dns_yc: fix TXT record removal failing with "Unknown key file format" (#7150)

* dns_yc: restore YC_SA_Key_File in dns_yc_rm before signing the JWT

dns_yc_rm() never rebuilt YC_SA_Key_File from YC_SA_Key_File_PEM_b64 /
YC_SA_Key_File_Path like dns_yc_add() does. Per the DNS API dev guide,
add()/rm() run in separate subshells, so rm() must repeat add()'s setup
steps rather than rely on variables set during add().

Without it, when _yc_login() needs a fresh JWT during removal (the IAM
token from the add phase isn't available), it signs with an empty/unset
key path, and openssl fails with "Unknown key file format". The
resulting auth failure then surfaces misleadingly as "invalid domain" in
_get_root, and the TXT record is never deleted.

Verified against a real Yandex Cloud account/zone with --staging: before
the fix, removal failed with the same errors reported in the issue;
after adding the missing key-restoration block, add + remove both
succeed and the TXT record is actually deleted.

* dns_yc: preserve other TXT values when removing one at the same name

dns_yc_rm previously sent the full current data array (all existing
TXT values at the name) to the deletions API, wiping out the whole
rrset instead of only the value being removed. This breaks wildcard +
base domain issuance, where both share the same _acme-challenge name
with two different values: removing the first one deleted both,
leaving nothing for the second removal to find.

* dns_yc: read persisted config from domain conf before account conf

YC_Zone_ID, YC_Folder_ID, YC_SA_ID, YC_SA_Key_ID (zone-ID mode) and
YC_SA_Key_File_PEM_b64/Path were always saved via _savedomainconf
(domain.conf), but only ever read back via _readaccountconf_mutable
(account.conf). Once the env vars were unset, none of these could be
recovered from the saved config, so dns_yc_add/dns_yc_rm failed with
"You didn't specify a YC_SA_ID or YC_SA_Key_ID or YC_SA_Key_File."
even though the values had been persisted correctly on the prior run.

* dns_yc: replace grep -Fxv/sed with a portable loop in dns_yc_rm

Solaris's /usr/bin/grep supports neither -F nor -x, so
_remaining_txtvalue was always empty there and the preserve-other-
values logic silently fell back to deleting the whole rrset (with a
grep usage error on stderr on every rm). The sed trailing-comma strip
had a matching issue on Solaris, whose sed drops an unterminated last
line. CI didn't catch this because the fallback path also returns
"done: true". Use a plain for-loop with word splitting instead.

* dns_yc: use upsertRecordSets.deletions to remove a single TXT value

updateRecordSets has no "merges" field (only deletions/additions), so
the previous preserve-other-values logic silently did nothing -- the
TXT record was never actually removed, a regression from before that
change (which at least deleted the whole rrset). CI didn't catch it
because _clearupdns runs dns_yc_rm in a subshell and ignores its exit
code.

upsertRecordSets.deletions removes only the specified value from the
rrset directly, so the getRecordSet read and the remaining-value
recomputation are no longer needed at all.

Verified against a real zone (base + wildcard domain sharing one
_acme-challenge name): adding both values then removing one leaves
the other in place, and removing the second cleans up fully.

* dns_yc: don't delete the user's own key file in YC_SA_Key_File_Path mode

_yc_login unconditionally rm'd $YC_SA_Key_File after signing. That's
fine for the PEM_b64 path, where it's a decoded temp file, but in
YC_SA_Key_File_Path mode it's the user's own persistent key file --
the first successful login permanently deleted it, so every
subsequent dns_yc_rm/renewal hit "Unknown key file format" (the exact
symptom this PR is about, just from a different cause). Track whether
the key file is our own temp copy and only delete it in that case.

Verified with a stubbed _yc_login: a temp-mode key gets removed after
login, a path-mode key survives.

* dns_yc: clear both domain and account conf on invalid config

The failure branch in dns_yc_add only ever called _clearaccountconf,
but YC_Zone_ID/YC_Folder_ID/YC_SA_Key_File_PEM_b64/Path are persisted
via _savedomainconf, and YC_SA_ID/YC_SA_Key_ID may have been saved via
_saveaccountconf_mutable (Folder_ID mode, which stores under a
SAVED_ prefix read back by _readaccountconf_mutable). Clearing only
one store left stale values behind in whichever one wasn't touched.

Verified by seeding both domain.conf and account.conf with leftover
values, then triggering this branch and confirming both config files
end up empty.

dnsapi/dns_yc.sh

@@ -22,21 +22,32 @@ dns_yc_add() {
   fulldomain="$(echo "$1". | _lower_case)" # Add dot at end of domain name
   txtvalue=$2
 
+  # YC_SA_Key_File_PEM_b64/Path are always persisted to the domain conf below,
+  # so they must be recovered from there first (account conf is only a
+  # fallback for the YC_Folder_ID case, see the SA_ID/SA_Key_ID save below).
+  YC_SA_Key_File_PEM_b64="${YC_SA_Key_File_PEM_b64:-$(_readdomainconf YC_SA_Key_File_PEM_b64)}"
   YC_SA_Key_File_PEM_b64="${YC_SA_Key_File_PEM_b64:-$(_readaccountconf_mutable YC_SA_Key_File_PEM_b64)}"
+  YC_SA_Key_File_Path="${YC_SA_Key_File_Path:-$(_readdomainconf YC_SA_Key_File_Path)}"
   YC_SA_Key_File_Path="${YC_SA_Key_File_Path:-$(_readaccountconf_mutable YC_SA_Key_File_Path)}"
 
   if [ "$YC_SA_Key_File_PEM_b64" ]; then
     echo "$YC_SA_Key_File_PEM_b64" | _dbase64 >private.key
     YC_SA_Key_File="private.key"
+    _yc_key_is_temp=1
     _savedomainconf YC_SA_Key_File_PEM_b64 "$YC_SA_Key_File_PEM_b64"
   else
     YC_SA_Key_File="$YC_SA_Key_File_Path"
+    _yc_key_is_temp=""
     _savedomainconf YC_SA_Key_File_Path "$YC_SA_Key_File_Path"
   fi
 
+  YC_Zone_ID="${YC_Zone_ID:-$(_readdomainconf YC_Zone_ID)}"
   YC_Zone_ID="${YC_Zone_ID:-$(_readaccountconf_mutable YC_Zone_ID)}"
+  YC_Folder_ID="${YC_Folder_ID:-$(_readdomainconf YC_Folder_ID)}"
   YC_Folder_ID="${YC_Folder_ID:-$(_readaccountconf_mutable YC_Folder_ID)}"
+  YC_SA_ID="${YC_SA_ID:-$(_readdomainconf YC_SA_ID)}"
   YC_SA_ID="${YC_SA_ID:-$(_readaccountconf_mutable YC_SA_ID)}"
+  YC_SA_Key_ID="${YC_SA_Key_ID:-$(_readdomainconf YC_SA_Key_ID)}"
   YC_SA_Key_ID="${YC_SA_Key_ID:-$(_readaccountconf_mutable YC_SA_Key_ID)}"
 
   if [ "$YC_SA_ID" ] && [ "$YC_SA_Key_ID" ] && [ "$YC_SA_Key_File" ]; then
@@ -65,11 +76,21 @@ dns_yc_add() {
       return 1
     fi
   else
+    # Clear both possible stores -- YC_Zone_ID/YC_Folder_ID/key material are
+    # persisted to the domain conf, while YC_SA_ID/YC_SA_Key_ID may have been
+    # saved account-wide (Folder_ID mode), so a plain _clearaccountconf alone
+    # would leave stale values behind in whichever store wasn't touched.
+    _cleardomainconf YC_Zone_ID
     _clearaccountconf YC_Zone_ID
+    _cleardomainconf YC_Folder_ID
     _clearaccountconf YC_Folder_ID
-    _clearaccountconf YC_SA_ID
-    _clearaccountconf YC_SA_Key_ID
+    _cleardomainconf YC_SA_ID
+    _clearaccountconf_mutable YC_SA_ID
+    _cleardomainconf YC_SA_Key_ID
+    _clearaccountconf_mutable YC_SA_Key_ID
+    _cleardomainconf YC_SA_Key_File_PEM_b64
     _clearaccountconf YC_SA_Key_File_PEM_b64
+    _cleardomainconf YC_SA_Key_File_Path
     _clearaccountconf YC_SA_Key_File_Path
     _err "You didn't specify a YC_SA_ID or YC_SA_Key_ID or YC_SA_Key_File."
     return 1
@@ -110,11 +131,30 @@ dns_yc_rm() {
   fulldomain="$(echo "$1". | _lower_case)" # Add dot at end of domain name
   txtvalue=$2
 
+  YC_Zone_ID="${YC_Zone_ID:-$(_readdomainconf YC_Zone_ID)}"
   YC_Zone_ID="${YC_Zone_ID:-$(_readaccountconf_mutable YC_Zone_ID)}"
+  YC_Folder_ID="${YC_Folder_ID:-$(_readdomainconf YC_Folder_ID)}"
   YC_Folder_ID="${YC_Folder_ID:-$(_readaccountconf_mutable YC_Folder_ID)}"
+  YC_SA_ID="${YC_SA_ID:-$(_readdomainconf YC_SA_ID)}"
   YC_SA_ID="${YC_SA_ID:-$(_readaccountconf_mutable YC_SA_ID)}"
+  YC_SA_Key_ID="${YC_SA_Key_ID:-$(_readdomainconf YC_SA_Key_ID)}"
   YC_SA_Key_ID="${YC_SA_Key_ID:-$(_readaccountconf_mutable YC_SA_Key_ID)}"
 
+  # See dns_yc_add() for why domain conf is checked before account conf.
+  YC_SA_Key_File_PEM_b64="${YC_SA_Key_File_PEM_b64:-$(_readdomainconf YC_SA_Key_File_PEM_b64)}"
+  YC_SA_Key_File_PEM_b64="${YC_SA_Key_File_PEM_b64:-$(_readaccountconf_mutable YC_SA_Key_File_PEM_b64)}"
+  YC_SA_Key_File_Path="${YC_SA_Key_File_Path:-$(_readdomainconf YC_SA_Key_File_Path)}"
+  YC_SA_Key_File_Path="${YC_SA_Key_File_Path:-$(_readaccountconf_mutable YC_SA_Key_File_Path)}"
+
+  if [ "$YC_SA_Key_File_PEM_b64" ]; then
+    echo "$YC_SA_Key_File_PEM_b64" | _dbase64 >private.key
+    YC_SA_Key_File="private.key"
+    _yc_key_is_temp=1
+  else
+    YC_SA_Key_File="$YC_SA_Key_File_Path"
+    _yc_key_is_temp=""
+  fi
+
   _debug "First detect the root zone"
   if ! _get_root "$fulldomain"; then
     _err "invalid domain"
@@ -124,16 +164,10 @@ dns_yc_rm() {
   _debug _sub_domain "$_sub_domain"
   _debug _domain "$_domain"
 
-  _debug "Getting txt records"
-  if _yc_rest GET "zones/${_domain_id}:getRecordSet?type=TXT&name=$_sub_domain"; then
-    exists_txtvalue=$(echo "$response" | _normalizeJson | _egrep_o "\"data\".*\][^,]*" | _egrep_o "[^:][^:]*$")
-    _debug exists_txtvalue "$exists_txtvalue"
-  else
-    _err "Error: $response"
-    return 1
-  fi
-
-  if _yc_rest POST "zones/$_domain_id:updateRecordSets" "{\"deletions\": [ { \"name\":\"$_sub_domain\",\"type\":\"TXT\",\"ttl\":\"120\",\"data\":$exists_txtvalue}]}"; then
+  # upsertRecordSets.deletions removes only the given value from the rrset,
+  # leaving any other values at the same name (e.g. base + wildcard domain)
+  # intact -- no need to read the current data set and recompute it.
+  if _yc_rest POST "zones/$_domain_id:upsertRecordSets" "{\"deletions\": [ { \"name\":\"$_sub_domain\",\"type\":\"TXT\",\"ttl\":\"120\",\"data\":[\"$txtvalue\"]}]}"; then
     if _contains "$response" "\"done\": true"; then
       _info "Delete, OK"
       return 0
@@ -255,7 +289,9 @@ _yc_login() {
   _signature=$(printf "%s.%s" "$header" "$payload" | _sign "$YC_SA_Key_File" "sha256 -sigopt rsa_padding_mode:pss -sigopt rsa_pss_saltlen:-1" | _url_replace)
   _debug2 _signature "$_signature"
 
-  rm -rf "$YC_SA_Key_File"
+  if [ "$_yc_key_is_temp" ]; then
+    rm -f "$YC_SA_Key_File"
+  fi
 
   _jwt=$(printf "{\"jwt\": \"%s.%s.%s\"}" "$header" "$payload" "$_signature")
   _debug2 _jwt "$_jwt"