IOS RSA Encryption and decryption

Turn from--ring IOS RSA encryption and decryption

RAS encryption requires two sets of keys, a set of public keys, and a set of private keys.

Build command:

OpenSSL req-x509-out public_key.der-outform der-new-newkey rsa:2048-keyout Private_key.pem

Public_key.der is a public key file and Private_key.pem is a private key file.

Generate a private key file that can be referenced by iOS. PFX:

1. OpenSSL rsa-in private_key.pem-out Private_key.key

2. OpenSSL Req-new-key private_key.key-out PRIVATE_KEY.CRT

3. OpenSSL x509-req-days 3650-in private_key.crt-signkey private_key.key-out rsacert.crt

4. OpenSSL x509-outform der-in rsacert.crt-out rsacert.der

5. OpenSSL pkcs12-export-out Private_key.pfx-inkey private_key.key-in rsacert.crt

PRIVATE_KEY.PFX is the resulting file

References to public keys:

-(SECKEYREF) Getpublickey

{

Seccertificateref mycertificate = nil;

NSString *path = [[NSBundle mainbundle] pathforresource:@ "Public_key" oftype:@ "der"];

NSData *certificatedata = [NSData Datawithcontentsoffile:path];

Mycertificate = Seccertificatecreatewithdata (Kcfallocatordefault, (__bridgecfdataref) certificateData);

Secpolicyref MyPolicy = SecPolicyCreateBasicX509 ();

Sectrustref Mytrust;

Osstatus status = Sectrustcreatewithcertificates (Mycertificate,mypolicy,&mytrust);

Sectrustresulttype Trustresult;

if (status = = NOERR) {

Status = Sectrustevaluate (Mytrust, &trustresult);

}

Return Sectrustcopypublickey (Mytrust);

}

References to private keys

-(SECKEYREF) Getprivatekey

{

NSString *publickeypath = [[NSBundle mainbundle] pathforresource:@ "Private_key" oftype:@ "PFX"];

NSData *pfxkeydata = [[NSData Alloc]initwithcontentsoffile:publickeypath];

nsmutabledictionary * options = [[Nsmutabledictionary alloc] init];

[Options setobject:@ "Password" Forkey: (__bridge ID) ksecimportexportpassphrase];

Cfarrayref items = cfarraycreate (null, 0, 0, NULL);

Osstatus Securityerror = Secpkcs12import ((__bridge cfdataref) Pfxkeydata,

(__bridge cfdictionaryref) options, &items);

Cfdictionaryref identitydict = cfarraygetvalueatindex (items, 0);

Secidentityref Identityapp =

(SECIDENTITYREF) Cfdictionarygetvalue (Identitydict,

ksecimportitemidentity);

ASSERT (Securityerror = = NOERR);

Seckeyref Privatekeyref;

Secidentitycopyprivatekey (Identityapp, &privatekeyref);

return privatekeyref;

}

Public Key cryptography:

-(nsdata*) Rsaencryptwithdata: (nsdata*) Data usingkey: (SECKEYREF) key{

size_t cipherbuffersize = seckeygetblocksize (key);

uint8_t *cipherbuffer = malloc (cipherbuffersize * sizeof (uint8_t));

memset (void *) Cipherbuffer, 0*0, cipherbuffersize);

NSData *plaintextbytes = data;

size_t blockSize = cipherBufferSize-11;

size_t Blockcount = (size_t) ceil ([Plaintextbytes length]/(double) blockSize);

Nsmutabledata *encrypteddata = [Nsmutabledata datawithcapacity:0];

for (int i=0; i<blockcount; i++) {

int buffersize = MIN (blocksize,[plaintextbytes length]-i * blockSize);

NSData *buffer = [Plaintextbytes subdatawithrange:nsmakerange (i * blockSize, buffersize)];

Osstatus status = Seckeyencrypt (key,

KSecPaddingPKCS1,

(Const uint8_t *) [Buffer bytes],

[Buffer length],

Cipherbuffer,

&cipherbuffersize);

if (status = = NOERR) {

NSData *encryptedbytes = [NSData datawithbytes: (const void *) Cipherbuffer length:cipherbuffersize];

[EncryptedData appenddata:encryptedbytes];

}else{

if (Cipherbuffer) {

Free (cipherbuffer);

}

return nil;

}

}

if (cipherbuffer) free (cipherbuffer);

return EncryptedData;

}

Private key decryption:

-(nsdata*) Rsadecryptwithdata: (nsdata*) Data usingkey: (SECKEYREF) key{

NSData *wrappedsymmetrickey = data;

size_t cipherbuffersize = seckeygetblocksize (key);

size_t keybuffersize = [Wrappedsymmetrickey length];

Nsmutabledata *bits = [Nsmutabledata datawithlength:keybuffersize];

Osstatus Sanitycheck = Seckeydecrypt (Key,

KSecPaddingPKCS1,

(Const uint8_t *) [Wrappedsymmetrickey bytes],

Cipherbuffersize,

[Bits mutablebytes],

&keybuffersize);

Nsassert (Sanitycheck = = NOERR, @ "Error decrypting, Osstatus =%ld.", Sanitycheck);

[Bits setlength:keybuffersize];

return bits;

}

Encryption and decryption on the internet has written a good ras.m, you can refer to:

http://code4app.com/ios/RSA-Encrypt-and-Decrypt/5061d6476803faf86c000001

IOS RSA Encryption and decryption