1 前言

一个问题，一篇文章，一出故事。
笔者之前使用NextCloud并没有特意要求用户分享链接时设置密码，因此留下一些安全破绽，因此本章总结应对方案。

2 最佳实践

2.1 创建分享链接密码生成代码

如何修改nextcloud分享链接密码？

2.2 创建修复脚本

vim ~/scripts/linkTool.sh

加入如下配置，

#!/bin/bash
source /etc/profile

mysqlHost="localhost"
mysqlPort="3306"
mysqlDataBase="nextcloud"
mysqlUser="root"
mysqlPasswd="nextcloudpwd"
linkFixLog="/var/log/nextcloud/linkFix.log"
senMailLog="/var/log/nextcloud/linkFixSendMail.log"
mailFrom="no_reply_nextcloud@cmdschool.org"

occ() {
    sudo -u apache /usr/bin/php -d apc.enable_cli=1 -d memory_limit=1024M /var/www/nextcloud/occ "$@"
}

getUser() {
        mysql -u"$mysqlUser" -p"$mysqlPasswd" -h "$mysqlHost" -P "$mysqlPort" \
		-e "SELECT uid_initiator FROM  $mysqlDataBase.oc_share \
			WHERE password IS NULL and token IS NOT NULL and \
			uid_initiator like '%@%' and uid_owner like '%@%'\G" | \
			grep 'uid_initiator:' | awk -F' ' '{print $2}' | sort -u
}

getUserLink() {
	nextcloudUser="$1"
        mysql -u"$mysqlUser" -p"$mysqlPasswd" -h "$mysqlHost" -P "$mysqlPort" \
		-e "SELECT CONCAT('https://nextcloud.cmdschool.org/index.php/s/', token) as link FROM  nextcloud.oc_share \
			WHERE password IS NULL and token IS NOT NULL and uid_initiator like '%@%' \
			and uid_owner like '%@%' and uid_initiator like '%$nextcloudUser%'\G" | \
			grep 'link:' | awk -F' ' '{print $2}'

}

getHashPassword() {
	local password="$1"
	local hashed=$(/usr/bin/php hasher.php "$password")
    	echo "$hashed"
}

setUserPassword() {
	nextcloudUser="$1"
	nextcloudPassword="$2"
        mysql -u"$mysqlUser" -p"$mysqlPasswd" -h "$mysqlHost" -P "$mysqlPort" \
		-e "UPDATE $mysqlDataBase.oc_share SET password='$nextcloudPassword' \
		WHERE password IS NULL and token IS NOT NULL and uid_initiator like '%@%' \
		and uid_owner like '%@%' and uid_initiator like '%$nextcloudUser%'"
}

writeLog() {
	nextcloudUser="$1"
	nextcloudPassword="$2"	
	for link in $(getUserLink "$nextcloudUser"); do
		echo $(date +"%Y-%m-%d %H:%M:%S") $nextcloudUser $nextcloudPassword $link | tee -a "$linkFixLog"
	done
}

fixUser() {
	for user in $(getUser); do
		userPassword="$(mkpasswd -l 12)"
		hasherPassword=$(getHashPassword "$userPassword")
		writeLog "$user" "$userPassword"
		setUserPassword "$user" "$hasherPassword"
	done
}

getSendUser() {
	cat "$linkFixLog" | awk -F' ' '{print $3}' | sort -u
}

getSendMail() {
	user="$1"
	occ user:info "$user" | grep "email:" | awk -F' ' '{print $3}'
}

getSendPassword() {
	user="$1"
	grep "$user" "$linkFixLog" | awk '{print $4}' | sort -u
}

getSendLink() {
	user="$1"
	readarray -t link < <(grep "$user" "$linkFixLog" | awk '{print $5}' | sort -u)
	i=0
	maxLength=${#link[@]}
	for item in "${link[@]}"; do
		let i++
		printf "%-3d %s\n" $i "[$item]"
	done
}

sendUserMail() {
	nextCloudUser="$1"
	sendPassword=$(getSendPassword "$nextCloudUser")
	sendLink=$(getSendLink "$nextCloudUser")
	mailTo=$(getSendMail "$nextCloudUser")

	if [[ -z "$sendPassword" || -z "$sendLink" || -z "$mailTo" ]]; then
		[[ -z "$sendPassword" ]] && echo "$(date +"%Y-%m-%d %H:%M:%S") $nextCloudUser sendPassword is empty." >> "$senMailLog"
		[[ -z "$sendLink" ]] && echo "$(date +"%Y-%m-%d %H:%M:%S") $nextCloudUser sendLink is empty." >> "$senMailLog"
		[[ -z "$mailTo" ]] && echo "$(date +"%Y-%m-%d %H:%M:%S") $nextCloudUser mailTo is empty." >> "$senMailLog"
		return
	fi

        mailSubject='Notification of Password Change for Unencrypted Links on NextCloud'
	cat <<-EOF | mail -s "$mailSubject" -r "$mailFrom" "$mailTo"
	Dear User,

	We found that some of your NextCloud links did not have access passwords set. For security reasons, the unencrypted links have been updated. The new access password is: $sendPassword

	Please notify any other users who need access to these links in a timely manner.

	The detailed links for which the passwords have been changed are as follows:

	$sendLink

	You may contact IT HelpDesk, if you need further assistance or queries. 
	HK IT Helpdesk: (31) 8222; D2 IT Helpdesk: (32)2998; CA IT Helpdesk: (33)7998

	Note: This email is an automatically generated email from [NextCloud], please do not respond to this email!
	EOF
	echo "$(date +"%Y-%m-%d %H:%M:%S") $nextCloudUser email was sent successfully." >> "$senMailLog"
}

sendMail() {
	for user in $(getSendUser); do
		sendUserMail "$user"
	done
}

case "$1" in
	fix)
		fixUser
                ;;
        mail)
                sendMail
                ;;
        *)
                echo "Usage: $0 {fix|mail}"
                ;;
esac
exit 0

2.3 修复密码

bash ~/scripts/linkTool.sh fix

2.4 通知用户

bash ~/scripts/linkTool.sh mail