Use vault_id when encrypted via vault-edit (#30772)

* Use vault_id when encrypted via vault-edit

On the encryption stage of
'ansible-vault edit --vault-id=someid@passfile somefile',
the vault id was not being passed to encrypt() so the files were
always saved with the default vault id in the 1.1 version format.

When trying to edit that file a second time, also with a --vault-id,
the file would be decrypted with the secret associated with the
provided vault-id, but since the encrypted file had no vault id
in the envelope there would be no match for 'default' secrets.
(Only the --vault-id was included in the potential matches, so
the vault id actually used to decrypt was not).

If that list was empty, there would be an IndexError when trying
to encrypted the changed file. This would result in the displayed
error:

ERROR! Unexpected Exception, this is probably a bug: list index out of range

Fix is two parts:

1) use the vault id when encrypting from edit

2) when matching the secret to use for encrypting after edit,
include the vault id that was used for decryption and not just
the vault id (or lack of vault id) from the envelope.

add unit tests for #30575 and intg tests for 'ansible-vault edit'

Fixes #30575

lib/ansible/parsing/vault/__init__.py

@@ -491,6 +491,20 @@ class VaultLib:
         return b_vaulttext
 
     def decrypt(self, vaulttext, filename=None):
+        '''Decrypt a piece of vault encrypted data.
+
+        :arg vaulttext: a string to decrypt.  Since vault encrypted data is an
+            ascii text format this can be either a byte str or unicode string.
+        :kwarg filename: a filename that the data came from.  This is only
+            used to make better error messages in case the data cannot be
+            decrypted.
+        :returns: a byte string containing the decrypted data and the vault-id that was used
+
+        '''
+        plaintext, vault_id = self.decrypt_and_get_vault_id(vaulttext, filename=filename)
+        return plaintext
+
+    def decrypt_and_get_vault_id(self, vaulttext, filename=None):
         """Decrypt a piece of vault encrypted data.
 
         :arg vaulttext: a string to decrypt.  Since vault encrypted data is an
@@ -498,7 +512,8 @@ class VaultLib:
         :kwarg filename: a filename that the data came from.  This is only
             used to make better error messages in case the data cannot be
             decrypted.
-        :returns: a byte string containing the decrypted data
+        :returns: a byte string containing the decrypted data and the vault-id that was used
+
         """
         b_vaulttext = to_bytes(vaulttext, errors='strict', encoding='utf-8')
 
@@ -536,6 +551,7 @@ class VaultLib:
         # we check it first.
 
         vault_id_matchers = []
+        vault_id_used = None
 
         if vault_id:
             display.vvvvv('Found a vault_id (%s) in the vaulttext' % (vault_id))
@@ -563,6 +579,7 @@ class VaultLib:
                 display.vvvv('Trying secret %s for vault_id=%s' % (vault_secret, vault_secret_id))
                 b_plaintext = this_cipher.decrypt(b_vaulttext, vault_secret)
                 if b_plaintext is not None:
+                    vault_id_used = vault_secret_id
                     display.vvvvv('decrypt succesful with secret=%s and vault_id=%s' % (vault_secret, vault_secret_id))
                     break
             except AnsibleError as e:
@@ -581,7 +598,7 @@ class VaultLib:
                 msg += " on %s" % filename
             raise AnsibleError(msg)
 
-        return b_plaintext
+        return b_plaintext, vault_id_used
 
 
 class VaultEditor:
@@ -692,6 +709,7 @@ class VaultEditor:
 
         # shuffle tmp file into place
         self.shuffle_files(tmp_path, filename)
+        display.vvvvv('Saved edited file "%s" encrypted using %s and  vault id "%s"' % (filename, secret, vault_id))
 
     def _real_path(self, filename):
         # '-' is special to VaultEditor, dont expand it.
@@ -754,7 +772,8 @@ class VaultEditor:
 
         try:
             # vaulttext gets converted back to bytes, but alas
-            plaintext = self.vault.decrypt(vaulttext)
+            # TODO: return the vault_id that worked?
+            plaintext, vault_id_used = self.vault.decrypt_and_get_vault_id(vaulttext)
         except AnsibleError as e:
             raise AnsibleError("%s for %s" % (to_bytes(e), to_bytes(filename)))
 
@@ -762,15 +781,25 @@ class VaultEditor:
         # (duplicates parts of decrypt, but alas...)
         dummy, dummy, cipher_name, vault_id = parse_vaulttext_envelope(b_vaulttext)
 
-        # if we could decrypt, the vault_id should be in secrets
+        # vault id here may not be the vault id actually used for decrypting
+        # as when the edited file has no vault-id but is decrypted by non-default id in secrets
+        # (vault_id=default, while a different vault-id decrypted)
+
+        # if we could decrypt, the vault_id should be in secrets or we use vault_id_used
         # though we could have multiple secrets for a given vault_id, pick the first one
-        secrets = match_secrets(self.vault.secrets, [vault_id])
+        secrets = match_secrets(self.vault.secrets, [vault_id_used, vault_id])
+
+        if not secrets:
+            raise AnsibleVaultError('Attempting to encrypt "%s" but no vault secrets were found for vault ids "%s" or "%s"' %
+                                    (filename, vault_id, vault_id_used))
+
         secret = secrets[0][1]
+
         if cipher_name not in CIPHER_WRITE_WHITELIST:
             # we want to get rid of files encrypted with the AES cipher
-            self._edit_file_helper(filename, secret, existing_data=plaintext, force_save=True)
+            self._edit_file_helper(filename, secret, existing_data=plaintext, force_save=True, vault_id=vault_id)
         else:
-            self._edit_file_helper(filename, secret, existing_data=plaintext, force_save=False)
+            self._edit_file_helper(filename, secret, existing_data=plaintext, force_save=False, vault_id=vault_id)
 
     def plaintext(self, filename):