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Insecure Encryption Algorithm - SHA1

Need​

To secure the information transmitted between the client and the server using cryptographically secure algorithms.

Context​

  • Usage of Elixir (1.12.0 and above) for building scalable and fault-tolerant applications
  • Usage of Plug (1.11.1 and above) for building composable web applications in Elixir
  • Usage of Plug.Crypto for cryptographic operations (version 1.2.0 and above)

Description​

Non compliant code​

defmodule MyApp.Encryption do
  def generate_hash(data) do
    :crypto.hash(:sha, data)
  end
end

This code is vulnerable because it uses the SHA1 encryption algorithm which is considered insecure. It could allow an attacker to reverse a summary function to find sensitive information.

Steps​

  • Replace the insecure SHA1 algorithm with a secure one like SHA256 or SHA3.
  • Ensure to use the appropriate hash function based on the encryption algorithm.

Compliant code​

defmodule MyApp.Encryption do
  def generate_hash(data) do
    :crypto.hash(:sha256, data)
  end
end

In this secure code example, we've replaced the SHA1 encryption algorithm with SHA256, which is considered secure. This will effectively mitigate the risks associated with SHA1.

References​

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