iOS RSA (Objc)
/* RSA.h @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 // enc with private key NOT working YET! //+ (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
/* RSA.m @author: ideawu @link: https://github.com/ideawu/Objective-C-RSA */ #import "RSA.h" #import <Security/Security.h> @implementation RSA /* static NSString *base64_encode(NSString *str){ NSData* data = [str dataUsingEncoding:NSUTF8StringEncoding]; if(!data){ return nil; } return base64_encode_data(data); } */ 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 header if (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_RSA static 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 buffer return([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 header if (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 22 if (0x04 != c_key[idx++]) return nil; //calculate length of the key unsigned 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 buffer return 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 buffer return [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 storage NSString *tag = @"RSAUtil_PubKey"; NSData *d_tag = [NSData dataWithBytes:[tag UTF8String] length:[tag length]]; // Delete any old lingering key with the same tag NSMutableDictionary *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 key SecKeyRef 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 storage NSString *tag = @"RSAUtil_PrivKey"; NSData *d_tag = [NSData dataWithBytes:[tag UTF8String] length:[tag length]]; // Delete any old lingering key with the same tag NSMutableDictionary *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 key SecKeyRef 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{ 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; idx<srclen; idx+=src_block_size){ //NSLog(@"%d/%d block_size: %d", idx, (int)srclen, (int)block_size); size_t data_len = srclen - idx; if(data_len > src_block_size){ data_len = src_block_size; } size_t outlen = block_size; OSStatus status = noErr; status = SecKeyEncrypt(keyRef, kSecPaddingPKCS1, srcbuf + idx, data_len, outbuf, &outlen ); if (status != 0) { NSLog(@"SecKeyEncrypt fail. Error Code: %d", (int)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]; } + (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; idx<srclen; idx+=src_block_size){ //NSLog(@"%d/%d block_size: %d", idx, (int)srclen, (int)block_size); size_t data_len = srclen - idx; if(data_len > src_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", (int)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]; } + (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
Stay hungry,stay foolish.
