An explanation of RSA encryption and decryption in PHP

PHP server to interact with the client, providing open APIs, usually need to encrypt the sensitive part of the API data transmission, the RSA asymmetric encryption can be used, the following example shows how to use PHP to achieve the encryption and decryption of data, hope to help everyone.

1, the first step of encryption and decryption is to generate a public key, a private key pair, the private key encrypted content can be decrypted by the public key (in turn, can also)

Download the open source RSA key generation tool OpenSSL (usually the Linux system comes with the program), unzip to a separate folder, enter the Bin directory, and execute the following command:

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 the PKCS8 format, and the third generates the RSA public key Rsa_public_key.pem
From the above, we can generate the corresponding public key through the private key, so we use the private key Private_key.pem on the server side, the public key is issued to the Android and iOS and other front

2, PHP with the generated public key, the private key for encryption and decryption, directly on the code

<?php$private_key = '-----BEGIN RSA private Key-----miicxqibaakbgqc3//sr2txw0wrc2dysx8vnglqt3y7ldu9+ lbli6e1ks5lfc5jltgf7kbtskchbm3ouehwqp1zj85ije59af5gib2klbd6h4wrbbha2xe1sq21ykja/gqx7/iria3zqfxgv/qekygox+ Xalvoolzqdwh76o2n1vp1d+ td3amhsk7qidaqabaogbakh14bmitesqd4pywodwmy7rrrvyfpenjjtecljvkb7ikrvxvdkp1xijngkh2h5syhq5qslpsgyj1m/ xkdnginwalvhvd3bokkgkg1bzn7ao5pxt+herqxavwws6ga63yvsic8jcodxiuvxjnumqrlaqof6aub/ 2vwc2t5mdmxlhakea3pwgpvxgliwl3h7qlyzlrlrbfrurn4cyl4uyaakokkavzly04glle8ycgoc2dzl4eil4l/+x/gaqdeju/ chlrqjbanozy0meovkwhu4bscsdnfm6usqowybewhyyh/otv1a3sqcce1f+ qbaclcqenihajccdmgyj53lfigyv0wcs54kcqaxapkahclrkqladquv5iwyyj25foiq+y8sgccs73qixru1ypjy9yka/meg9smsl4oh9ioigi+ zuygh9ydsmeq0cqqc24g3ip2g3lndrdzim5nz7pfnmyrabxk/ Ugvuwdk47iwtzhfkdhxkfc8qepuhbsahlqjifgxy4ejkubm3fpdgjakafwuxyssijjvrhwnhfbg0rfkvvy63osmnrxil4x6eyyi9lblcsyfpl25l7l5zmjrah n45zaioobrwqpm5edu7c-----END RSA PRIVATE KEY-----'; $public _key = '-----BEGIN public KEY-----migfma0gcsqgsib3dqebaquaa4gnadcbiqkbgqc3//sr2txw0wrc2dysx8vnglqt3y7ldu9+lbli6e1ks5lfc5jltgf7kbtskchbm3ouehwqp1zj85ije59af5gib2klbd6h4wrbbha2xe1sq21ykja/gqx7/iria3zqfxgv/ Qekygox+xalvoolzqdwh76o2n1vp1d+td3amhsk7qidaqab-----END Public KEY-----';//echo $private _key; $pi _key = Openssl_pkey _get_private ($private _key);//This function can be used to determine if the private key is available, return the resource id Resource id$pu_key = openssl_pkey_get_public ($public _key) The function can be used to determine if the public key is available Print_r ($pi _key), echo "\ n";p rint_r ($pu _key); echo "\ n"; $data = "aassssasssddd";//Raw Data $encrypted = ""; $decrypted = ""; echo "Source data:", $data, "\ n"; echo "private key encrypt:\n"; Openssl_private_encrypt ($data, $encrypted, $pi _key);// Private key Encryption $encrypted = Base64_encode ($encrypted);//The encrypted content usually contains special characters that need to be encoded under conversion, to be aware that Base64 encoding is a URL-safe echo $ when transferring over a URL between networks encrypted, "\ n"; echo "public key decrypt:\n"; Openssl_public_decrypt (Base64_decode ($encrypted), $decrypted, $pu _key) ;//The contents of the private key encryption can be decrypted by the public key echo $decrypted, "\ n"; echo "---------------------------------------\ n"; echo "publicly key encrypt : \ n "; Openssl_public_encrypt ($data, $encrypted, $pu _key);//public key Encryption $encrypted = Base64_Encode ($encrypted); Echo $encrypted, "\ n"; echo "private key decrypt:\n"; Openssl_private_decrypt (Base64_decode ($ encrypted), $decrypted, $pi _key);//private key decryption echo $decrypted, "\ n";