Upstream in commit 972d723484d8 ("split signkey_type and signature_type
for RSA sha1 vs sha256") has added strict checking of pubkey algorithms
which made keys with SHA-256 hashing algorithm unusable as they still
reuse the `ssh-rsa` public key format. So fix this by disabling the
check for `rsa-sha2-256` pubkeys.Ref: https://tools.ietf.org/html/rfc8332#section-3 Cc: Matt Johnston <[email protected]> Fixes: d4c80f5b172e ("dropbear: bump to 2020.80") Signed-off-by: Petr Štetiar <[email protected]> --- I'm unable to connect with the latest Dropbear with my rsa-sha2-256: debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,ssh-rsa> debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey debug1: Next authentication method: publickey debug1: Offering public key: RSA SHA256:ZLONs7adjPBljemwKAX5dXDiKPDVh4fsStkqi2eJsiI cardno:000610530066 debug1: Server accepts key: pkalg rsa-sha2-256 blen 535 Connection closed by 192.168.1.1 port 22 Upstreamed in https://github.com/mkj/dropbear/pull/106 ...nkey-fix-use-of-rsa-sha2-256-pubkeys.patch | 40 +++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 package/network/services/dropbear/patches/910-signkey-fix-use-of-rsa-sha2-256-pubkeys.patch diff --git a/package/network/services/dropbear/patches/910-signkey-fix-use-of-rsa-sha2-256-pubkeys.patch b/package/network/services/dropbear/patches/910-signkey-fix-use-of-rsa-sha2-256-pubkeys.patch new file mode 100644 index 000000000000..afa0ebb310c9 --- /dev/null +++ b/package/network/services/dropbear/patches/910-signkey-fix-use-of-rsa-sha2-256-pubkeys.patch @@ -0,0 +1,40 @@ +From 667d9b75df86ec9ee1205f9101beb8dbbe4a00ae Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Petr=20=C5=A0tetiar?= <[email protected]> +Date: Wed, 1 Jul 2020 11:38:33 +0200 +Subject: [PATCH] signkey: fix use of rsa-sha2-256 pubkeys +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Commit 972d723484d8 ("split signkey_type and signature_type for RSA sha1 +vs sha256") has added strict checking of pubkey algorithms which made +keys with SHA-256 hashing algorithm unusable as they still reuse the +`ssh-rsa` public key format. So fix this by disabling the check for +rsa-sha2-256 pubkeys. + +Ref: https://tools.ietf.org/html/rfc8332#section-3 +Fixes: 972d723484d8 ("split signkey_type and signature_type for RSA sha1 vs sha256") +Signed-off-by: Petr Štetiar <[email protected]> +--- + signkey.c | 8 ++++++-- + 1 file changed, 6 insertions(+), 2 deletions(-) + +diff --git a/signkey.c b/signkey.c +index 92fe6a242cd0..d16ab174d83a 100644 +--- a/signkey.c ++++ b/signkey.c +@@ -657,8 +657,12 @@ int buf_verify(buffer * buf, sign_key *key, enum signature_type expect_sigtype, + sigtype = signature_type_from_name(type_name, type_name_len); + m_free(type_name); + +- if (expect_sigtype != sigtype) { +- dropbear_exit("Non-matching signing type"); ++ if (sigtype == DROPBEAR_SIGNATURE_NONE) { ++ dropbear_exit("No signature type"); ++ } ++ ++ if ((expect_sigtype != DROPBEAR_SIGNATURE_RSA_SHA256) && (expect_sigtype != sigtype)) { ++ dropbear_exit("Non-matching signing type"); + } + + keytype = signkey_type_from_signature(sigtype); _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/mailman/listinfo/openwrt-devel
