[ https://issues.apache.org/jira/browse/SSHD-1216?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Ben Humphreys updated SSHD-1216: -------------------------------- Description: In the recently released OpenSSH 8.8 for RSA keys the public key signature algorithm that depends on SHA-1 has been disabled by default: {quote}This release disables RSA signatures using the SHA-1 hash algorithm 2by default. This change has been made as the SHA-1 hash algorithm is cryptographically broken, and it is possible to create chosen-prefix 4hash collisions for <USD$50K [1] {quote} As a result OpenSSH 8.8 clients are unable to authenticate with Mina SSHD servers with RSA based keys (it is however possible to reenable ssh-rsa). OpenSSH since 7.2 does however support RFC 8332 RSA/SHA-256/512 signatures. It appears Mina SSHD partly implements support for RFC 8332, indeed the client code appears to support it (see SSHD-1141). However the server appears to lack full support because it doesn't full implement the"server-sig-algs" extension. The basic framework for supporting this seems to be present, specifically {{AbstractKexFactoryManager.setKexExtensionHandler()}} could perhaps permit such a "server-sig-algs" extension. was: In the recently released OpenSSH 8.8 for "ssh-rsa" keys the public key signature algorithm that depends on SHA-1 has been disabled by default: {quote}This release disables RSA signatures using the SHA-1 hash algorithm 2by default. This change has been made as the SHA-1 hash algorithm is 3cryptographically broken, and it is possible to create chosen-prefix 4hash collisions for <USD$50K [1] {quote} As a result OpenSSH 8.8 clients are unable to authenticate with Mina SSHD servers with RSA based keys (it is however possible to reenable ssh-rsa). OpenSSH since 7.2 does however support RFC 8332 RSA/SHA-256/512 signatures. It appears Mina SSHD partly implements support for RFC 8332, indeed the client code appears to support it (see SSHD-1141). However the server appears to lack full support because it doesn't full implement the"server-sig-algs" extension. The basic framework for supporting this seems to be present, specifically {{AbstractKexFactoryManager.setKexExtensionHandler()}} could perhaps permit such a "server-sig-algs" extension. > Implement RFC 8332 server-sig-algs on the server > ------------------------------------------------ > > Key: SSHD-1216 > URL: https://issues.apache.org/jira/browse/SSHD-1216 > Project: MINA SSHD > Issue Type: Improvement > Reporter: Ben Humphreys > Priority: Major > > In the recently released OpenSSH 8.8 for RSA keys the public key signature > algorithm that depends on SHA-1 has been disabled by default: > {quote}This release disables RSA signatures using the SHA-1 hash algorithm > 2by default. This change has been made as the SHA-1 hash algorithm is > cryptographically broken, and it is possible to create chosen-prefix 4hash > collisions for <USD$50K [1] > {quote} > As a result OpenSSH 8.8 clients are unable to authenticate with Mina SSHD > servers with RSA based keys (it is however possible to reenable ssh-rsa). > OpenSSH since 7.2 does however support RFC 8332 RSA/SHA-256/512 signatures. > It appears Mina SSHD partly implements support for RFC 8332, indeed the > client code appears to support it (see SSHD-1141). However the server appears > to lack full support because it doesn't full implement the"server-sig-algs" > extension. > The basic framework for supporting this seems to be present, specifically > {{AbstractKexFactoryManager.setKexExtensionHandler()}} could perhaps permit > such a "server-sig-algs" extension. > -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@mina.apache.org For additional commands, e-mail: dev-h...@mina.apache.org