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Signify: Cryptographically Sign and Verify Files
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|description=HowTo: Use Signify on Debian (based) Distributions
|image=Signify1323.jpg
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HowTo: Use Signify on Debian (based) Distributions
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= Introduction =

Written in 2014 for OpenBSD, signify is a tool to cryptographically sign and verify files: <ref name=signify>https://isopenbsdsecu.re/mitigations/signify/</ref>
<blockquote>It only supports a single algorithm, Ed25519, created by djb and his gang. It’s fast, immune to timing attacks by design, produce deterministic signatures, uses small keys and produce small signatures, … it does look like a sound choice.</blockquote>

Signify's main benefits is that it has a small codebase and is not based on GnuPG. On the downside, there is no revocation mechanism <ref>Meaning if the key is stolen, people can only be informed the key should not be trusted anymore.</ref> and the trust path relies on getting the key directly from a trusted developer. <ref name=signify />

Signify's usage is not just limited to OpenBSD and the tool has also been been packaged in Debian.  <ref>https://packages.debian.org/{{Stable project version based on Debian codename}}/signify-openbsd</ref> To learn more about signify, refer to [https://flak.tedunangst.com/post/signify this blog post] by the original author.

= Installation and Usage =

{{mbox
| type    = notice
| image   = [[File:Ambox_notice.png|40px|alt=Info]]
| text    = In the steps below, installing package <code>qrencode</code> is optional and only needed if you intend to create QR codes.
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'''1.''' Install signify.

{{Install_Package
|package=signify-openbsd qrencode
}}

'''2.''' Create a key.

This only needs to be done once unless multiple keys are desired; in that case different key names should be used. In the following example, <code>keyname</code> is used as the sample key name.

{{CodeSelect|code=
signify-openbsd -G -p keyname.pub -s keyname.sec
}}

'''3.''' ''Optional:'' Add a key comment.

Replace <code>comments here</code> with the actual comment but keep the <code>"</code>. The comment could be a name, position, website, e-mail address and/or anything else.

{{CodeSelect|code=
signify-openbsd -G -p keyname.pub -s keyname.sec -c "comments here"
}}

<u>Note</u>:
* The private key file <code>keyname.sec</code> needs to stay private -- never share <code>keyname.sec</code> with anyone as this would defeat the purpose of signing files!
* The public key file <code>keyname.pub</code> can be shared with anyone.

'''4.''' Utilize signify.

To sign a file <code>message.txt</code> (which has to be created by the user beforehand).

{{CodeSelect|code=
signify-openbsd -S -s keyname.sec -m message.txt
}}

This will create a signature file <code>message.txt.sig</code>.

To verify a file <code>message.txt</code> with signature file <code>message.txt.sig</code>.

{{CodeSelect|code=
signify-openbsd -V -p keyname.pub -m message.txt
}}

'''5.''' ''Optional:'' Create a QR code for the public key.

{{CodeSelect|code=
qrencode -r keyname.pub -o keyname.pub.png
}}

File <code>keyname.pub.png</code> would be the QR code of the public key.

Refer to the Debian [https://manpages.debian.org/signify-openbsd signify-openbsd Manual Page] for further options.

<ref>
* https://www.openbsd.org/papers/bsdcan-signify.html
* https://forums.whonix.org/t/signify-openbsd/7842
</ref>
}}

= See Also =
* [[Verify the images#Signify_Signatures|Verify the {{project_name_long}} Signify Signatures]]

= Footnotes =
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[[Category:Documentation]]