ethereum/go-ethereum · critical

Could not create random uuid: %v

Error message

Could not create random uuid: %v

What it means

newKeyFromECDSA assigns each freshly generated keystore key a random UUID (uuid.NewRandom). UUID generation requires OS entropy; if that fails the library cannot produce a valid key file identifier and panics with the underlying error. This is effectively an unrecoverable environment failure, not a usage error.

Source

Thrown at accounts/keystore/key.go:135

	addr, err := hex.DecodeString(keyJSON.Address)
	if err != nil {
		return err
	}
	privkey, err := crypto.HexToECDSA(keyJSON.PrivateKey)
	if err != nil {
		return err
	}

	k.Address = common.BytesToAddress(addr)
	k.PrivateKey = privkey

	return nil
}

func newKeyFromECDSA(privateKeyECDSA *ecdsa.PrivateKey) *Key {
	id, err := uuid.NewRandom()
	if err != nil {
		panic(fmt.Sprintf("Could not create random uuid: %v", err))
	}
	key := &Key{
		Id:         id,
		Address:    crypto.PubkeyToAddress(privateKeyECDSA.PublicKey),
		PrivateKey: privateKeyECDSA,
	}
	return key
}

// NewKeyForDirectICAP generates a key whose address fits into < 155 bits so it can fit
// into the Direct ICAP spec. for simplicity and easier compatibility with other libs, we
// retry until the first byte is 0.
func NewKeyForDirectICAP(rand io.Reader) *Key {
	randBytes := make([]byte, 64)
	_, err := rand.Read(randBytes)
	if err != nil {
		panic("key generation: could not read from random source: " + err.Error())
	}

View on GitHub (pinned to 6bb0588ad8)

Solutions

1. Ensure /dev/urandom exists and is readable inside the environment (docker run with a proper /dev).
2. On VMs, install haveged or a virtio-rng device so entropy is available.
3. Check the wrapped error in the panic message to identify the blocked syscall and adjust the sandbox policy.
4. Retry key creation once the entropy source is fixed; pre-existing keys are unaffected.

When it happens

Trigger: Any key creation path — newAccount, account creation in geth/clef, NewKeyForDirectICAP — on a system where the entropy source is broken: exhausted entropy in a container/VM, /dev/urandom unavailable, or a hardened runtime blocking random reads.

Common situations: Minimal Docker images or chroots without /dev/urandom properly mounted, early-boot VMs with low entropy, restrictive seccomp/sandbox profiles blocking getrandom(2).

Related errors

• key generation: could not read from random source:
• key generation: ecdsa.GenerateKey failed:
• reading from crypto/rand failed:
• nil chainID
• error decoding contract deployer hex %s: %v

AI-assisted analysis of ethereum/go-ethereum@6bb0588ad8 (2026-08-15). Data as JSON: /api/errors/5ac9cee66673dbcc. Report an issue: GitHub.