registry/pkg/model/types.go
Radoslav Dimitrov 7a6d1bc30a
fix(cargo): harden README fetch, clarify status handling, strengthen tests (#1330)
Follow-up to #1207, addressing items from the cargo validator review.
**Scoped to cargo + shared helpers — no behavior change for existing
npm/pypi/nuget/oci/mcpb publishers.** Safe to merge and promote.

### Changes
**SSRF hardening of the two-call README retrieval**
- Pin the step-2 README URL to an allowed host (`static.crates.io` in
prod; the base host under test) *before* fetching, so a metadata
response can't steer the validator at an internal/attacker host.
- `CheckRedirect` policy pins every redirect hop to the same allowlist
(the initial URL being pinned isn't enough if an upstream 3xx is
followed).
- Cap the README body with `io.LimitReader` (5 MiB).

> Not publisher-exploitable today (the URL comes from crates.io), so
this is defense-in-depth — but it makes the "host is pinned" guarantee
hold in code rather than rely on crates.io's behavior.

**Clearer status handling** (previously any non-5xx/non-200 collapsed to
"not found")
- **429** → reported as transient/retryable, at both the metadata and
README steps.
- **403** → disambiguated via the crate-version endpoint:
genuinely-missing stays "not found"; *exists-but-no-README* gets an
actionable "add a README with `mcp-name` and republish" message (mirrors
the NuGet validator). This continues the 5xx-vs-403 diagnostic split
@P4ST4S started in the #1207 review — thanks!

**Shared `containsMCPNameToken` helper**
Boundary-anchored ownership-token match (prevents prefix confusion, e.g.
a README declaring `io.github.acme/widget-pro` satisfying a claim for
`io.github.acme/widget`), used here **by the cargo validator only**.
Adopting it in PyPI/NuGet is a separate follow-up because it's a
behavior change for those already-live registries.

**Tests & docs**
Hermetic positive `ServerNameFormats`; combined fixture gains a
version-existence endpoint + cases for 403-missing vs 403-no-README,
429, and prefix-confusion rejection; new foreign-README-host (SSRF)
test; internal test for the helper. Docs: list `crates.io` in the
registry-requirements list + the `Package` model doc.

### Testing
`go build`, `go vet`, full `./internal/validators/...` suite (incl. live
cargo positive), `make check-schema`, `validate-examples` all pass. No
new `golangci-lint` findings.

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

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-04 17:34:54 -04:00

111 lines
9.7 KiB
Go

package model
type Status string
const (
StatusActive Status = "active"
StatusDeprecated Status = "deprecated"
StatusDeleted Status = "deleted"
)
// Transport represents transport configuration for both Package and Remote contexts.
// For Remote context, the Variables field can be used for URL templating.
type Transport struct {
Type string `json:"type" doc:"Transport type (stdio, streamable-http, or sse)" example:"stdio"`
URL string `json:"url,omitempty" doc:"URL for streamable-http or sse transports" example:"https://api.example.com/mcp"`
Headers []KeyValueInput `json:"headers,omitempty" doc:"HTTP headers for streamable-http or sse transports"`
Variables map[string]Input `json:"variables,omitempty" doc:"Variables for URL templating in remote transports"`
}
// Package represents a package configuration.
// The RegistryType field determines which other fields are relevant:
// - NPM: RegistryType, Identifier (package name), Version, RegistryBaseURL (optional)
// - PyPI: RegistryType, Identifier (package name), Version, RegistryBaseURL (optional)
// - NuGet: RegistryType, Identifier (package ID), Version, RegistryBaseURL (optional)
// - Cargo: RegistryType, Identifier (crate name), Version, RegistryBaseURL (optional)
// - OCI: RegistryType, Identifier (full image reference like "ghcr.io/owner/repo:tag")
// - MCPB: RegistryType, Identifier (download URL), Version (optional), FileSHA256 (required)
type Package struct {
// RegistryType indicates how to download packages (e.g., "npm", "pypi", "cargo", "oci", "nuget", "mcpb")
RegistryType string `json:"registryType" minLength:"1" doc:"Registry type indicating how to download packages (e.g., 'npm', 'pypi', 'cargo', 'oci', 'nuget', 'mcpb')" example:"npm"`
// RegistryBaseURL is the base URL of the package registry (used by npm, pypi, nuget, cargo; not used by oci, mcpb)
RegistryBaseURL string `json:"registryBaseUrl,omitempty" format:"uri" doc:"Base URL of the package registry" example:"https://registry.npmjs.org"`
// Identifier is the package identifier:
// - For NPM/PyPI/NuGet: package name or ID
// - For OCI: full image reference (e.g., "ghcr.io/owner/repo:v1.0.0")
// - For MCPB: direct download URL
Identifier string `json:"identifier" minLength:"1" doc:"Package identifier - either a package name (for registries) or URL (for direct downloads)" example:"@modelcontextprotocol/server-brave-search"`
// Version is the package version (required for npm, pypi, nuget; optional for mcpb; not used by oci where version is in the identifier)
Version string `json:"version,omitempty" minLength:"1" maxLength:"255" doc:"Package version. Must be a specific version. Version ranges are rejected (e.g., '^1.2.3', '~1.2.3', '>=1.2.3', '1.x', '1.*')." example:"1.0.2"`
// FileSHA256 is the SHA-256 hash for integrity verification (required for mcpb, optional for others)
FileSHA256 string `json:"fileSha256,omitempty" pattern:"^[a-f0-9]{64}$" doc:"SHA-256 hash of the package file for integrity verification. Required for MCPB packages and optional for other package types. Authors are responsible for generating correct SHA-256 hashes when creating server.json. If present, MCP clients must validate the downloaded file matches the hash before running packages to ensure file integrity." example:"fe333e598595000ae021bd27117db32ec69af6987f507ba7a63c90638ff633ce"`
// RunTimeHint suggests the appropriate runtime for the package
RunTimeHint string `json:"runtimeHint,omitempty" doc:"A hint to help clients determine the appropriate runtime for the package. This field should be provided when runtimeArguments are present." example:"npx"`
// Transport is required and specifies the transport protocol configuration
Transport Transport `json:"transport" doc:"Transport protocol configuration for the package"`
// RuntimeArguments are passed to the package's runtime command (e.g., docker, npx)
RuntimeArguments []Argument `json:"runtimeArguments,omitempty" doc:"A list of arguments to be passed to the package's runtime command (such as docker or npx). The runtimeHint field should be provided when runtimeArguments are present."`
// PackageArguments are passed to the package's binary
PackageArguments []Argument `json:"packageArguments,omitempty" doc:"A list of arguments to be passed to the package's binary."`
// EnvironmentVariables are set when running the package
EnvironmentVariables []KeyValueInput `json:"environmentVariables,omitempty" doc:"A mapping of environment variables to be set when running the package."`
}
type Repository struct {
URL string `json:"url,omitempty" format:"uri" doc:"Repository URL for browsing source code. Should support both web browsing and git clone operations." example:"https://github.com/modelcontextprotocol/servers"`
Source string `json:"source,omitempty" doc:"Repository hosting service identifier. Used by registries to determine validation and API access methods." example:"github"`
ID string `json:"id,omitempty" doc:"Repository identifier from the hosting service (e.g., GitHub repo ID). Owned and determined by the source forge. Should remain stable across repository renames and may be used to detect repository resurrection attacks - if a repository is deleted and recreated, the ID should change. For GitHub, use: gh api repos/<owner>/<repo> --jq '.id'" example:"b94b5f7e-c7c6-d760-2c78-a5e9b8a5b8c9"`
Subfolder string `json:"subfolder,omitempty" doc:"Optional relative path from repository root to the server location within a monorepo or nested package structure. Must be a clean relative path." example:"src/everything"`
}
type Format string
const (
FormatString Format = "string"
FormatNumber Format = "number"
FormatBoolean Format = "boolean"
FormatFilePath Format = "filepath"
)
type Input struct {
Description string `json:"description,omitempty" doc:"A description of the input, which clients can use to provide context to the user."`
IsRequired bool `json:"isRequired,omitempty" doc:"Whether the input is required"`
Format Format `json:"format,omitempty" enum:"string,number,boolean,filepath" doc:"Specifies the input format. Supported values include filepath, which should be interpreted as a file on the user's filesystem."`
Value string `json:"value,omitempty" doc:"The value for the input. If this is not set, the user may be prompted to provide a value. Identifiers wrapped in {curly_braces} will be replaced with the corresponding properties from the input variables map."`
IsSecret bool `json:"isSecret,omitempty" doc:"Indicates whether the input is a secret value (e.g., password, token). If true, clients should handle the value securely."`
Default string `json:"default,omitempty" doc:"The default value for the input. This should be a valid value for the input. If you want to provide input examples or guidance, use the placeholder field instead."`
Placeholder string `json:"placeholder,omitempty" doc:"A placeholder for the input to be displaying during configuration. This is used to provide examples or guidance about the expected form or content of the input."`
Choices []string `json:"choices,omitempty" doc:"A list of possible values for the input. If provided, the user must select one of these values."`
}
type InputWithVariables struct {
Input
Variables map[string]Input `json:"variables,omitempty" doc:"A map of variable names to their values. Keys in the input value that are wrapped in {curly_braces} will be replaced with the corresponding variable values."`
}
type KeyValueInput struct {
InputWithVariables
Name string `json:"name" doc:"Name of the header or environment variable." example:"SOME_VARIABLE"`
}
type ArgumentType string
const (
ArgumentTypePositional ArgumentType = "positional"
ArgumentTypeNamed ArgumentType = "named"
)
type Argument struct {
InputWithVariables
Type ArgumentType `json:"type" doc:"Argument type: 'positional' or 'named'" example:"positional"`
Name string `json:"name,omitempty" doc:"The flag name (for named arguments), including any leading dashes. Empty for positional arguments." example:"--port"`
ValueHint string `json:"valueHint,omitempty" doc:"An identifier for positional arguments. Used in transport URL variable substitution." example:"file_path"`
IsRepeated bool `json:"isRepeated,omitempty" doc:"Whether the argument can be repeated multiple times."`
}
type Icon struct {
Src string `json:"src" required:"true" format:"uri" maxLength:"255" doc:"A standard URI pointing to an icon resource. Must be an HTTPS URL. Consumers SHOULD take steps to ensure URLs serving icons are from the same domain as the server or a trusted domain. Consumers SHOULD take appropriate precautions when consuming SVGs as they can contain executable JavaScript." example:"https://example.com/icon.png"`
MimeType *string `json:"mimeType,omitempty" enum:"image/png,image/jpeg,image/jpg,image/svg+xml,image/webp" doc:"Optional MIME type override if the source MIME type is missing or generic. Must be one of: image/png, image/jpeg, image/jpg, image/svg+xml, image/webp." example:"image/png"`
Sizes []string `json:"sizes,omitempty" doc:"Optional array of strings that specify sizes at which the icon can be used. Each string should be in WxH format (e.g., '48x48', '96x96') or 'any' for scalable formats like SVG. If not provided, the client should assume that the icon can be used at any size." items.pattern:"^(\\d+x\\d+|any)$"`
Theme *string `json:"theme,omitempty" enum:"light,dark" doc:"Optional specifier for the theme this icon is designed for. 'light' indicates the icon is designed to be used with a light background, and 'dark' indicates the icon is designed to be used with a dark background. If not provided, the client should assume the icon can be used with any theme."`
}