Hi,
You can also use the well-known PuTTYgen that can import pem encoded
keys and export the public key in OpenSSH authorized_keys file format.
Concerning the ssh-rsa format itself, it's rather simple. Each line is
as follows :
ssh-rsa XXXXXXXXXXXXXXXXXXXXXX rsa-key-description
where the XXX filed is the base-64 encoding of the following content :
(all non explicit values are in big-endian)
4 bytes : 00 00 00 07 (for public key type)
7 bytes : 73 73 68 2D 72 73 61 (ssh-rsa in ascii)
4 bytes : length of the public exponent encoding
E bytes : public exponent value (i.e if 0x010001, then E=3 and encoding
is 01 00 01)
4 bytes : length of the unsigned modulus encoding. If the MSB of modulus
is set, then the length must count an extra 00 that will be added to the
content.
N bytes: modulus value. If its MSB is set, then an extra 00 must precede
its real value.
For example, if the public exponent is 0x25 and the modulus is
0xFEDCBA91, we will have :
00 00 00 07 73 73 68 2D 72 73 61 00 00 00 01 25 00 00 00 05 00 FE DC BA 91
and in base-64 encoding :
AAAAB3NzaC1yc2EAAAABJQAAAAUA/ty6kQ==
So, the OpenSSH public key will be :
ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAAUA/ty6kQ== sample-openssh-key
I hope this will help,
--
Mounir IDRASSI
IDRIX
http://www.idrix.fr
Shahin Khorasani wrote:
Hi,
You can download simple utility to transform PKCS#1 RSA public key to
opnessh public key format from here:
http://www.parssign.com/openssh_pk_linux.tar.gz
It is free to use and linked statically on Linux (must works on most
distributions)
Regards,
Shahin Khorasani
Dhiva wrote:
openssl x509 -in sample.pem -pubkey -noout
What is the format of the pubkey ?
How can i convert or transform this key to ssh-rsa format? I am talking
about the ssh keys that are available in "authorized_keys" file.
Or
Does openssl has any tools to manage the pubkey ? like dismantle and
assemble again.
thanks
dhiva
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OpenSSL Project http://www.openssl.org
Development Mailing List openssl-dev@openssl.org
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______________________________________________________________________
OpenSSL Project http://www.openssl.org
Development Mailing List openssl-dev@openssl.org
Automated List Manager majord...@openssl.org
______________________________________________________________________
OpenSSL Project http://www.openssl.org
Development Mailing List openssl-dev@openssl.org
Automated List Manager majord...@openssl.org
