Initial commit: Touch ID Keychain CLI tool

- Touch ID authentication for all commands
- Secure password input (no echo)
- macOS Keychain storage with encryption

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

3 files changed, 420 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
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+# Compiled binary
+keychain-fingerprint
+
+# macOS
+.DS_Store
+
+# Xcode
+*.xcodeproj
+*.xcworkspace
+DerivedData/
diff --git a/README.md b/README.md
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+# keychain-fingerprint
+
+Touch ID 인증으로 macOS Keychain 비밀번호에 안전하고 편리하게 접근하는 CLI 도구
+
+## Why?
+
+macOS Keychain에 저장된 비밀번호에 접근할 때 두 가지 불편함이 있습니다:
+
+### 문제 1: 보안 vs 편의성 딜레마
+
+`security find-generic-password` 명령어로 비밀번호에 접근하면:
+
+```
+"security"가 키체인의 "myapp"에 저장된 기밀 정보를 사용하려고 합니다.
+[거부] [허용] [항상 허용]
+```
+
+- **"허용"**: 매번 Mac 비밀번호를 입력해야 함 → 번거로움
+- **"항상 허용"**: 이후 어떤 앱에서든 비밀번호 없이 접근 가능 → 보안 취약
+
+### 문제 2: 비밀번호 입력의 불편함
+
+Mac 비밀번호는 보통 길고 복잡해서 매번 입력하기 번거롭습니다.
+
+### 해결책: Touch ID
+
+이 도구는 **Touch ID**로 인증하여:
+- **빠르고 편리함**: 손가락 한 번으로 인증 (비밀번호 입력 불필요)
+- **보안 유지**: 다른 앱에서 접근 시 여전히 Mac 비밀번호 필요
+
+## Installation
+
+```bash
+# Clone
+git clone https://github.com/dss99911/keychain-fingerprint.git
+cd keychain-fingerprint
+
+# Compile
+swiftc -o keychain-fingerprint main.swift -framework LocalAuthentication -framework Security
+
+# Install (optional)
+sudo cp keychain-fingerprint /usr/local/bin/
+```
+
+## Usage
+
+```bash
+# Save password (Touch ID → secure input)
+keychain-fingerprint set myapp user@example.com
+
+# Get password (Touch ID → stdout)
+keychain-fingerprint get myapp user@example.com
+
+# List saved items (Touch ID)
+keychain-fingerprint list
+
+# Delete password (Touch ID)
+keychain-fingerprint delete myapp user@example.com
+```
+
+### Shell Variable (Recommended)
+
+```bash
+# Capture password in variable (not displayed on screen)
+PASSWORD=$(keychain-fingerprint get myapp user@example.com)
+
+# Use the password
+echo "Using password..."
+
+# Clear the variable when done
+unset PASSWORD
+```
+
+## Security
+
+| Access Method | Authentication Required |
+|---------------|------------------------|
+| This app | Touch ID |
+| Other apps / `security` command | Mac password |
+
+### How it works
+
+```
+┌─────────────────────────────────────────┐
+│         keychain-fingerprint            │
+├─────────────────────────────────────────┤
+│  1. Touch ID authentication             │
+│  2. Access Keychain (auto-authorized)   │
+└─────────────────────────────────────────┘
+
+┌─────────────────────────────────────────┐
+│         Other apps / terminal           │
+├─────────────────────────────────────────┤
+│  Keychain access → Mac password prompt  │
+└─────────────────────────────────────────┘
+```
+
+### Features
+
+- All commands require Touch ID
+- Passwords stored encrypted in macOS Keychain
+- Password input is hidden (no echo)
+- Passwords only output to stdout (for variable capture)
+- Device-only access (`kSecAttrAccessibleWhenUnlockedThisDeviceOnly`)
+
+## Requirements
+
+- macOS with Touch ID
+- Xcode Command Line Tools (`xcode-select --install`)
+
+## License
+
+MIT
diff --git a/main.swift b/main.swift
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+import Foundation
+import LocalAuthentication
+import Security
+
+// MARK: - Touch ID Authentication
+
+func authenticateWithTouchID(reason: String) -> Bool {
+    let context = LAContext()
+    var error: NSError?
+
+    // Check if Touch ID is available
+    guard context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) else {
+        if let error = error {
+            fputs("Touch ID not available: \(error.localizedDescription)\n", stderr)
+        }
+        return false
+    }
+
+    let semaphore = DispatchSemaphore(value: 0)
+    var success = false
+
+    context.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: reason) { result, authError in
+        success = result
+        if let authError = authError {
+            fputs("Authentication failed: \(authError.localizedDescription)\n", stderr)
+        }
+        semaphore.signal()
+    }
+
+    semaphore.wait()
+    return success
+}
+
+// MARK: - Keychain Operations
+
+func getKeychainPassword(service: String, account: String) -> String? {
+    let query: [String: Any] = [
+        kSecClass as String: kSecClassGenericPassword,
+        kSecAttrService as String: service,
+        kSecAttrAccount as String: account,
+        kSecReturnData as String: true,
+        kSecMatchLimit as String: kSecMatchLimitOne
+    ]
+
+    var result: AnyObject?
+    let status = SecItemCopyMatching(query as CFDictionary, &result)
+
+    if status == errSecSuccess, let data = result as? Data {
+        return String(data: data, encoding: .utf8)
+    } else if status == errSecItemNotFound {
+        fputs("Error: Password not found\n", stderr)
+    } else if status == errSecAuthFailed {
+        fputs("Error: Authentication failed\n", stderr)
+    } else {
+        fputs("Error: Keychain error (status: \(status))\n", stderr)
+    }
+
+    return nil
+}
+
+func setKeychainPassword(service: String, account: String, password: String) -> Bool {
+    // First, try to delete existing item
+    let deleteQuery: [String: Any] = [
+        kSecClass as String: kSecClassGenericPassword,
+        kSecAttrService as String: service,
+        kSecAttrAccount as String: account
+    ]
+    SecItemDelete(deleteQuery as CFDictionary)
+
+    // Add new item (without Access Control - requires paid Developer Program)
+    // Security is provided at app level via Touch ID authentication
+    guard let passwordData = password.data(using: .utf8) else {
+        fputs("Error: Failed to encode password\n", stderr)
+        return false
+    }
+
+    let addQuery: [String: Any] = [
+        kSecClass as String: kSecClassGenericPassword,
+        kSecAttrService as String: service,
+        kSecAttrAccount as String: account,
+        kSecValueData as String: passwordData,
+        kSecAttrAccessible as String: kSecAttrAccessibleWhenUnlockedThisDeviceOnly
+    ]
+
+    let status = SecItemAdd(addQuery as CFDictionary, nil)
+
+    if status != errSecSuccess {
+        fputs("Error: Failed to save password (status: \(status))\n", stderr)
+        return false
+    }
+
+    return true
+}
+
+func deleteKeychainPassword(service: String, account: String) -> Bool {
+    let query: [String: Any] = [
+        kSecClass as String: kSecClassGenericPassword,
+        kSecAttrService as String: service,
+        kSecAttrAccount as String: account
+    ]
+
+    let status = SecItemDelete(query as CFDictionary)
+
+    if status == errSecSuccess || status == errSecItemNotFound {
+        return true
+    }
+
+    fputs("Error: Failed to delete password (status: \(status))\n", stderr)
+    return false
+}
+
+func listKeychainItems(service: String? = nil) -> [(service: String, account: String)] {
+    var query: [String: Any] = [
+        kSecClass as String: kSecClassGenericPassword,
+        kSecReturnAttributes as String: true,
+        kSecMatchLimit as String: kSecMatchLimitAll
+    ]
+
+    if let service = service {
+        query[kSecAttrService as String] = service
+    }
+
+    var result: AnyObject?
+    let status = SecItemCopyMatching(query as CFDictionary, &result)
+
+    var items: [(service: String, account: String)] = []
+
+    if status == errSecSuccess, let itemList = result as? [[String: Any]] {
+        for item in itemList {
+            if let service = item[kSecAttrService as String] as? String,
+               let account = item[kSecAttrAccount as String] as? String {
+                items.append((service: service, account: account))
+            }
+        }
+    }
+
+    return items
+}
+
+// MARK: - Secure Input
+
+func readSecurePassword() -> String? {
+    // Disable echo for secure input
+    var oldTermios = termios()
+    tcgetattr(FileHandle.standardInput.fileDescriptor, &oldTermios)
+
+    var newTermios = oldTermios
+    newTermios.c_lflag &= ~UInt(ECHO)
+    tcsetattr(FileHandle.standardInput.fileDescriptor, TCSANOW, &newTermios)
+
+    defer {
+        // Restore echo
+        tcsetattr(FileHandle.standardInput.fileDescriptor, TCSANOW, &oldTermios)
+        print("") // New line after hidden input
+    }
+
+    return readLine()
+}
+
+// MARK: - Main
+
+func printUsage() {
+    fputs("""
+    Usage: keychain-fingerprint <command> [options]
+
+    Commands:
+      get <service> <account>     Get password (requires Touch ID)
+      set <service> <account>     Set password (requires Touch ID)
+      delete <service> <account>  Delete password (requires Touch ID)
+      list [service]              List items (requires Touch ID)
+
+    Security:
+      - All commands require Touch ID authentication
+      - Passwords stored in macOS Keychain (encrypted)
+      - Password input is hidden (no echo)
+      - Other apps require Mac password to access
+
+    Examples:
+      keychain-fingerprint get myapp user@example.com
+      keychain-fingerprint set myapp user@example.com
+      keychain-fingerprint list
+      keychain-fingerprint delete myapp user@example.com
+
+    Shell variable usage:
+      PASSWORD=$(keychain-fingerprint get myapp user@example.com)
+      # use $PASSWORD
+      unset PASSWORD
+    """, stderr)
+}
+
+func main() {
+    let args = CommandLine.arguments
+
+    guard args.count >= 2 else {
+        printUsage()
+        exit(1)
+    }
+
+    let command = args[1]
+
+    switch command {
+    case "get":
+        guard args.count >= 4 else {
+            fputs("Error: 'get' requires <service> and <account>\n", stderr)
+            exit(1)
+        }
+
+        let service = args[2]
+        let account = args[3]
+
+        // Touch ID authentication
+        guard authenticateWithTouchID(reason: "Keychain 비밀번호 조회를 위해 인증이 필요합니다") else {
+            exit(1)
+        }
+
+        if let password = getKeychainPassword(service: service, account: account) {
+            print(password)
+        } else {
+            exit(1)
+        }
+
+    case "set":
+        guard args.count >= 4 else {
+            fputs("Error: 'set' requires <service> and <account>\n", stderr)
+            exit(1)
+        }
+
+        let service = args[2]
+        let account = args[3]
+
+        // Touch ID authentication first
+        guard authenticateWithTouchID(reason: "Keychain 비밀번호 저장을 위해 인증이 필요합니다") else {
+            exit(1)
+        }
+
+        fputs("Enter password: ", stderr)
+        guard let password = readSecurePassword(), !password.isEmpty else {
+            fputs("Error: No password provided\n", stderr)
+            exit(1)
+        }
+
+        if setKeychainPassword(service: service, account: account, password: password) {
+            fputs("Password saved successfully\n", stderr)
+        } else {
+            exit(1)
+        }
+
+    case "delete":
+        guard args.count >= 4 else {
+            fputs("Error: 'delete' requires <service> and <account>\n", stderr)
+            exit(1)
+        }
+
+        let service = args[2]
+        let account = args[3]
+
+        // Touch ID authentication
+        guard authenticateWithTouchID(reason: "Keychain 비밀번호 삭제를 위해 인증이 필요합니다") else {
+            exit(1)
+        }
+
+        if deleteKeychainPassword(service: service, account: account) {
+            fputs("Password deleted successfully\n", stderr)
+        } else {
+            exit(1)
+        }
+
+    case "list":
+        // Touch ID authentication
+        guard authenticateWithTouchID(reason: "Keychain 목록 조회를 위해 인증이 필요합니다") else {
+            exit(1)
+        }
+
+        let service = args.count >= 3 ? args[2] : nil
+        let items = listKeychainItems(service: service)
+
+        if items.isEmpty {
+            fputs("No items found\n", stderr)
+        } else {
+            fputs("Service\t\t\tAccount\n", stderr)
+            fputs("-------\t\t\t-------\n", stderr)
+            for item in items {
+                fputs("\(item.service)\t\t\(item.account)\n", stderr)
+            }
+        }
+
+    case "help", "-h", "--help":
+        printUsage()
+
+    default:
+        fputs("Unknown command: \(command)\n", stderr)
+        printUsage()
+        exit(1)
+    }
+}
+
+main()