From: Tobias Brunner <tobias@strongswan.org>
Date: Thu, 26 Feb 2015 16:36:41 +0000 (+0100)
Subject: ikev2: Fall back to SHA-1 signatures for RSA
X-Git-Tag: 5.3.0dr1~39^2~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cc048f0c50f8e5e45de66f9368232727efba76bd;p=thirdparty%2Fstrongswan.git

ikev2: Fall back to SHA-1 signatures for RSA

This is really just a fallback to "classic" IKEv2 authentication if the other
peer supports no stronger hash algorithms.
---

diff --git a/src/libcharon/sa/ikev2/authenticators/pubkey_authenticator.c b/src/libcharon/sa/ikev2/authenticators/pubkey_authenticator.c
index 576aa4c630..d8c4570dcc 100644
--- a/src/libcharon/sa/ikev2/authenticators/pubkey_authenticator.c
+++ b/src/libcharon/sa/ikev2/authenticators/pubkey_authenticator.c
@@ -153,6 +153,13 @@ static signature_scheme_t select_signature_scheme(keymat_v2_t *keymat,
 			}
 		}
 		enumerator->destroy(enumerator);
+
+		/* default to the scheme we'd use with classic authentication */
+		if (selected == SIGN_UNKNOWN && key_type == KEY_RSA &&
+			keymat->hash_algorithm_supported(keymat, HASH_SHA1))
+		{
+			selected = SIGN_RSA_EMSA_PKCS1_SHA1;
+		}
 	}
 	return selected;
 }