php项目中由许多使用rsa 签名调用java 或其他语言api的， php中使用的是 RSAWITHMD5 pksc1

php代码

$private_key = ` // 实际上是三个 ` 编辑器不能打三个`
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
`
$pkeyid = openssl_get_privatekey($private_key);
if (!$pkeyid) {
       throw new \Exception("获取私钥失败");
}

$sign_str = "iaaaaaaaaaaaaaaddd";
$verify = openssl_sign($sign_str, $signature, $pkeyid, OPENSSL_ALGO_MD5);
openssl_free_key($pkeyid);
$result = base64_encode($signature); //最终签名结果

对应的golang 签名计算代码

package main

import (
    "crypto"
    "crypto/md5"
    "crypto/rand"
    "crypto/rsa"
    "crypto/x509"
    "encoding/base64"
    "encoding/pem"
    "errors"
    "fmt"
)

func main() {
    pemKey := []byte(`
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
`)

    data := []byte("iaaaaaaaaaaaaaaddd")
    hashMd5 := md5.Sum(data)
    hashed := hashMd5[:]

    block, _ := pem.Decode(pemKey)
    if block == nil {
        panic(errors.New("private key error"))
    }
    privateKey, err := x509.ParsePKCS1PrivateKey(block.Bytes)
    if err != nil {
        fmt.Println("ParsePKCS1PrivateKey err", err)
        panic(err)
    }
    signature, err := rsa.SignPKCS1v15(rand.Reader, privateKey, crypto.MD5, hashed)
    fmt.Println("消息的签名信息： ", base64.StdEncoding.EncodeToString(signature))

}