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mirror of https://github.com/drduh/YubiKey-Guide.git synced 2024-12-22 05:38:13 +00:00

Rewrite keys generation tutorial

The master key is now created with `--batch` and a configuration script.
The subkeys are created with the quick key manipulation
interface (`--quick-add-key`).

Also provided two configuration scripts as templates for a RSA4096 or a
ED25519 master key.

Signed-off-by: apiraino <apiraino@users.noreply.github.com>
This commit is contained in:
apiraino 2021-08-22 21:21:50 +02:00
parent 31074ac13d
commit 5182d5e3d8
No known key found for this signature in database
GPG Key ID: EE6A89440C49992C
3 changed files with 117 additions and 273 deletions

329
README.md
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@ -469,98 +469,38 @@ BSSYMUGGTJQVWZZWOPJG
**Tip** On Linux or OpenBSD, select the password using the mouse or by double-clicking on it to copy to clipboard. Paste using the middle mouse button or `Shift`-`Insert`.
Generate a new key with GPG, selecting `(8) RSA (set your own capabilities)`, `Certify` capability only and `4096` bit key size.
Note: when creating the keys, we need to generate a lot of random bytes. It is a good idea to perform some other action (type on the keyboard, move the mouse, utilize the disks) during the prime generation; this gives the random number generator a better chance to gain enough entropy.
Do not set the master key to expire - see [Note #3](#notes).
To remove some complexity from the process we will create the keys using a template and the `--batch` parameter. For futher details, full GNUPG documentation can be found at: https://www.gnupg.org/documentation/manuals/gnupg/Unattended-GPG-key-generation.html
For your convenience you can start from this RSA4096 key template: [gen-params-rsa4096](contrib/gen-params-rsa4096). If you're using GnuPG v2.1.7 or newer we strongly recommend generating ED25519 keys ([gen-params-ed25519](contrib/gen-params-ed25519), the procedure is the same). These templates will not set the master key to expire - see [Note #3](#notes).
Generate a RSA4096 master key:
```console
$ gpg --expert --full-generate-key
Please select what kind of key you want:
(1) RSA and RSA (default)
(2) DSA and Elgamal
(3) DSA (sign only)
(4) RSA (sign only)
(7) DSA (set your own capabilities)
(8) RSA (set your own capabilities)
(9) ECC and ECC
(10) ECC (sign only)
(11) ECC (set your own capabilities)
(13) Existing key
Your selection? 8
Possible actions for a RSA key: Sign Certify Encrypt Authenticate
Current allowed actions: Sign Certify Encrypt
(S) Toggle the sign capability
(E) Toggle the encrypt capability
(A) Toggle the authenticate capability
(Q) Finished
Your selection? E
Possible actions for a RSA key: Sign Certify Encrypt Authenticate
Current allowed actions: Sign Certify
(S) Toggle the sign capability
(E) Toggle the encrypt capability
(A) Toggle the authenticate capability
(Q) Finished
Your selection? S
Possible actions for a RSA key: Sign Certify Encrypt Authenticate
Current allowed actions: Certify
(S) Toggle the sign capability
(E) Toggle the encrypt capability
(A) Toggle the authenticate capability
(Q) Finished
Your selection? Q
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 4096
Requested keysize is 4096 bits
Please specify how long the key should be valid.
0 = key does not expire
<n> = key expires in n days
<n>w = key expires in n weeks
<n>m = key expires in n months
<n>y = key expires in n years
Key is valid for? (0) 0
Key does not expire at all
Is this correct? (y/N) y
$ gpg --batch --generate-key gen-params-rsa4096
gpg: Generating a basic OpenPGP key
gpg: key 0xEA5DE91459B80592 marked as ultimately trusted
gpg: revocation certificate stored as '/tmp.FLZC0xcM/openpgp-revocs.d/D6F924841F78D62C65ABB9588B461860159FFB7B.rev'
gpg: done
```
Input any name and email address:
Let's check the result:
```console
GnuPG needs to construct a user ID to identify your key.
Real name: Dr Duh
Email address: doc@duh.to
Comment: [Optional - leave blank]
You selected this USER-ID:
"Dr Duh <doc@duh.to>"
Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
gpg: /tmp.FLZC0xcM/trustdb.gpg: trustdb created
gpg: key 0xFF3E7D88647EBCDB marked as ultimately trusted
gpg: directory '/tmp.FLZC0xcM/openpgp-revocs.d' created
gpg: revocation certificate stored as '/tmp.FLZC0xcM/openpgp-revocs.d/011CE16BD45B27A55BA8776DFF3E7D88647EBCDB.rev'
public and secret key created and signed.
pub rsa4096/0xFF3E7D88647EBCDB 2017-10-09 [C]
Key fingerprint = 011C E16B D45B 27A5 5BA8 776D FF3E 7D88 647E BCDB
uid Dr Duh <doc@duh.to>
$ gpg --list-key
gpg: checking the trustdb
gpg: marginals needed: 3 completes needed: 1 trust model: pgp
gpg: depth: 0 valid: 1 signed: 0 trust: 0-, 0q, 0n, 0m, 0f, 1u
/tmp.FLZC0xcM/pubring.kbx
-------------------------------
pub rsa4096/0xFF3E7D88647EBCDB 2021-08-22 [C]
Key fingerprint = 011C E16B D45B 27A5 5BA8 776D FF3E 7D88 647E BCDB
uid [ultimate] Dr Duh <doc@duh.to>
```
The key fingerprint (`011C E16B D45B 27A5 5BA8 776D FF3E 7D88 647E BCDB`) will be used to create the three subkeys for signing, authentication and encryption.
Export the key ID as a [variable](https://stackoverflow.com/questions/1158091/defining-a-variable-with-or-without-export/1158231#1158231) (`KEYID`) for use later:
```console
@ -585,214 +525,57 @@ $ gpg --default-key $OLDKEY --sign-key $KEYID
# Sub-keys
Edit the master key to add sub-keys:
Now create the three subkeys for signing, authentication and encryption. Use a 1 year expiration for sub-keys - they can be renewed using the offline master key. See [rotating keys](#rotating-keys).
We will use the the quick key manipulation interface of GNUPG (with `--quick-add-key`). See [the documentation](https://www.gnupg.org/documentation/manuals/gnupg/Unattended-GPG-key-generation.html#Unattended-GPG-key-generation).
Create a [signing subkey](https://stackoverflow.com/questions/5421107/can-rsa-be-both-used-as-encryption-and-signature/5432623#5432623):
```console
$ gpg --expert --edit-key $KEYID
Secret key is available.
sec rsa4096/0xEA5DE91459B80592
created: 2017-10-09 expires: never usage: C
trust: ultimate validity: ultimate
[ultimate] (1). Dr Duh <doc@duh.to>
$ gpg --quick-add-key "011C E16B D45B 27A5 5BA8 776D FF3E 7D88 647E BCDB" \
rsa4096 sign 1y
```
Use 4096-bit RSA keys.
Use a 1 year expiration for sub-keys - they can be renewed using the offline master key. See [rotating keys](#rotating-keys).
## Signing
Create a [signing key](https://stackoverflow.com/questions/5421107/can-rsa-be-both-used-as-encryption-and-signature/5432623#5432623) by selecting `addkey` then `(4) RSA (sign only)`:
Now create an [encryption subkey](https://www.cs.cornell.edu/courses/cs5430/2015sp/notes/rsa_sign_vs_dec.php):
```console
gpg> addkey
Key is protected.
You need a passphrase to unlock the secret key for
user: "Dr Duh <doc@duh.to>"
4096-bit RSA key, ID 0xFF3E7D88647EBCDB, created 2016-05-24
Please select what kind of key you want:
(3) DSA (sign only)
(4) RSA (sign only)
(5) Elgamal (encrypt only)
(6) RSA (encrypt only)
(7) DSA (set your own capabilities)
(8) RSA (set your own capabilities)
Your selection? 4
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 4096
Requested keysize is 4096 bits
Please specify how long the key should be valid.
0 = key does not expire
<n> = key expires in n days
<n>w = key expires in n weeks
<n>m = key expires in n months
<n>y = key expires in n years
Key is valid for? (0) 1y
Key expires at Mon 10 Sep 2018 00:00:00 PM UTC
Is this correct? (y/N) y
Really create? (y/N) y
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
sec rsa4096/0xFF3E7D88647EBCDB
created: 2017-10-09 expires: never usage: C
trust: ultimate validity: ultimate
ssb rsa4096/0xBECFA3C1AE191D15
created: 2017-10-09 expires: 2018-10-09 usage: S
[ultimate] (1). Dr Duh <doc@duh.to>
$ gpg --quick-add-key "011C E16B D45B 27A5 5BA8 776D FF3E 7D88 647E BCDB" \
rsa4096 encrypt 1y
```
## Encryption
Next, create an [encryption key](https://www.cs.cornell.edu/courses/cs5430/2015sp/notes/rsa_sign_vs_dec.php) by selecting `(6) RSA (encrypt only)`:
Finally, create an [authentication subkey](https://superuser.com/questions/390265/what-is-a-gpg-with-authenticate-capability-used-for):
```console
gpg> addkey
Please select what kind of key you want:
(3) DSA (sign only)
(4) RSA (sign only)
(5) Elgamal (encrypt only)
(6) RSA (encrypt only)
(7) DSA (set your own capabilities)
(8) RSA (set your own capabilities)
(10) ECC (sign only)
(11) ECC (set your own capabilities)
(12) ECC (encrypt only)
(13) Existing key
Your selection? 6
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 4096
Requested keysize is 4096 bits
Please specify how long the key should be valid.
0 = key does not expire
<n> = key expires in n days
<n>w = key expires in n weeks
<n>m = key expires in n months
<n>y = key expires in n years
Key is valid for? (0) 1y
Key expires at Mon 10 Sep 2018 00:00:00 PM UTC
Is this correct? (y/N) y
Really create? (y/N) y
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
sec rsa4096/0xFF3E7D88647EBCDB
created: 2017-10-09 expires: never usage: C
trust: ultimate validity: ultimate
ssb rsa4096/0xBECFA3C1AE191D15
created: 2017-10-09 expires: 2018-10-09 usage: S
ssb rsa4096/0x5912A795E90DD2CF
created: 2017-10-09 expires: 2018-10-09 usage: E
[ultimate] (1). Dr Duh <doc@duh.to>
$ gpg --quick-add-key "011C E16B D45B 27A5 5BA8 776D FF3E 7D88 647E BCDB" \
rsa4096 auth 1y
```
## Authentication
Finally, create an [authentication key](https://superuser.com/questions/390265/what-is-a-gpg-with-authenticate-capability-used-for).
GPG doesn't provide an authenticate-only key type, so select `(8) RSA (set your own capabilities)` and toggle the required capabilities until the only allowed action is `Authenticate`:
Let's check the final result:
```console
gpg> addkey
Please select what kind of key you want:
(3) DSA (sign only)
(4) RSA (sign only)
(5) Elgamal (encrypt only)
(6) RSA (encrypt only)
(7) DSA (set your own capabilities)
(8) RSA (set your own capabilities)
(10) ECC (sign only)
(11) ECC (set your own capabilities)
(12) ECC (encrypt only)
(13) Existing key
Your selection? 8
Possible actions for a RSA key: Sign Encrypt Authenticate
Current allowed actions: Sign Encrypt
(S) Toggle the sign capability
(E) Toggle the encrypt capability
(A) Toggle the authenticate capability
(Q) Finished
Your selection? S
Possible actions for a RSA key: Sign Encrypt Authenticate
Current allowed actions: Encrypt
(S) Toggle the sign capability
(E) Toggle the encrypt capability
(A) Toggle the authenticate capability
(Q) Finished
Your selection? E
Possible actions for a RSA key: Sign Encrypt Authenticate
Current allowed actions:
(S) Toggle the sign capability
(E) Toggle the encrypt capability
(A) Toggle the authenticate capability
(Q) Finished
Your selection? A
Possible actions for a RSA key: Sign Encrypt Authenticate
Current allowed actions: Authenticate
(S) Toggle the sign capability
(E) Toggle the encrypt capability
(A) Toggle the authenticate capability
(Q) Finished
Your selection? Q
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 4096
Requested keysize is 4096 bits
Please specify how long the key should be valid.
0 = key does not expire
<n> = key expires in n days
<n>w = key expires in n weeks
<n>m = key expires in n months
<n>y = key expires in n years
Key is valid for? (0) 1y
Key expires at Mon 10 Sep 2018 00:00:00 PM UTC
Is this correct? (y/N) y
Really create? (y/N) y
We need to generate a lot of random bytes. It is a good idea to perform
some other action (type on the keyboard, move the mouse, utilize the
disks) during the prime generation; this gives the random number
generator a better chance to gain enough entropy.
sec rsa4096/0xFF3E7D88647EBCDB
created: 2017-10-09 expires: never usage: C
trust: ultimate validity: ultimate
ssb rsa4096/0xBECFA3C1AE191D15
created: 2017-10-09 expires: 2018-10-09 usage: S
ssb rsa4096/0x5912A795E90DD2CF
created: 2017-10-09 expires: 2018-10-09 usage: E
ssb rsa4096/0x3F29127E79649A3D
created: 2017-10-09 expires: 2018-10-09 usage: A
[ultimate] (1). Dr Duh <doc@duh.to>
$ gpg --list-keys
/tmp.FLZC0xcM/pubring.kbx
-------------------------------
pub rsa4096/0xFF3E7D88647EBCDB 2021-08-22 [C]
Key fingerprint = 011C E16B D45B 27A5 5BA8 776D FF3E 7D88 647E BCDB
uid [ultimate] Dr Duh <doc@duh.to>
sub rsa4096/0xBECFA3C1AE191D15 2017-10-09 [S] [expires: 2018-10-09]
sub rsa4096/0x5912A795E90DD2CF 2017-10-09 [E] [expires: 2018-10-09]
sub rsa4096/0x3F29127E79649A3D 2017-10-09 [A] [expires: 2018-10-09]
```
Finish by saving the keys.
If you want to add an extra UID, open the keyring:
```console
gpg> save
```
-gpg> save
## Add extra identities
(Optional) To add additional email addresses or identities, use `adduid`:
(Optional) To add additional email addresses or identities, use `adduid`.
First open the keyring:
```console
$ gpg --expert --edit-key $KEYID
```
Then add the new identity:
```console
gpg> adduid

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# GnuPG v2.1.7 or newer
%echo Generating a OpenPGP key
# uncomment the following line to remove asking for a passphrase
#%no-protection
Key-Type: eddsa
Key-Curve: Ed25519
# Key generated is a master key ("certificate")
Key-Usage: cert
# Parameters to generate a subkey
# Subkey-Type: ecdh
# Subkey-Curve: Curve25519
# Choose one of following options
# Subkey-Usage: sign
# Subkey-Usage: auth
# Subkey-Usage: encrypt
# select a name and email address - neither has to be valid nor existing
Name-Real: Dr Duh
Name-Email: <doc@duh.to>
# Do not set the key to expire
Expire-Date: 0
# Do a commit here, so that we can later print "done" :-)
%commit
%echo done

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%echo Generating a OpenPGP key
# uncomment the following line to remove asking for a passphrase
#%no-protection
Key-Type: RSA
Key-Length: 4096
# Key generated is a master key ("certificate")
Key-Usage: cert
# Parameters to generate a subkey
# Subkey-Type: ELG-E
# Subkey-Length: 4096
# Choose one of following options
# Subkey-Usage: encrypt
# Subkey-Usage: sign
# Subkey-Usage: auth
# select a name and email address - neither has to be valid nor existing
Name-Real: Dr Duh
Name-Email: <doc@duh.to>
# Do not set the key to expire
Expire-Date: 0
# Do a commit here, so that we can later print "done" :-)
%commit
%echo done