Libreswan Documentation

Status	Description
vN.N	first implementation, see comments for limitations
in-progress	by who, and date of last time this file was updated
yes-please	very high on our wish list, interested?
N/A	not applicable
X	not really interested

Current and Proposed IP Security Maintenance and Extensions Working Group (IPSECME) RFCs

IKEv2: RFC 7296
AH: RFC 4302
ESP: RFC 4303

IPSECME Internet-Drafts Active with the IESG

I.e., about to be adopted, likely in last call.

This table should track the “Active with the IESG Internet-Drafts” section of the IPSECME documents page.

Standard	Area	Description	Status	Comments
RFC TBD	IKE	Downgrade Prevention for the Internet Key Exchange Protocol Version 2 (IKEv2)	in-progress	Vinnu124 2026-05-29, In Last Call (ends 2026-06-12)
RFC TBD	IKE	Signature Authentication in the Internet Key Exchange Version 2 (IKEv2) using PQC	in-progress	Sahana 2026-04-14, Publication Requested
RFC TBD	IKE	Post-quantum Key Exchange with ML-KEM in the Internet Key Exchange Protocol Version 2 (IKEv2)	v5.4	2026-03-15, In Last Call (ends 2026-06-15)

This table is a sorted merge of two tables.

This table should track the “RFCs” and “Related RFCs” sections of the IPSECME documents page.

Standard	Area	Description	Status	Comments
RFC 9867	IKE	Mixing Preshared Keys in the IKE_INTERMEDIATE and CREATE_CHILD_SA Exchanges of the Internet Key Exchange Protocol Version 2 (IKEv2) for Post-Quantum Security	v5.2	IKE_INTERMEDIATE: v5.2 CREATE_CHILD_SA: to-be-done
RFC 9838	IKE	Group Key Management Using the Internet Key Exchange Protocol Version 2 (IKEv2)
RFC 9827	IKE	Renaming the Extended Sequence Numbers (ESN) Transform Type in the Internet Key Exchange Protocol Version 2 (IKEv2)	v5.4
RFC 9611	IKE	Internet Key Exchange Protocol Version 2 (IKEv2) Support for Per-Resource Child Security Associations (SAs)	in-progress	omoris
RFC 9593	IKE	Announcing Supported Authentication Methods in the Internet Key Exchange Protocol Version 2 (IKEv2)	in-progress	fazzel vukasink
RFC 9478	IKE	Labeled IPsec Traffic Selector Support for the Internet Key Exchange Protocol Version 2 (IKEv2)	v4.4
RFC 9464	IKE	Internet Key Exchange Protocol Version 2 (IKEv2) Configuration for Encrypted DNS
RFC 9395	IKE	Deprecation of the Internet Key Exchange Version 1 (IKEv1) Protocol and Obsoleted Algorithms
RFC 9370	IKE	Multiple Key Exchanges in the Internet Key Exchange Protocol Version 2 (IKEv2)	v5.4 in-progress	addke1: v5.4 IKE_INTERMEDIATE: v4.0 IKE_FOLLOW_UP_KE (IKE): v5.4 IKE_FOLLOW_UP_KE (Child): daiki
RFC 9349	IKE	Definitions of Managed Objects for IP Traffic Flow Security
RFC 9348	IKE	A YANG Data Model for IP Traffic Flow Security
RFC 9347	IKE	Aggregation and Fragmentation Mode for Encapsulating Security Payload (ESP) and Its Use for IP Traffic Flow Security (IP-TFS)	v5.2
RFC 9329	IKE	TCP Encapsulation of Internet Key Exchange Protocol (IKE) and IPsec Packets	v4.0		Updated RFC 8229?
RFC 9242	IKE	Intermediate Exchange in the Internet Key Exchange Protocol Version 2 (IKEv2)	v4.0
RFC 9227	IKE	Using GOST Ciphers in the Encapsulating Security Payload (ESP) and Internet Key Exchange Version 2 (IKEv2) Protocols
RFC 8983	IKE	Internet Key Exchange Protocol Version 2 (IKEv2) Notification Status Types for IPv4/IPv6 Coexistence
RFC 8784	IKE	Mixing Preshared Keys in the Internet Key Exchange Protocol Version 2 (IKEv2) for Post-quantum Security	v3.28
RFC 8750	IKE	Implicit Initialization Vector (IV) for Counter-Based Ciphers in Encapsulating Security Payload (ESP)
RFC 8598	IKE	Split DNS Configuration for the Internet Key Exchange Protocol Version 2 (IKEv2)
RFC 8420	IKE	Using the Edwards-Curve Digital Signature Algorithm (EdDSA) in the Internet Key Exchange Protocol Version 2 (IKEv2)	v5.4	Limited by NSS
RFC 8247	IKE	Algorithm Implementation Requirements and Usage Guidance for the Internet Key Exchange Protocol Version 2 (IKEv2)
RFC 8229	IKE	~~TCP Encapsulation of IKE and IPsec Packets~~	v4.0	Updated by RFC 9329
RFC 8221	IPsec	Cryptographic Algorithm Implementation Requirements and Usage Guidance for Encapsulating Security Payload (ESP) and Authentication Header (AH)
RFC 8031	IKE	Curve25519 and Curve448 for the Internet Key Exchange Protocol Version 2 (IKEv2) Key Agreement	v3.25	Curve25519 (dh31): v3.25 Curve448 (dh32): Needs NSS support
RFC 8019	IKE	Protecting Internet Key Exchange Protocol Version 2 (IKEv2) Implementations from Distributed Denial-of-Service Attacks
RFC 7791	IKE	Cloning the IKE Security Association in the Internet Key Exchange Protocol Version 2 (IKEv2)
RFC 7634	IKE	“ChaCha20, Poly1305, and Their Use in the Internet Key Exchange Protocol (IKE) and IPsec”	v3.26
RFC 7619	IKE	The NULL Authentication Method in the Internet Key Exchange Protocol Version 2 (IKEv2)	v2.x
RFC 7427	IKE	Signature Authentication in the Internet Key Exchange Version 2 (IKEv2)	v3.26	aka DIGSIG
RFC 7383	IKE	Internet Key Exchange Protocol Version 2 (IKEv2) Message Fragmentation	v3.14
RFC 7321	IPsec	Cryptographic Algorithm Implementation Requirements and Usage Guidance for Encapsulating Security Payload (ESP) and Authentication Header (AH)
RFC 7296	IKE	Internet Key Exchange Protocol Version 2 (IKEv2)	yes
RFC 7018	IPsec	Auto-Discovery VPN Problem Statement and Requirements
RFC 6989	IKE	Additional Diffie-Hellman Tests for the Internet Key Exchange Protocol Version 2 (IKEv2)	N/A
RFC 6867	IKE	An Internet Key Exchange Protocol Version 2 (IKEv2) Extension to Support EAP Re-authentication Protocol (ERP)
RFC 6631	IKE	Password Authenticated Connection Establishment with the Internet Key Exchange Protocol version 2 (IKEv2)
RFC 6628	IKE	Efficient Augmented Password-Only Authentication and Key Exchange for IKEv2
RFC 6617	IKE	Secure Pre-Shared Key (PSK) Authentication for the Internet Key Exchange Protocol (IKE)
RFC 6479	IPsec	IPsec Anti-Replay Algorithm without Bit Shifting	N/A	kernel
RFC 6467	IKE	Secure Password Framework for Internet Key Exchange Version 2 (IKEv2)
RFC 6380	IPsec	Suite B Profile for Internet Protocol Security (IPsec)	v
RFC 6379	IPsec	Suite B Cryptographic Suites for IPsec	v	Not all ciphers are implemented
RFC 6311	IKE	Protocol Support for High Availability of IKEv2/IPsec
RFC 6290	IKE	A Quick Crash Detection Method for the Internet Key Exchange Protocol (IKE)
RFC 6071	IKE	IP Security (IPsec) and Internet Key Exchange (IKE) Document Roadmap
RFC 6027	IKE	IPsec Cluster Problem Statement
RFC 6023	IKE	A Childless Initiation of the Internet Key Exchange Version 2 (IKEv2) Security Association (SA)
RFC 5998	IKE	An Extension for EAP-Only Authentication in IKEv2	v4.7	server only
RFC 5996	IKE	~~Internet Key Exchange Protocol Version 2 (IKEv2)~~		Obsolete, see RFC 7296
RFC 5930	IKE	Using Advanced Encryption Standard Counter Mode (AES-CTR) with the Internet Key Exchange version 02 (IKEv2) Protocol	v3.14
RFC 5903	IKE	Elliptic Curve Groups modulo a Prime (ECP Groups) for IKE and IKEv2	v3.20	added to defaults in v3.28
RFC 5879	IPsec	Heuristics for Detecting ESP-NULL Packets	N/A	kernel
RFC 5857	IKE	IKEv2 Extensions to Support Robust Header Compression over IPsec
RFC 5840	IPsec	Wrapped Encapsulating Security Payload (ESP) for Traffic Visibility	X
RFC 5739	IKE	IPv6 Configuration in Internet Key Exchange Protocol Version 2 (IKEv2)
RFC 5723	IKE	Internet Key Exchange Protocol Version 2 (IKEv2) Session Resumption	v5.2
RFC 5685	IKE	Redirect Mechanism for the Internet Key Exchange Protocol Version 2 (IKEv2)	v3.28
RFC 5660	IPsec	IPsec Channels: Connection Latching	X
RFC 5529	IPsec	Modes of Operation for Camellia for Use with IPsec	v3.11
RFC 5282	IKE	Using Authenticated Encryption Algorithms with the Encrypted Payload of the Internet Key Exchange version 2 (IKEv2) Protocol	v3.7
RFC 5114	IPsec	Additional Diffie-Hellman Groups for Use with IETF Standards	v3.20	secp256r1 (dh19): v3.20 secp384r1 (dh20): v3.20 secp521r1 (dh21): v3.20 dh22: v2.x dh23: v2.x dh24: v2.x dh25: to-be-done dh26: to-be-done
RFC 4868	IPsec	Using HMAC-SHA-256, HMAC-SHA-384, and HMAC-SHA-512 with IPsec	v3.14
RFC 4806	IKE	Online Certificate Status Protocol (OCSP) Extensions to IKEv2	v3.19	Uses NSS
RFC 4754	IKE	IKE and IKEv2 Authentication Using the Elliptic Curve Digital Signature Algorithm (ECDSA)	v3.28	Discouraged, use SECKEY still neded by Android and microsoft?
RFC 4739	IKE	Multiple Authentication Exchanges in the Internet Key Exchange (IKEv2) Protocol
RFC 4615	IKE	The Advanced Encryption Standard-Cipher-based Message Authentication Code-Pseudo-Random Function-128 (AES-CMAC-PRF-128) Algorithm for the Internet Key Exchange Protocol (IKE)	v3.25
RFC 4555	IKE	IKEv2 Mobility and Multihoming Protocol (MOBIKE)	v3.25	“Additional Addresses” not supported
RFC 4543	IPsec	The Use of Galois Message Authentication Code (GMAC) in IPsec ESP and AH	X	Kernel support is availble, ike support is not
RFC 4494	IPsec	The AES-CMAC-96 Algorithm and Its Use with IPsec	X
RFC 4478	IKE	Repeated Authentication in Internet Key Exchange (IKEv2) Protocol
RFC 4434	IKE	The AES-XCBC-PRF-128 Algorithm for the Internet Key Exchange Protocol (IKE)	v3.25
RFC 4309	IPsec	Using Advanced Encryption Standard (AES) CCM Mode with IPsec ESP	v3.7
RFC 4308	IPsec	Cryptographic Suites for IPsec
RFC 4304	IPsec	Extended Sequence Number (ESN) Addendum to IPsec DOI for ISAKMP	v3.17
RFC 4303	IPsec	IP Encapsulating Security Payload (ESP)	v2.x	Obsoletes: 2406
RFC 4302	IPsec	IP Authentication Header (AH)	v2.x	Obsoletes: 2402
RFC 4301	IPsec	Security Architecture for the Internet Protocol	v2.x
RFC 4106	IPsec	The Use of Galois/Counter Mode (GCM) in IPsec ESP	v3.17
RFC 3948	IPsec	UDP Encapsulation of IPsec ESP Packets	v2.x
RFC 3686	IPsec	Using Advanced Encryption Standard (AES) Counter Mode With IPsec Encapsulating Security Payload (ESP)	v
RFC 3602	IPsec	The AES-CBC Cipher Algorithm and Its Use with IPsec	v2.x
RFC 3566	IPsec	The AES-XCBC-MAC-96 Algorithm and Its Use With IPsec	v2.x
RFC 3526	IKE	More Modular Exponential (MODP) Diffie-Hellman groups for Internet Key Exchange (IKE)
RFC 2451	IPsec	The ESP CBC-Mode Cipher Algorithms	v2.x
RFC 2410	IPsec	The NULL Encryption Algorithm and Its Use With IPsec	v2.x
RFC 2405	IPsec	The ESP DES-CBC Cipher Algorithm With Explicit IV	v2.x
RFC 2404	IPsec	The Use of HMAC-SHA-1-96 within ESP and AH	v2.x
RFC 2403	IPsec	The Use of HMAC-MD5-96 within ESP and AH	v2.x
RFC 2104	IKE	HMAC: Keyed-Hashing for Message Authentication	v2.x

Active IPSECME Internet Drafts

This table should track the “Active Internet-Drafts “ section of the the IPSECME documents page.

Standard	Area	Description	Status	Comments
draft	IKE	IKEv2 negotiation for Bound End-to-End Tunnel (BEET) mode ESP
draft	IKE	Separate Transports for IKE and ESP
draft	IPsec	Encrypted ESP Echo Protocol
draft	IKE	IKEv2 Support for Child SA PFS Policy Information	in-progress	paul
draft	IKE	Use of Variable-Length Output Pseudo-Random Functions (PRFs) in the Internet Key Exchange Protocol Version 2 (IKEv2)
draft	IPsec	A Bound End-to-End Tunnel (BEET) mode for ESP
draft	IKE	Optimized Rekeys in the Internet Key Exchange Protocol Version 2 (IKEv2)	in-progress	paul
draft	IKE	Post-quantum Hybrid Key Exchange in IKEv2 with FrodoKEM
draft	IPsec	Enhanced Encapsulating Security Payload (EESP)
draft	IKE	IKEv2 negotiation for Enhanced Encapsulating Security Payload (EESP)
draft	IPsec	ESP Echo Protocol
draft	IPsec	ESP Header Compression with Diet-ESP
draft	IKE	Internet Key Exchange version 2 (IKEv2) extension for Header Compression Profile (HCP)
draft	IKE	Use of SHA-3 in the Internet Key Exchange Protocol Version 2 (IKEv2) and IPsec

RFCs from Other Working Groups and/or Sponsored by Area Directors

IKEv2 Specific RFCs

Standard	Area	Description	Status	Comments
RFC 7815	IKE	Minimal Internet Key Exchange Version 2 (IKEv2) Initiator Implementation		This is a really just a subset of RFC 7296: Internet Key Exchange Protocol Version 2 (IKEv2)
RFC 7670	IKE	Generic Raw Public-Key Support for IKEv2	v3.26	This defines the material used by RFC 7427: Signature Authentication in the Internet Key Exchange Version 2 (IKEv2)
RFC 7651		3GPP IP Multimedia Subsystems (IMS) Option for the Internet Key Exchange Protocol Version 2 (IKEv2)
RFC 6954	IKE	Using the Elliptic Curve Cryptography (ECC) Brainpool Curves for the Internet Key Exchange Protocol Version 2 (IKEv2)
RFC 6932		Brainpool Elliptic Curves for the IKE Group Description Registry

EAP

Standard	Area	Description	Status	Comments
RFC 9190	EAP	EAP-TLS 1.3: Using the Extensible Authentication Protocol with TLS 1.3	v4.7	server only
RFC 5998	EAP	An Extension for EAP-Only Authentication in IKEv2	v4.7	server only
RFC 5216	EAP	The EAP-TLS Authentication Protocol	v4.7	server only, Updated by RFC 9190
RFC 3748	EAP	Extensible Authentication Protocol (EAP)
RFC 2716	EAP	~~PPP EAP TLS Authentication Protocol~~		Obsolete, see RFC 5216

Certificates and PKIX

Standard	Area	Description	Status	Comments
RFC 4945	PKIX	The Internet IP Security PKI Profile of IKEv1/ISAKMP, IKEv2, and PKIX	v2.x	Changed to NSS in v3.14

PF KEY V2

FreeBSD and NetBSD implement a flavour of PF KEY v2 using the KAME code base as a starting point.

OpenBSD’s PF KEY v2’s implementation does not.
Linux, which implements XFRM, has borrowed concepts from PF KEY v2

Standard	Area	Description	Status	Comments
RFC 2367	PFKEYv2	PF_KEY Key Management API, Version 2	v4.7	SADB messages to set up kernel state on BSD machines
draft-schilcher-mobike-pfkey-extension-01	PFKEYv2	MOBIKE Extensions for PF_KEY	v4.7	also defines KAME’s SPD extensions to set up kernel policy on BSD machine
	PFKEYv2	PF_KEY Extensions for IPsec Policy Management in KAME Stack		Post to KAME mailing list about PF KEY

Cryptography: AEAD, Public Keys (formats, standards, DNS records) …

Standard	Description	Status	Comments
RFC 8813	Clarifications for Elliptic Curve Cryptography Subject Public Key Information
RFC 7468	Textual Encodings of PKIX, PKCS, and CMS Structures	v	`ipsec showhostkey --pem` outputs Textual Encoding of Subject Public Key Info
RFC 6605	Elliptic Curve Digital Signature Algorithm (DSA) for DNSSEC		`ipsec --ipseckey` and `ipseckey --{left,right}` both dump ECDSA keys using the format described in 4. DNSKEY and RRSIG Resource Records for ECDSA
RFC 5280	Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile		See 4.1.2.7. Subject Public Key Info
RFC 4648	The Base16, Base32, and Base64 Data Encodings	v	see `datatot()`
RFC 4034	Resource Records for the DNS Security Extensions
RFC 4025	A Method for Storing IPsec Keying Material in DNS	v	`ipsec showhostkey --ipseckey` outputs the text for an IPSECKEY RR record: Algorithm 1, DSA: RFC 2536 2. DSA KEY Resource Records Algorithm 2, RSA: RFC 3110 2. RSA Public KEY Resource Records Algorithm 3, ECDSA:RFC 6605 4. DNSKEY and RRSIG Resource Records for ECDSA Algorithm 4 will probably use RFC 5280 4.1.2.7. Subject Public Key Info
RFC 3110	RSA/SHA-1 SIGs and RSA KEYs in the Domain Name System (DNS)	v	`ipsec --ipseckey` and `ipseckey --{left,right}` dump RSA keys using the format described in RFC 3112 2. RSA Public KEY Resource Records
RFC 2536	DSA KEYs and SIGs in the Domain Name System (DNS)		This won’t be implemented.
RFC 1421	Privacy Enhancement for Internet Electronic Mail: Part I: Message Encryption and Authentication Procedures		Origins of PEM format
draft-irtf-cfrg-aead-limits	Usage Limits on AEAD Algorithms		Hopefully answers the question of what limits to place on AEAD.

Obsolete IKEv1 RFCs

Standard	Area	Description	Status	Comments
RFC 3947	IKEv1	Negotiation of NAT-Traversal in the IKE	v	known as “NATT” or “ESPinUDP”
RFC 3706	IKEv1	A Traffic-Based Method of Detecting Dead Internet Key Exchange (IKE) Peers	v	known as “DPD”; IKEv2’s equivalent is “liveness”
RFC 3526	IKEv1	More Modular Exponential (MODP) Diffie-Hellman groups	v
RFC 2409	IKEv1	Internet Key Exchange (IKE)	v	Revised Mode not implemented
RFC 2408	IKEv1	Internet Security Association and Key Management Protocol (ISAKMP)	v
RFC 2407	IKEv1	IPsec Domain of Interpretation for ISAKMP (IPsec DoI)	v
draft-dukes-ike-mode-cfg	MODECFG	The ISAKMP Configuration Method	v
draft-ietf-ipsec-isakmp-xauth	XAUTH	Extended Authentication within ISAKMP/Oakley (XAUTH)	v
draft-jenkins-ipsec-rekeying	IKEv1	IPsec Re-keying Issues	v	Implementation differs on some point but accomplishes the same
draft-ietf-ipsec-isakmp-hybrid-auth	IKEv1	A Hybrid Authentication Mode for IKE	X