由于http请求是无状态，所以我们不知道请求方到底是谁。于是就诞生了签名，接收方和请求方协商一种签名方式进行验证，来取得互相信任，进行下一步业务逻辑交流。
其中签名用得很多的就是公钥私钥，用私钥签名，公钥验签，或者公钥加密，私钥解密。
不管是公钥和私钥，我们首先要进行格式化，当然如果你获取的就是格式化后的可忽略这一步
1、公钥私钥的格式化
********************私钥格式化********************/function formatPriKey($priKey) { ???$fKey = "-----BEGIN PRIVATE KEY-----\n"; ???$len = strlen($priKey); ???for($i = 0; $i < $len; ) { ???????$fKey = $fKey . substr($priKey, $i, 64) . "\n"; ???????$i += 64; ???} ???$fKey .= "-----END PRIVATE KEY-----"; ???return $fKey;}/********************公钥格式化********************/function formatPubKey($pubKey) { ???$fKey = "-----BEGIN PUBLIC KEY-----\n"; ???$len = strlen($pubKey); ???for($i = 0; $i < $len; ) { ???????$fKey = $fKey . substr($pubKey, $i, 64) . "\n"; ???????$i += 64; ???} ???$fKey .= "-----END PUBLIC KEY-----"; ???return $fKey;}格式化也就是加上前后缀，然后每64位进行换行，还可如下简单格式化：
//私钥格式化$fKey = "-----BEGIN PRIVATE KEY-----\n".chunk_split($public_key, 64,"\n").‘-----END PRIVATE KEY-----‘;//公钥格式化$fKey = "-----BEGIN PUBLIC KEY-----\n".chunk_split($public_key, 64,"\n").‘-----END PUBLIC KEY-----‘;
2、私钥签名和公钥验签
/********************私钥签名********************/function get_private_sign($sign_str,$private_key,$signature_alg=OPENSSL_ALGO_SHA1){ ???$private_key = openssl_pkey_get_private(private_key);//加载密钥 ???openssl_sign($sign_str,$signature,$private_key,$signature_alg);//生成签名 ???$signature = base64_encode($signature); ???openssl_free_key($private_key); ???return $signature;}/********************公钥验签********************/function public_verify($sign_str,$sign,$public_key,$signature_alg=OPENSSL_ALGO_SHA1){ ???$public_key = openssl_get_publickey($public_key); ???$verify = openssl_verify($sign_str, base64_decode($sign), $public_key, $signature_alg); ???openssl_free_key($public_key); ???return $verify==1;//false or true}$sign_str为签名字符串或者验签字符串，$sign为签名，公钥私钥都必须是格式化后的，否则会无法识别。
3、公钥加密和私钥解密
/********************公钥加密********************/function get_public_sign($sign_str,$public_key,$signature_alg=OPENSSL_ALGO_SHA1){ ???$public_key = openssl_pkey_get_public($public_key);//加载密钥 ???openssl_sign($sign_str,$signature,$public_key,$signature_alg);//生成签名 ???$signature = base64_encode($signature); ???openssl_free_key($public); ???return $signature;}/********************私钥解密********************/ function private_verify($sign_str,$sign,$private_key,$signature_alg=OPENSSL_ALGO_SHA1){ ???$private_key = openssl_get_privatekey($private_key); ???$verify = openssl_verify($sign_str, base64_decode($sign), $private_key, $signature_alg); ???openssl_free_key($private_key); ???return $verify==1;//false or true}php中签名公钥、私钥详解
原文地址：https://www.cnblogs.com/myIvan/p/9320649.html