Merge pull request #332 from tlm/ssh-key-concat

Adds a new concat func for keys.

ssh/authorisedkeys.go

@@ -66,6 +66,22 @@ func ParseAuthorisedKey(line string) (*AuthorisedKey, error) {
 	}, nil
 }
 
+// ConcatAuthorisedKeys will joing two or more authorised keys together to form
+// a string based list of authorised keys that can be read by ssh programs. Keys
+// joined with a newline as the separator.
+func ConcatAuthorisedKeys(a, b string) string {
+	if a == "" {
+		return b
+	}
+	if b == "" {
+		return a
+	}
+	if a[len(a)-1] != '\n' {
+		return a + "\n" + b
+	}
+	return a + b
+}
+
 // SplitAuthorisedKeys extracts a key slice from the specified key data,
 // by splitting the key data into lines and ignoring comments and blank lines.
 func SplitAuthorisedKeys(keyData string) []string {

ssh/authorisedkeys_test.go

@@ -273,3 +273,14 @@ func (s *AuthorisedKeysKeysSuite) TestParseAuthorisedKey(c *gc.C) {
 		}
 	}
 }
+
+func (s *AuthorisedKeysKeysSuite) TestConcatAuthorisedKeys(c *gc.C) {
+	for _, test := range []struct{ a, b, result string }{
+		{"a", "", "a"},
+		{"", "b", "b"},
+		{"a", "b", "a\nb"},
+		{"a\n", "b", "a\nb"},
+	} {
+		c.Check(ssh.ConcatAuthorisedKeys(test.a, test.b), gc.Equals, test.result)
+	}
+}