IKEv2 Cipher Suites

The keywords listed below can be used with the ike and esp directives in ipsec.conf to define cipher suites.

Encryption Algorithms

Keyword Description IANA IKE ESP
3des 168 bit 3DES-EDE-CBC 3 x o g a k
cast128 128 bit CAST-CBC 6 o g a k
blowfish128 or blowfish 128 bit Blowfish-CBC 7 x o g a k
blowfish192 192 bit Blowfish-CBC x o a k
blowfish256 256 bit Blowfish-CBC x o a k
null Null encryption 11 - k
aes128 or aes 128 bit AES-CBC 12 x o g a k
aes192 192 bit AES-CBC x o g a k
aes256 256 bit AES-CBC x o g a k
aes128ctr 128 bit AES-COUNTER 13 x o g a k
aes192ctr 192 bit AES-COUNTER x o g a k
aes256ctr 256 bit AES-COUNTER x o g a k
aes128ccm8 or aes128ccm64 128 bit AES-CCM with 64 bit ICV 14 x o g a k
aes192ccm8 or aes192ccm64 192 bit AES-CCM with 64 bit ICV x o g a k
aes256ccm8 or aes256ccm64 256 bit AES-CCM with 64 bit ICV x o g a k
aes128ccm12 or aes128ccm96 128 bit AES-CCM with 96 bit ICV 15 x o g a k
aes192ccm12 or aes192ccm96 192 bit AES-CCM with 96 bit ICV x o g a k
aes256ccm12 or aes256ccm96 256 bit AES-CCM with 96 bit ICV x o g a k
aes128ccm16 or aes128ccm128 128 bit AES-CCM with 128 bit ICV 16 x o g a k
aes192ccm16 or aes192ccm128 192 bit AES-CCM with 128 bit ICV x o g a k
aes256ccm16 or aes256ccm128 256 bit AES-CCM with 128 bit ICV x o g a k
aes128gcm8 or aes128gcm64 128 bit AES-GCM with 64 bit ICV 18 x o g a k
aes192gcm8 or aes192gcm64 192 bit AES-GCM with 64 bit ICV x o g a k
aes256gcm8 or aes256gcm64 256 bit AES-GCM with 64 bit ICV x o g a k
aes128gcm12 or aes128gcm96 128 bit AES-GCM with 96 bit ICV 19 x o g a k
aes192gcm12 or aes192gcm96 192 bit AES-GCM with 96 bit ICV x o g a k
aes256gcm12 or aes256gcm96 256 bit AES-GCM with 96 bit ICV x o g a k
aes128gcm16 or aes128gcm128 128 bit AES-GCM with 128 bit ICV 20 x o g a k
aes192gcm16 or aes192gcm128 192 bit AES-GCM with 128 bit ICV x o g a k
aes256gcm16 or aes256gcm128 256 bit AES-GCM with 128 bit ICV x o g a k
aes128gmac Null encryption with 128 bit AES-GMAC 21 - k
aes192gmac Null encryption with 192 bit AES-GMAC - k
aes256gmac Null encryption with 256 bit AES-GMAC - k
camellia128 or camellia 128 bit Camellia-CBC 23 o g a k
camellia192 192 bit Camellia-CBC o g a k
camellia256 256 bit Camellia-CBC o g a k
camellia128ctr 128 bit Camellia-COUNTER 24 o g a k
camellia192ctr 192 bit Camellia-COUNTER o g a k
camellia256ctr 256 bit Camellia-COUNTER o g a k
camellia128ccm8 or camellia128ccm64 128 bit Camellia-CCM with 64 bit ICV 25 o g a
camellia192ccm8 or camellia192ccm64 192 bit Camellia-CCM with 64 bit ICV o g a
camellia256ccm8 or camellia256ccm64 256 bit Camellia-CCM with 64 bit ICV o g a
camellia128ccm12 or camellia128ccm96 128 bit Camellia-CCM with 96 bit ICV 26 o g a
camellia192ccm12 or camellia192ccm96 192 bit Camellia-CCM with 96 bit ICV o g a
camellia256ccm12 or camellia256ccm96 256 bit Camellia-CCM with 96 bit ICV o g a
camellia128ccm16 or camellia128ccm128 128 bit Camellia-CCM with 128 bit ICV 27 o g a
camellia192ccm16 or camellia192ccm128 192 bit Camellia-CCM with 128 bit ICV o g a
camellia256ccm16 or camellia256ccm128 256 bit Camellia-CCM with 128 bit ICV o g a

x default built-in crypto library
o OpenSSL crypto library
g Gcrypt crypto library
a AF_ALG userland crypto API for Linux 2.6.38 kernel or newer
k Linux 2.6 kernel

Integrity Algorithms

Keyword Description IANA IKE ESP Info
md5 MD5 HMAC 1 96 bit 96 bit
md5_128 MD5_128 HMAC 6 n/a 128 bit x
sha1 or sha SHA1 HMAC 2 96 bit 96 bit
sha1_160 SHA1_160 HMAC 7 n/a 160 bit x
aesxcbc AES XCBC 5 96 bit 96 bit
sha2_256 or sha256 SHA2_256_128 HMAC 12 128 bit 128 bit t
sha2_384 or sha384 SHA2_384_192 HMAC 13 192 bit 192 bit
sha2_512 or sha512 SHA2_512_256 HMAC 14 256 bit 256 bit
sha2_256_96 or sha256_96 SHA2_256_96 HMAC p 96 bit 96 bit t

p strongSwan uses the value 1026 from the IANA private use range
x requires a Linux 2.6.33 kernel or newer
t before version 2.6.33 the Linux kernel incorrectly used 96 bit truncation for SHA-256

Diffie Hellman Groups

Modulo Prime Groups

Keyword DH Group Modulus IKE
modp768 1 768 bits m o g
modp1024 2 1024 bits m o g
modp1536 5 1536 bits m o g
modp2048 14 2048 bits m o g
modp3072 15 3072 bits m o g
modp4096 16 4096 bits m o g
modp6144 17 6144 bits m o g
modp8192 18 8192 bits m o g

Modulo Prime Groups with Prime Order Subgroup

Keyword DH Group Modulus Subgroup IKE
modp1024s160 22 1024 bits 160 bits m o g
modp2048s224 23 2048 bits 224 bits m o g
modp2048s256 24 2048 bits 256 bits m o g

Elliptic Curve Groups

Keyword DH Group Modulus IKE
ecp192 25 192 bits o
ecp224 26 224 bits o
ecp256 19 256 bits o
ecp384 20 384 bits o
ecp521 21 521 bits o

m GMP multi-precision library
o OpenSSL crypto library
g Gcrypt crypto library