feat: add input validation with path traversal protection

- validate_storage_key: reject ../, null bytes, absolute paths
- validate_docker_name: OCI distribution spec compliance
- validate_digest: sha256/sha512 format validation
- validate_docker_reference: tag and digest reference validation
- Integrate validation in storage wrapper and Docker handlers

nora-registry/src/registry/docker.rs

@@ -1,3 +1,4 @@
+use crate::validation::{validate_digest, validate_docker_name, validate_docker_reference};
 use crate::AppState;
 use axum::{
     body::Bytes,
@@ -33,6 +34,13 @@ async fn check_blob(
     State(state): State<Arc<AppState>>,
     Path((name, digest)): Path<(String, String)>,
 ) -> Response {
+    if let Err(e) = validate_docker_name(&name) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+    if let Err(e) = validate_digest(&digest) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+
     let key = format!("docker/{}/blobs/{}", name, digest);
     match state.storage.get(&key).await {
         Ok(data) => (
@@ -48,6 +56,13 @@ async fn download_blob(
     State(state): State<Arc<AppState>>,
     Path((name, digest)): Path<(String, String)>,
 ) -> Response {
+    if let Err(e) = validate_docker_name(&name) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+    if let Err(e) = validate_digest(&digest) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+
     let key = format!("docker/{}/blobs/{}", name, digest);
     match state.storage.get(&key).await {
         Ok(data) => (
@@ -61,6 +76,10 @@ async fn download_blob(
 }
 
 async fn start_upload(Path(name): Path<String>) -> Response {
+    if let Err(e) = validate_docker_name(&name) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+
     let uuid = uuid::Uuid::new_v4().to_string();
     let location = format!("/v2/{}/blobs/uploads/{}", name, uuid);
     (
@@ -79,10 +98,19 @@ async fn upload_blob(
     axum::extract::Query(params): axum::extract::Query<std::collections::HashMap<String, String>>,
     body: Bytes,
 ) -> Response {
+    if let Err(e) = validate_docker_name(&name) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+
     let digest = match params.get("digest") {
         Some(d) => d,
-        None => return StatusCode::BAD_REQUEST.into_response(),
+        None => return (StatusCode::BAD_REQUEST, "Missing digest parameter").into_response(),
     };
+
+    if let Err(e) = validate_digest(digest) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+
     let key = format!("docker/{}/blobs/{}", name, digest);
     match state.storage.put(&key, &body).await {
         Ok(()) => {
@@ -97,6 +125,13 @@ async fn get_manifest(
     State(state): State<Arc<AppState>>,
     Path((name, reference)): Path<(String, String)>,
 ) -> Response {
+    if let Err(e) = validate_docker_name(&name) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+    if let Err(e) = validate_docker_reference(&reference) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+
     let key = format!("docker/{}/manifests/{}.json", name, reference);
     match state.storage.get(&key).await {
         Ok(data) => (
@@ -117,6 +152,13 @@ async fn put_manifest(
     Path((name, reference)): Path<(String, String)>,
     body: Bytes,
 ) -> Response {
+    if let Err(e) = validate_docker_name(&name) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+    if let Err(e) = validate_docker_reference(&reference) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+
     let key = format!("docker/{}/manifests/{}.json", name, reference);
     match state.storage.put(&key, &body).await {
         Ok(()) => {
@@ -139,7 +181,11 @@ async fn put_manifest(
 async fn list_tags(
     State(state): State<Arc<AppState>>,
     Path(name): Path<String>,
-) -> (StatusCode, Json<Value>) {
+) -> Response {
+    if let Err(e) = validate_docker_name(&name) {
+        return (StatusCode::BAD_REQUEST, e.to_string()).into_response();
+    }
+
     let prefix = format!("docker/{}/manifests/", name);
     let keys = state.storage.list(&prefix).await;
     let tags: Vec<String> = keys
@@ -150,5 +196,5 @@ async fn list_tags(
                 .map(String::from)
         })
         .collect();
-    (StatusCode::OK, Json(json!({"name": name, "tags": tags})))
+    (StatusCode::OK, Json(json!({"name": name, "tags": tags}))).into_response()
 }

nora-registry/src/storage/mod.rs

@@ -4,10 +4,11 @@ mod s3;
 pub use local::LocalStorage;
 pub use s3::S3Storage;
 
+use crate::validation::{validate_storage_key, ValidationError};
 use async_trait::async_trait;
 use axum::body::Bytes;
-use std::fmt;
 use std::sync::Arc;
+use thiserror::Error;
 
 /// File metadata
 #[derive(Debug, Clone)]
@@ -16,25 +17,21 @@ pub struct FileMeta {
     pub modified: u64, // Unix timestamp
 }
 
-#[derive(Debug)]
+#[derive(Debug, Error)]
 pub enum StorageError {
+    #[error("Network error: {0}")]
     Network(String),
+
+    #[error("Object not found")]
     NotFound,
+
+    #[error("IO error: {0}")]
     Io(String),
-}
 
-impl fmt::Display for StorageError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Network(msg) => write!(f, "Network error: {}", msg),
-            Self::NotFound => write!(f, "Object not found"),
-            Self::Io(msg) => write!(f, "IO error: {}", msg),
-        }
-    }
+    #[error("Validation error: {0}")]
+    Validation(#[from] ValidationError),
 }
 
-impl std::error::Error for StorageError {}
-
 pub type Result<T> = std::result::Result<T, StorageError>;
 
 /// Storage backend trait
@@ -68,18 +65,29 @@ impl Storage {
     }
 
     pub async fn put(&self, key: &str, data: &[u8]) -> Result<()> {
+        validate_storage_key(key)?;
         self.inner.put(key, data).await
     }
 
     pub async fn get(&self, key: &str) -> Result<Bytes> {
+        validate_storage_key(key)?;
         self.inner.get(key).await
     }
 
     pub async fn list(&self, prefix: &str) -> Vec<String> {
+        // Empty prefix is valid for listing all
+        if !prefix.is_empty() {
+            if let Err(_) = validate_storage_key(prefix) {
+                return Vec::new();
+            }
+        }
         self.inner.list(prefix).await
     }
 
     pub async fn stat(&self, key: &str) -> Option<FileMeta> {
+        if validate_storage_key(key).is_err() {
+            return None;
+        }
         self.inner.stat(key).await
     }
 

nora-registry/src/validation.rs

@@ -0,0 +1,552 @@
+//! Input validation for artifact registry paths and identifiers
+//!
+//! Provides security validation to prevent path traversal attacks and
+//! ensure inputs conform to protocol specifications.
+
+use std::fmt;
+
+/// Validation errors
+#[derive(Debug, Clone, PartialEq)]
+pub enum ValidationError {
+    /// Path contains traversal sequences (../, etc.)
+    PathTraversal,
+    /// Docker image name is invalid
+    InvalidDockerName(String),
+    /// Content digest is invalid
+    InvalidDigest(String),
+    /// Tag/reference is invalid
+    InvalidReference(String),
+    /// Input is empty
+    EmptyInput,
+    /// Input exceeds maximum length
+    TooLong { max: usize, actual: usize },
+    /// Contains forbidden characters
+    ForbiddenCharacter(char),
+}
+
+impl fmt::Display for ValidationError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::PathTraversal => write!(f, "Path traversal detected"),
+            Self::InvalidDockerName(reason) => write!(f, "Invalid Docker name: {}", reason),
+            Self::InvalidDigest(reason) => write!(f, "Invalid digest: {}", reason),
+            Self::InvalidReference(reason) => write!(f, "Invalid reference: {}", reason),
+            Self::EmptyInput => write!(f, "Input cannot be empty"),
+            Self::TooLong { max, actual } => {
+                write!(f, "Input exceeds maximum length ({} > {})", actual, max)
+            }
+            Self::ForbiddenCharacter(c) => write!(f, "Forbidden character: {:?}", c),
+        }
+    }
+}
+
+impl std::error::Error for ValidationError {}
+
+/// Maximum allowed storage key length
+const MAX_KEY_LENGTH: usize = 1024;
+
+/// Maximum Docker name length
+const MAX_DOCKER_NAME_LENGTH: usize = 256;
+
+/// Maximum tag/reference length
+const MAX_REFERENCE_LENGTH: usize = 128;
+
+/// Validate and sanitize a storage key to prevent path traversal attacks.
+///
+/// Rejects keys containing:
+/// - `..` path traversal sequences
+/// - Leading `/` or `\` (absolute paths)
+/// - Null bytes
+/// - Empty segments
+pub fn validate_storage_key(key: &str) -> Result<(), ValidationError> {
+    if key.is_empty() {
+        return Err(ValidationError::EmptyInput);
+    }
+
+    if key.len() > MAX_KEY_LENGTH {
+        return Err(ValidationError::TooLong {
+            max: MAX_KEY_LENGTH,
+            actual: key.len(),
+        });
+    }
+
+    // Check for null bytes
+    if key.contains('\0') {
+        return Err(ValidationError::ForbiddenCharacter('\0'));
+    }
+
+    // Check for absolute paths
+    if key.starts_with('/') || key.starts_with('\\') {
+        return Err(ValidationError::PathTraversal);
+    }
+
+    // Check for path traversal patterns
+    if key.contains("..") {
+        return Err(ValidationError::PathTraversal);
+    }
+
+    // Check for backslash (Windows path separator)
+    if key.contains('\\') {
+        return Err(ValidationError::PathTraversal);
+    }
+
+    // Check each segment
+    for segment in key.split('/') {
+        if segment.is_empty() && key != "" {
+            // Allow trailing slash but not double slashes
+            continue;
+        }
+        if segment == "." || segment == ".." {
+            return Err(ValidationError::PathTraversal);
+        }
+    }
+
+    Ok(())
+}
+
+/// Validate Docker image name per OCI distribution spec.
+///
+/// Valid names:
+/// - Lowercase letters, digits, underscores, dots, hyphens
+/// - May contain path separators (/)
+/// - Each component must start with alphanumeric
+/// - Max 256 characters
+///
+/// Examples:
+/// - `nginx` ✓
+/// - `library/nginx` ✓
+/// - `my-org/my-image` ✓
+/// - `NGINX` ✗ (uppercase)
+/// - `../escape` ✗ (path traversal)
+pub fn validate_docker_name(name: &str) -> Result<(), ValidationError> {
+    if name.is_empty() {
+        return Err(ValidationError::EmptyInput);
+    }
+
+    if name.len() > MAX_DOCKER_NAME_LENGTH {
+        return Err(ValidationError::TooLong {
+            max: MAX_DOCKER_NAME_LENGTH,
+            actual: name.len(),
+        });
+    }
+
+    // Check for path traversal
+    if name.contains("..") {
+        return Err(ValidationError::PathTraversal);
+    }
+
+    // Must contain only valid characters
+    for c in name.chars() {
+        if !matches!(c, 'a'..='z' | '0'..='9' | '_' | '.' | '-' | '/') {
+            if c.is_ascii_uppercase() {
+                return Err(ValidationError::InvalidDockerName(
+                    "must be lowercase".to_string(),
+                ));
+            }
+            return Err(ValidationError::ForbiddenCharacter(c));
+        }
+    }
+
+    // Cannot start with separator
+    if name.starts_with('/') || name.starts_with('.') || name.starts_with('-') {
+        return Err(ValidationError::InvalidDockerName(
+            "cannot start with separator or special character".to_string(),
+        ));
+    }
+
+    // Cannot end with separator
+    if name.ends_with('/') {
+        return Err(ValidationError::InvalidDockerName(
+            "cannot end with /".to_string(),
+        ));
+    }
+
+    // No consecutive separators (except ..)
+    if name.contains("//") || name.contains("--") || name.contains("__") {
+        return Err(ValidationError::InvalidDockerName(
+            "consecutive separators not allowed".to_string(),
+        ));
+    }
+
+    // Each path segment must start with alphanumeric
+    for segment in name.split('/') {
+        if segment.is_empty() {
+            return Err(ValidationError::InvalidDockerName(
+                "empty path segment".to_string(),
+            ));
+        }
+        let first = segment.chars().next().unwrap();
+        if !first.is_ascii_alphanumeric() {
+            return Err(ValidationError::InvalidDockerName(
+                "segment must start with alphanumeric".to_string(),
+            ));
+        }
+    }
+
+    Ok(())
+}
+
+/// Validate content digest format.
+///
+/// Supported formats:
+/// - `sha256:<64 hex chars>`
+/// - `sha512:<128 hex chars>`
+///
+/// Examples:
+/// - `sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4` ✓
+/// - `sha256:ABC` ✗ (uppercase)
+/// - `md5:abc` ✗ (unsupported algorithm)
+pub fn validate_digest(digest: &str) -> Result<(), ValidationError> {
+    if digest.is_empty() {
+        return Err(ValidationError::EmptyInput);
+    }
+
+    // Check for path traversal (shouldn't be in digest but defensive check)
+    if digest.contains("..") || digest.contains('/') {
+        return Err(ValidationError::PathTraversal);
+    }
+
+    let parts: Vec<&str> = digest.splitn(2, ':').collect();
+    if parts.len() != 2 {
+        return Err(ValidationError::InvalidDigest(
+            "missing algorithm prefix (expected algo:hash)".to_string(),
+        ));
+    }
+
+    let (algo, hash) = (parts[0], parts[1]);
+
+    match algo {
+        "sha256" => {
+            if hash.len() != 64 {
+                return Err(ValidationError::InvalidDigest(format!(
+                    "sha256 hash must be 64 characters, got {}",
+                    hash.len()
+                )));
+            }
+        }
+        "sha512" => {
+            if hash.len() != 128 {
+                return Err(ValidationError::InvalidDigest(format!(
+                    "sha512 hash must be 128 characters, got {}",
+                    hash.len()
+                )));
+            }
+        }
+        _ => {
+            return Err(ValidationError::InvalidDigest(format!(
+                "unsupported algorithm: {} (use sha256 or sha512)",
+                algo
+            )));
+        }
+    }
+
+    // Hash must be lowercase hex
+    for c in hash.chars() {
+        if !matches!(c, '0'..='9' | 'a'..='f') {
+            if c.is_ascii_uppercase() {
+                return Err(ValidationError::InvalidDigest(
+                    "hash must be lowercase hex".to_string(),
+                ));
+            }
+            return Err(ValidationError::InvalidDigest(format!(
+                "invalid character in hash: {:?}",
+                c
+            )));
+        }
+    }
+
+    Ok(())
+}
+
+/// Validate Docker tag or reference (tag or digest).
+///
+/// Tags:
+/// - Alphanumeric, dots, underscores, hyphens
+/// - Max 128 characters
+/// - Must start with alphanumeric
+///
+/// References may also be digests (sha256:...).
+pub fn validate_docker_reference(reference: &str) -> Result<(), ValidationError> {
+    if reference.is_empty() {
+        return Err(ValidationError::EmptyInput);
+    }
+
+    if reference.len() > MAX_REFERENCE_LENGTH {
+        return Err(ValidationError::TooLong {
+            max: MAX_REFERENCE_LENGTH,
+            actual: reference.len(),
+        });
+    }
+
+    // Check for path traversal
+    if reference.contains("..") || reference.contains('/') {
+        return Err(ValidationError::PathTraversal);
+    }
+
+    // If it looks like a digest, validate as digest
+    if reference.starts_with("sha256:") || reference.starts_with("sha512:") {
+        return validate_digest(reference);
+    }
+
+    // Validate as tag
+    let first = reference.chars().next().unwrap();
+    if !first.is_ascii_alphanumeric() {
+        return Err(ValidationError::InvalidReference(
+            "tag must start with alphanumeric".to_string(),
+        ));
+    }
+
+    for c in reference.chars() {
+        if !matches!(c, 'a'..='z' | 'A'..='Z' | '0'..='9' | '.' | '_' | '-') {
+            return Err(ValidationError::ForbiddenCharacter(c));
+        }
+    }
+
+    Ok(())
+}
+
+/// Validate Maven artifact path.
+///
+/// Maven paths follow the pattern: groupId/artifactId/version/filename
+/// Example: `org/apache/commons/commons-lang3/3.12.0/commons-lang3-3.12.0.jar`
+pub fn validate_maven_path(path: &str) -> Result<(), ValidationError> {
+    validate_storage_key(path)
+}
+
+/// Validate npm package name.
+pub fn validate_npm_name(name: &str) -> Result<(), ValidationError> {
+    if name.is_empty() {
+        return Err(ValidationError::EmptyInput);
+    }
+
+    if name.len() > 214 {
+        return Err(ValidationError::TooLong {
+            max: 214,
+            actual: name.len(),
+        });
+    }
+
+    // Check for path traversal
+    if name.contains("..") {
+        return Err(ValidationError::PathTraversal);
+    }
+
+    Ok(())
+}
+
+/// Validate Cargo crate name.
+pub fn validate_crate_name(name: &str) -> Result<(), ValidationError> {
+    if name.is_empty() {
+        return Err(ValidationError::EmptyInput);
+    }
+
+    if name.len() > 64 {
+        return Err(ValidationError::TooLong {
+            max: 64,
+            actual: name.len(),
+        });
+    }
+
+    // Check for path traversal
+    if name.contains("..") || name.contains('/') {
+        return Err(ValidationError::PathTraversal);
+    }
+
+    // Crate names: alphanumeric, underscores, hyphens
+    for c in name.chars() {
+        if !matches!(c, 'a'..='z' | 'A'..='Z' | '0'..='9' | '_' | '-') {
+            return Err(ValidationError::ForbiddenCharacter(c));
+        }
+    }
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // Storage key tests
+    #[test]
+    fn test_storage_key_valid() {
+        assert!(validate_storage_key("docker/nginx/blobs/sha256:abc").is_ok());
+        assert!(validate_storage_key("maven/org/apache/commons").is_ok());
+        assert!(validate_storage_key("simple").is_ok());
+    }
+
+    #[test]
+    fn test_storage_key_path_traversal() {
+        assert!(matches!(
+            validate_storage_key("../etc/passwd"),
+            Err(ValidationError::PathTraversal)
+        ));
+        assert!(matches!(
+            validate_storage_key("foo/../bar"),
+            Err(ValidationError::PathTraversal)
+        ));
+        assert!(matches!(
+            validate_storage_key("foo/.."),
+            Err(ValidationError::PathTraversal)
+        ));
+    }
+
+    #[test]
+    fn test_storage_key_absolute_path() {
+        assert!(matches!(
+            validate_storage_key("/etc/passwd"),
+            Err(ValidationError::PathTraversal)
+        ));
+        assert!(matches!(
+            validate_storage_key("\\windows\\system32"),
+            Err(ValidationError::PathTraversal)
+        ));
+    }
+
+    #[test]
+    fn test_storage_key_null_byte() {
+        assert!(matches!(
+            validate_storage_key("foo\0bar"),
+            Err(ValidationError::ForbiddenCharacter('\0'))
+        ));
+    }
+
+    #[test]
+    fn test_storage_key_empty() {
+        assert!(matches!(
+            validate_storage_key(""),
+            Err(ValidationError::EmptyInput)
+        ));
+    }
+
+    #[test]
+    fn test_storage_key_too_long() {
+        let long_key = "a".repeat(1025);
+        assert!(matches!(
+            validate_storage_key(&long_key),
+            Err(ValidationError::TooLong { .. })
+        ));
+    }
+
+    // Docker name tests
+    #[test]
+    fn test_docker_name_valid() {
+        assert!(validate_docker_name("nginx").is_ok());
+        assert!(validate_docker_name("library/nginx").is_ok());
+        assert!(validate_docker_name("my-org/my-image").is_ok());
+        assert!(validate_docker_name("my_image").is_ok());
+        assert!(validate_docker_name("image.name").is_ok());
+        assert!(validate_docker_name("a/b/c/d").is_ok());
+    }
+
+    #[test]
+    fn test_docker_name_uppercase() {
+        assert!(matches!(
+            validate_docker_name("NGINX"),
+            Err(ValidationError::InvalidDockerName(_))
+        ));
+        assert!(matches!(
+            validate_docker_name("MyImage"),
+            Err(ValidationError::InvalidDockerName(_))
+        ));
+    }
+
+    #[test]
+    fn test_docker_name_path_traversal() {
+        assert!(matches!(
+            validate_docker_name("../escape"),
+            Err(ValidationError::PathTraversal)
+        ));
+        assert!(matches!(
+            validate_docker_name("foo/../bar"),
+            Err(ValidationError::PathTraversal)
+        ));
+    }
+
+    #[test]
+    fn test_docker_name_invalid_start() {
+        assert!(validate_docker_name("/nginx").is_err());
+        assert!(validate_docker_name(".nginx").is_err());
+        assert!(validate_docker_name("-nginx").is_err());
+    }
+
+    #[test]
+    fn test_docker_name_consecutive_separators() {
+        assert!(validate_docker_name("foo//bar").is_err());
+        assert!(validate_docker_name("foo--bar").is_err());
+        assert!(validate_docker_name("foo__bar").is_err());
+    }
+
+    // Digest tests
+    #[test]
+    fn test_digest_valid_sha256() {
+        let valid = format!("sha256:{}", "a".repeat(64));
+        assert!(validate_digest(&valid).is_ok());
+    }
+
+    #[test]
+    fn test_digest_valid_sha512() {
+        let valid = format!("sha512:{}", "a".repeat(128));
+        assert!(validate_digest(&valid).is_ok());
+    }
+
+    #[test]
+    fn test_digest_wrong_length() {
+        assert!(validate_digest("sha256:abc").is_err());
+        assert!(validate_digest(&format!("sha256:{}", "a".repeat(63))).is_err());
+        assert!(validate_digest(&format!("sha256:{}", "a".repeat(65))).is_err());
+    }
+
+    #[test]
+    fn test_digest_uppercase() {
+        let upper = format!("sha256:{}", "A".repeat(64));
+        assert!(matches!(
+            validate_digest(&upper),
+            Err(ValidationError::InvalidDigest(_))
+        ));
+    }
+
+    #[test]
+    fn test_digest_unsupported_algorithm() {
+        assert!(matches!(
+            validate_digest("md5:abc"),
+            Err(ValidationError::InvalidDigest(_))
+        ));
+    }
+
+    #[test]
+    fn test_digest_missing_prefix() {
+        assert!(matches!(
+            validate_digest("abcdef123456"),
+            Err(ValidationError::InvalidDigest(_))
+        ));
+    }
+
+    // Reference tests
+    #[test]
+    fn test_reference_valid_tag() {
+        assert!(validate_docker_reference("latest").is_ok());
+        assert!(validate_docker_reference("v1.0.0").is_ok());
+        assert!(validate_docker_reference("1.0").is_ok());
+        assert!(validate_docker_reference("my-tag_v2").is_ok());
+    }
+
+    #[test]
+    fn test_reference_valid_digest() {
+        let digest = format!("sha256:{}", "a".repeat(64));
+        assert!(validate_docker_reference(&digest).is_ok());
+    }
+
+    #[test]
+    fn test_reference_path_traversal() {
+        assert!(matches!(
+            validate_docker_reference("../escape"),
+            Err(ValidationError::PathTraversal)
+        ));
+    }
+
+    #[test]
+    fn test_reference_invalid_start() {
+        assert!(validate_docker_reference(".hidden").is_err());
+        assert!(validate_docker_reference("-dash").is_err());
+    }
+}