3 files changed, 14 insertions, 2 deletions

diff --git a/regress/Makefile b/regress/Makefile
index 781400fd0..491a3a46a 100644
--- a/regress/Makefile
+++ b/regress/Makefile
@@ -114,7 +114,7 @@ CLEANFILES=	*.core actual agent-key.* authorized_keys_${USERNAME} \
                 rsa_ssh2_crnl.prv scp-ssh-wrapper.exe \
                 scp-ssh-wrapper.scp setuid-allowed sftp-server.log \
                 sftp-server.sh sftp.log ssh-log-wrapper.sh \
-                ssh-rsa_oldfmt \
+                ssh-rsa_oldfmt ssh-rsa_oldfmt.pub \
                 ssh.log ssh_config ssh_config.* ssh_proxy ssh_proxy_bak \
                 ssh_proxy_envpass sshd.log sshd_config sshd_config_minimal \
                 sshd_config.orig sshd_proxy sshd_proxy.* sshd_proxy_bak \
diff --git a/regress/conch-ciphers.sh b/regress/conch-ciphers.sh
index 51e3b705f..fa24552b0 100644
--- a/regress/conch-ciphers.sh
+++ b/regress/conch-ciphers.sh
@@ -16,7 +16,7 @@ for c in aes256-ctr aes256-cbc aes192-ctr aes192-cbc aes128-ctr aes128-cbc \
         rm -f ${COPY}
         # XXX the 2nd "cat" seems to be needed because of buggy FD handling
         # in conch
-        ${CONCH} --identity $OBJ/ssh-rsa --port $PORT --user $USER -e none \
+        ${CONCH} --identity $OBJ/ssh-rsa_oldfmt --port $PORT --user $USER -e none \
             --known-hosts $OBJ/known_hosts --notty --noagent --nox11 -n \
             127.0.0.1 "cat ${DATA}" 2>/dev/null | cat > ${COPY}
         if [ $? -ne 0 ]; then
diff --git a/regress/test-exec.sh b/regress/test-exec.sh
index efde6a173..83c7d02e6 100644
--- a/regress/test-exec.sh
+++ b/regress/test-exec.sh
@@ -500,6 +500,18 @@ REGRESS_INTEROP_CONCH=no
 if test -x "$CONCH" ; then
         REGRESS_INTEROP_CONCH=yes
 fi
+case "$SCRIPT" in
+*conch*)        ;;
+*)              REGRESS_INTEROP_CONCH=no
+esac
+
+if test "$REGRESS_INTEROP_CONCH" = "yes" ; then
+        # Convert rsa key to old format to work around
+        # https://twistedmatrix.com/trac/ticket/9515
+        cp $OBJ/ssh-rsa $OBJ/ssh-rsa_oldfmt
+        cp $OBJ/ssh-rsa.pub $OBJ/ssh-rsa_oldfmt.pub
+        ${SSHKEYGEN} -p -N '' -m PEM -f $OBJ/ssh-rsa_oldfmt >/dev/null
+fi
 
 # If PuTTY is present and we are running a PuTTY test, prepare keys and
 # configuration