openpgp and golang - go

Question

I have some problems with the documentation.
Here is my program:
package main
import (
"bytes"
"code.google.com/p/go.crypto/openpgp"
"encoding/base64"
"fmt"
)
func main() {
var entity *openpgp.Entity
entity, err := openpgp.NewEntity("bussiere", "test", "bussiere#gmail.com", nil)
if err != nil {
}
var (
buffer bytes.Buffer
)
entity.SerializePrivate(&buffer, nil)
data := base64.StdEncoding.EncodeToString([]byte(buffer.String()))
fmt.Printf("%q\n", data)
entity.Serialize(&buffer)
data2 := base64.StdEncoding.EncodeToString([]byte(buffer.String()))
fmt.Printf("%q\n", data2)
entity.PrivateKey.Serialize(&buffer)
data3 := base64.StdEncoding.EncodeToString([]byte(buffer.String()))
fmt.Printf("%q\n", data3)
entity.PrimaryKey.Serialize(&buffer)
data4 := base64.StdEncoding.EncodeToString([]byte(buffer.String()))
fmt.Printf("%q\n", data4)
//fmt.Printf(buffer.String())
}
Here are the data:
https://gist.github.com/bussiere/5159890
here is the code on gist:
https://gist.github.com/bussiere/5159897
What is the public key?
And how to use it?
And how to make bigger key?

Answer 1

UPDATE: This issue has been fixed: see here
Son the solution/description below is no longer appropriate.
---------------- legacy answer starts below --------------------
Concering your question of How to build keys of an other size: it's impossible.
I ran into the exact same Problem, look at: the source code for the NewEntityFunction:
383 const defaultRSAKeyBits = 2048
384
385 // NewEntity returns an Entity that contains a fresh RSA/RSA keypair with a
386 // single identity composed of the given full name, comment and email, any of
387 // which may be empty but must not contain any of "()<>\x00".
388 // If config is nil, sensible defaults will be used.
389 func NewEntity(name, comment, email string, config *packet.Config) (*Entity, error) {
390 currentTime := config.Now()
391
392 uid := packet.NewUserId(name, comment, email)
393 if uid == nil {
394 return nil, errors.InvalidArgumentError("user id field contained invalid characters")
395 }
396 signingPriv, err := rsa.GenerateKey(config.Random(), defaultRSAKeyBits)
397 if err != nil {
398 return nil, err
399 }
400 encryptingPriv, err := rsa.GenerateKey(config.Random(), defaultRSAKeyBits)
401 if err != nil {
402 return nil, err
403 }
defaultRSAKeyBits is a pkg-level unexported constant. So no chance of modifing this beheavior.
I ended up copying the whole function out, adding a parameter for the keybits and keeping it in my codebase,
if someone has a better solution, I'd be glad to hear it.