diff options
Diffstat (limited to 'security/nss/lib/ssl/ssl3gthr.c')
| -rw-r--r-- | security/nss/lib/ssl/ssl3gthr.c | 823 |
1 files changed, 823 insertions, 0 deletions
diff --git a/security/nss/lib/ssl/ssl3gthr.c b/security/nss/lib/ssl/ssl3gthr.c new file mode 100644 index 0000000000..674ea89da9 --- /dev/null +++ b/security/nss/lib/ssl/ssl3gthr.c @@ -0,0 +1,823 @@ +/* -*- 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) +{ + gs->state = GS_INIT; + gs->writeOffset = 0; + gs->readOffset = 0; + gs->dtlsPacketOffset = 0; + gs->dtlsPacket.len = 0; + gs->rejectV2Records = PR_FALSE; + /* Allocate plaintext buffer to maximum possibly needed size. It needs to + * be larger than recordSizeLimit for TLS 1.0 and 1.1 compatability. + * The TLS 1.2 ciphertext is larger than the TLS 1.3 ciphertext. */ + return sslBuffer_Grow(&gs->buf, TLS_1_2_MAX_CTEXT_LENGTH); +} + +/* 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++; + } + } + + /* If it is NOT an SSLv2 header */ + if (!v2HdrLength) { + /* Check if default RFC specified max ciphertext/record + * limits are respected. Checks for used record size limit + * extension boundaries are done in + * ssl3con.c/ssl3_HandleRecord() for tls and dtls records. + * + * -> For TLS 1.2 records MUST NOT be longer than + * 2^14 + 2048 bytes. + * -> For TLS 1.3 records MUST NOT exceed 2^14 + 256 bytes. + * -> For older versions this MAY be enforced, we do it. + * [RFC8446 Section 5.2, RFC5246 Section 6.2.3]. */ + if (gs->remainder > TLS_1_2_MAX_CTEXT_LENGTH || + (gs->remainder > TLS_1_3_MAX_CTEXT_LENGTH && + ss->version >= SSL_LIBRARY_VERSION_TLS_1_3)) { + 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 = SECSuccess; + 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 leads to record_overflow errors if records/ciphertexts greater + * than the buffer (= maximum record) size are to be received. + * DTLS Record errors are dropped silently. [RFC6347, Section 4.1.2.7]. + * Checks for record size limit extension boundaries are performed in + * ssl3con.c/ssl3_HandleRecord() for tls and dtls records. + * + * -> For TLS 1.2 records MUST NOT be longer than 2^14 + 2048 bytes. + * -> For TLS 1.3 records MUST NOT exceed 2^14 + 256 bytes. + * -> For older versions this MAY be enforced, we do it. + * [RFC8446 Section 5.2, RFC5246 Section 6.2.3]. */ + if (ss->version <= SSL_LIBRARY_VERSION_TLS_1_2) { + if (gs->dtlsPacket.space < DTLS_1_2_MAX_PACKET_LENGTH) { + rv = sslBuffer_Grow(&gs->dtlsPacket, DTLS_1_2_MAX_PACKET_LENGTH); + } + } else { /* version >= TLS 1.3 */ + if (gs->dtlsPacket.space != DTLS_1_3_MAX_PACKET_LENGTH) { + /* During Hello and version negotiation older DTLS versions with + * greater possible packets are used. The buffer must therefore + * be "truncated" by clearing and reallocating it */ + sslBuffer_Clear(&gs->dtlsPacket); + rv = sslBuffer_Grow(&gs->dtlsPacket, DTLS_1_3_MAX_PACKET_LENGTH); + } + } + + 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())); + /* DTLS Record Errors, including overlong records, are silently + * dropped [RFC6347, Section 4.1.2.7]. */ + 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. + * + * This condition is met on all invalid outer content types. + * For lower DTLS versions as well as the inner content types, + * this is checked in ssl3con.c/ssl3_HandleNonApplicationData(). + * + * In DTLS generally invalid records SHOULD be silently discarded, + * no alert is sent [RFC6347, Section 4.1.2.7]. + */ + 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); + } + +#ifdef DEBUG + /* In Debug builds free gather ciphertext buffer after each decryption + * for advanced ASAN coverage/utilization. The buffer content has been + * used at this point, ssl3_HandleRecord() and thereby the decryption + * functions are only called from this point of the implementation. */ + sslBuffer_Clear(&ss->gs.inbuf); +#endif + + 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; +} + +static SECStatus +ssl_HandleZeroRttRecordData(sslSocket *ss, const PRUint8 *data, unsigned int len) +{ + PORT_Assert(ss->sec.isServer); + if (ss->ssl3.hs.zeroRttState == ssl_0rtt_accepted) { + sslBuffer buf = { CONST_CAST(PRUint8, data), len, len, PR_TRUE }; + return tls13_HandleEarlyApplicationData(ss, &buf); + } + if (ss->ssl3.hs.zeroRttState == ssl_0rtt_ignored && + ss->ssl3.hs.zeroRttIgnore != ssl_0rtt_ignore_none) { + /* We're ignoring 0-RTT so drop this record quietly. */ + return SECSuccess; + } + PORT_SetError(SSL_ERROR_RX_UNEXPECTED_APPLICATION_DATA); + return SECFailure; +} + +/* Ensure that application data in the wrong epoch is blocked. */ +static PRBool +ssl_IsApplicationDataPermitted(sslSocket *ss, PRUint16 epoch) +{ + /* Epoch 0 is never OK. */ + if (epoch == 0) { + return PR_FALSE; + } + if (ss->version < SSL_LIBRARY_VERSION_TLS_1_3) { + return ss->firstHsDone; + } + /* TLS 1.3 application data. */ + if (epoch >= TrafficKeyApplicationData) { + return ss->firstHsDone; + } + /* TLS 1.3 early data is server only. Further checks aren't needed + * as those are handled in ssl_HandleZeroRttRecordData. */ + if (epoch == TrafficKeyEarlyApplicationData) { + return ss->sec.isServer; + } + return PR_FALSE; +} + +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. */ + } + + if (contentType == ssl_ct_application_data && + !ssl_IsApplicationDataPermitted(ss, epoch)) { + 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) { + /* If a TLS 1.3 server is not expecting EndOfEarlyData, + * moving from 1 to 2 is a signal to execute the code + * as though that message had been received. Let that pass. */ + if (ss->version >= SSL_LIBRARY_VERSION_TLS_1_3 && + ss->opt.suppressEndOfEarlyData && + ss->sec.isServer && + ss->ssl3.crSpec->epoch == TrafficKeyEarlyApplicationData && + epoch == TrafficKeyHandshake) { + epochError = 0; + } else { + 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. */ + rv = ssl_Do1stHandshake(ss); + if (rv != SECSuccess && PORT_GetError() != PR_WOULD_BLOCK_ERROR) { + goto early_loser; + } + + /* 0-RTT needs its own special handling here. */ + if (ss->version >= SSL_LIBRARY_VERSION_TLS_1_3 && + epoch == TrafficKeyEarlyApplicationData && + contentType == ssl_ct_application_data) { + rv = ssl_HandleZeroRttRecordData(ss, data, len); + ssl_Release1stHandshakeLock(ss); + return rv; + } + + /* 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; +} |