1 files changed, 126 insertions, 0 deletions
diff --git a/crates/common/certificate/src/device_id.rs b/crates/common/certificate/src/device_id.rs
new file mode 100644
index 00000000..c5dc707e
--- /dev/null
+++ b/crates/common/certificate/src/device_id.rs
@@ -0,0 +1,126 @@
+fn is_valid_device_id_char(ch: char) -> bool {
+    matches!(ch, 'A'..='Z'
+    | 'a'..='z'
+    | '0'..='9'
+    | '\''
+    | '='
+    | '('
+    | ')'
+    | ','
+    | '-'
+    | '.'
+    | '?'
+    | '_'
+    | '*'
+    | '@'
+    | '!'
+    | '%')
+}
+
+pub fn is_valid_device_id(id: &str, max_cn_size: usize) -> Result<(), DeviceIdError> {
+    if id.is_empty() {
+        return Err(DeviceIdError::EmptyName);
+    } else if id.len() > max_cn_size {
+        return Err(DeviceIdError::TooLongName {
+            name: id.into(),
+            max_cn_size,
+        });
+    } else if !id.chars().all(is_valid_device_id_char) {
+        return Err(DeviceIdError::InvalidCharacter { name: id.into() });
+    }
+
+    Ok(())
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum DeviceIdError {
+    #[error(r#"The string '{name:?}' contains characters which cannot be used in a name [use only A-Z, a-z, 0-9, ' = ( ) , - . ? % * _ ! @]"#)]
+    InvalidCharacter { name: String },
+
+    #[error(r#"The empty string cannot be used as a name"#)]
+    EmptyName,
+
+    #[error(
+    r#"The string '{name:?}' is more than {max_cn_size} characters long and cannot be used as a name"#
+    )]
+    TooLongName { name: String, max_cn_size: usize },
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use assert_matches::*;
+
+    #[test]
+    fn valid_device_id_with_alphabets() -> anyhow::Result<()> {
+        assert_eq!((), is_valid_device_id("ThinEdgeDevice", 64)?);
+        Ok(())
+    }
+
+    #[test]
+    fn valid_device_id_with_digits() -> anyhow::Result<()> {
+        assert_eq!((), is_valid_device_id("123ThinEdgeDevice", 64)?);
+        Ok(())
+    }
+    #[test]
+    fn valid_device_id_with_special_chars() -> anyhow::Result<()> {
+        assert_eq!(
+            (),
+            is_valid_device_id("'?=()*@!%,-.123ThinEdgeDevice-id", 64)?
+        );
+        Ok(())
+    }
+    #[test]
+    fn invalid_device_ids() -> anyhow::Result<()> {
+        for id in vec![
+            "thinedge>",
+            "thinedge<",
+            "thinedge|",
+            "thinedge[",
+            "thinedge]",
+            "thinedge}",
+            "thinedge{",
+            "thinedge^",
+            "thinedge&",
+            "thinedge#",
+            "thinedge$",
+            "thinedge+",
+            "thin/edge",
+            "thin:edge",
+            "thin$edge",
+            "thin edge",
+        ]
+        .iter()
+        {
+            let output_err = is_valid_device_id(id, 64);
+            assert_matches!(
+                output_err,
+                Err(DeviceIdError::InvalidCharacter { ref name }) if name == id
+            );
+        }
+        Ok(())
+    }
+
+    #[test]
+    fn empty_device_id() -> anyhow::Result<()> {
+        let output_err = is_valid_device_id("", 64);
+        assert_matches!(output_err, Err(DeviceIdError::EmptyName));
+
+        Ok(())
+    }
+
+    #[test]
+    fn too_long_device_id() -> anyhow::Result<()> {
+        let id = "thinedgethinedgethinedgethinedgethinedgethinedgethinedgethinedgethinedge";
+        let output_err = is_valid_device_id(id, 64);
+        assert_matches!(
+            output_err,
+            Err(DeviceIdError::TooLongName {
+                name,
+                max_cn_size: 64
+            }) if name == id
+        );
+
+        Ok(())
+    }
+}