openssl genrsa -out rsa_private_key.pem 1024

openssl pkcs8 -topk8 -inform PEM -in rsa_private_key.pem -outform PEM -nocrypt -out private_key.pem

openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem

第一條命令生成原始 RSA私鑰文件 rsa_private_key.pem，第二條命令將原始 RSA私鑰轉(zhuǎn)換為 pkcs8格式，第三條生成RSA公鑰 rsa_public_key.pem
從上面看出通過私鑰能生成對(duì)應(yīng)的公鑰，因此我們將私鑰private_key.pem用在服務(wù)器端，公鑰發(fā)放給android跟ios等前端

2、php中用生成的公鑰、私鑰進(jìn)行加密解密，直接上代碼

復(fù)制代碼代碼如下:

$fp=fopen("rsa/rsa_private_key.pem","r"); //你的私鑰文件路徑

$private_key=fread($fp,8192);

fclose($fp);

$fp1=fopen("rsa/rsa_public_key.pem","r"); //你的公鑰文件路徑

$public_key=fread($fp1,8192);

fclose($fp1);

//echo $private_key; 

$pi_key=openssl_pkey_get_private($private_key);//這個(gè)函數(shù)可用來判斷私鑰是否是可用的，可用返回資源id Resource id 

$pu_key=openssl_pkey_get_public($public_key );//這個(gè)函數(shù)可用來判斷公鑰是否是可用的

print_r($pi_key);echo "\n"; echo "<br>";

print_r($pu_key);echo "\n"; echo "<br>";

echo "<hr>";

$data='php ras加密算法';

$encrypted = ""; 

$decrypted = ""; 

echo "加密的源數(shù)據(jù):".$data."\n"; echo "<br>";

echo "private key encrypt:\n"; echo "<br>";

openssl_private_encrypt($data,$encrypted,$pi_key);//私鑰加密 

$encrypted = base64_encode($encrypted);//加密后的內(nèi)容通常含有特殊字符，需要編碼轉(zhuǎn)換下，在網(wǎng)絡(luò)間通過url傳輸時(shí)要注意base64編碼是否是url安全的 

echo '私鑰加密后：'.$encrypted."\n"; echo "<br>";echo "<br>";

echo "public key decrypt:\n"; echo "<br>";

openssl_public_decrypt(base64_decode($encrypted),$decrypted,$pu_key);//私鑰加密的內(nèi)容通過公鑰可用解密出來 

echo '公鑰解密后：'.$decrypted."\n"; echo "<br>";

echo "<hr>";

echo "public key encrypt:\n"; echo "<br>";

openssl_public_encrypt($data,$encrypted,$pu_key);//公鑰加密 

$encrypted = base64_encode($encrypted); 

echo $encrypted,"\n"; echo "<br>";

echo "private key decrypt:\n"; echo "<br>";

openssl_private_decrypt(base64_decode($encrypted),$decrypted,$pi_key);//私鑰解密 

echo $decrypted,"\n"; echo "<br>";