{"id":31053,"date":"2021-04-16T07:35:32","date_gmt":"2021-04-16T05:35:32","guid":{"rendered":"https:\/\/eltallerdelbit.com\/?p=31053"},"modified":"2021-04-16T04:13:45","modified_gmt":"2021-04-16T02:13:45","slug":"no-rsa-host-key-is-known","status":"publish","type":"post","link":"https:\/\/eltallerdelbit.com\/no-rsa-host-key-is-known\/","title":{"rendered":"No RSA host key is known and you have requested strict checking"},"content":{"rendered":"<h2>Vamos a ver c\u00f3mo solucionar el error &#8220;<em><strong>No RSA host key is known and you have requested strict checking<\/strong><\/em>&#8221; al intentar acceder por ssh.<\/h2>\n<p>&nbsp;<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-large wp-image-31104\" src=\"https:\/\/eltallerdelbit.com\/wp-content\/uploads\/2021\/04\/No-RSA-host-key-is-known-and-you-have-requested-strict-checking-1024x546.jpg\" alt=\"No RSA host key is known and you have requested strict checking\" width=\"1024\" height=\"546\" srcset=\"https:\/\/eltallerdelbit.com\/wp-content\/uploads\/2021\/04\/No-RSA-host-key-is-known-and-you-have-requested-strict-checking-1024x546.jpg 1024w, https:\/\/eltallerdelbit.com\/wp-content\/uploads\/2021\/04\/No-RSA-host-key-is-known-and-you-have-requested-strict-checking-300x160.jpg 300w, https:\/\/eltallerdelbit.com\/wp-content\/uploads\/2021\/04\/No-RSA-host-key-is-known-and-you-have-requested-strict-checking-768x410.jpg 768w, https:\/\/eltallerdelbit.com\/wp-content\/uploads\/2021\/04\/No-RSA-host-key-is-known-and-you-have-requested-strict-checking-1080x576.jpg 1080w, https:\/\/eltallerdelbit.com\/wp-content\/uploads\/2021\/04\/No-RSA-host-key-is-known-and-you-have-requested-strict-checking.jpg 1200w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/p>\n<ul>\n<li><a href=\"#error_no_rsa_host_key\">\u00bfQu\u00e9 es el error &#8220;<em>No RSA host key is known<\/em>&#8220;?<\/a><\/li>\n<li><a href=\"#no_rsa_host_key\">C\u00f3mo solucionar el error &#8220;<em>No RSA host key is known and you have requested strict checking<\/em><\/a>&#8221;\n<ul>\n<li><a href=\"#errores_directorios_ficheros_necesarios_ssh\">Solucionar errores con los directorios y ficheros de ssh<\/a>\n<ul>\n<li><a href=\"#crear_directorio_ssh\">crear directorio <em>.ssh<\/em><\/a><\/li>\n<li><a href=\"#permisos_directorio_ssh\">permisos directorio <em>.ssh<\/em><\/a><\/li>\n<li><a href=\"#fichero_authorized_keys\">Creamos fichero <em>authorized_keys<\/em><\/a><\/li>\n<li><a href=\"#permisos_authorized_keys\">permisos del fichero <em>authorized_keys<\/a><\/em><\/li>\n<\/ul>\n<\/li>\n<li><a href=\"#errores_clave_publica_ssh\">Solucionar errores con la clave p\u00fablica SSH<\/a><\/li>\n<li><a href=\"#errores_known_hosts\">Solucionar errores en el fichero <em>known_hosts<\/em><\/a><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p id=\"error_no_rsa_host_key\">El mensaje de error &#8220;<strong><em>No RSA host key is known and you have requested strict checking<\/em><\/strong>&#8221; especifica que ha ocurrido un<a title=\"Modo de depuraci\u00f3n SSH | Debug\" href=\"\/modo-depuracion-ssh-debug\/\" target=\"_blank\" rel=\"noopener\"> error en la conexi\u00f3n ssh, que podemos analizar con el modo debug de SSH<\/a>, y normalmente es un error provocado por el cambio de las claves p\u00fablicas de una m\u00e1quina, ya que la m\u00e1quina entera ha sido reinstalada o las claves p\u00fablicas pueden haber sido actualizadas;<\/p>\n<p>&nbsp;<br \/>\neste error tambi\u00e9n ocurre\u00a0\u00a0porque faltan no solo las claves p\u00fablicas (o son err\u00f3neas) sino porque faltan incluso los directorios y ficheros necesarios para que funcione el acceso ssh con clave p\u00fablica, tendremos que revisar que los ficheros existen y tienen los permisos correctos.<\/p>\n<p>&nbsp;<br \/>\n<img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-31105\" src=\"https:\/\/eltallerdelbit.com\/wp-content\/uploads\/2021\/04\/No-RSA-host-key-is-known.jpg\" alt=\"resolver error ssh : No RSA host key is known\" width=\"754\" height=\"156\" srcset=\"https:\/\/eltallerdelbit.com\/wp-content\/uploads\/2021\/04\/No-RSA-host-key-is-known.jpg 754w, https:\/\/eltallerdelbit.com\/wp-content\/uploads\/2021\/04\/No-RSA-host-key-is-known-300x62.jpg 300w\" sizes=\"(max-width: 754px) 100vw, 754px\" \/><br \/>\n&nbsp;<\/p>\n<pre lang=\"xml\" escaped=\"true\">\r\n-bash-4.2$ ssh 192.168.8.140\r\nNo RSA host key is known for 192.168.8.140 and you have requested strict checking.\r\nHost key verification failed.\r\n<\/pre>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<h3 id=\"no_rsa_host_key\" style=\"text-align: center;\"><span style=\"text-decoration: underline;\">C\u00f3mo solucionar el error <strong><em><a href=\"https:\/\/serverfault.com\/questions\/6233\/how-to-remove-strict-rsa-key-checking-in-ssh-and-whats-the-problem-here\" target=\"_blank\" rel=\"nofollow noopener\">No RSA host key is known<\/a> and you have requested strict checking<\/em><\/strong><\/span><\/h3>\n<p>&nbsp;<\/p>\n<p>Comprobamos que existe el fichero de clave p\u00fablica en el cliente (<em>\/home\/usuario\/.ssh\/id_rsa.pub<\/em>) , y la estructura de directorios de <em>.ssh<\/em>, as\u00ed como los ficheros <em>authorized_keys<\/em> y <em>known_hosts<\/em>, si es necesario generamos la clave p\u00fablica del cliente si no existe.<br \/>\n&nbsp;<\/p>\n<h4 id=\"errores_directorios_ficheros_necesarios_ssh\" style=\"text-align: center;\"><span style=\"text-decoration: underline;\">Solucionar errores con los directorios de ssh y los ficheros de ssh necesarios<\/span><\/h4>\n<p>&nbsp;<\/p>\n<p id=\"crear_directorio_ssh\">&#8211;> Creamos el directorio .ssh:<\/p>\n<pre lang=\"xml\" escaped=\"true\">\r\ncd ~\r\n\r\nmkdir .ssh\r\n<\/pre>\n<p>&nbsp;<\/p>\n<p id=\"permisos_directorio_ssh\">&#8211;> le damos permisos correctos al directorio <em>.ssh<\/em>:<\/p>\n<pre lang=\"xml\" escaped=\"true\">\r\nchmod 700 \/home\/usuario\/.ssh\r\n<\/pre>\n<p>o <\/p>\n<pre lang=\"xml\" escaped=\"true\">\r\nchmod 700 ~\/.ssh\r\n<\/pre>\n<p>&nbsp;<\/p>\n<p id=\"fichero_authorized_keys\">&#8211;> Creamos el fichero authorized_keys :<\/p>\n<pre lang=\"xml\" escaped=\"true\">\r\ntouch ~\/.ssh\/authorized_keys\r\n<\/pre>\n<p>&nbsp;<\/p>\n<p id=\"permisos_authorized_keys\">&#8211;> le damos permisos correctos al fichero <em>authorized_keys<\/em>:<\/p>\n<pre lang=\"xml\" escaped=\"true\">\r\nchmod 644 \/home\/usuario\/.ssh\/authorized_keys\r\n<\/pre>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>Si fuera necesario revisamos los permisos del directorio home ($HOME) del usuario y aplicamos los permisos correctos para evitar problemas de paso:<\/p>\n<pre lang=\"xml\" escaped=\"true\">\r\nchmod 751 ~\r\nchmod go-w ~\r\n<\/pre>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<h4 id=\"errores_clave_publica_ssh\" style=\"text-align: center;\"><span style=\"text-decoration: underline;\">Solucionar errores con la clave p\u00fablica SSH<\/span><\/h4>\n<p>&nbsp;<br \/>\nCopiamos la clave p\u00fablica del cliente y la a\u00f1adimos en el fichero <a href=\"\/open-ssh-server-linux\/#authorizedkeys\" target=\"_blank\" rel=\"noopener\"><em>authorized_keys<\/em> en el servidor ssh<\/a>. <a href=\"\/copiar-clave-publica-ssh-scp-ssh-copy-id\/\" target=\"_blank\" rel=\"noopener\">Copiamos la clave p\u00fablica ssh del cliente al servidor con <em>ssh-copy-id<\/em><\/a>, o <a href=\"\/copiar-clave-publica-ssh-scp-ssh-copy-id\/#copiar_clave_publica_con_scp\" target=\"_blank\" rel=\"noopener\">copiamos rem\u00f3tamente la clave con scp<\/a>, o directamente a mano.<br \/>\n&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<h4 id=\"errores_known_hosts\" style=\"text-align: center;\"><span style=\"text-decoration: underline;\">Solucionar <a href=\"https:\/\/serverfault.com\/questions\/321167\/add-correct-host-key-in-known-hosts-multiple-ssh-host-keys-per-hostname\" target=\"_blank\" rel=\"nofollow noopener\">errores en el fichero <em>known_hosts<\/em><\/a><\/span><\/h4>\n<p>&nbsp;<br \/>\nRevisamos que exista el fichero <em>known_hosts<\/em> tanto en el servidor como en el cliente. Si no existe lo creamos:<\/p>\n<pre lang=\"xml\" escaped=\"true\">\r\ntouch \/home\/usuario\/.ssh\/known_hosts\r\n<\/pre>\n<p>&nbsp;<br \/>\nSi ya exist\u00eda el fichero <em>known_hosts<\/em>, buscamos en el cliente y en el servidor referencias antiguas a ese hostname o su IP en el fichero <em>known_hosts<\/em>, y las eliminamos.<\/p>\n<p>Actualizamos el fichero <em>known_hosts<\/em> del cliente, con la clave que tenga el servidor, que la sacamos con el comando <em>ssh-keyscan<\/em> y la ip del servidor:<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<pre lang=\"xml\" escaped=\"true\">\r\n-bash-4.2$ ssh-keyscan -t rsa ip_del_servidor\r\n# 192.168.8.140:22 SSH-2.0-OpenSSH_5.3\r\n192.168.8.140 ssh-rsa ABAAB3NzbC1yc2EAABAAIwAAAREA1yg6wu6+PUzS9nggWA3ttjt3gDuzrdpDpGdjdCZ6g5CJCbpeRO1TL4J\/KzqVsUOWKimHQNcAUan\r\n<\/pre>\n<p>y en el cliente creamos el fichero <em>known_hosts<\/em> y le agregamos la info anterior del servidor.<\/p>\n<p>&nbsp;<br \/>\nSi realizamos todos estos pasos y verificaciones seguro que encontramos errores y finalmente solucionamos el error &#8220;<em><strong>No RSA host key is known and you have requested strict checking<\/strong><\/em>&#8220;.<br \/>\n&nbsp;<\/p>\n\n<div style=\"font-size: 0px; height: 0px; line-height: 0px; margin: 0; padding: 0; clear: both;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>El error \u201cNo RSA host key is known and you have requested strict checking\u201d tiene que ver con problemas en ficheros o directorios ssh, as\u00ed como las claves p\u00fablicas.<\/p>\n","protected":false},"author":1,"featured_media":31104,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false},"categories":[1268],"tags":[366,1119],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/posts\/31053"}],"collection":[{"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/comments?post=31053"}],"version-history":[{"count":24,"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/posts\/31053\/revisions"}],"predecessor-version":[{"id":31132,"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/posts\/31053\/revisions\/31132"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/media\/31104"}],"wp:attachment":[{"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/media?parent=31053"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/categories?post=31053"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/eltallerdelbit.com\/wp-json\/wp\/v2\/tags?post=31053"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}