fix(security): parse shell separators only when unquoted

src/security/policy.rs

@@ -167,45 +167,221 @@ fn skip_env_assignments(s: &str) -> &str {
     }
 }
 
-/// Detect a single `&` operator (background/chain). `&&` is allowed.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum QuoteState {
+    None,
+    Single,
+    Double,
+}
+
+/// Split a shell command into sub-commands by unquoted separators.
+///
+/// Separators:
+/// - `;` and newline
+/// - `|`
+/// - `&&`, `||`
+///
+/// Characters inside single or double quotes are treated as literals, so
+/// `sqlite3 db "SELECT 1; SELECT 2;"` remains a single segment.
+fn split_unquoted_segments(command: &str) -> Vec<String> {
+    let mut segments = Vec::new();
+    let mut current = String::new();
+    let mut quote = QuoteState::None;
+    let mut escaped = false;
+    let mut chars = command.chars().peekable();
+
+    let push_segment = |segments: &mut Vec<String>, current: &mut String| {
+        let trimmed = current.trim();
+        if !trimmed.is_empty() {
+            segments.push(trimmed.to_string());
+        }
+        current.clear();
+    };
+
+    while let Some(ch) = chars.next() {
+        match quote {
+            QuoteState::Single => {
+                if ch == '\'' {
+                    quote = QuoteState::None;
+                }
+                current.push(ch);
+            }
+            QuoteState::Double => {
+                if escaped {
+                    escaped = false;
+                    current.push(ch);
+                    continue;
+                }
+                if ch == '\\' {
+                    escaped = true;
+                    current.push(ch);
+                    continue;
+                }
+                if ch == '"' {
+                    quote = QuoteState::None;
+                }
+                current.push(ch);
+            }
+            QuoteState::None => {
+                if escaped {
+                    escaped = false;
+                    current.push(ch);
+                    continue;
+                }
+                if ch == '\\' {
+                    escaped = true;
+                    current.push(ch);
+                    continue;
+                }
+
+                match ch {
+                    '\'' => {
+                        quote = QuoteState::Single;
+                        current.push(ch);
+                    }
+                    '"' => {
+                        quote = QuoteState::Double;
+                        current.push(ch);
+                    }
+                    ';' | '\n' => push_segment(&mut segments, &mut current),
+                    '|' => {
+                        if chars.next_if_eq(&'|').is_some() {
+                            // Consume full `||`; both characters are separators.
+                        }
+                        push_segment(&mut segments, &mut current);
+                    }
+                    '&' => {
+                        if chars.next_if_eq(&'&').is_some() {
+                            // `&&` is a separator; single `&` is handled separately.
+                            push_segment(&mut segments, &mut current);
+                        } else {
+                            current.push(ch);
+                        }
+                    }
+                    _ => current.push(ch),
+                }
+            }
+        }
+    }
+
+    let trimmed = current.trim();
+    if !trimmed.is_empty() {
+        segments.push(trimmed.to_string());
+    }
+
+    segments
+}
+
+/// Detect a single unquoted `&` operator (background/chain). `&&` is allowed.
 ///
 /// We treat any standalone `&` as unsafe in policy validation because it can
 /// chain hidden sub-commands and escape foreground timeout expectations.
-fn contains_single_ampersand(s: &str) -> bool {
+fn contains_unquoted_single_ampersand(command: &str) -> bool {
-    let bytes = s.as_bytes();
+    let mut quote = QuoteState::None;
-    for (i, b) in bytes.iter().enumerate() {
+    let mut escaped = false;
-        if *b != b'&' {
+    let mut chars = command.chars().peekable();
-            continue;
+
-        }
+    while let Some(ch) = chars.next() {
-        let prev_is_amp = i > 0 && bytes[i - 1] == b'&';
+        match quote {
-        let next_is_amp = i + 1 < bytes.len() && bytes[i + 1] == b'&';
+            QuoteState::Single => {
-        if !prev_is_amp && !next_is_amp {
+                if ch == '\'' {
-            return true;
+                    quote = QuoteState::None;
+                }
+            }
+            QuoteState::Double => {
+                if escaped {
+                    escaped = false;
+                    continue;
+                }
+                if ch == '\\' {
+                    escaped = true;
+                    continue;
+                }
+                if ch == '"' {
+                    quote = QuoteState::None;
+                }
+            }
+            QuoteState::None => {
+                if escaped {
+                    escaped = false;
+                    continue;
+                }
+                if ch == '\\' {
+                    escaped = true;
+                    continue;
+                }
+                match ch {
+                    '\'' => quote = QuoteState::Single,
+                    '"' => quote = QuoteState::Double,
+                    '&' => {
+                        if chars.next_if_eq(&'&').is_none() {
+                            return true;
+                        }
+                    }
+                    _ => {}
+                }
+            }
         }
     }
+
+    false
+}
+
+/// Detect an unquoted character in a shell command.
+fn contains_unquoted_char(command: &str, target: char) -> bool {
+    let mut quote = QuoteState::None;
+    let mut escaped = false;
+
+    for ch in command.chars() {
+        match quote {
+            QuoteState::Single => {
+                if ch == '\'' {
+                    quote = QuoteState::None;
+                }
+            }
+            QuoteState::Double => {
+                if escaped {
+                    escaped = false;
+                    continue;
+                }
+                if ch == '\\' {
+                    escaped = true;
+                    continue;
+                }
+                if ch == '"' {
+                    quote = QuoteState::None;
+                    continue;
+                }
+            }
+            QuoteState::None => {
+                if escaped {
+                    escaped = false;
+                    continue;
+                }
+                if ch == '\\' {
+                    escaped = true;
+                    continue;
+                }
+                match ch {
+                    '\'' => quote = QuoteState::Single,
+                    '"' => quote = QuoteState::Double,
+                    _ if ch == target => return true,
+                    _ => {}
+                }
+            }
+        }
+    }
+
     false
 }
 
 impl SecurityPolicy {
     /// Classify command risk. Any high-risk segment marks the whole command high.
     pub fn command_risk_level(&self, command: &str) -> CommandRiskLevel {
-        let mut normalized = command.to_string();
-        for sep in ["&&", "||"] {
-            normalized = normalized.replace(sep, "\x00");
-        }
-        for sep in ['\n', ';', '|', '&'] {
-            normalized = normalized.replace(sep, "\x00");
-        }
-
         let mut saw_medium = false;
 
-        for segment in normalized.split('\x00') {
+        for segment in split_unquoted_segments(command) {
-            let segment = segment.trim();
+            let cmd_part = skip_env_assignments(&segment);
-            if segment.is_empty() {
-                continue;
-            }
-
-            let cmd_part = skip_env_assignments(segment);
             let mut words = cmd_part.split_whitespace();
             let Some(base_raw) = words.next() else {
                 continue;
@@ -369,8 +545,9 @@ impl SecurityPolicy {
             return false;
         }
 
-        // Block output redirections — they can write to arbitrary paths
+        // Block output redirections (`>`, `>>`) — they can write to arbitrary paths.
-        if command.contains('>') {
+        // Ignore quoted literals, e.g. `echo "a>b"`.
+        if contains_unquoted_char(command, '>') {
             return false;
         }
 
@@ -385,26 +562,13 @@ impl SecurityPolicy {
 
         // Block background command chaining (`&`), which can hide extra
         // sub-commands and outlive timeout expectations. Keep `&&` allowed.
-        if contains_single_ampersand(command) {
+        if contains_unquoted_single_ampersand(command) {
             return false;
         }
 
-        // Split on command separators and validate each sub-command.
+        // Split on unquoted command separators and validate each sub-command.
-        // We collect segments by scanning for separator characters.
+        let segments = split_unquoted_segments(command);
-        let mut normalized = command.to_string();
+        for segment in &segments {
-        for sep in ["&&", "||"] {
-            normalized = normalized.replace(sep, "\x00");
-        }
-        for sep in ['\n', ';', '|'] {
-            normalized = normalized.replace(sep, "\x00");
-        }
-
-        for segment in normalized.split('\x00') {
-            let segment = segment.trim();
-            if segment.is_empty() {
-                continue;
-            }
-
             // Strip leading env var assignments (e.g. FOO=bar cmd)
             let cmd_part = skip_env_assignments(segment);
 
@@ -432,7 +596,7 @@ impl SecurityPolicy {
         }
 
         // At least one command must be present
-        let has_cmd = normalized.split('\x00').any(|s| {
+        let has_cmd = segments.iter().any(|s| {
             let s = skip_env_assignments(s.trim());
             s.split_whitespace().next().is_some_and(|w| !w.is_empty())
         });
@@ -832,6 +996,19 @@ mod tests {
         assert!(result.unwrap_err().contains("high-risk"));
     }
 
+    #[test]
+    fn validate_command_full_mode_skips_medium_risk_approval_gate() {
+        let p = SecurityPolicy {
+            autonomy: AutonomyLevel::Full,
+            require_approval_for_medium_risk: true,
+            allowed_commands: vec!["touch".into()],
+            ..SecurityPolicy::default()
+        };
+
+        let result = p.validate_command_execution("touch test.txt", false);
+        assert_eq!(result.unwrap(), CommandRiskLevel::Medium);
+    }
+
     #[test]
     fn validate_command_rejects_background_chain_bypass() {
         let p = default_policy();
@@ -1027,6 +1204,32 @@ mod tests {
         assert!(!p.is_command_allowed("ls;rm -rf /"));
     }
 
+    #[test]
+    fn quoted_semicolons_do_not_split_sqlite_command() {
+        let p = SecurityPolicy {
+            allowed_commands: vec!["sqlite3".into()],
+            ..SecurityPolicy::default()
+        };
+        assert!(p.is_command_allowed(
+            "sqlite3 /tmp/test.db \"CREATE TABLE t(id INT); INSERT INTO t VALUES(1); SELECT * FROM t;\""
+        ));
+        assert_eq!(
+            p.command_risk_level(
+                "sqlite3 /tmp/test.db \"CREATE TABLE t(id INT); INSERT INTO t VALUES(1); SELECT * FROM t;\""
+            ),
+            CommandRiskLevel::Low
+        );
+    }
+
+    #[test]
+    fn unquoted_semicolon_after_quoted_sql_still_splits_commands() {
+        let p = SecurityPolicy {
+            allowed_commands: vec!["sqlite3".into()],
+            ..SecurityPolicy::default()
+        };
+        assert!(!p.is_command_allowed("sqlite3 /tmp/test.db \"SELECT 1;\"; rm -rf /"));
+    }
+
     #[test]
     fn command_injection_backtick_blocked() {
         let p = default_policy();
@@ -1089,6 +1292,13 @@ mod tests {
         assert!(!p.is_command_allowed("ls >> /tmp/exfil.txt"));
     }
 
+    #[test]
+    fn quoted_ampersand_and_redirect_literals_are_not_treated_as_operators() {
+        let p = default_policy();
+        assert!(p.is_command_allowed("echo \"A&B\""));
+        assert!(p.is_command_allowed("echo \"A>B\""));
+    }
+
     #[test]
     fn command_argument_injection_blocked() {
         let p = default_policy();