MySQL用户和权限及破解root口令的方法示例
MySQL用户和权限
在MySQL中有一个系统自身就带有的数据库叫MySQL,数据库装好以后系统自带了好几个数据库MySQL就是其中过一个,MySQL数据库有个用户账户权限相关的表叫user表,在其中就有创建的用户。
MySQL中完整的用户名是由用户+主机名形成,主机名决定了这个用户在哪个主机上能登陆。
一、用户的创建和密码修改
1.用户的创建
createuser'USERNAME'@'HOST'identifiedby'PASSWORD';
USERNAME:用户名
HOST:主机地址
PASSWORD:密码
示例:
MariaDB[(none)]>createusermasuri@192.168.73.133identifiedby'centos'; QueryOK,0rowsaffected(0.01sec) MariaDB[(none)]>selectuser,host,passwordfrommysql.user; +--------+-----------------------+-------------------------------------------+ |user|host|password| +--------+-----------------------+-------------------------------------------+ |root|localhost|| |root|localhost.localdomain|| |root|127.0.0.1|| |root|::1|| ||localhost|| ||localhost.localdomain|| |masuri|192.168.73.133|*128977E278358FF80A246B5046F51043A2B1FCED| +--------+-----------------------+-------------------------------------------+ 7rowsinset(0.00sec)
MySQL中有匿名账户,可以通过跑安全加固脚本mysql_secure_installation来进行删除,也可以手动将其删除。
删除用户:
DROPUSER'USERNAME'@'HOST';
示例:
MariaDB[(none)]>selectuser,host,passwordfrommysql.user; +--------+-----------------------+-------------------------------------------+ |user|host|password| +--------+-----------------------+-------------------------------------------+ |root|localhost|| |root|localhost.localdomain|| |root|127.0.0.1|| |root|::1|| ||localhost|| ||localhost.localdomain|| |masuri|192.168.73.133|*128977E278358FF80A246B5046F51043A2B1FCED| +--------+-----------------------+-------------------------------------------+ 7rowsinset(0.00sec) MariaDB[(none)]>DROPUSER''@'localhost'; QueryOK,0rowsaffected(0.00sec) MariaDB[(none)]>DROPUSER''@'localhost.localdomain'; QueryOK,0rowsaffected(0.00sec) MariaDB[(none)]>selectuser,host,passwordfrommysql.user; +--------+-----------------------+-------------------------------------------+ |user|host|password| +--------+-----------------------+-------------------------------------------+ |root|localhost|| |root|localhost.localdomain|| |root|127.0.0.1|| |root|::1|| |masuri|192.168.73.133|*128977E278358FF80A246B5046F51043A2B1FCED| +--------+-----------------------+-------------------------------------------+ 5rowsinset(0.00sec)
2.密码的修改
mysql密码的修改
SETPASSWORDFORuser=PASSWORD('cleartextpassword') UPDATEtableSETpassword=password('cleartextpassword')
示例:
对masuri用户做密码的修改
MariaDB[(none)]>SETPASSWORDFORmasuri@192.168.73.133=PASSWORD('magedu'); QueryOK,0rowsaffected(0.00sec) MariaDB[(none)]>selectuser,host,passwordfrommysql.user; +--------+-----------------------+-------------------------------------------+ |user|host|password| +--------+-----------------------+-------------------------------------------+ |root|localhost|| |root|localhost.localdomain|| |root|127.0.0.1|| |root|::1|| |masuri|192.168.73.133|*6B8CCC83799A26CD19D7AD9AEEADBCD30D8A8664| +--------+-----------------------+-------------------------------------------+ #此时密码已经发生改变
root账号口令为空,为root口令设置口令,由于一条一条的设置太过麻烦也可以使用修改表的操作来修改密码
MariaDB[(none)]>updatemysql.usersetpassword=password('centos')whereuser='root'; QueryOK,4rowsaffected(0.01sec) Rowsmatched:4Changed:4Warnings:0 MariaDB[(none)]>selectuser,host,passwordfrommysql.user; +--------+-----------------------+-------------------------------------------+ |user|host|password| +--------+-----------------------+-------------------------------------------+ |root|localhost|*128977E278358FF80A246B5046F51043A2B1FCED| |root|localhost.localdomain|*128977E278358FF80A246B5046F51043A2B1FCED| |root|127.0.0.1|*128977E278358FF80A246B5046F51043A2B1FCED| |root|::1|*128977E278358FF80A246B5046F51043A2B1FCED| |masuri|192.168.73.133|*6B8CCC83799A26CD19D7AD9AEEADBCD30D8A8664| +--------+-----------------------+-------------------------------------------+ 5rowsinset(0.00sec)
此时密码已经修改但依旧无法登陆,需要将权限刷新
MariaDB[(none)]>FLUSHPRIVILEGES; QueryOK,0rowsaffected(0.00sec)
二、MySQL权限管理
权限管理涉及到多种权限的类别,比如说有管理类、程序类、数据库级别、表级别和字段级别
管理类:能否创建用户,能否显示数据库列表,能否重新加载配置文件,能否关闭数据库,和复制相关的能否执行,能否管理进程,能否创建临时表,能否创建数据库中的文件。
程序类主要涉及3个程序,函数,存储过程和触发器,例如能否创建,修改,删除和执行这些程序库,表和字段级别的权限:比如能否在库,表字段里进行增、删、查、改等操作
1.授权GRANT
授权用户时如果用户不存在可以将其创建出来,在授权前首先要确认自己是管理员有授权的权限。
GRANT priv_type[(column_list)] [,priv_type[(column_list)]]... ON[object_type]priv_level TOuser_specification[,user_specification]... [REQUIRE{NONE|ssl_option[[AND]ssl_option]...}] [WITHwith_option...]
示例:
创建一个wordpress的用户,并授权。
MariaDB[(none)]>CREATEDATABASEwordpress; QueryOK,1rowaffected(0.02sec) MariaDB[(none)]>GRANTALLONwordpress.*TOwpuser@'192.168.73.%'identifiedby'mylinuxops'; QueryOK,0rowsaffected(0.00sec)
2.查看用户的权限
MariaDB[(none)]>showgrantsforwpuser@'192.168.73.%'; +------------------------------------------------------------------------------------------------------------------+ |Grantsforwpuser@192.168.73.%| +------------------------------------------------------------------------------------------------------------------+ |GRANTUSAGEON*.*TO'wpuser'@'192.168.73.%'IDENTIFIEDBYPASSWORD'*EC0DBFB480593BB6ED2EC028A4231A72D8137406'| |GRANTALLPRIVILEGESON`wordpress`.*TO'wpuser'@'192.168.73.%'| +------------------------------------------------------------------------------------------------------------------+ 2rowsinset(0.00sec)
3.授权的其他选项
MAX_QUESRIES_PER_HOURcount#每小时最多查多少次 MAX_UPDATES_PER_HOURcount#每小时最多改多少次 MAX_CONNECTIONS_PER_HOURcount#每小时最多连多少次 MAX_USER_CONNECTIONScount#用户的最大数连接数
取消权限
REVOKE priv_type[(column_list)] [,priv_type[(column_list)]]... ON[object_type]priv_level FROMuser[,user]...
示例:
MariaDB[(none)]>revokedeleteonwordpress.*fromwpuser@'192.168.73.%'; QueryOK,0rowsaffected(0.00sec) MariaDB[(none)]>showgrantsforwpuser@'192.168.73.%'; +----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ |Grantsforwpuser@192.168.73.%| +----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ |GRANTUSAGEON*.*TO'wpuser'@'192.168.73.%'IDENTIFIEDBYPASSWORD'*EC0DBFB480593BB6ED2EC028A4231A72D8137406'| |GRANTSELECT,INSERT,UPDATE,CREATE,DROP,REFERENCES,INDEX,ALTER,CREATETEMPORARYTABLES,LOCKTABLES,EXECUTE,CREATEVIEW,SHOWVIEW,CREATEROUTINE,ALTERROUTINE,EVENT,TRIGGERON`wordpress`.*TO'wpuser'@'192.168.73.%'| +----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 2rowsinset(0.00sec) #此时wpuser@'192.168.73.%'已经没有了delete权限
MySQL的root口令破解
工作中有时候可能会遇到root口令丢失的情况,此时可以通过以下方法进行找回root口令
以下为示范如何破解root口令
一、密码未知无法登陆MySQL
[root@localhost~]#mysql ERROR1045(28000):Accessdeniedforuser'root'@'localhost'(usingpassword:NO)
二、破解
1.修改配置文件/etc/my.cnf,添加两行参数
skip_grant_tables:跳过授权表信息,此项生效后再次使用MySQL就无需使用密码了,但是远程的其他用户也可以不使用密码登陆,有一定的风险性
skip_networking:关闭网路功能,由于光启用skip_grant_tables选项,其他用户也可以无需密码登陆MySQL非常危险,所以需要关闭网路功能只允许本地的用户进行操作。
[root@localhost~]#vim/etc/my.cnf [mysqld] skip_networking=on#不启用网络功能 skip_grant_tables=on#跳过授权表 [root@localhost~]#servicemysqldrestart#对位置文件修改后需要重新启动服务 Restartingmysqld(viasystemctl):[OK]
2.登陆MySQL,进行密码修改
[root@localhost~]#mysql#此时已经无需输入密码就能登陆 WelcometotheMariaDBmonitor.Commandsendwith;or\g. YourMariaDBconnectionidis11 Serverversion:10.2.23-MariaDB-logSourcedistribution Copyright(c)2000,2018,Oracle,MariaDBCorporationAbandothers. Type'help;'or'\h'forhelp.Type'\c'toclearthecurrentinputstatement. MariaDB[(none)]>UPDATEmysql.userSETpassword=PASSWORD('123456')whereuser='root';#对root的口令进行修改 QueryOK,4rowsaffected(0.01sec) Rowsmatched:4Changed:4Warnings:0
3.口令修改完毕后,需要将配置文件恢复
将刚才启用的两个选项进行注销或者删除,然后重启服务
[root@localhost~]#vim/etc/my.cnf [mysqld] #skip_networking=on #skip_grant_tables=on [root@localhost~]#servicemysqldrestart Restartingmysqld(viasystemctl):[OK]
4.使用新口令登陆MySQL
[root@localhost~]#mysql-uroot-p123456 WelcometotheMariaDBmonitor.Commandsendwith;or\g. YourMariaDBconnectionidis10 Serverversion:10.2.23-MariaDB-logSourcedistribution Copyright(c)2000,2018,Oracle,MariaDBCorporationAbandothers. Type'help;'or'\h'forhelp.Type'\c'toclearthecurrentinputstatement. MariaDB[(none)]>
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