Use curve25519-sha256 kex where possible. Except where we're explicitly

testing a different kex, use curve25519-sha256 since it's faster than the
default and supported even when configured without OpenSSL.  Add a check
to ensure that the kex we intended to test is the one we actually tested.
Speeds test up by ~5%.

diff --git a/regress/usr.bin/ssh/rekey.sh b/regress/usr.bin/ssh/rekey.sh
index 061e654..79e52f2 100644 (file)
--- a/regress/usr.bin/ssh/rekey.sh
+++ b/regress/usr.bin/ssh/rekey.sh
@@ -1,4 +1,4 @@
-#      $OpenBSD: rekey.sh,v 1.26 2024/08/20 12:36:59 dtucker Exp $
+#      $OpenBSD: rekey.sh,v 1.27 2024/08/21 06:59:08 dtucker Exp $
 #      Placed in the Public Domain.
 
 tid="rekey"
@@ -11,6 +11,7 @@ cp $OBJ/sshd_proxy $OBJ/sshd_proxy_bak
 
 echo "Compression no" >> $OBJ/ssh_proxy
 echo "RekeyLimit 256k" >> $OBJ/ssh_proxy
+echo "KexAlgorithms curve25519-sha256" >> ssh_proxy
 
 # Test rekeying based on data volume only.
 # Arguments: rekeylimit, kex method, optional remaining opts are passed to ssh.
@@ -31,7 +32,7 @@ ssh_data_rekeying()
        rm -f ${COPY} ${COPY2} ${LOG}
        # Create data file just big enough to reach rekey threshold.
        dd if=${DATA} of=${COPY} bs=$_bytes count=1 2>/dev/null
-       ${SSH} <${COPY} $_opts -v \
+       ${SSH} <${COPY} $_opts -vv \
            -oRekeyLimit=$_bytes -F $OBJ/ssh_proxy somehost "cat >${COPY2}"
        if [ $? -ne 0 ]; then
                fail "ssh failed ($@)"
@@ -39,6 +40,16 @@ ssh_data_rekeying()
        cmp ${COPY} ${COPY2}            || fail "corrupted copy ($@)"
        n=`grep 'NEWKEYS sent' ${LOG} | wc -l`
        n=`expr $n - 1`
+       case "$_kexopt" in
+       KexAlgorithms*)
+               _want=`echo $_kexopt | cut -f2 -d=`
+               _got=`awk 'BEGIN{FS="[ \r]+"} /kex: algorithm: /{print $4}' \
+                   ${LOG} | sort -u`
+               if [ "$_want" != "$_got" ]; then
+                       fail "expected kex $_want, got $_got"
+               fi
+                ;;
+       esac
        trace "$n rekeying(s)"
        if [ $n -lt 1 ]; then
                fail "no rekeying occurred ($@)"