Files
CLIProxyAPI/internal/auth/claude/pkce.go
2025-09-25 10:32:48 +08:00

57 lines
2.0 KiB
Go

// Package claude provides authentication and token management functionality
// for Anthropic's Claude AI services. It handles OAuth2 token storage, serialization,
// and retrieval for maintaining authenticated sessions with the Claude API.
package claude
import (
"crypto/rand"
"crypto/sha256"
"encoding/base64"
"fmt"
)
// GeneratePKCECodes generates a PKCE code verifier and challenge pair
// following RFC 7636 specifications for OAuth 2.0 PKCE extension.
// This provides additional security for the OAuth flow by ensuring that
// only the client that initiated the request can exchange the authorization code.
//
// Returns:
// - *PKCECodes: A struct containing the code verifier and challenge
// - error: An error if the generation fails, nil otherwise
func GeneratePKCECodes() (*PKCECodes, error) {
// Generate code verifier: 43-128 characters, URL-safe
codeVerifier, err := generateCodeVerifier()
if err != nil {
return nil, fmt.Errorf("failed to generate code verifier: %w", err)
}
// Generate code challenge using S256 method
codeChallenge := generateCodeChallenge(codeVerifier)
return &PKCECodes{
CodeVerifier: codeVerifier,
CodeChallenge: codeChallenge,
}, nil
}
// generateCodeVerifier creates a cryptographically random string
// of 128 characters using URL-safe base64 encoding
func generateCodeVerifier() (string, error) {
// Generate 96 random bytes (will result in 128 base64 characters)
bytes := make([]byte, 96)
_, err := rand.Read(bytes)
if err != nil {
return "", fmt.Errorf("failed to generate random bytes: %w", err)
}
// Encode to URL-safe base64 without padding
return base64.URLEncoding.WithPadding(base64.NoPadding).EncodeToString(bytes), nil
}
// generateCodeChallenge creates a SHA256 hash of the code verifier
// and encodes it using URL-safe base64 encoding without padding
func generateCodeChallenge(codeVerifier string) string {
hash := sha256.Sum256([]byte(codeVerifier))
return base64.URLEncoding.WithPadding(base64.NoPadding).EncodeToString(hash[:])
}