🕵️‍♀️ Linter for the crypto/rsa package.

$ go install github.com/picatz/rsalint/cmd/rsalint@latest

package main

import (
    "crypto/rsa"
    "fmt"
    "math/rand"
)

func main() {
    privateKey, err := rsa.GenerateKey(rand.New(rand.NewSource(0)), 1024)
    if err != nil {
        panic(err)
    }
    fmt.Println(privateKey)
}

rsalint can identify a number of potential security problems:

• Weak entropy source (not using crypto/rand.Reader).
• Weak number of bits (less than 2048, and not a multiple of 8).
• Weak number of primes for the given number of bits.
• Deprecated functions (rsa.GenerateMultiPrimeKey).
• Insecure encryption schemes (rsa.EncryptPKCS1v15).

$ rsalint ./path/to/vulnerable/code/...
./path/to/vulnerable/code/main.go:10:37: use the crypto/rand.Reader instead for a cryptographically secure random number generator
./path/to/vulnerable/code/main.go:10:66: use 2048 bits or greater