Integrate web3Auth on Starknet

[stephaniegb.dev]

I am trying to generate a Starknet public key from the private key that i get from the provider after logging in — but I get an error that suggests that the private key too large

deploying account: Error: expected valid private key: 1 <= n < 3618502788666131213697322783095070105526743751716087489154079457884512865583, got 17360750792901381499093437725998992665915670589152183762989159320684614737379

has anyone faced this issue?

[w3abot]

Thank you for providing detailed context and error information regarding integrating Web3Auth with Starknet.

Summary of Your Issue:

• Goal: Generate a Starknet public key from the private key received from Web3Auth after login.
• Error: The private key obtained is too large for Starknet’s expected range.
  • Error message:

    Error: expected valid private key: 1 <= n < 3618502788666131213697322783095070105526743751716087489154079457884512865583, got 17360750792901381499093437725998992665915670589152183762989159320684614737379
    

• SDK/Platform: Web3Auth Plug n Play (likely Web SDK, but please confirm if it’s React Native, Web, or another platform).

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What’s Happening?

Starknet uses a specific elliptic curve (Stark curve), which has a much smaller valid private key range than secp256k1 (used by EVM chains). The private key you receive from Web3Auth might be a random 32-byte value, which can sometimes be out of Starknet’s valid range.

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Next Steps & Suggestions

1. Check How You’re Deriving the Starknet Key:

   • You should use the private key from Web3Auth as entropy to derive a valid Starknet private key, not use it directly.
   • See Web3Auth Starknet Integration Guide for reference.

2. Recommended Approach (Key Derivation):

   • Use a hash function (e.g., SHA-256) to hash the Web3Auth private key, then mod it by the Starknet curve order to ensure it falls within the valid range.
   • Example (pseudo-code):

     import { ec as starkEc } from "starknet";
     import { keccak256 } from "js-sha3";
     
     const rawPrivKey = await web3authProvider.request({ method: "private_key" });
     // Hash the private key
     const hashedPrivKey = keccak256(rawPrivKey);
     // Modulo with Stark curve order to ensure it's in range
     const starkCurveOrder = "3618502788666131213697322783095070105526743751716087489154079457884512865583";
     const validPrivKey = BigInt("0x" + hashedPrivKey) % BigInt(starkCurveOrder);
     // Use validPrivKey to generate Starknet keypair
     const keyPair = starkEc.getKeyPair(validPrivKey.toString(16));
     

   • This ensures your key is always valid for Starknet.

3. Reference Docs:

   • Web3Auth Starknet Integration
   • Starknet JS Key Management

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Action Required

• If possible, share your key derivation code snippet so we can provide more targeted help.
• Confirm the SDK/platform you’re using (Web, React Native, etc.) for more precise guidance.

Let us know if this helps or if you need further clarification!

Note: This response was generated by an AI bot and may require further verification. The Web3Auth support team has tracked this issue and will be responding as soon as possible.

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