Detailed explanation of php rsa encryption and decryption, detailed explanation of rsa encryption and decryption

Detailed explanation of php rsa encryption and decryption, detailed explanation of rsa encryption and decryption_PHP tutorial

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Release： 2016-07-13 10:09:38

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Detailed explanation of the use of php rsa encryption and decryption, detailed explanation of the use of rsa encryption and decryption

1. The first step in encryption and decryption is to generate a public key and private key pair. The content encrypted by the private key can be decrypted by the public key (and vice versa)

Download the open source RSA key generation tool openssl (usually Linux systems come with this program), unzip it to a separate folder, enter the bin directory, and execute the following command:

Copy code The code is as follows:

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

The first command generates the original RSA private key file rsa_private_key.pem, the second command converts the original RSA private key to pkcs8 format, and the third command generates the RSA public key rsa_public_key.pem
It can be seen from the above that the corresponding public key can be generated through the private key, so we use the private key private_key.pem on the server side, and the public key is distributed to front-ends such as android and ios

2. Use the generated public key and private key for encryption and decryption in php, directly enter the code

Copy code The code is as follows:

$fp=fopen("rsa/rsa_private_key.pem","r"); //Your private key file path
$private_key=fread($fp,8192);
fclose($fp);
$fp1=fopen("rsa/rsa_public_key.pem","r"); //Your public key file path
$public_key=fread($fp1,8192);
fclose($fp1);
//echo $private_key;
$pi_key=openssl_pkey_get_private($private_key);//This function can be used to determine whether the private key is available and can return the resource id Resource id
$pu_key=openssl_pkey_get_public($public_key );//This function can be used to determine whether the public key is available
print_r($pi_key);echo "n"; echo "
";
print_r($pu_key);echo "n"; echo "
";
echo "

";
$data='php ras encryption algorithm';
$encrypted = "";
$decrypted = "";
echo "Encrypted source data:".$data."n"; echo "
";
echo "private key encrypt:n"; echo "
";
openssl_private_encrypt($data,$encrypted,$pi_key);//Private key encryption
$encrypted = base64_encode($encrypted);//Encrypted content usually contains special characters and requires encoding conversion. When transmitting through URLs between networks, pay attention to whether base64 encoding is URL safe
echo 'After private key encryption:'.$encrypted."n"; echo "
";echo "
";
echo "public key decrypt:n"; echo "
";
openssl_public_decrypt(base64_decode($encrypted),$decrypted,$pu_key);//The content encrypted by the private key can be decrypted by the public key
echo 'After public key decryption:'.$decrypted."n"; echo "
";
echo "

";
echo "public key encrypt:n"; echo "
";
openssl_public_encrypt($data,$encrypted,$pu_key);//Public key encryption
$encrypted = base64_encode($encrypted);
echo $encrypted,"n"; echo "
";
echo "private key decrypt:n"; echo "
";
openssl_private_decrypt(base64_decode($encrypted),$decrypted,$pi_key);//Private key decryption
echo $decrypted,"n"; echo "
";

FAQ about PHP RSA configuration:

●Usage of 3 DLL files in the openssl folder in the code example of PHP development language

1. If your system is a windows system and there are no libeay32.dll and ssleay32.dll files in the system32 file directory
Then you need to copy these two files to the system32 file directory.

2. If there is no php_openssl.dll in your php installation directory (phpext)

Then please put php_openssl.dll in this folder

Friends who like encryption and decryption must read this article carefully and benefit a lot. . .