function getSigner()

in modules/material-management-node/src/material_helpers.ts [88:115]

• 17 lines of code
• 4 McCabe index (conditional complexity)

  function getSigner() {
    /* Precondition: The NodeEncryptionMaterial must have not been zeroed.
     * hasUnencryptedDataKey will check that the unencrypted data key has been set
     * *and* that it has not been zeroed.  At this point it must have been set
     * because the KDF function operated on it.  So at this point
     * we are protecting that someone has zeroed out the material
     * because the Encrypt process has been complete.
     */
    needs(
      material.hasUnencryptedDataKey,
      'Unencrypted data key has been zeroed.'
    )

    if (!signatureHash) throw new Error('Material does not support signature.')
    const { signatureKey } = material
    if (!signatureKey) throw new Error('Material does not support signature.')
    const { privateKey } = signatureKey
    if (typeof privateKey !== 'string')
      throw new Error('Material does not support signature.')

    const signer = Object.assign(
      createSign(signatureHash),
      // don't export the private key if we don't have to
      { awsCryptoSign: () => signer.sign(privateKey) }
    )

    return signer
  }