feat: add MCP support (#20716)

Co-authored-by: QuantumGhost <obelisk.reg+git@gmail.com>

api/core/mcp/auth/auth_provider.py

@@ -0,0 +1,81 @@
+from typing import Optional
+
+from configs import dify_config
+from core.mcp.types import (
+    OAuthClientInformation,
+    OAuthClientInformationFull,
+    OAuthClientMetadata,
+    OAuthTokens,
+)
+from models.tools import MCPToolProvider
+from services.tools.mcp_tools_mange_service import MCPToolManageService
+
+LATEST_PROTOCOL_VERSION = "1.0"
+
+
+class OAuthClientProvider:
+    mcp_provider: MCPToolProvider
+
+    def __init__(self, provider_id: str, tenant_id: str, for_list: bool = False):
+        if for_list:
+            self.mcp_provider = MCPToolManageService.get_mcp_provider_by_provider_id(provider_id, tenant_id)
+        else:
+            self.mcp_provider = MCPToolManageService.get_mcp_provider_by_server_identifier(provider_id, tenant_id)
+
+    @property
+    def redirect_url(self) -> str:
+        """The URL to redirect the user agent to after authorization."""
+        return dify_config.CONSOLE_API_URL + "/console/api/mcp/oauth/callback"
+
+    @property
+    def client_metadata(self) -> OAuthClientMetadata:
+        """Metadata about this OAuth client."""
+        return OAuthClientMetadata(
+            redirect_uris=[self.redirect_url],
+            token_endpoint_auth_method="none",
+            grant_types=["authorization_code", "refresh_token"],
+            response_types=["code"],
+            client_name="Dify",
+            client_uri="https://github.com/langgenius/dify",
+        )
+
+    def client_information(self) -> Optional[OAuthClientInformation]:
+        """Loads information about this OAuth client."""
+        client_information = self.mcp_provider.decrypted_credentials.get("client_information", {})
+        if not client_information:
+            return None
+        return OAuthClientInformation.model_validate(client_information)
+
+    def save_client_information(self, client_information: OAuthClientInformationFull) -> None:
+        """Saves client information after dynamic registration."""
+        MCPToolManageService.update_mcp_provider_credentials(
+            self.mcp_provider,
+            {"client_information": client_information.model_dump()},
+        )
+
+    def tokens(self) -> Optional[OAuthTokens]:
+        """Loads any existing OAuth tokens for the current session."""
+        credentials = self.mcp_provider.decrypted_credentials
+        if not credentials:
+            return None
+        return OAuthTokens(
+            access_token=credentials.get("access_token", ""),
+            token_type=credentials.get("token_type", "Bearer"),
+            expires_in=int(credentials.get("expires_in", "3600") or 3600),
+            refresh_token=credentials.get("refresh_token", ""),
+        )
+
+    def save_tokens(self, tokens: OAuthTokens) -> None:
+        """Stores new OAuth tokens for the current session."""
+        # update mcp provider credentials
+        token_dict = tokens.model_dump()
+        MCPToolManageService.update_mcp_provider_credentials(self.mcp_provider, token_dict, authed=True)
+
+    def save_code_verifier(self, code_verifier: str) -> None:
+        """Saves a PKCE code verifier for the current session."""
+        MCPToolManageService.update_mcp_provider_credentials(self.mcp_provider, {"code_verifier": code_verifier})
+
+    def code_verifier(self) -> str:
+        """Loads the PKCE code verifier for the current session."""
+        # get code verifier from mcp provider credentials
+        return str(self.mcp_provider.decrypted_credentials.get("code_verifier", ""))