ecies: shared key is too big

[zeroXten]

I am able to reliably get the "ecies: shared key is too big" error after a largish number of tries using the following test code:

package main

import (
        "crypto/ecdsa"
        "crypto/elliptic"
        "crypto/rand"
        "fmt"
        "github.com/pki-io/ecies" // forked from this repo
)

func GenerateECKey() (*ecdsa.PrivateKey, error) {
    key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
    if err != nil {
        return nil, fmt.Errorf("Can't create ECDSA keys: %s", err)
        }
    return key, nil
}

func eciesEncrypt(plaintext []byte, publicKey *ecdsa.PublicKey) ([]byte, error) {
    pub := ecies.ImportECDSAPublic(publicKey)
    return ecies.Encrypt(rand.Reader, pub, plaintext, nil, nil)
}

func main() {
        key, err := GenerateECKey()
    if err != nil {
        panic(err)
    }
    message := []byte("this is a test")
    _, err = eciesEncrypt(message, &key.PublicKey)
    if err != nil {
        panic(err)
    }
}

Running this command:

$ i=0; while :; do echo $i; let i=i+1; date; gom run ecies-test.go || break; done

And getting this result:

347
Fri 27 Mar 2015 22:17:42 GMT
348
Fri 27 Mar 2015 22:17:42 GMT
panic: ecies: shared key is too big

goroutine 1 [running]:
main.main()
    ..../ecies-test.go:32 +0x107
exit status 2
gom:  exit status 1

[obscuren]

I've tried to reproduce the error using the code above using this repo. I've given up after 50.000 tries. Are you sure this problem isn't related to just your own fork?

[zeroXten]

Ah yes, my bad. Looks like this was fixed in commit 04c1a81509576c898f4d30a76f9d84d087e2a4cf after our fork was taken. I've updated our fork to your current master and the problem is resolved.

[obscuren]

If you don't modify the fork and simply do this out of a security reason I'd recommend to use godep over your own fork.