/* @author: ideawu @link: https://github.com/ideawu/Objective-C-RSA*/
#import <Foundation/Foundation.h>
@interface RSA : NSObject
// return base64 encoded string
+ (NSString *)encryptString:(NSString *)str publicKey:(NSString *)pubKey;
// return raw data
+ (NSData *)encryptData:(NSData *)data publicKey:(NSString *)pubKey;
// return base64 encoded string
+ (NSString *)encryptString:(NSString *)str privateKey:(NSString *)privKey;
// return raw data
+ (NSData *)encryptData:(NSData *)data privateKey:(NSString *)privKey;
// decrypt base64 encoded string, convert result to string(not base64 encoded)
+ (NSString *)decryptString:(NSString *)str publicKey:(NSString *)pubKey;
+ (NSData *)decryptData:(NSData *)data publicKey:(NSString *)pubKey;
+ (NSString *)decryptString:(NSString *)str privateKey:(NSString *)privKey;
+ (NSData *)decryptData:(NSData *)data privateKey:(NSString *)privKey;
@end
/* @author: ideawu @link: https://github.com/ideawu/Objective-C-RSA*/
#import "RSA.h"
#import <Security/Security.h>
@implementation RSA
static NSString *base64_encode_data(NSData *data){data = [data base64EncodedDataWithOptions:0];NSString *ret = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];return ret;}static NSData *base64_decode(NSString *str){NSData *data = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];return data;}+ (NSData *)stripPublicKeyHeader:(NSData *)d_key{// Skip ASN.1 public key headerif (d_key == nil) return(nil);unsigned long len = [d_key length];if (!len) return(nil);unsigned char *c_key = (unsigned char *)[d_key bytes];unsigned int idx = 0;if (c_key[idx++] != 0x30) return(nil);if (c_key[idx] > 0x80) idx += c_key[idx] - 0x80 + 1;else idx++;// PKCS #1 rsaEncryption szOID_RSA_RSAstatic unsigned char seqiod[] ={ 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01,0x01, 0x05, 0x00 };if (memcmp(&c_key[idx], seqiod, 15)) return(nil);idx += 15;if (c_key[idx++] != 0x03) return(nil);if (c_key[idx] > 0x80) idx += c_key[idx] - 0x80 + 1;else idx++;if (c_key[idx++] != '\0') return(nil);// Now make a new NSData from this bufferreturn([NSData dataWithBytes:&c_key[idx] length:len - idx]);}//credit: http://hg.mozilla.org/services/fx-home/file/tip/Sources/NetworkAndStorage/CryptoUtils.m#l1036+ (NSData *)stripPrivateKeyHeader:(NSData *)d_key{// Skip ASN.1 private key headerif (d_key == nil) return(nil);unsigned long len = [d_key length];if (!len) return(nil);unsigned char *c_key = (unsigned char *)[d_key bytes];unsigned int idx = 22; //magic byte at offset 22if (0x04 != c_key[idx++]) return nil;//calculate length of the keyunsigned int c_len = c_key[idx++];int det = c_len & 0x80;if (!det) {c_len = c_len & 0x7f;} else {int byteCount = c_len & 0x7f;if (byteCount + idx > len) {//rsa length field longer than bufferreturn nil;}unsigned int accum = 0;unsigned char *ptr = &c_key[idx];idx += byteCount;while (byteCount) {accum = (accum << 8) + *ptr;ptr++;byteCount--;}c_len = accum;}// Now make a new NSData from this bufferreturn [d_key subdataWithRange:NSMakeRange(idx, c_len)];}+ (SecKeyRef)addPublicKey:(NSString *)key{NSRange spos = [key rangeOfString:@"-----BEGIN PUBLIC KEY-----"];NSRange epos = [key rangeOfString:@"-----END PUBLIC KEY-----"];if(spos.location != NSNotFound && epos.location != NSNotFound){NSUInteger s = spos.location + spos.length;NSUInteger e = epos.location;NSRange range = NSMakeRange(s, e-s);key = [key substringWithRange:range];}key = [key stringByReplacingOccurrencesOfString:@"\r" withString:@""];key = [key stringByReplacingOccurrencesOfString:@"\n" withString:@""];key = [key stringByReplacingOccurrencesOfString:@"\t" withString:@""];key = [key stringByReplacingOccurrencesOfString:@" " withString:@""];// This will be base64 encoded, decode it.NSData *data = base64_decode(key);data = [RSA stripPublicKeyHeader:data];if(!data){return nil;}//a tag to read/write keychain storageNSString *tag = @"RSAUtil_PubKey";NSData *d_tag = [NSData dataWithBytes:[tag UTF8String] length:[tag length]];// Delete any old lingering key with the same tagNSMutableDictionary *publicKey = [[NSMutableDictionary alloc] init];[publicKey setObject:(__bridge id) kSecClassKey forKey:(__bridge id)kSecClass];[publicKey setObject:(__bridge id) kSecAttrKeyTypeRSA forKey:(__bridge id)kSecAttrKeyType];[publicKey setObject:d_tag forKey:(__bridge id)kSecAttrApplicationTag];SecItemDelete((__bridge CFDictionaryRef)publicKey);// Add persistent version of the key to system keychain[publicKey setObject:data forKey:(__bridge id)kSecValueData];[publicKey setObject:(__bridge id) kSecAttrKeyClassPublic forKey:(__bridge id) kSecAttrKeyClass];[publicKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridge id) kSecReturnPersistentRef];CFTypeRef persistKey = nil;OSStatus status = SecItemAdd((__bridge CFDictionaryRef)publicKey, &persistKey);if (persistKey != nil){CFRelease(persistKey);}if ((status != noErr) && (status != errSecDuplicateItem)) {return nil;}[publicKey removeObjectForKey:(__bridge id)kSecValueData];[publicKey removeObjectForKey:(__bridge id)kSecReturnPersistentRef];[publicKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridge id)kSecReturnRef];[publicKey setObject:(__bridge id) kSecAttrKeyTypeRSA forKey:(__bridge id)kSecAttrKeyType];// Now fetch the SecKeyRef version of the keySecKeyRef keyRef = nil;status = SecItemCopyMatching((__bridge CFDictionaryRef)publicKey, (CFTypeRef *)&keyRef);if(status != noErr){return nil;}return keyRef;}+ (SecKeyRef)addPrivateKey:(NSString *)key{NSRange spos;NSRange epos;spos = [key rangeOfString:@"-----BEGIN RSA PRIVATE KEY-----"];if(spos.length > 0){epos = [key rangeOfString:@"-----END RSA PRIVATE KEY-----"];}else{spos = [key rangeOfString:@"-----BEGIN PRIVATE KEY-----"];epos = [key rangeOfString:@"-----END PRIVATE KEY-----"];}if(spos.location != NSNotFound && epos.location != NSNotFound){NSUInteger s = spos.location + spos.length;NSUInteger e = epos.location;NSRange range = NSMakeRange(s, e-s);key = [key substringWithRange:range];}key = [key stringByReplacingOccurrencesOfString:@"\r" withString:@""];key = [key stringByReplacingOccurrencesOfString:@"\n" withString:@""];key = [key stringByReplacingOccurrencesOfString:@"\t" withString:@""];key = [key stringByReplacingOccurrencesOfString:@" " withString:@""];// This will be base64 encoded, decode it.NSData *data = base64_decode(key);data = [RSA stripPrivateKeyHeader:data];if(!data){return nil;}//a tag to read/write keychain storageNSString *tag = @"RSAUtil_PrivKey";NSData *d_tag = [NSData dataWithBytes:[tag UTF8String] length:[tag length]];// Delete any old lingering key with the same tagNSMutableDictionary *privateKey = [[NSMutableDictionary alloc] init];[privateKey setObject:(__bridge id) kSecClassKey forKey:(__bridge id)kSecClass];[privateKey setObject:(__bridge id) kSecAttrKeyTypeRSA forKey:(__bridge id)kSecAttrKeyType];[privateKey setObject:d_tag forKey:(__bridge id)kSecAttrApplicationTag];SecItemDelete((__bridge CFDictionaryRef)privateKey);// Add persistent version of the key to system keychain[privateKey setObject:data forKey:(__bridge id)kSecValueData];[privateKey setObject:(__bridge id) kSecAttrKeyClassPrivate forKey:(__bridge id) kSecAttrKeyClass];[privateKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridge id) kSecReturnPersistentRef];CFTypeRef persistKey = nil;OSStatus status = SecItemAdd((__bridge CFDictionaryRef)privateKey, &persistKey);if (persistKey != nil){CFRelease(persistKey);}if ((status != noErr) && (status != errSecDuplicateItem)) {return nil;}[privateKey removeObjectForKey:(__bridge id)kSecValueData];[privateKey removeObjectForKey:(__bridge id)kSecReturnPersistentRef];[privateKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridge id)kSecReturnRef];[privateKey setObject:(__bridge id) kSecAttrKeyTypeRSA forKey:(__bridge id)kSecAttrKeyType];// Now fetch the SecKeyRef version of the keySecKeyRef keyRef = nil;status = SecItemCopyMatching((__bridge CFDictionaryRef)privateKey, (CFTypeRef *)&keyRef);if(status != noErr){return nil;}return keyRef;}/* START: Encryption & Decryption with RSA private key */+ (NSData *)encryptData:(NSData *)data withKeyRef:(SecKeyRef) keyRef isSign:(BOOL)isSign {const uint8_t *srcbuf = (const uint8_t *)[data bytes];size_t srclen = (size_t)data.length;size_t block_size = SecKeyGetBlockSize(keyRef) * sizeof(uint8_t);void *outbuf = malloc(block_size);size_t src_block_size = block_size - 11;NSMutableData *ret = [[NSMutableData alloc] init];for(int idx=0; idxsrc_block_size){data_len = src_block_size;}size_t outlen = block_size;OSStatus status = noErr; if (isSign) { status = SecKeyRawSign(keyRef, kSecPaddingPKCS1, srcbuf + idx, data_len, outbuf, &outlen ); } else { status = SecKeyEncrypt(keyRef, kSecPaddingPKCS1, srcbuf + idx, data_len, outbuf, &outlen ); }if (status != 0) {NSLog(@"SecKeyEncrypt fail. Error Code: %d", status);ret = nil;break;}else{[ret appendBytes:outbuf length:outlen];}}free(outbuf);CFRelease(keyRef);return ret;}+ (NSString *)encryptString:(NSString *)str privateKey:(NSString *)privKey{NSData *data = [RSA encryptData:[str dataUsingEncoding:NSUTF8StringEncoding] privateKey:privKey];NSString *ret = base64_encode_data(data);return ret;}+ (NSData *)encryptData:(NSData *)data privateKey:(NSString *)privKey{if(!data || !privKey){return nil;}SecKeyRef keyRef = [RSA addPrivateKey:privKey];if(!keyRef){return nil;}return [RSA encryptData:data withKeyRef:keyRef isSign:YES];}+ (NSData *)decryptData:(NSData *)data withKeyRef:(SecKeyRef) keyRef{const uint8_t *srcbuf = (const uint8_t *)[data bytes];size_t srclen = (size_t)data.length;size_t block_size = SecKeyGetBlockSize(keyRef) * sizeof(uint8_t);UInt8 *outbuf = malloc(block_size);size_t src_block_size = block_size;NSMutableData *ret = [[NSMutableData alloc] init];for(int idx=0; idxsrc_block_size){
data_len = src_block_size;
}
size_t outlen = block_size;
OSStatus status = noErr;
status = SecKeyDecrypt(keyRef,
kSecPaddingNone,
srcbuf + idx,
data_len,
outbuf,
&outlen
);
if (status != 0) {
NSLog(@"SecKeyEncrypt fail. Error Code: %d", status);
ret = nil;
break;
}else{
//the actual decrypted data is in the middle, locate it!
int idxFirstZero = -1;
int idxNextZero = (int)outlen;
for ( int i = 0; i < outlen; i++ ) {
if ( outbuf[i] == 0 ) {
if ( idxFirstZero < 0 ) {
idxFirstZero = i;
} else {
idxNextZero = i;
break;
}
}
}
[ret appendBytes:&outbuf[idxFirstZero+1] length:idxNextZero-idxFirstZero-1];
}
}
free(outbuf);
CFRelease(keyRef);
return ret;
}
+ (NSString *)decryptString:(NSString *)str privateKey:(NSString *)privKey{
NSData *data = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];
data = [RSA decryptData:data privateKey:privKey];
NSString *ret = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
return ret;
}
+ (NSData *)decryptData:(NSData *)data privateKey:(NSString *)privKey{
if(!data || !privKey){
return nil;
}
SecKeyRef keyRef = [RSA addPrivateKey:privKey];
if(!keyRef){
return nil;
}
return [RSA decryptData:data withKeyRef:keyRef];
}
/* END: Encryption & Decryption with RSA private key */
/* START: Encryption & Decryption with RSA public key */
+ (NSString *)encryptString:(NSString *)str publicKey:(NSString *)pubKey{
NSData *data = [RSA encryptData:[str dataUsingEncoding:NSUTF8StringEncoding] publicKey:pubKey];
NSString *ret = base64_encode_data(data);
return ret;
}
+ (NSData *)encryptData:(NSData *)data publicKey:(NSString *)pubKey{
if(!data || !pubKey){
return nil;
}
SecKeyRef keyRef = [RSA addPublicKey:pubKey];
if(!keyRef){
return nil;
}
return [RSA encryptData:data withKeyRef:keyRef isSign:NO];
}
+ (NSString *)decryptString:(NSString *)str publicKey:(NSString *)pubKey{
NSData *data = [[NSData alloc] initWithBase64EncodedString:str options:NSDataBase64DecodingIgnoreUnknownCharacters];
data = [RSA decryptData:data publicKey:pubKey];
NSString *ret = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
return ret;
}
+ (NSData *)decryptData:(NSData *)data publicKey:(NSString *)pubKey{
if(!data || !pubKey){
return nil;
}
SecKeyRef keyRef = [RSA addPublicKey:pubKey];
if(!keyRef){
return nil;
}
return [RSA decryptData:data withKeyRef:keyRef];
}
/* END: Encryption & Decryption with RSA public key */
@end
