无法使用golang的openpgp数据包签署有效的gpg密钥

我想用go语言的私有密钥用ascii盔甲签名一个公共密钥。为此，我开发了以下代码，但问题是当我在gpg --check-sigs中检查签名时，由代码创建的签名显示为“坏签名”。请帮忙，因为我找不到解决方法。我已经在golang-nuts上发帖了。我正在为我的大学项目学习golang，现在被困在这里，请帮忙。

    // signer
package main

import (
    "bytes"
    "code.google.com/p/go.crypto/openpgp"
    "code.google.com/p/go.crypto/openpgp/armor"
    "code.google.com/p/go.crypto/openpgp/packet"
    "fmt"
)

// This function takes asciiarmored private key which will sign the public key
//Public key is also ascii armored,pripwd is password of private key in string
//This function will return ascii armored signed public key i.e. (pubkey+sign by prikey)
func SignPubKeyPKS(asciiPub string, asciiPri string, pripwd string) (asciiSignedKey string) {
    //get Private key from armor
    _, priEnt := getPri(asciiPri, pripwd) //pripwd is the password todecrypt the private key
    _, pubEnt := getPub(asciiPub)         //This will generate signature and add it to pubEnt
    usrIdstring := ""
    for _, uIds := range pubEnt.Identities {
        usrIdstring = uIds.Name

    }
    fmt.Println(usrIdstring)
    errSign := pubEnt.SignIdentity(usrIdstring, &priEnt, nil)
    if errSign != nil {
        fmt.Println("Signing Key ", errSign.Error())
        return
    }
    asciiSignedKey = PubEntToAsciiArmor(pubEnt)
    return
}

//get packet.PublicKey and openpgp.Entity of Public Key from ascii armor
func getPub(asciiPub string) (pubKey packet.PublicKey, retEntity openpgp.Entity) {
    read1 := bytes.NewReader([]byte(asciiPub))
    entityList, errReadArm := openpgp.ReadArmoredKeyRing(read1)
    if errReadArm != nil {
        fmt.Println("Reading Pubkey ", errReadArm.Error())
        return
    }
    for _, pubKeyEntity := range entityList {
        if pubKeyEntity.PrimaryKey != nil {
            pubKey = *pubKeyEntity.PrimaryKey
            retEntity = *pubKeyEntity
        }
    }
    return
}

//get packet.PrivateKEy and openpgp.Entity of Private Key from ascii armor
func getPri(asciiPri string, pripwd string) (priKey packet.PrivateKey, priEnt openpgp.Entity) {
    read1 := bytes.NewReader([]byte(asciiPri))
    entityList, errReadArm := openpgp.ReadArmoredKeyRing(read1)
    if errReadArm != nil {
        fmt.Println("Reading PriKey ", errReadArm.Error())
        return
    }
    for _, can_pri := range entityList {
        smPr := can_pri.PrivateKey
        retEntity := can_pri
        if smPr == nil {
            fmt.Println("No Private Key")
            return
        }

        priKey = *smPr

        errDecr := priKey.Decrypt([]byte(pripwd))
        if errDecr != nil {
            fmt.Println("Decrypting ", errDecr.Error())
            return
        }
        retEntity.PrivateKey = &priKey
        priEnt = *retEntity
    }
    return
}

//Create ASscii Armor from openpgp.Entity
func PubEntToAsciiArmor(pubEnt openpgp.Entity) (asciiEntity string) {
    gotWriter := bytes.NewBuffer(nil)
    wr, errEncode := armor.Encode(gotWriter, openpgp.PublicKeyType, nil)
    if errEncode != nil {
        fmt.Println("Encoding Armor ", errEncode.Error())
        return
    }
    errSerial := pubEnt.Serialize(wr)
    if errSerial != nil {
        fmt.Println("Serializing PubKey ", errSerial.Error())
    }
    errClosing := wr.Close()
    if errClosing != nil {
        fmt.Println("Closing writer ", errClosing.Error())
    }
    asciiEntity = gotWriter.String()
    return
}