Skip to main content

Insecure encryption algorithm - Insecure Elliptic Curve

Need​

Implementation of secure elliptic curves for encryption

Context​

  • Usage of Go 1.16 for building efficient and scalable applications
  • Usage of crypto/elliptic for elliptic curve cryptography operations
  • Usage of crypto/rand for generating random numbers and cryptographic operations
  • Usage of crypto/ecdsa for generating and verifying ECDSA cryptographic signatures
  • Usage of fmt for formatting strings and values

Description​

Non compliant code​

package main

import (
	"crypto/elliptic"
	"crypto/rand"
	"crypto/ecdsa"
	"fmt"
)

func main() {
	// Using an insecure elliptic curve - P224
	curve := elliptic.P224()

	privateKey, err := ecdsa.GenerateKey(curve, rand.Reader)
	if err != nil {
		fmt.Println(err.Error())
	}

	fmt.Println(privateKey)
}

In the example above, the Go code generates an ECDSA private key using the elliptic.P224() curve. The elliptic.P224() curve is considered weak and insecure for cryptographic operations due to its small key size which makes it vulnerable to attacks.

The ecdsa.GenerateKey(curve, rand.Reader) function is used to generate the private key. This function takes two parameters: the elliptic curve to use and a reader that generates random numbers. In this case, the insecure elliptic.P224() curve is used, which makes the generated private key insecure.

The generated private key could be used in various cryptographic operations, such as signing data, creating a public key, etc. However, due to the use of the insecure elliptic.P224() curve, these operations would not be secure and the data could be vulnerable to attacks.

Steps​

  • Replace the insecure elliptic curve with a stronger one, such as P256 or P384.
  • Ensure that the chosen elliptic curve is considered secure and widely accepted.
  • Update the code to use the new elliptic curve when generating the private key.
  • Verify that the new elliptic curve is supported by the crypto/elliptic package in the Go standard library.
  • Consider using a cryptographically secure random number generator (CSPRNG) instead of rand.Reader for key generation.

Compliant code​

package main

import (
	"crypto/elliptic"
	"crypto/rand"
	"crypto/ecdsa"
	"fmt"
)

func main() {
	// Using a secure elliptic curve - P256
	curve := elliptic.P256()

	privateKey, err := ecdsa.GenerateKey(curve, rand.Reader)
	if err != nil {
		fmt.Println(err.Error())
	}

	fmt.Println(privateKey)
}

The original code was using an insecure elliptic curve (P224) for generating the private key. This curve is considered weak and could potentially be exploited by attackers.

The updated code now uses a stronger elliptic curve (P256). This curve is considered secure and is widely accepted in the cryptographic community. The private key is generated using this curve, which should provide a higher level of security.

The crypto/ecdsa.GenerateKey function is used to generate the private key. This function takes two parameters: the elliptic curve and a reader that generates random numbers. In this case, the rand.Reader from the crypto/rand package is used, which is a cryptographically secure pseudorandom number generator (CSPRNG).

The error handling remains the same: if there's an error during the key generation, it will be printed to the console. If the key generation is successful, the private key will be printed to the console.

This change should fix the vulnerability related to the use of an insecure elliptic curve. However, it's always recommended to keep the cryptographic libraries up to date and follow the best practices for cryptographic key generation.

References​

Last updated on