPacket.buf); } } /* Checks whether a given buffer is likely an SSLv3 record header. */ PRBool ssl3_isLikelyV3Hello(const unsigned char *buf) { /* Even if this was a V2 record header we couldn't possibly parse it * correctly as the second bit denotes a vaguely-defined security escape. */ if (buf[0] & 0x40) { return PR_TRUE; } /* Check for a typical V3 record header. */ return (PRBool)(buf[0] >= ssl_ct_change_cipher_spec && buf[0] <= ssl_ct_application_data && buf[1] == MSB(SSL_LIBRARY_VERSION_3_0)); } /* * 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, ssl2Gather *ssl2gs) { unsigned char *bp; unsigned char *lbp; int nb; int err; int rv = 1; PRUint8 v2HdrLength = 0; 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((unsigned int)nb <= gs->remainder); if ((unsigned int)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: /* Check for SSLv2 handshakes. Always assume SSLv3 on clients, * support SSLv2 handshakes only when ssl2gs != NULL. * Always assume v3 after we received the first record. */ if (!ssl2gs || ss->gs.rejectV2Records || ssl3_isLikelyV3Hello(gs->hdr)) { /* Should have a non-SSLv2 record header in gs->hdr. Extract * the length of the following encrypted data, and then * read in the rest of the record into gs->inbuf. */ gs->remainder = (gs->hdr[3] << 8) | gs->hdr[4]; gs->hdrLen = SSL3_RECORD_HEADER_LENGTH; } else { /* Probably an SSLv2 record header. No need to handle any * security escapes (gs->hdr[0] & 0x40) as we wouldn't get * here if one was set. See ssl3_isLikelyV3Hello(). */ gs->remainder = ((gs->hdr[0] & 0x7f) << 8) | gs->hdr[1]; ssl2gs->isV2 = PR_TRUE; v2HdrLength = 2; /* Is it a 3-byte header with padding? */ if (!(gs->hdr[0] & 0x80)) { ssl2gs->padding = gs->hdr[2]; v2HdrLength++; } } /* This is the max length for an encrypted SSLv3+ fragment. */ if (!v2HdrLength && gs->remainder > (MAX_FRAGMENT_LENGTH + 2048)) { SSL3_SendAlert(ss, alert_fatal, record_overflow); 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; } /* When we encounter an SSLv2 hello we've read 2 or 3 bytes too * many into the gs->hdr[] buffer. Copy them over into inbuf so * that we can properly process the hello record later. */ if (v2HdrLength) { /* Reject v2 records that don't even carry enough data to * resemble a valid ClientHello header. */ if (gs->remainder < SSL_HL_CLIENT_HELLO_HBYTES) { SSL3_SendAlert(ss, alert_fatal, illegal_parameter); PORT_SetError(SSL_ERROR_RX_MALFORMED_CLIENT_HELLO); return SECFailure; } PORT_Assert(lbp); gs->inbuf.len = 5 - v2HdrLength; PORT_Memcpy(lbp, gs->hdr + v2HdrLength, gs->inbuf.len); gs->remainder -= gs->inbuf.len; lbp += gs->inbuf.len; } if (gs->remainder > 0) { break; /* End this case. Continue around the loop. */ } /* FALL THROUGH if (gs->remainder == 0) as we just received * an empty record and there's really no point in calling * ssl_DefRecv() with buf=NULL and len=0. */ case GS_DATA: /* ** SSL3 record has been completely received. */ SSL_TRC(10, ("%d: SSL[%d]: got record of %d bytes", SSL_GETPID(), ss->fd, gs->inbuf.len)); /* reject any v2 records from now on */ ss->gs.rejectV2Records = PR_TRUE; 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; PRUint8 contentType; unsigned int headerLen; SECStatus rv; PRBool dtlsLengthPresent = PR_TRUE; 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) { rv = sslBuffer_Grow(&gs->dtlsPacket, MAX_FRAGMENT_LENGTH + 2048 + 13); if (rv != SECSuccess) { return -1; /* Code already set. */ } } /* 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)); return 0; } else /* if (nb < 0) */ { SSL_DBG(("%d: SSL3[%d]: recv error %d", SSL_GETPID(), ss->fd, PR_GetError())); return -1; } gs->dtlsPacket.len = nb; } contentType = gs->dtlsPacket.buf[gs->dtlsPacketOffset]; if (dtls_IsLongHeader(ss->version, contentType)) { headerLen = 13; } else if (contentType == ssl_ct_application_data) { headerLen = 7; } else if (dtls_IsDtls13Ciphertext(ss->version, contentType)) { /* We don't support CIDs. */ if (contentType & 0x10) { PORT_Assert(PR_FALSE); PORT_SetError(SSL_ERROR_RX_UNKNOWN_RECORD_TYPE); gs->dtlsPacketOffset = 0; gs->dtlsPacket.len = 0; return -1; } dtlsLengthPresent = (contentType & 0x04) == 0x04; PRUint8 dtlsSeqNoSize = (contentType & 0x08) ? 2 : 1; PRUint8 dtlsLengthBytes = dtlsLengthPresent ? 2 : 0; headerLen = 1 + dtlsSeqNoSize + dtlsLengthBytes; } else { SSL_DBG(("%d: SSL3[%d]: invalid first octet (%d) for DTLS", SSL_GETPID(), ss->fd, contentType)); PORT_SetError(SSL_ERROR_RX_UNKNOWN_RECORD_TYPE); gs->dtlsPacketOffset = 0; gs->dtlsPacket.len = 0; return -1; } /* At this point we should have >=1 complete records lined up in * dtlsPacket. Read off the header. */ if ((gs->dtlsPacket.len - gs->dtlsPacketOffset) < headerLen) { SSL_DBG(("%d: SSL3[%d]: rest of DTLS packet " "too short to contain header", SSL_GETPID(), ss->fd)); PORT_SetError(PR_WOULD_BLOCK_ERROR); gs->dtlsPacketOffset = 0; gs->dtlsPacket.len = 0; return -1; } memcpy(gs->hdr, SSL_BUFFER_BASE(&gs->dtlsPacket) + gs->dtlsPacketOffset, headerLen); gs->hdrLen = headerLen; gs->dtlsPacketOffset += headerLen; /* Have received SSL3 record header in gs->hdr. */ if (dtlsLengthPresent) { gs->remainder = (gs->hdr[headerLen - 2] << 8) | gs->hdr[headerLen - 1]; } else { gs->remainder = gs->dtlsPacket.len - gs->dtlsPacketOffset; } 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)); PORT_SetError(PR_WOULD_BLOCK_ERROR); gs->dtlsPacketOffset = 0; gs->dtlsPacket.len = 0; return -1; } /* OK, we have at least one complete packet, copy into inbuf */ gs->inbuf.len = 0; rv = sslBuffer_Append(&gs->inbuf, SSL_BUFFER_BASE(&gs->dtlsPacket) + gs->dtlsPacketOffset, gs->remainder); if (rv != SECSuccess) { return -1; /* code already set. */ } gs->offset = gs->remainder; gs->dtlsPacketOffset += gs->remainder; gs->state = GS_INIT; SSL_TRC(20, ("%d: SSL3[%d]: dtls gathered record type=%d len=%d", SSL_GETPID(), ss->fd, contentType, gs->inbuf.len)); 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. * * 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) { int rv; SSL3Ciphertext cText; PRBool keepGoing = PR_TRUE; if (ss->ssl3.fatalAlertSent) { SSL_TRC(3, ("%d: SSL3[%d] Cannot gather data; fatal alert already sent", SSL_GETPID(), ss->fd)); PORT_SetError(SSL_ERROR_HANDSHAKE_FAILED); return -1; } SSL_TRC(30, ("%d: SSL3[%d]: ssl3_GatherCompleteHandshake", SSL_GETPID(), ss->fd)); /* 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 processingEarlyData; ssl_GetSSL3HandshakeLock(ss); processingEarlyData = ss->ssl3.hs.zeroRttState == ssl_0rtt_accepted; /* 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 -1; } /* If we have a detached record layer, don't ever gather. */ if (ss->recordWriteCallback) { PRBool done = ss->firstHsDone; ssl_ReleaseSSL3HandshakeLock(ss); if (done) { return 1; } PORT_SetError(PR_WOULD_BLOCK_ERROR); return -1; } ssl_ReleaseSSL3HandshakeLock(ss); /* State for SSLv2 client hello support. */ ssl2Gather ssl2gs = { PR_FALSE, 0 }; ssl2Gather *ssl2gs_ptr = NULL; /* If we're a server and waiting for a client hello, accept v2. */ if (ss->sec.isServer && ss->opt.enableV2CompatibleHello && ss->ssl3.hs.ws == wait_client_hello) { ssl2gs_ptr = &ssl2gs; } /* 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)) { /* If we're a server waiting for a ClientHello then pass * ssl2gs to support SSLv2 ClientHello messages. */ rv = ssl3_GatherData(ss, &ss->gs, flags, ssl2gs_ptr); } 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)) { dtls_CheckTimer(ss); /* Restore the error in case something succeeded */ PORT_SetError(PR_WOULD_BLOCK_ERROR); } } if (rv <= 0) { return rv; } if (ssl2gs.isV2) { rv = ssl3_HandleV2ClientHello(ss, ss->gs.inbuf.buf, ss->gs.inbuf.len, ssl2gs.padding); if (rv < 0) { return rv; } } else { /* 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 only needs to be valid for this next function call, so * it can borrow gs.hdr. */ cText.hdr = ss->gs.hdr; cText.hdrLen = ss->gs.hdrLen; cText.buf = &ss->gs.inbuf; rv = ssl3_HandleRecord(ss, &cText); } 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); 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_WaitingForServerSecondRound(ss)) { keepGoing = PR_FALSE; } else { ss->ssl3.hs.canFalseStart = PR_FALSE; } } else if (processingEarlyData && ss->ssl3.hs.zeroRttState == ssl_0rtt_done && !PR_CLIST_IS_EMPTY(&ss->ssl3.hs.bufferedEarlyData)) { /* If we were processing early data and we are no longer, then force * the handshake to block. This ensures that early data is * delivered to the application before the handshake completes. */ ssl_ReleaseSSL3HandshakeLock(ss); PORT_SetError(PR_WOULD_BLOCK_ERROR); return -1; } ssl_ReleaseSSL3HandshakeLock(ss); } while (keepGoing); /* Service the DTLS timer so that the post-handshake timers * fire. */ if (IS_DTLS(ss) && (ss->ssl3.hs.ws == idle_handshake)) { dtls_CheckTimer(ss); } 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. * * 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; } SECStatus SSLExp_RecordLayerData(PRFileDesc *fd, PRUint16 epoch, SSLContentType contentType, const PRUint8 *data, unsigned int len) { SECStatus rv; sslSocket *ss = ssl_FindSocket(fd); if (!ss) { return SECFailure; } if (IS_DTLS(ss) || data == NULL || len == 0) { PORT_SetError(SEC_ERROR_INVALID_ARGS); return SECFailure; } /* Run any handshake function. If SSL_RecordLayerData is the only way that * the handshake is driven, then this is necessary to ensure that * ssl_BeginClientHandshake or ssl_BeginServerHandshake is called. Note that * the other function that might be set to ss->handshake, * ssl3_GatherCompleteHandshake, does nothing when this function is used. */ ssl_Get1stHandshakeLock(ss); rv = ssl_Do1stHandshake(ss); if (rv != SECSuccess && PORT_GetError() != PR_WOULD_BLOCK_ERROR) { goto early_loser; /* Rely on the existing code. */ } /* Don't allow application data before handshake completion. */ if (contentType == ssl_ct_application_data && !ss->firstHsDone) { PORT_SetError(SEC_ERROR_INVALID_ARGS); goto early_loser; } /* Then we can validate the epoch. */ PRErrorCode epochError; ssl_GetSpecReadLock(ss); if (epoch < ss->ssl3.crSpec->epoch) { epochError = SEC_ERROR_INVALID_ARGS; /* Too c/old. */ } else if (epoch > ss->ssl3.crSpec->epoch) { epochError = PR_WOULD_BLOCK_ERROR; /* Too warm/new. */ } else { epochError = 0; /* Just right. */ } ssl_ReleaseSpecReadLock(ss); if (epochError) { PORT_SetError(epochError); goto early_loser; } /* If the handshake is still running, we need to run that. */ ssl_Get1stHandshakeLock(ss); rv = ssl_Do1stHandshake(ss); if (rv != SECSuccess && PORT_GetError() != PR_WOULD_BLOCK_ERROR) { ssl_Release1stHandshakeLock(ss); return SECFailure; } /* Finally, save the data... */ ssl_GetRecvBufLock(ss); rv = sslBuffer_Append(&ss->gs.buf, data, len); if (rv != SECSuccess) { goto loser; } /* ...and process it. Just saving application data is enough for it to be * available to PR_Read(). */ if (contentType != ssl_ct_application_data) { rv = ssl3_HandleNonApplicationData(ss, contentType, 0, 0, &ss->gs.buf); /* This occasionally blocks, but that's OK here. */ if (rv != SECSuccess && PORT_GetError() != PR_WOULD_BLOCK_ERROR) { goto loser; } } ssl_ReleaseRecvBufLock(ss); ssl_Release1stHandshakeLock(ss); return SECSuccess; loser: /* Make sure that any data is not used again. */ ss->gs.buf.len = 0; ssl_ReleaseRecvBufLock(ss); early_loser: ssl_Release1stHandshakeLock(ss); return SECFailure; } SECStatus SSLExp_GetCurrentEpoch(PRFileDesc *fd, PRUint16 *readEpoch, PRUint16 *writeEpoch) { sslSocket *ss = ssl_FindSocket(fd); if (!ss) { return SECFailure; } ssl_GetSpecReadLock(ss); if (readEpoch) { *readEpoch = ss->ssl3.crSpec->epoch; } if (writeEpoch) { *writeEpoch = ss->ssl3.cwSpec->epoch; } ssl_ReleaseSpecReadLock(ss); return SECSuccess; }