只需 使用一个空白通 使用-N标志：

ssh-keygen -t rsa -N ''

要覆盖密钥文件 （在此示例中id_rsa）：

 ssh-keygen -q -t rsa -N '' -f ~/.ssh/id_rsa 2>/dev/null <<< y >/dev/null

从ssh-keygen 手册 页：

  -N new_passphrase provides the new passphrase.
  -q                silence ssh-keygen.
  -f filename       specifies the filename of the key file.

逐步说明

$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/klashxx/.ssh/id_rsa):

1 ）为避免输入密钥，请使用-f：

$ ssh-keygen -t rsa -f ~/.ssh/id_rsa
Generating public/private rsa key pair.
/home/klashxx/.ssh/id_rsa already exists.
Overwrite (y/n)?

2 ）现在我们需要对 覆盖问题 自动回答“ y ” （让我们为该作业使用
here字符串 ）： __
__

$ ssh-keygen -t rsa -f ~/.ssh/id_rsa <<< y
Generating public/private rsa key pair.
/home/klashxx/.ssh/id_rsa already exists.
Overwrite (y/n)? Enter passphrase (empty for no passphrase):

3 ）最后，我们将使用该-N标志输入无效通行证：

$ ssh-keygen -t rsa -N '' -f ~/.ssh/id_rsa <<< y
Generating public/private rsa key pair.
/home/klashxx/.ssh/id_rsa already exists.
Overwrite (y/n)? Your identification has been saved in /home/klashxx/.ssh/id_rsa.
Your public key has been saved in /home/klashxx/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:Xo0t6caMB/8TSsigxfY28JIfqYjyqxRZrFrPncx5yiU klashxx@server
The key's randomart image is:
+---[RSA 2048]----+
|                 |
|  .              |
|   o .           |
|  +   *    =     |
| +.  + BSo= o    |
|...o.+o+XO...    |
|.. .o.E==+B. .   |
|o . ...=.o...    |
|.+o.  o     ..   |
+----[SHA256]-----+

4 ） 多余的球 ，清理输出，只需检查返回码：

$ ssh-keygen -q -t rsa -N '' -f ~/.ssh/id_rsa 2>/dev/null <<< y >/dev/null
$ echo $?
0

荣誉

@ lukasz-dynowski，@ redochka，@ mellow-yellow和该线程中的其他成员。