From Apache OpenOffice Wiki
To get read/write access with TortoiseSVN with your existing private and uploaded public key, you have to do some additionals steps:
- get Puttygen and Pageant from http://www.chiark.greenend.org.uk/~sgtatham/putty/
- convert your private file into a format putty understands. This is because the private key file format is not specified by some standard body. To do this we simple open "puttygen" and open the "conversions" menu and chose "Import Key". Then browse to your file private key and enter your provided passphrase upon creation of the key. Finally click "Save private key" and save the file as "mykey.PPK" somewhere on disk.
- start PageAnt and Add your just converted key
- now just use the ssh+svn repository address inside TortoiseSVN such as svn+ssh://firstname.lastname@example.org/ooo/tags/DEV300_m32
You can find more information here: http://tortoisesvn.net/node/5