ssh-util: allow cloudinit to merge all ssh keys into a custom user file, defined in AuthorizedKeysFile (#937)

This patch aims to fix LP1911680, by analyzing the files provided
in sshd_config and merge all keys into an user-specific file. Also
introduces additional tests to cover this specific case.

The file is picked by analyzing the path given in AuthorizedKeysFile.

If it points inside the current user folder (path is /home/user/*), it
means it is an user-specific file, so we can copy all user-keys there.
If it contains a %u or %h, it means that there will be a specific
authorized_keys file for each user, so we can copy all user-keys there.
If no path points to an user-specific file, for example when only
/etc/ssh/authorized_keys is given, default to ~/.ssh/authorized_keys.
Note that if there are more than a single user-specific file, the last
one will be picked.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Co-authored-by: James Falcon <therealfalcon@gmail.com>

LP: #1911680
RHBZ:1862967

6 files changed, 117 insertions, 0 deletions

diff --git a/tests/integration_tests/assets/keys/id_rsa.test1 b/tests/integration_tests/assets/keys/id_rsa.test1
new file mode 100644
index 00000000..bd4c822e
--- /dev/null
+++ b/tests/integration_tests/assets/keys/id_rsa.test1
@@ -0,0 +1,38 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAABlwAAAAdzc2gtcn
+NhAAAAAwEAAQAAAYEAtRlG96aJ23URvAgO/bBsuLl+lquc350aSwV98/i8vlvOn5GVcHye
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+CHbTWbsFrHR1qFAAAACmphbWVzQG5ld3Q=
+-----END OPENSSH PRIVATE KEY-----
diff --git a/tests/integration_tests/assets/keys/id_rsa.test1.pub b/tests/integration_tests/assets/keys/id_rsa.test1.pub
new file mode 100644
index 00000000..3d2e26e1
--- /dev/null
+++ b/tests/integration_tests/assets/keys/id_rsa.test1.pub
@@ -0,0 +1 @@
+ssh-rsa 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 test1@host
diff --git a/tests/integration_tests/assets/keys/id_rsa.test2 b/tests/integration_tests/assets/keys/id_rsa.test2
new file mode 100644
index 00000000..5854d901
--- /dev/null
+++ b/tests/integration_tests/assets/keys/id_rsa.test2
@@ -0,0 +1,38 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAABlwAAAAdzc2gtcn
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+-----END OPENSSH PRIVATE KEY-----
diff --git a/tests/integration_tests/assets/keys/id_rsa.test2.pub b/tests/integration_tests/assets/keys/id_rsa.test2.pub
new file mode 100644
index 00000000..f3831a57
--- /dev/null
+++ b/tests/integration_tests/assets/keys/id_rsa.test2.pub
@@ -0,0 +1 @@
+ssh-rsa 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 test2@host
diff --git a/tests/integration_tests/assets/keys/id_rsa.test3 b/tests/integration_tests/assets/keys/id_rsa.test3
new file mode 100644
index 00000000..2596c762
--- /dev/null
+++ b/tests/integration_tests/assets/keys/id_rsa.test3
@@ -0,0 +1,38 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
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+-----END OPENSSH PRIVATE KEY-----
diff --git a/tests/integration_tests/assets/keys/id_rsa.test3.pub b/tests/integration_tests/assets/keys/id_rsa.test3.pub
new file mode 100644
index 00000000..057db632
--- /dev/null
+++ b/tests/integration_tests/assets/keys/id_rsa.test3.pub
@@ -0,0 +1 @@
+ssh-rsa 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 test3@host