Why verification of ECDSA 384 signature fails in GO but not in PHP?

I am facing a issue where I have to verify a signature produced by a Smart Card. The signature is in ECDSA 384 and the message being used is two byte arrays (concatenated together) of SHA-384 hashed strings. I have a sample code written in PHP to perform the signature verification and it works as expected. However when I try to reproduce the same sort of verification in GO, I cannot get the signature verified no matter how I try it.

I believe that something is wrong with the original message hashing in GO that it does not verify it but I cannot figure out what I am doing wrong. Maybe someone can pin point out what the actual cause can be? I will put both PHP and GO code samples with sample data for verification here:

This is the code for PHP ECDSA 384 signature verification:

<?php
function p1363_to_asn1(string $p1363): string {
// P1363 format: r followed by s.
// ASN.1 format: 0x30 b1 0x02 b2 r 0x02 b3 s.
//
// r and s must be prefixed with 0x00 if their first byte is > 0x7f.
//
// b1 = length of contents.
// b2 = length of r after being prefixed if necessary.
// b3 = length of s after being prefixed if necessary.
$asn1  = '';                        // ASN.1 contents.
$len   = 0;                         // Length of ASN.1 contents.
$c_len = intdiv(strlen($p1363), 2); // Length of each P1363 component.
// Separate P1363 signature into its two equally sized components.
foreach (str_split($p1363, $c_len) as $c) {
// 0x02 prefix before each component.
$asn1 .= "\x02";
if (unpack('C', $c)[1] > 0x7f) {
// Add 0x00 because first byte of component > 0x7f.
// Length of component = ($c_len + 1).
$asn1 .= pack('C', $c_len + 1) . "\x00";
$len += 2 + ($c_len + 1);
} else {
$asn1 .= pack('C', $c_len);
$len += 2 + $c_len;
}
// Append formatted component to ASN.1 contents.
$asn1 .= $c;
}
// 0x30 b1, then contents.
return "\x30" . pack('C', $len) . $asn1;
}
$public_key_pem = "-----BEGIN PUBLIC KEY-----
MHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEJ4dnbrsp2Ee8HstJ3ubDDzJuf5E2+N7J
H36jxJtX568mL7hGYo/U/ooUqtcZLd5pS6kLBFkLWeP58BlVxxru+n225WTp0PiI
kJudSFwdmHR16+WTbxJSyOaQAoyM6xWA
-----END PUBLIC KEY-----";
$public_key = openssl_pkey_get_public($public_key_pem);
$signature = "QfXwpqkDtL95mmcTA2BknDY32Ds6i+NdLPRqlbi2+niQOLgsSJMRVVALLQ7b50LQXRsRiPfiYi+m9WXAJxCE3aO20feTQWcVR1SP+LYXQUIZKqrijm3VW/GHtGMhjlqv";
$nounce = "MPAeifrL7Z/dFPZcAukaTWxsZ+h4E7jtWsKzltx3YujjJuOOWw8dgzgKfm3a";
$origin = "https://192.168.1.3:8441";
$origin_digest = openssl_digest($origin, "sha384", true);
$nounce_digest = openssl_digest($nounce, "sha384", true);
$result = openssl_verify($origin_digest.$nounce_digest, p1363_to_asn1(base64_decode($signature)), $public_key, OPENSSL_ALGO_SHA384);
if ($result == 1) {
echo "signature is valid for given data.";
} elseif ($result == 0) {
echo "signature is invalid for given data.";
} else {
echo "Error: ".openssl_error_string();
}

Here is the code I used in GO to try to verify ECDSA 384 signature:

package main
import (
"crypto/ecdsa"
"crypto/sha512"
"crypto/x509"
"encoding/base64"
"encoding/pem"
"fmt"
"math/big"
)
func main() {
idCardPublicKey := []byte(LoadIDCardPublicPem())
nonce := "MPAeifrL7Z/dFPZcAukaTWxsZ+h4E7jtWsKzltx3YujjJuOOWw8dgzgKfm3a"
origin := "https://192.168.1.3:8441"
webeidSig := "QfXwpqkDtL95mmcTA2BknDY32Ds6i+NdLPRqlbi2+niQOLgsSJMRVVALLQ7b50LQXRsRiPfiYi+m9WXAJxCE3aO20feTQWcVR1SP+LYXQUIZKqrijm3VW/GHtGMhjlqv"
sigVerified := VerifySignature(idCardPublicKey, nonce, origin, webeidSig)
fmt.Println("SIG VERIFIED: ", sigVerified)
}
func VerifySignature(publicKeyByte []byte, nounce string, origin string, signatureBase64 string) bool {
block, _ := pem.Decode(publicKeyByte)
parseResultPublicKey, err := x509.ParsePKIXPublicKey(block.Bytes)
fmt.Println("PARSE ERR: ", err)
publicKey := parseResultPublicKey.(*ecdsa.PublicKey)
originHash := sha512.New384()
_, err2 := originHash.Write([]byte(origin))
if err2 != nil {
panic(err2)
}
originHashSum := originHash.Sum(nil)
nounceHash := sha512.New384()
_, err2 = nounceHash.Write([]byte(nounce))
if err2 != nil {
panic(err2)
}
nounceHashSum := nounceHash.Sum(nil)
originHashSum = append(originHashSum, nounceHashSum...)
signature := []byte(Base64Decoding(signatureBase64))
rByte, sByte := signature[:len(signature)/2], signature[len(signature)/2:]
r := new(big.Int)
r.SetBytes(rByte)
s := new(big.Int)
s.SetBytes(sByte)
valid := ecdsa.Verify(publicKey, originHashSum[:], r, s)
return valid
}
func LoadIDCardPublicPem() []byte {
return []byte(`-----BEGIN PUBLIC KEY-----
MHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEJ4dnbrsp2Ee8HstJ3ubDDzJuf5E2+N7J
H36jxJtX568mL7hGYo/U/ooUqtcZLd5pS6kLBFkLWeP58BlVxxru+n225WTp0PiI
kJudSFwdmHR16+WTbxJSyOaQAoyM6xWA
-----END PUBLIC KEY-----`)
}
func Base64Decoding(input string) []byte {
data, err := base64.StdEncoding.DecodeString(input)
if err != nil {
return data
}
return data
}

openssl_verify() hashes implicitly, ecdsa.Verify() does not. I.e. in the Go code the hashing of originHashSum is missing:

...
originHashSum = append(originHashSum, nounceHashSum...)

// Fix: Explicit hashing
finalHash := sha512.New384()
_, err2 = finalHash.Write([]byte(originHashSum))
if err2 != nil {
	panic(err2)
}
finalHashSum := finalHash.Sum(nil)
	
...
	
valid := ecdsa.Verify(publicKey, finalHashSum[:], r, s)
...