diff options
Diffstat (limited to 'security/nss/lib/ssl/ssl3exthandle.c')
| -rw-r--r-- | security/nss/lib/ssl/ssl3exthandle.c | 181 |
1 files changed, 79 insertions, 102 deletions
diff --git a/security/nss/lib/ssl/ssl3exthandle.c b/security/nss/lib/ssl/ssl3exthandle.c index e6388945e1..d1f286dc3c 100644 --- a/security/nss/lib/ssl/ssl3exthandle.c +++ b/security/nss/lib/ssl/ssl3exthandle.c @@ -242,33 +242,11 @@ ssl_AlpnTagAllowed(const sslSocket *ss, const SECItem *tag) return PR_FALSE; } -/* handle an incoming Next Protocol Negotiation extension. */ -SECStatus -ssl3_ServerHandleNextProtoNegoXtn(const sslSocket *ss, TLSExtensionData *xtnData, - SECItem *data) -{ - PORT_Assert(ss->version < SSL_LIBRARY_VERSION_TLS_1_3); - - if (ss->firstHsDone || data->len != 0) { - /* Clients MUST send an empty NPN extension, if any. */ - PORT_SetError(SSL_ERROR_NEXT_PROTOCOL_DATA_INVALID); - return SECFailure; - } - - xtnData->negotiated[xtnData->numNegotiated++] = ssl_next_proto_nego_xtn; - - /* TODO: server side NPN support would require calling - * ssl3_RegisterServerHelloExtensionSender here in order to echo the - * extension back to the client. */ - - return SECSuccess; -} - -/* ssl3_ValidateNextProtoNego checks that the given block of data is valid: none +/* ssl3_ValidateAppProtocol checks that the given block of data is valid: none * of the lengths may be 0 and the sum of the lengths must equal the length of * the block. */ SECStatus -ssl3_ValidateNextProtoNego(const unsigned char *data, unsigned int length) +ssl3_ValidateAppProtocol(const unsigned char *data, unsigned int length) { unsigned int offset = 0; @@ -286,7 +264,7 @@ ssl3_ValidateNextProtoNego(const unsigned char *data, unsigned int length) return SECSuccess; } -/* protocol selection handler for ALPN (server side) and NPN (client side) */ +/* Protocol selection handler for ALPN. */ static SECStatus ssl3_SelectAppProtocol(const sslSocket *ss, TLSExtensionData *xtnData, PRUint16 extension, SECItem *data) @@ -295,7 +273,7 @@ ssl3_SelectAppProtocol(const sslSocket *ss, TLSExtensionData *xtnData, unsigned char resultBuffer[255]; SECItem result = { siBuffer, resultBuffer, 0 }; - rv = ssl3_ValidateNextProtoNego(data->data, data->len); + rv = ssl3_ValidateAppProtocol(data->data, data->len); if (rv != SECSuccess) { ssl3_ExtSendAlert(ss, alert_fatal, decode_error); PORT_SetError(SSL_ERROR_NEXT_PROTOCOL_DATA_INVALID); @@ -303,11 +281,13 @@ ssl3_SelectAppProtocol(const sslSocket *ss, TLSExtensionData *xtnData, } PORT_Assert(ss->nextProtoCallback); - /* For ALPN, the cipher suite isn't selected yet. Note that extensions + /* The cipher suite isn't selected yet. Note that extensions * sometimes affect what cipher suite is selected, e.g., for ECC. */ PORT_Assert((ss->ssl3.hs.preliminaryInfo & ssl_preinfo_all & ~ssl_preinfo_cipher_suite) == (ssl_preinfo_all & ~ssl_preinfo_cipher_suite)); + /* The callback has to make sure that either rv != SECSuccess or that result + * is not set if there is no common protocol. */ rv = ss->nextProtoCallback(ss->nextProtoArg, ss->fd, data->data, data->len, result.data, &result.len, sizeof(resultBuffer)); if (rv != SECSuccess) { @@ -320,21 +300,20 @@ ssl3_SelectAppProtocol(const sslSocket *ss, TLSExtensionData *xtnData, * stack. */ if (result.len > sizeof(resultBuffer)) { PORT_SetError(SEC_ERROR_OUTPUT_LEN); - /* TODO: crash */ + PORT_Assert(PR_FALSE); return SECFailure; } SECITEM_FreeItem(&xtnData->nextProto, PR_FALSE); - if (extension == ssl_app_layer_protocol_xtn && - xtnData->nextProtoState != SSL_NEXT_PROTO_NEGOTIATED) { - /* The callback might say OK, but then it picks a default value - one - * that was not listed. That's OK for NPN, but not ALPN. */ + if (result.len < 1 || !result.data) { + /* Check that we actually got a result. */ ssl3_ExtSendAlert(ss, alert_fatal, no_application_protocol); PORT_SetError(SSL_ERROR_NEXT_PROTOCOL_NO_PROTOCOL); return SECFailure; } + xtnData->nextProtoState = SSL_NEXT_PROTO_NEGOTIATED; xtnData->negotiated[xtnData->numNegotiated++] = extension; return SECITEM_CopyItem(NULL, &xtnData->nextProto, &result); } @@ -356,7 +335,7 @@ ssl3_ServerHandleAppProtoXtn(const sslSocket *ss, TLSExtensionData *xtnData, return SECFailure; } - /* Unlike NPN, ALPN has extra redundant length information so that + /* ALPN has extra redundant length information so that * the extension is the same in both ClientHello and ServerHello. */ rv = ssl3_ExtConsumeHandshakeNumber(ss, &count, 2, &data->data, &data->len); if (rv != SECSuccess || count != data->len) { @@ -389,39 +368,6 @@ ssl3_ServerHandleAppProtoXtn(const sslSocket *ss, TLSExtensionData *xtnData, } SECStatus -ssl3_ClientHandleNextProtoNegoXtn(const sslSocket *ss, TLSExtensionData *xtnData, - SECItem *data) -{ - PORT_Assert(ss->version < SSL_LIBRARY_VERSION_TLS_1_3); - PORT_Assert(!ss->firstHsDone); - - if (ssl3_ExtensionNegotiated(ss, ssl_app_layer_protocol_xtn)) { - /* If the server negotiated ALPN then it has already told us what - * protocol to use, so it doesn't make sense for us to try to negotiate - * a different one by sending the NPN handshake message. However, if - * we've negotiated NPN then we're required to send the NPN handshake - * message. Thus, these two extensions cannot both be negotiated on the - * same connection. */ - ssl3_ExtSendAlert(ss, alert_fatal, illegal_parameter); - PORT_SetError(SSL_ERROR_BAD_SERVER); - return SECFailure; - } - - /* We should only get this call if we sent the extension, so - * ss->nextProtoCallback needs to be non-NULL. However, it is possible - * that an application erroneously cleared the callback between the time - * we sent the ClientHello and now. */ - if (!ss->nextProtoCallback) { - PORT_Assert(0); - ssl3_ExtSendAlert(ss, alert_fatal, internal_error); - PORT_SetError(SSL_ERROR_NEXT_PROTOCOL_NO_CALLBACK); - return SECFailure; - } - - return ssl3_SelectAppProtocol(ss, xtnData, ssl_next_proto_nego_xtn, data); -} - -SECStatus ssl3_ClientHandleAppProtoXtn(const sslSocket *ss, TLSExtensionData *xtnData, SECItem *data) { @@ -475,19 +421,6 @@ ssl3_ClientHandleAppProtoXtn(const sslSocket *ss, TLSExtensionData *xtnData, } SECStatus -ssl3_ClientSendNextProtoNegoXtn(const sslSocket *ss, TLSExtensionData *xtnData, - sslBuffer *buf, PRBool *added) -{ - /* Renegotiations do not send this extension. */ - if (!ss->opt.enableNPN || !ss->nextProtoCallback || ss->firstHsDone) { - return SECSuccess; - } - - *added = PR_TRUE; - return SECSuccess; -} - -SECStatus ssl3_ClientSendAppProtoXtn(const sslSocket *ss, TLSExtensionData *xtnData, sslBuffer *buf, PRBool *added) { @@ -499,35 +432,15 @@ ssl3_ClientSendAppProtoXtn(const sslSocket *ss, TLSExtensionData *xtnData, return SECSuccess; } - /* NPN requires that the client's fallback protocol is first in the - * list. However, ALPN sends protocols in preference order. So move the - * first protocol to the end of the list. */ - if (len > 0) { /* Each protocol string is prefixed with a single byte length. */ - unsigned int i; - rv = sslBuffer_AppendNumber(buf, len, 2); if (rv != SECSuccess) { return SECFailure; } - - i = ss->opt.nextProtoNego.data[0] + 1; - if (i <= len) { - rv = sslBuffer_Append(buf, &ss->opt.nextProtoNego.data[i], len - i); - if (rv != SECSuccess) { - return SECFailure; - } - rv = sslBuffer_Append(buf, ss->opt.nextProtoNego.data, i); - if (rv != SECSuccess) { - return SECFailure; - } - } else { - /* This seems to be invalid data so we'll send as-is. */ - rv = sslBuffer_Append(buf, ss->opt.nextProtoNego.data, len); - if (rv != SECSuccess) { - return SECFailure; - } + rv = sslBuffer_Append(buf, ss->opt.nextProtoNego.data, len); + if (rv != SECSuccess) { + return SECFailure; } } @@ -1955,3 +1868,67 @@ ssl_HandleSupportedGroupsXtn(const sslSocket *ss, TLSExtensionData *xtnData, return SECSuccess; } + +SECStatus +ssl_HandleRecordSizeLimitXtn(const sslSocket *ss, TLSExtensionData *xtnData, + SECItem *data) +{ + SECStatus rv; + PRUint32 limit; + PRUint32 maxLimit = (ss->version >= SSL_LIBRARY_VERSION_TLS_1_3) + ? (MAX_FRAGMENT_LENGTH + 1) + : MAX_FRAGMENT_LENGTH; + + rv = ssl3_ExtConsumeHandshakeNumber(ss, &limit, 2, &data->data, &data->len); + if (rv != SECSuccess) { + return SECFailure; + } + if (data->len != 0 || limit < 64) { + ssl3_ExtSendAlert(ss, alert_fatal, illegal_parameter); + PORT_SetError(SSL_ERROR_RX_MALFORMED_HANDSHAKE); + return SECFailure; + } + + if (ss->sec.isServer) { + rv = ssl3_RegisterExtensionSender(ss, xtnData, ssl_record_size_limit_xtn, + &ssl_SendRecordSizeLimitXtn); + if (rv != SECSuccess) { + return SECFailure; /* error already set. */ + } + } else if (limit > maxLimit) { + /* The client can sensibly check the maximum. */ + ssl3_ExtSendAlert(ss, alert_fatal, illegal_parameter); + PORT_SetError(SSL_ERROR_RX_MALFORMED_HANDSHAKE); + return SECFailure; + } + + /* We can't enforce the maximum on a server. But we do need to ensure + * that we don't apply a limit that is too large. */ + xtnData->recordSizeLimit = PR_MIN(maxLimit, limit); + xtnData->negotiated[xtnData->numNegotiated++] = ssl_record_size_limit_xtn; + return SECSuccess; +} + +SECStatus +ssl_SendRecordSizeLimitXtn(const sslSocket *ss, TLSExtensionData *xtnData, + sslBuffer *buf, PRBool *added) +{ + PRUint32 maxLimit; + if (ss->sec.isServer) { + maxLimit = (ss->version >= SSL_LIBRARY_VERSION_TLS_1_3) + ? (MAX_FRAGMENT_LENGTH + 1) + : MAX_FRAGMENT_LENGTH; + } else { + maxLimit = (ss->vrange.max >= SSL_LIBRARY_VERSION_TLS_1_3) + ? (MAX_FRAGMENT_LENGTH + 1) + : MAX_FRAGMENT_LENGTH; + } + PRUint32 limit = PR_MIN(ss->opt.recordSizeLimit, maxLimit); + SECStatus rv = sslBuffer_AppendNumber(buf, limit, 2); + if (rv != SECSuccess) { + return SECFailure; + } + + *added = PR_TRUE; + return SECSuccess; +} |