From 636b2e9b2ae29012b82901e6e5d85a159c359478 Mon Sep 17 00:00:00 2001 From: Tobias Brunner Date: Thu, 13 Aug 2015 18:54:34 +0200 Subject: [PATCH] ikev1: Assume a default key length of 128-bit for AES-CBC Some implementations don't send a Key Length attribute for AES-128. This was allowed for IKE in early drafts of RFC 3602, however, some implementations also seem to do it for ESP, where it never was allowed. And the final version of RFC 3602 demands a Key Length attribute for both phases so they shouldn't do it anymore anyway. Fixes #1064. --- .../encoding/payloads/proposal_substructure.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/src/libcharon/encoding/payloads/proposal_substructure.c b/src/libcharon/encoding/payloads/proposal_substructure.c index 48dcfeb24..65ce667c7 100644 --- a/src/libcharon/encoding/payloads/proposal_substructure.c +++ b/src/libcharon/encoding/payloads/proposal_substructure.c @@ -914,6 +914,11 @@ static void add_to_proposal_v1_ike(proposal_t *proposal, if (encr != ENCR_UNDEFINED) { + if (encr == ENCR_AES_CBC && !key_length) + { /* some implementations don't send a Key Length attribute for + * AES-128, early drafts of RFC 3602 allowed that */ + key_length = 128; + } proposal->add_algorithm(proposal, ENCRYPTION_ALGORITHM, encr, key_length); } } @@ -962,6 +967,12 @@ static void add_to_proposal_v1(proposal_t *proposal, transform->get_transform_id(transform)); if (encr) { + if (encr == ENCR_AES_CBC && !key_length) + { /* some implementations don't send a Key Length attribute for + * AES-128, early drafts of RFC 3602 allowed that for IKE, some + * also seem to do it for ESP */ + key_length = 128; + } proposal->add_algorithm(proposal, ENCRYPTION_ALGORITHM, encr, key_length); }