regy 0.1.0

Private-by-default desktop agent for the Regy web interface
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147

use crate::domain::errors::{AgentError, AgentResult, ErrorCode};
use std::fs;
use std::path::{Component, Path};

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ValidatedCommand {
    pub command: Vec<String>,
    pub cwd: Option<String>,
}

#[derive(Debug, Clone)]
pub struct CommandPolicy {
    allowed_commands: Vec<String>,
    allowed_workdirs: Vec<String>,
}

impl CommandPolicy {
    pub fn new(allowed_commands: Vec<String>, allowed_workdirs: Vec<String>) -> Self {
        Self {
            allowed_commands,
            allowed_workdirs,
        }
    }

    pub fn validate(&self, command: &[String], cwd: Option<&str>) -> AgentResult<ValidatedCommand> {
        if command.is_empty()
            || command[0].trim().is_empty()
            || command.iter().any(|part| part.contains('\0'))
        {
            return Err(AgentError::new(ErrorCode::CommandDenied, "command denied"));
        }

        if !self.allowed_commands.is_empty()
            && !self
                .allowed_commands
                .iter()
                .any(|allowed| allowed == &command[0])
        {
            return Err(AgentError::new(ErrorCode::CommandDenied, "command denied"));
        }

        let cwd = if let Some(cwd) = cwd {
            Some(self.validate_cwd(cwd)?)
        } else {
            if !self.allowed_workdirs.is_empty() {
                return Err(AgentError::new(ErrorCode::CwdDenied, "cwd denied"));
            }
            None
        };

        Ok(ValidatedCommand {
            command: command.to_vec(),
            cwd,
        })
    }
}

impl CommandPolicy {
    pub(crate) fn validate_chat_cwd(&self, cwd: &str) -> AgentResult<String> {
        self.validate_cwd(cwd)
    }

    pub(crate) fn validate_workspace(&self, workspace: &Path) -> AgentResult<String> {
        let canonical = workspace
            .canonicalize()
            .map_err(|_| AgentError::new(ErrorCode::SkillScopeDenied, "workspace denied"))?;
        self.validate_canonical_cwd(&canonical)
            .map_err(|_| AgentError::new(ErrorCode::SkillScopeDenied, "workspace denied"))
    }

    /// Returns true if `path` is under one of the configured `allowed_workdirs`
    /// roots. Does not perform cwd-validity checks (sensitive roots, ssh
    /// segments) — callers that need those should use `validate_canonical_cwd`.
    pub fn is_under_allowed_workdir(&self, path: &Path) -> bool {
        if self.allowed_workdirs.is_empty() {
            return false;
        }
        self.allowed_workdirs
            .iter()
            .any(|root| matches_workdir(root, path))
    }

    fn validate_cwd(&self, cwd: &str) -> AgentResult<String> {
        if cwd.contains('\0') || has_dot_segments(cwd) || has_ssh_segment(Path::new(cwd)) {
            return Err(AgentError::new(ErrorCode::CwdDenied, "cwd denied"));
        }

        let cwd = canonicalize_path(cwd)?;
        self.validate_canonical_cwd(&cwd)
    }

    pub(crate) fn validate_canonical_cwd(&self, cwd: &Path) -> AgentResult<String> {
        if is_sensitive_cwd(cwd) {
            return Err(AgentError::new(ErrorCode::CwdDenied, "cwd denied"));
        }

        if !self.allowed_workdirs.is_empty()
            && !self
                .allowed_workdirs
                .iter()
                .any(|root| matches_workdir(root, cwd))
        {
            return Err(AgentError::new(ErrorCode::CwdDenied, "cwd denied"));
        }

        canonicalized_cwd_string(cwd)
    }
}

pub(crate) fn canonicalized_cwd_string(cwd: &Path) -> AgentResult<String> {
    cwd.to_str()
        .map(str::to_owned)
        .ok_or_else(|| AgentError::new(ErrorCode::CwdDenied, "cwd denied"))
}

fn has_dot_segments(cwd: &str) -> bool {
    Path::new(cwd)
        .components()
        .any(|component| matches!(component, Component::CurDir | Component::ParentDir))
}

fn canonicalize_path(path: &str) -> AgentResult<std::path::PathBuf> {
    fs::canonicalize(path).map_err(|_| AgentError::new(ErrorCode::CwdDenied, "cwd denied"))
}

fn is_sensitive_cwd(cwd: &Path) -> bool {
    cwd == Path::new("/")
        || has_ssh_segment(cwd)
        || sensitive_roots()
            .iter()
            .skip(1)
            .any(|root| canonicalize_path(root).is_ok_and(|root| cwd.starts_with(root)))
}

fn matches_workdir(root: &str, cwd: &Path) -> bool {
    canonicalize_path(root).is_ok_and(|root| cwd.starts_with(root))
}

fn has_ssh_segment(cwd: &Path) -> bool {
    cwd.components().any(|component| {
        matches!(component, Component::Normal(segment) if segment.to_string_lossy().eq_ignore_ascii_case(".ssh"))
    })
}

fn sensitive_roots() -> &'static [&'static str] {
    &["/", "/etc", "/root", "/var/lib", "/var/root"]
}