how to convert dsa PublicKey to PEM Files use golang

• when i use an rsa pem string the follow code can work fine, generate to rsa public key object and regenerate to rsa pem string
• when i use an dsa pem string the follow code can not work fine, only can generate to dsa public key object

> x509: unsupported public key type: *dsa.PublicKey

i want to konw how to make dsa public key object regenerate dsa pem string

this is my code

package main

import (
	"C"
	"crypto/x509"
	"encoding/pem"
	"fmt"
	"os"
)

var rsaBytes = `-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyQubwvMR1ctRTTylCJ9u
imYlIMo8rkOXV8S7NaRB2pdEoeG1RiGVanTKwu1N6D7CNbXV+o+QVOpSB823iTb+
kxHaTpGcJwVvA1K3pJOgSSAx3bbr8Ekv1FXNZ3bGFOrzoD0OOWICDGnNQznQ8cJ8
+EFwjLBoqqqWM892BkGQuQTRLEmjrFOrLlTB99yXMeiD4c2iQFCtNZHpFviS9ahp
Irb/sEyhs2hFYqUUByZQQqo0ewv8MFiHGXG68t2LMnTkbff3KyUxgChEPiqAUNAb
LJ1JaFwypZdHr7KyJqatCIOk2m1Yz3umnW/KsM0Q+N9C4UZdn6GbZyStELGBJjsv
aQIDAQAB
-----END PUBLIC KEY-----`

var dsaBytes = `-----BEGIN PUBLIC KEY-----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-----END PUBLIC KEY-----`

func main() {
	// pemBlock, _ := pem.Decode([]byte(rsaBytes))
	pemBlock, _ := pem.Decode([]byte(dsaBytes))

	pubInterface, err := x509.ParsePKIXPublicKey(pemBlock.Bytes)
	pubkeyByte, err := x509.MarshalPKIXPublicKey(pubInterface)
	if err != nil {
		fmt.Println(err)
		os.Exit(0)
	}
	block := &pem.Block{
		Type:  "PUBLIC KEY",
		Bytes: pubkeyByte,
	}
	pemByte := pem.EncodeToMemory(block)
	fmt.Println(string(pemByte))

}

i follow java of sun from

org.bouncycastle.jce.provider.JDKDSAPublicKey
org.bouncycastle.asn1.x509.SubjectPublicKeyInfo

package transform
import (
"crypto/dsa"
"encoding/base64"
"encoding/pem"
)
func getDsaPem(publicKey *dsa.PublicKey) string {
p := publicKey.P.Bytes()
if publicKey.P.BitLen()/8+1 > len(p) {
p = append([]byte{0}, p...)
}
q := publicKey.Q.Bytes()
if publicKey.Q.BitLen()/8+1 > len(q) {
q = append([]byte{0}, q...)
}
g := publicKey.G.Bytes()
if publicKey.G.BitLen()/8+1 > len(g) {
g = append([]byte{0}, g...)
}
y := publicKey.Y.Bytes()
if publicKey.Y.BitLen()/8+1 > len(y) {
y = append([]byte{0}, y...)
}
p = (&SunDerOutputStream{Data: make([]byte, 0)}).sunPutInteger(p).Data
q = (&SunDerOutputStream{Data: make([]byte, 0)}).sunPutInteger(q).Data
g = (&SunDerOutputStream{Data: make([]byte, 0)}).sunPutInteger(g).Data
y = (&SunDerOutputStream{Data: make([]byte, 0)}).sunPutInteger(y).Data
params := append(p, append(q, g...)...)
paramData := &SunDerOutputStream{Data: make([]byte, 0)}
paramData.write(48, params)
oidAndParams := paramData.sunPutOID().Data
publicKeyBodyData := &SunDerOutputStream{Data: make([]byte, 0)}
publicKeyBodyData.write(48, oidAndParams)
publicKeyBodyData.sunPutUnalignedBitString(y)
publicKeyData := &SunDerOutputStream{Data: make([]byte, 0)}
publicKeyData.write(48, publicKeyBodyData.Data)
block := &pem.Block{
Type:  "PUBLIC KEY",
Bytes: publicKeyData.Data,
}
pubkeyByte := pem.EncodeToMemory(block)
return string(pubkeyByte)
}
type SunDerOutputStream struct {
Data []byte
}
func (s *SunDerOutputStream) write(dataItem byte, data []byte) *SunDerOutputStream {
s.Data = append(s.Data, dataItem)
s.sunPutLength(len(data))
s.Data = append(s.Data, data...)
return s
}
func (s *SunDerOutputStream) sunPutOID() *SunDerOutputStream {
// OID 1.2.840.10040.4.1
oid, _ := base64.StdEncoding.DecodeString("BgcqhkjOOAQB")
s.Data = append(oid, s.Data...)
return s
}
func (s *SunDerOutputStream) sunPutInteger(data []byte) *SunDerOutputStream {
s.Data = append(s.Data, 2)
s.sunPutLength(len(data))
s.Data = append(s.Data, data...)
return s
}
func (s *SunDerOutputStream) sunPutLength(lenData int) *SunDerOutputStream {
if lenData < 128 {
s.Data = append(s.Data, []byte{byte(lenData)}...)
} else if lenData < 256 {
s.Data = append(s.Data, []byte{129, byte(lenData)}...)
} else if lenData < 65536 {
s.Data = append(s.Data, []byte{130, byte(lenData >> 8), byte(lenData)}...)
}
return s
}
func (s *SunDerOutputStream) sunPutUnalignedBitString(data []byte) *SunDerOutputStream {
s.Data = append(s.Data, 3)
s.sunPutLength(len(data) + 1)
s.Data = append(s.Data, 0)
s.Data = append(s.Data, data...)
return s
}

Below is the comment of MarshalPKIXPublicKey function in x509 package:

// MarshalPKIXPublicKey converts a public key to PKIX, ASN.1 DER form.
// The encoded public key is a SubjectPublicKeyInfo structure
// (see RFC 5280, Section 4.1).
//
// The following key types are currently supported: *rsa.PublicKey, *ecdsa.PublicKey
// and ed25519.PublicKey. Unsupported key types result in an error.
//
// This kind of key is commonly encoded in PEM blocks of type "PUBLIC KEY".

You can also get the same information on the package documentation:
https://pkg.go.dev/crypto/x509#MarshalPKIXPublicKey

So what you need is not available in Go 1.19.

If you don't want to code yourself the ASN1 encoding of DSA private keys, I suppose the simpler is to use Openssl dsa function.
https://www.mkssoftware.com/docs/man1/openssl_dsa.1.asp