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Insecure encryption algorithm - SSLContext

Need​

Implementation of secure encryption algorithms for SSLContext

Context​

  • Usage of Go 1.16 for developing high-performance and efficient applications
  • Usage of crypto/tls for secure communication using TLS (Transport Layer Security) protocol
  • Usage of gin-gonic/gin for building web applications and APIs in Go
  • Usage of net/http for creating HTTP servers in a Node.js application

Description​

Non compliant code​

package main

import (
    "crypto/tls"
    "github.com/gin-gonic/gin"
    "net/http"
)

func main() {
    router := gin.Default()

    router.GET("/", func(c *gin.Context) {
        c.String(http.StatusOK, "Hello World!")
    })

    // Insecure SSL configuration
    insecureConfig := &tls.Config{
        InsecureSkipVerify: true,
        MinVersion:         tls.VersionSSL30,
    }

    server := &http.Server{
        Addr:      ":8080",
        Handler:   router,
        TLSConfig: insecureConfig,
    }

    server.ListenAndServeTLS("", "")
}

The above code is a simple implementation of a Gin web server in Go, which serves a "Hello World!" response on the root ("/") path.

The vulnerability lies in the TLS configuration of the server. The InsecureSkipVerify field is set to true, which means the server will accept any certificate presented by the client and hence won't validate it. This can lead to Man-in-The-Middle (MITM) attacks.

Moreover, the MinVersion field is set to tls.VersionSSL30 which means the server will accept SSL 3.0 protocol for the TLS handshake. SSL 3.0 is considered insecure and deprecated due to several known vulnerabilities like the POODLE (Padding Oracle On Downgraded Legacy Encryption) vulnerability.

By using this insecure configuration, the server is exposed to unnecessary risks. It's recommended to always validate certificates and use secure and updated versions of SSL/TLS protocols.

Steps​

  • Replace the insecure SSL configuration with a secure one.
  • Use a secure SSL/TLS protocol version, such as TLS 1.2 or TLS 1.3.
  • Enable certificate verification to ensure the authenticity of the server.
  • Obtain a valid SSL certificate from a trusted certificate authority (CA).
  • Configure the server to use the obtained SSL certificate.
  • Update the code to use the secure SSL configuration.

Compliant code​

package main

import (
    "crypto/tls"
    "github.com/gin-gonic/gin"
    "net/http"
)

func main() {
    router := gin.Default()

    router.GET("/", func(c *gin.Context) {
        c.String(http.StatusOK, "Hello World!")
    })

    // Secure SSL configuration
    secureConfig := &tls.Config{
        MinVersion:               tls.VersionTLS12,
        PreferServerCipherSuites: true,
        InsecureSkipVerify:       false,
    }

    server := &http.Server{
        Addr:      ":8080",
        Handler:   router,
        TLSConfig: secureConfig,
    }

    // Replace with paths to your server.crt and server.key files
    server.ListenAndServeTLS("path/to/server.crt", "path/to/server.key")
}

The original code was using an insecure SSL configuration. It was using an outdated SSL protocol version (SSL 3.0) and was skipping the verification of the server's SSL certificate. This could allow an attacker to perform a man-in-the-middle attack, intercepting and potentially altering the data being sent between the client and the server.

The updated code uses a secure SSL configuration. It uses a modern and secure version of the SSL/TLS protocol (TLS 1.2) and enables the verification of the server's SSL certificate. This ensures that the client is communicating with the genuine server and not an imposter.

The server is also configured to prefer the cipher suites that the server has been configured to use, which can help to ensure that the most secure cipher suite is used for the connection.

Finally, the server is configured to use an SSL certificate and a private key. These should be obtained from a trusted certificate authority (CA) and installed on the server. The paths to these files are passed to the ListenAndServeTLS function. This ensures that the server's identity can be verified by the client.

References​

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