[PM-13420] Support case-insensitive TOTP generation (#1144)

## 🎟️ Tracking

<!-- Paste the link to the Jira or GitHub issue or otherwise describe /
point to where this change is coming from. -->

https://bitwarden.atlassian.net/browse/PM-13420

## 📔 Objective

Update TOTP parsing to be case insensitive by lowercasing the input
initially. `decode_b32` is already converting the input to uppercase so
secret decoding will still work the same.

I've also removed the `to_uppercase` from algorithm now that we know the
string is lowercase.

## ⏰ Reminders before review

- Contributor guidelines followed
- All formatters and local linters executed and passed
- Written new unit and / or integration tests where applicable
- Protected functional changes with optionality (feature flags)
- Used internationalization (i18n) for all UI strings
- CI builds passed
- Communicated to DevOps any deployment requirements
- Updated any necessary documentation (Confluence, contributing docs) or
informed the documentation
  team

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- 🤔 (`:thinking:`) or 💭 (`:thought_balloon:`) for more open inquiry
that's not quite a confirmed
  issue and could potentially benefit from discussion
- 🎨 (`:art:`) for suggestions / improvements
- ❌ (`:x:`) or ⚠️ (`:warning:`) for more significant problems or
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crates/bitwarden-vault/src/totp.rs

@@ -157,17 +157,19 @@ impl FromStr for Totp {
     /// - OTP Auth URI
     /// - Steam URI
     fn from_str(key: &str) -> Result<Self, Self::Err> {
+        let key = key.to_lowercase();
+
         let params = if key.starts_with("otpauth://") {
-            let url = Url::parse(key).map_err(|_| TotpError::InvalidOtpauth)?;
+            let url = Url::parse(&key).map_err(|_| TotpError::InvalidOtpauth)?;
             let parts: HashMap<_, _> = url.query_pairs().collect();
 
             Totp {
                 algorithm: parts
                     .get("algorithm")
-                    .and_then(|v| match v.to_uppercase().as_ref() {
-                        "SHA1" => Some(Algorithm::Sha1),
-                        "SHA256" => Some(Algorithm::Sha256),
-                        "SHA512" => Some(Algorithm::Sha512),
+                    .and_then(|v| match v.as_ref() {
+                        "sha1" => Some(Algorithm::Sha1),
+                        "sha256" => Some(Algorithm::Sha256),
+                        "sha512" => Some(Algorithm::Sha512),
                         _ => None,
                     })
                     .unwrap_or(DEFAULT_ALGORITHM),
@@ -200,7 +202,7 @@ impl FromStr for Totp {
                 algorithm: DEFAULT_ALGORITHM,
                 digits: DEFAULT_DIGITS,
                 period: DEFAULT_PERIOD,
-                secret: decode_b32(key),
+                secret: decode_b32(&key),
             }
         };
 
@@ -285,6 +287,7 @@ mod tests {
             ("PIUD1IS!EQYA=", "829846"),    // sanitized
             // Steam
             ("steam://HXDMVJECJJWSRB3HWIZR4IFUGFTMXBOZ", "7W6CJ"),
+            ("StEam://HXDMVJECJJWSRB3HWIZR4IFUGFTMXBOZ", "7W6CJ"),
             ("steam://ABCD123", "N26DF"),
             // Various weird lengths
             ("ddfdf", "932653"),
@@ -321,6 +324,20 @@ mod tests {
         assert_eq!(response.period, 30);
     }
 
+    #[test]
+    fn test_generate_otpauth_uppercase() {
+        let key = "OTPauth://totp/test-account?secret=WQIQ25BRKZYCJVYP".to_string();
+        let time = Some(
+            DateTime::parse_from_rfc3339("2023-01-01T00:00:00.000Z")
+                .unwrap()
+                .with_timezone(&Utc),
+        );
+        let response = generate_totp(key, time).unwrap();
+
+        assert_eq!(response.code, "194506".to_string());
+        assert_eq!(response.period, 30);
+    }
+
     #[test]
     fn test_generate_otpauth_period() {
         let key = "otpauth://totp/test-account?secret=WQIQ25BRKZYCJVYP&period=60".to_string();
@@ -335,6 +352,21 @@ mod tests {
         assert_eq!(response.period, 60);
     }
 
+    #[test]
+    fn test_generate_otpauth_algorithm_sha256() {
+        let key =
+            "otpauth://totp/test-account?secret=WQIQ25BRKZYCJVYP&algorithm=SHA256".to_string();
+        let time = Some(
+            DateTime::parse_from_rfc3339("2023-01-01T00:00:00.000Z")
+                .unwrap()
+                .with_timezone(&Utc),
+        );
+        let response = generate_totp(key, time).unwrap();
+
+        assert_eq!(response.code, "842615".to_string());
+        assert_eq!(response.period, 30);
+    }
+
     #[test]
     fn test_generate_totp_cipher_view() {
         let view = CipherListView {