Preserve preferred-challenges on renewal (#4112)

* use challenge type strings, not objectS

* Factor out parse_preferred_challenges

* restore pref_challs

* save pref_challs

* Make CheckCertCount more flexible

* improve integration tests

* Make pref_challs more flexible

tests/boulder-integration.sh

@@ -96,7 +96,7 @@ common certonly -a manual -d le.wtf --rsa-key-size 4096 \
     --pre-hook 'echo wtf2.pre >> "$HOOK_TEST"' \
     --post-hook 'echo wtf2.post >> "$HOOK_TEST"'
 
-common certonly -a manual -d dns.le.wtf --preferred-challenges dns-01 \
+common certonly -a manual -d dns.le.wtf --preferred-challenges dns,tls-sni \
     --manual-auth-hook ./tests/manual-dns-auth.sh
 
 export CSR_PATH="${root}/csr.der" KEY_PATH="${root}/key.pem" \
@@ -113,29 +113,30 @@ common --domains le3.wtf install \
        --key-path "${root}/csr/key.pem"
 
 CheckCertCount() {
-    CERTCOUNT=`ls "${root}/conf/archive/le.wtf/cert"* | wc -l`
-    if [ "$CERTCOUNT" -ne "$1" ] ; then
-        echo Wrong cert count, not "$1" `ls "${root}/conf/archive/le.wtf/"*`
+    CERTCOUNT=`ls "${root}/conf/archive/$1/cert"* | wc -l`
+    if [ "$CERTCOUNT" -ne "$2" ] ; then
+        echo Wrong cert count, not "$2" `ls "${root}/conf/archive/$1/"*`
         exit 1
     fi
 }
 
-CheckCertCount 1
+CheckCertCount "le.wtf" 1
 # This won't renew (because it's not time yet)
 common_no_force_renew renew
-CheckCertCount 1
+CheckCertCount "le.wtf" 1
 
-# --renew-by-default is used, so renewal should occur
-[ -f "$HOOK_TEST" ] && rm -f "$HOOK_TEST"
-common renew
-CheckCertCount 2
-CheckHooks
+# renew using HTTP manual auth hooks
+common renew --cert-name le.wtf --authenticator manual
+CheckCertCount "le.wtf" 2
 
+# renew using DNS manual auth hooks
+common renew --cert-name dns.le.wtf --authenticator manual
+CheckCertCount "dns.le.wtf" 2
 
 # This will renew because the expiry is less than 10 years from now
 sed -i "4arenew_before_expiry = 4 years" "$root/conf/renewal/le.wtf.conf"
 common_no_force_renew renew --rsa-key-size 2048
-CheckCertCount 3
+CheckCertCount "le.wtf" 3
 
 # The 4096 bit setting should persist to the first renewal, but be overriden in the second
 
@@ -149,6 +150,12 @@ if [ "$size1" -lt 3000 ] || [ "$size2" -lt 3000 ] || [ "$size3" -gt 1800 ] ; the
     exit 1
 fi
 
+# --renew-by-default is used, so renewal should occur
+[ -f "$HOOK_TEST" ] && rm -f "$HOOK_TEST"
+common renew
+CheckCertCount "le.wtf" 4
+CheckHooks
+
 # ECDSA
 openssl ecparam -genkey -name secp384r1 -out "${root}/privkey-p384.pem"
 SAN="DNS:ecdsa.le.wtf" openssl req -new -sha256 \