I2NSF S. Hares
Internet-Draft Huawei
Intended status: Standards Track R. Moskowitz
Expires: September 22, 2016 HTT Consulting
March 21, 2016

Secure Session Layer Services
draft-hares-i2nsf-ssls-00.txt

Abstract

Each I2NSF agent and I2NSF client needs to provide application level support for management traffic during periods of DDoS and network security attacks to deal with congestion (burst and/or continuous), high error rates and packet loss due to the attacks, and the inability to utilize a transport protocol (E.g. TCP) due to a specific protocol attack. This application level support needs to be able to select the key management system and provide "chunking" of data (in order to fit in reduced effective MTUs), compression of data (in order to fit into reduced bandwidth), small security envelope )in order to maximize room for mangement payload), and fragmentation and reassembly at the application layer for those protocols which do not support fragmentation/reassembly (E.g. UDP or SMS). The application layer needs to be able to turn off this features if the system detects these features are no longer needed.

This draft specifies a security session layer services(SSLs) which provide these features in terms of an API, and the component features (interface to key management systems, data compression, chunking of data, secure session envelope (SSE) to send data, and fragmentation and reassembly, and ability to detect existence of attack).

Status of This Memo

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This Internet-Draft will expire on September 22, 2016.

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Table of Contents

1. Introduction

Each I2NSF agent and I2NSF client needs to provide application level support for management traffic during periods of DDoS and network security attacks to deal with congestion (burst and/or continuous), high error rates and packet loss due to the attacks, and the inability to utilize a transport protocol (E.g. TCP) due to a specific protocol attack. Some of the services the I2NSF controller must provide during these periods of DDoS or network security attacks are:

This application level support for I2NSF client-agent communication needs to be able to select the key management system and provide "chunking" of data (in order to fit in reduced effective MTUs), compression of data (in order to fit into reduced bandwidth), small security envelope )in order to maximize room for mangement payload), and fragmentation and reassembly at the application layer for those protocols which do not support fragmentation/reassembly (E.g. UDP or SMS). The application layer needs to be able to turn off this features if the system detects these features are no longer needed.

This draft specifies a security session layer (SSL) which provides these features in terms of:

A diagram of the SSLS with these process is in figure 1.

The API for this SSLS allows the application to select the types of key management, and the different types of services (data compression, chunking of data, secure e)

	
	Secure Session Layer Services(SSLS)
        | API |
        |     |
  +------------------------------+
  |     | Key Mangement(KMP)     |
  |     |........................|
  |     | Detection of network   |
  |     | conditions + selection |
  |     | of transport (optional | 
  |     |  proprietary code)     |
  |     .........................|
  |SSLS | Compression (GPComp)   |
  |     |........................|
  |     | Chunking of data       |
  |     | (this draft)           |
  |     .........................|
  |     | Session Security       |
  |     | Envelope (SSE)         |
  |     |........................|
  |     | fragmentation and      |
  |     | reassembly at          | 
  |     | application layer      |
  |     | (This draft)           |
  +------------------------------+
	

2. API for SSLS

2.1. SSLS socket calls

The SSLS uses socket calls to set up the application session layer. The calls are shown below.

s = int socket(int domain, int type, int protocol)

where:

  int setsockopt(int sockfd, int level, int optname,
             const void *optval, socklen_t optlen); 

 int getsocketopt(int sockfd, int level, int optname
                    const void *optval, socket			 
  where: 
   sockfd:      # socket file descriptor    
   optname:     # option name (see below) 
   optval;	    # points to *sse_transport structure;  
   optlen;	    # length of option 
   
   optnam:
   SSLS_AUTH_PRIV ]1]
   SSLS_AES_MODE[2]
   SSLS_ALGS[3]
   SSLS_SSE [4]

   Where the opt_val structure are define in the figure below.
   
       Figure 2 
 

2.1.1. KMP related options

 Security Keying structures for:  
 SSLS_AUTH_PRV, SSLS_AES_MODE, SSLS_ALGS 
 options of setsockopt, getsockopt

 #struture for SSL_AUTH-PRIV optval 
    struct *ssls_auth-priv_opts  {
	   *ssls-x509-auth [SSLS-X509-LIMIT]
	}  

	#SSL-X509-limit 
	typedef struct ssls-x509-auth {
	   const char name;
	   void *x509-cert;  #cert struture by API
	}
	

	#structure for SSL_AES_MODE optval 
	struct *ssls_aes_mode_opts {
      ... IKEV2 options # openikev2 API
      ... HIPv2 options # HIPv2 API 
					    #[RFC6317 + HIPv2] 
       struct ssls_algs_opts;
	}
	
	#compression options 
	struct *ssls_algs_opts {
  	  boolean  gpcomp-kmp; # computed with keys 
      enum gmcomp-type;    #        								  
	 }
	 
  figure 3: setsockopt structure 
            for KMP related optins 

2.1.2. SSE Envelope related options

  Security Session Envelope Related options 
	 #structure for SSL_SSE optval 
	 # SPI - is generated by KMP
	 # SSE - sequence number - by SSE
	 # Flags = Fragment (5 bits [0-5],          
	
    struct *ssls_sse_opts {
	 int nt_sockfd;   # new transport socket
	 int *protocol;   # transport protocol for SSLS SSE 
	                  # can choose from (1-n )
	 int *known_ports # known ports 
	 int chunk-size;  # chunk size 
	 int frag-size;   # fragment size 
	                  # greater than 0 means fragment]
	 int SSEs-at-once # number of SSEs sent at once 
	 enum SSE_size;   # (compact, large, extreme)
	 enum SSE-FLAG;   # compression flags
	 ); 
	 
	 Figure 4 
 

2.2. OpenSSL X.509 API calls used

TBD

2.3. HIPv2 API calls used

(API calls will be added later based on HIP [RFC6317] upgraded to HIPv2.

2.3.1. HIP Structures

         struct addrinfo {
            int       ai_flags;          /* e.g., AI_CANONNAME */
            int       ai_family;         /* e.g., AF_HIP */
            int       ai_socktype;       /* e.g., SOCK_STREAM */
            int       ai_protocol;       /* 0 or IPPROTO_HIP */
            socklen_t ai_addrlen;        /* size of *ai_addr  */
            struct    sockaddr *ai_addr; /* sockaddr_hip */
            char     *ai_canonname;      /* canon. name of the host */
            struct    addrinfo *ai_next; /* next endpoint */
            int       ai_eflags;         /* RFC 5014 extension */
        };

2.3.2. HIP KMP calls

 	#HIP uses 
	#   #include <netdb.h>
      int getaddrinfo(const char *nodename,
                      const char *servname,
                      const struct addrinfo *hints,
                       struct addrinfo **res)
	  void free_addrinfo(struct addrinfo *res)
  	
	Figure 3  
 

3. Data Compression

The first step in making the application data easier to send through the network is to compress the data. The data compression algorithm is defined in draft-moskowitz-gpcomp-00.txt. The result of the compressed data is handed to the chunking function.

The user can disable or enable the compression function by setting SSE-DATA types to be one of the following:

Setting this flag to:

will skip the data compression step.

4. SSLS Processes

4.1. Chunking of Data

The process that "chunks" data breaks down the application stream after the compression process. If the compression process has compressed the data, the chunking process will chunk compressed data. If the user has requested no compression, this chunking process will chunk uncompressed data. The size of chunks of data the SSLS process creates to encapsulate in the secure session envelope (SSE) is specified on SSL_SSE setsockopt call.

The secure session envelope must be bigger than the chunk.

If the SSE is using TCP or STCP, that assembles the application flow into a byte stream, then the SSE packages will contain a chunk within the secure session envelope.

If Transports that do not fragment and re-assembly are being specified, the SSL will support application layer fragmentation and reassembly. (see the fragmentation section below

4.2. Secure Session Envelope

The Secure Session Envelope (SSE) creates a secure envelope using the SPI created by the key management and running over the transport selected by the user. The SSE has three forms: compact, Large, Extreme. The SSE compact form is below in figure x. SSL defines 4 bytes of the reserved field in the FLAGS field. See [I-D.moskowitz-sse] for details on secure session envelope sizes and formats.

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                             SPI               |    FLAGS      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       Length          |             Sequence Number           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              Encrypted Payload and ICV (Variable)             |
   ~                                                               ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   
        2          3
    4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+ 
   | Reserve     |C|
   +---------------+
   |  Flag field   |
   +---------------+
   
   Figure 5 - Compact format of SSE 

The SSLS utilizes 6 bits of the 8 bit flag in order to provide provide fragmentation and reassembly checks when the SSE gets fragmented into multiple transport packets. Each time the SSE fragments the packet to fit in the transport, it increments the fragment count in bits [24-28]. The bits for the flag word shown in figure 6.

    2           3
    4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+ 
   |Frag     |R R|C|
   +---------------+
   |  Flag field   |
   +---------------+

   Flag work in SSE header

Bits [4-8] - 1-30 bit value for the fragment number
              0 - no fragmentation
             31 - indicates an fragmentation ACK response 
Bits 5-6  - reserved
Bit    7  - compression 
	
 Figure 6 - SSLS redefined SSE Flag byte 	

4.3. Application Packet Fragmentation and Reassembly

SSE's secure envelope may be passed over UDP to avoid transport-level security attacks. Alternatively SSE's secure transport may go over the extremely limited SMS fabric so that some security management information gets through. In both cases, the user (or the "detection log") can select the transport and fragmentation.

If fragmentation is turned on, the individual SSE envelopes will track the IP messages the SSE envelope is broken into by placing the fragment number in the lowest 5 bits of the SSE Flag byte [24-28]. The SSE process receiving the traffic will send back an acknowledge SSE packet [Flag value in bits 0-4 is 0x1F or 31] within 30 bit map of sequences acked [1-30] in first 4 bits of SSE data. It is anticipate that the fragmentation process will attempt to bundle some acks.

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                             SPI               |    FLAGS      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       Length          |             Sequence Number           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Encrypted Payload and ICV (Variable) [4 byte flag word] [data]|
   ~                                                               ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   
        2          3
    4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+ 
   |1|1|1|1|1|0|0|C|     
   +---------------+
   |  Flag field   |
   +---------------+
   
   
    SSLS Fragment ACK 
       0                   1                   2                  3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   bit mask ack for fragments [0-31]                           |
   +---------------------------------------------------------------+
   [bit 0, 31 - are illegal, bit [1-31] fragments of sequence # ]
   
   Figure 7 - SSLS ACK flag filed and first 4 bytes of payload 

 SSLS-process-1--------IP/SMS---------SSLS Process-2 
  [E.g. I2NSF Client -----------------I2NSF Agent]
  
 SSE-packet (SPI,(flags(fragment=1,C=1),
      length, seq 1, data )---->
	  
  SSE-packet (SPI,(flags(fragment=2,C=1),
      length, seq 1, data )---->
	  
  SSE-packet (SPI,(flags(fragment=3,C=1),
      length, seq 1, data )---->

  SSE-packet (SPI,(flags(fragment=1,C=1),
      length, seq 2, data )---->
	  
   SSE-packet (SPI,(flags(fragment=2,C=1),
      length, seq 2, data )---->
	         <--SSE-packet (SPI)(flags fragment=31,C=1)
              length, seq1,[ack-fragment 1,2])
   			 <--SSE-packet (SPI)(flags fragment=32,C=1)
			   length, seq2,[ack-fragment1,2]
 	  
  SSE-packet (SPI,(flags(fragment=3,C=1),
      length, seq 1, data )---->
	         <--SSE-packet (SPI)(flags fragment=31,C=1)
              length, seq1,[ack-fragment 3])

An example Fragmentation and ACK exchange

  pseudo 
 struct sse_opts = {};
 optlen=size(sse_opts);
 optname= SSLS_SSE; #4
 s = int socket(int domain, int type, int protocol) 
 errno =  int setsockopt(sockfd,level,optname,
          void struct *sse_opts,optlen); 
 
 Errors: (Exact ERNOS added later)
  - protocol not support
  - error in known ports
  - error in chunk_size
  - error in fragment size
  - error in SSE-at-once
  - error - unsupported SSE 
  - error in compression flags 
  
  [Add read-write to socket ]

Below is a set of pseudo call for the calls to socket

The SSE window size for fragmentation is 30 IP fragments or 30 SMS fragments per SSE chunk. The SSE process SHOULD assign the SSE fragments in order if possible. The SSE process will send an error response to the SSE if the data chunk does not fit in 30 IP/SM fragments.

If the SSE transmitting process has not received an acknowlegement for all IP fragments for a particular SSE envelope (identified by sequence number) with a SSE-retransmit-time, it sill retransmit the unacknowledged fragments.

Several SSE envelopes may be sent with fragmentation at once. The user signals the number sent at once with multiple SSE with fragment variable on the options. If fragmentation is selected, each of these SSE envelopes may need to track up to 30 IP fragments.

4.4. Proprietary Plugins: Detect Conditions + Select Transport

The SSL process allows two properitary plugins:

  1. Plugin to detect error conditions which require SSLS services which include:

  2. Proprietary actions may select transport based on input from other standardize security services (DOTS, CERT, MILE) or proprietary services.

Prototype code will provide instances to show plugin values.

5. IANA Considerations

TBD

6. Security Considerations

The SSLS shares the following security considerations with the SSE Technology:

7. Acknowledgements

The authos would like to thank Frank (Liang) Xia for his comments and suggestions on this draft.

8. References

8.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997.

8.2. Informative References

[I-D.hares-i2nsf-mgtflow-reqs] Hares, S., "I2NSF Management Traffic Flow Requirement", Internet-Draft draft-hares-i2nsf-mgtflow-reqs-01, March 2016.
[I-D.moskowitz-sse] Moskowitz, R., Faynberg, I., Lu, H., Hares, S. and P. Giacomin, "Session Security Envelope", Internet-Draft draft-moskowitz-sse-02, February 2016.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011.
[RFC6317] Komu, M. and T. Henderson, "Basic Socket Interface Extensions for the Host Identity Protocol (HIP)", RFC 6317, DOI 10.17487/RFC6317, July 2011.
[RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P. and T. Kivinen, "Internet Key Exchange Protocol Version 2 (IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October 2014.
[RFC7401] Moskowitz, R., Heer, T., Jokela, P. and T. Henderson, "Host Identity Protocol Version 2 (HIPv2)", RFC 7401, DOI 10.17487/RFC7401, April 2015.

Authors' Addresses

Susan Hares Huawei Saline, US EMail: shares@ndzh.com
Robert Moskowitz HTT Consulting Oak Park, MI 48237 USA Phone: +1-248-968-9809 EMail: rgm@htt-consult.com