| 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-slss-00.txt
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).
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 22, 2016.
Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
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) |
+------------------------------+
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
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
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
TBD
(API calls will be added later based on HIP [RFC6317] upgraded to HIPv2.
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 */
};
#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
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.
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
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
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.
The SSL process allows two properitary plugins:
Prototype code will provide instances to show plugin values.
TBD
The SSLS shares the following security considerations with the SSE Technology:
The authos would like to thank Frank (Liang) Xia for his comments and suggestions on this draft.
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [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. |