Several tools exist to generate SSH public/private key pairs. The following sections show how to generate an SSH key pair on UNIX, UNIX-like and Windows platforms.

1. Generate Rsa Key Without Passphrase Verification
2. Generate Rsa Key Without Passphrase Code
3. Secure Passphrase Generator

Generating an SSH Key Pair on UNIX and UNIX-Like Platforms Using the ssh-keygen Utility

If the /.ssh/idrsa file already exists, the command will exit without modifying anything. If not, you get a brand new key, in that filename. Either way, you haven't overwritten anything, and you know at the end you have a key.

• I am trying to crack a password protected idrsa, with john the ripper.But it doesn't find the correct password for some reason. I have create a new user and generated a new idrsa with ssh-keygen (the password used is 'password').
• Generating a Secure Shell (SSH) Public/Private Key Pair; Generating a Secure Shell (SSH) Public/Private Key Pair. Or press Enter to create a private key without a passphrase: Enter passphrase (empty for no passphrase). Set the Type of key to generate option to SSH-2 RSA. In the Number of bits in a generated key.

UNIX and UNIX-like platforms (including Solaris and Linux) include the ssh-keygen utility to generate SSH key pairs.

1. Navigate to your home directory:
2. Run the ssh-keygen utility, providing as filename your choice of file name for the private key:

   The ssh-keygen utility prompts you for a passphrase for the private key.

3. Enter a passphrase for the private key, or press Enter to create a private key without a passphrase:

   Note:

   While a passphrase is not required, you should specify one as a security measure to protect the private key from unauthorized use. When you specify a passphrase, a user must enter the passphrase every time the private key is used.

   Code 39 font download mac. The ssh-keygen utility prompts you to enter the passphrase again.

4. Enter the passphrase again, or press Enter again to continue creating a private key without a passphrase:
5. The ssh-keygen utility displays a message indicating that the private key has been saved as filename and the public key has been saved as filename.pub. It also displays information about the key fingerprint and randomart image.

Generating an SSH Key Pair on Windows Using the PuTTYgen Program

The PuTTYgen program is part of PuTTY, an open source networking client for the Windows platform.

1. Download and install PuTTY or PuTTYgen.

   To download PuTTY or PuTTYgen, go to http://www.putty.org/ and click the You can download PuTTY here link.

2. Run the PuTTYgen program.
3. Set the Type of key to generate option to SSH-2 RSA.
4. In the Number of bits in a generated key box, enter 2048.
5. Click Generate to generate a public/private key pair.

   As the key is being generated, move the mouse around the blank area as directed.

6. (Optional) Enter a passphrase for the private key in the Key passphrase box and reenter it in the Confirm passphrase box.

   Note:

   While a passphrase is not required, you should specify one as a security measure to protect the private key from unauthorized use. When you specify a passphrase, a user must enter the passphrase every time the private key is used.

7. Click Save private key to save the private key to a file. To adhere to file-naming conventions, you should give the private key file an extension of .ppk (PuTTY private key).

   Note:

   The .ppk file extension indicates that the private key is in PuTTY's proprietary format. You must use a key of this format when using PuTTY as your SSH client. It cannot be used with other SSH client tools. Refer to the PuTTY documentation to convert a private key in this format to a different format.
8. Select all of the characters in the Public key for pasting into OpenSSH authorized_keys file box.

   Make sure you select all the characters, not just the ones you can see in the narrow window. If a scroll bar is next to the characters, you aren't seeing all the characters.

9. Right-click somewhere in the selected text and select Copy from the menu.
10. Open a text editor and paste the characters, just as you copied them. Start at the first character in the text editor, and do not insert any line breaks.
11. Save the text file in the same folder where you saved the private key, using the .pub extension to indicate that the file contains a public key.
12. If you or others are going to use an SSH client that requires the OpenSSH format for private keys (such as the ssh utility on Linux), export the private key:
    1. On the Conversions menu, choose Export OpenSSH key.
    2. Save the private key in OpenSSH format in the same folder where you saved the private key in .ppk format, using an extension such as .openssh to indicate the file's content.

Previous: The quick key manipulation interface, Up: Unattended Usage of GPG [Contents][Index]

4.5.4 Unattended key generation

The command --generate-key may be used along with the option--batch for unattended key generation. This is the mostflexible way of generating keys, but it is also the most complex one.Consider using the quick key manipulation interface described in theprevious subsection “The quick key manipulation interface”.

The parameters for the key are either read from stdin or given as afile on the command line. The format of the parameter file is asfollows:

• Text only, line length is limited to about 1000 characters.
• UTF-8 encoding must be used to specify non-ASCII characters.
• Empty lines are ignored.
• Leading and trailing white space is ignored.
• A hash sign as the first non white space character indicates a comment line.
• Control statements are indicated by a leading percent sign, the arguments are separated by white space from the keyword.
• Parameters are specified by a keyword, followed by a colon. Arguments are separated by white space.
• The first parameter must be ‘Key-Type’; control statements may be placed anywhere.
• The order of the parameters does not matter except for ‘Key-Type’ which must be the first parameter. The parameters are only used for the generated keyblock (primary and subkeys); parameters from previous sets are not used. Some syntactically checks may be performed.
• Key generation takes place when either the end of the parameter file is reached, the next ‘Key-Type’ parameter is encountered or at the control statement ‘%commit’ is encountered.

Control statements:

Print text as diagnostic.

Suppress actual key generation (useful for syntax checking).

Perform the key generation. Note that an implicit commit is done atthe next Key-Type parameter.

Do not write the key to the default or commandline given keyring butto filename. This must be given before the first commit to takeplace, duplicate specification of the same filename is ignored, thelast filename before a commit is used. The filename is used until anew filename is used (at commit points) and all keys are written tothat file. If a new filename is given, this file is created (andoverwrites an existing one).

See the previous subsection “Ephemeral home directories” for a morerobust way to contain side-effects.

This option is a no-op for GnuPG 2.1 and later.

See the previous subsection “Ephemeral home directories”.

This option is a no-op for GnuPG 2.1 and later.

Using this option allows the creation of keys without any passphraseprotection. This option is mainly intended for regression tests.

If given the keys are created using a faster and a somewhat lesssecure random number generator. This option may be used for keyswhich are only used for a short time and do not require fullcryptographic strength. It takes only effect if used together withthe control statement ‘%no-protection’.

General Parameters:

Generate Rsa Key Without Passphrase Verification

Generate Rsa Key Without Passphrase Code

Starts a new parameter block by giving the type of the primarykey. The algorithm must be capable of signing. This is a requiredparameter. algo may either be an OpenPGP algorithm number or astring with the algorithm name. The special value ‘default’ maybe used for algo to create the default key type; in this case a‘Key-Usage’ shall not be given and ‘default’ also be usedfor ‘Subkey-Type’.

The requested length of the generated key in bits. The default isreturned by running the command ‘gpg --gpgconf-list’.

This is optional and used to generate a CSR or certificate for analready existing key. Key-Length will be ignored when given.

Space or comma delimited list of key usages. Allowed values are‘encrypt’, ‘sign’, and ‘auth’. This is used togenerate the key flags. Please make sure that the algorithm iscapable of this usage. Note that OpenPGP requires that all primarykeys are capable of certification, so no matter what usage is givenhere, the ‘cert’ flag will be on. If no ‘Key-Usage’ isspecified and the ‘Key-Type’ is not ‘default’, all allowedusages for that particular algorithm are used; if it is not given but‘default’ is used the usage will be ‘sign’.

This generates a secondary key (subkey). Currently only one subkeycan be handled. See also ‘Key-Type’ above.

Length of the secondary key (subkey) in bits. The default is returnedby running the command ‘gpg --gpgconf-list’.

Key usage lists for a subkey; similar to ‘Key-Usage’.

If you want to specify a passphrase for the secret key, enter it here.Default is to use the Pinentry dialog to ask for a passphrase.

The three parts of a user name. Remember to use UTF-8 encoding here.If you don’t give any of them, no user ID is created.

Set the expiration date for the key (and the subkey). It may eitherbe entered in ISO date format (e.g. '20000815T145012') or as number ofdays, weeks, month or years after the creation date. The specialnotation 'seconds=N' is also allowed to specify a number of secondssince creation. Without a letter days are assumed. Note that thereis no check done on the overflow of the type used by OpenPGP fortimestamps. Thus you better make sure that the given value makesense. Although OpenPGP works with time intervals, GnuPG uses anabsolute value internally and thus the last year we can represent is2105.

Set the creation date of the key as stored in the key information andwhich is also part of the fingerprint calculation. Either a date like'1986-04-26' or a full timestamp like '19860426T042640' may be used.The time is considered to be UTC. The special notation 'seconds=N'may be used to directly specify a the number of seconds since Epoch(Unix time). If it is not given the current time is used.

Set the cipher, hash, and compression preference values for this key.This expects the same type of string as the sub-command ‘setpref’in the --edit-key menu.

Secure Passphrase Generator

Add a designated revoker to the generated key. Algo is the public keyalgorithm of the designated revoker (i.e. RSA=1, DSA=17, etc.)fpr is the fingerprint of the designated revoker. The optional‘sensitive’ flag marks the designated revoker as sensitiveinformation. Only v4 keys may be designated revokers.

This is an optional parameter that specifies the preferred keyserverURL for the key.

This is an optional parameter only used with the status linesKEY_CREATED and KEY_NOT_CREATED. string may be up to 100characters and should not contain spaces. It is useful for batch keygeneration to associate a key parameter block with a status line.

Here is an example on how to create a key in an ephemeral home directory:

If you want to create a key with the default algorithms you would usethese parameters:

Previous: The quick key manipulation interface, Up: Unattended Usage of GPG [Contents][Index]