ikev1: Assume a default key length of 128-bit for AES-CBC

[strongswan.git] / src / libcharon / encoding / payloads / proposal_substructure.c

diff --git a/src/libcharon/encoding/payloads/proposal_substructure.c b/src/libcharon/encoding/payloads/proposal_substructure.c
index 48dcfeb..65ce667 100644 (file)
--- 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);
                }