问题描述：

电脑新装git，连接gitee仓库，生成ssh密钥

ssh-keygen -t rsa -C "your_email@example.com"

测试连接，发现连接拒绝：git@gitee.com: Permission denied (publickey)
提示失败信息为：send_pubkey_test: no mutual signature algorithm

高版本OpenSSH没有启用ssh-rsa

ssh -vT git@gitee.com

OpenSSH_8.8p1, OpenSSL 1.1.1l 24 Aug 2021
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to gitee.com [180.97.125.228] port 22.
debug1: Connection established.
debug1: identity file /c/Users/Eleven/.ssh/id_rsa type 0
debug1: identity file /c/Users/Eleven/.ssh/id_rsa-cert type -1
debug1: identity file /c/Users/Eleven/.ssh/id_dsa type -1
debug1: identity file /c/Users/Eleven/.ssh/id_dsa-cert type -1
debug1: identity file /c/Users/Eleven/.ssh/id_ecdsa type -1
debug1: identity file /c/Users/Eleven/.ssh/id_ecdsa-cert type -1
debug1: identity file /c/Users/Eleven/.ssh/id_ecdsa_sk type -1
debug1: identity file /c/Users/Eleven/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /c/Users/Eleven/.ssh/id_ed25519 type -1
debug1: identity file /c/Users/Eleven/.ssh/id_ed25519-cert type -1
debug1: identity file /c/Users/Eleven/.ssh/id_ed25519_sk type -1
debug1: identity file /c/Users/Eleven/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /c/Users/Eleven/.ssh/id_xmss type -1
debug1: identity file /c/Users/Eleven/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.8
debug1: Remote protocol version 2.0, remote software version Basalt-3.0.4
debug1: compat_banner: no match: Basalt-3.0.4
debug1: Authenticating to gitee.com:22 as ‘git’
debug1: load_hostkeys: fopen /c/Users/Eleven/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: SSH2_MSG_KEX_ECDH_REPLY received
debug1: Server host key: ssh-ed25519 SHA256:+ULzij2u99B9eWYFTw1Q4ErYG/aepHLbu96PAUCoV88
debug1: load_hostkeys: fopen /c/Users/Eleven/.ssh/known_hosts2: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts: No such file or directory
debug1: load_hostkeys: fopen /etc/ssh/ssh_known_hosts2: No such file or directory
debug1: Host ‘gitee.com’ is known and matches the ED25519 host key.
debug1: Found key in /c/Users/Eleven/.ssh/known_hosts:1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: rekey in after 134217728 blocks
debug1: Will attempt key: /c/Users/Eleven/.ssh/id_rsa RSA SHA256:wLXN6hWihm5KFvbGwUbSeC+7atMLYyknqhk+1Rkru5c
debug1: Will attempt key: /c/Users/Eleven/.ssh/id_dsa
debug1: Will attempt key: /c/Users/Eleven/.ssh/id_ecdsa
debug1: Will attempt key: /c/Users/Eleven/.ssh/id_ecdsa_sk
debug1: Will attempt key: /c/Users/Eleven/.ssh/id_ed25519
debug1: Will attempt key: /c/Users/Eleven/.ssh/id_ed25519_sk
debug1: Will attempt key: /c/Users/Eleven/.ssh/id_xmss
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /c/Users/Eleven/.ssh/id_rsa RSA SHA256:wLXN6hWihm5KFvbGwUbSeC+7atMLYyknqhk+1Rkru5c
debug1: send_pubkey_test: no mutual signature algorithm
debug1: Trying private key: /c/Users/Eleven/.ssh/id_dsa
debug1: Trying private key: /c/Users/Eleven/.ssh/id_ecdsa
debug1: Trying private key: /c/Users/Eleven/.ssh/id_ecdsa_sk
debug1: Trying private key: /c/Users/Eleven/.ssh/id_ed25519
debug1: Trying private key: /c/Users/Eleven/.ssh/id_ed25519_sk
debug1: Trying private key: /c/Users/Eleven/.ssh/id_xmss
debug1: No more authentication methods to try.
git@gitee.com: Permission denied (publickey).

解决方案：

1、添加 PubkeyAcceptedKeyTypes +ssh-rsa 配置即可
2、更换秘钥生成算法，使用 ed25519 算法生成
ssh-keygen -t ed25519 -C “your email”
3、降低 OpenSSH版本

参考：
无法将代码推送到gitee仓库故障处理(no mutual signature algorithm)
SSH-RSA key rejected with message “no mutual signature algorithm”