iOS: How to get the IP Address from Host name Objective C

- (NSString *)getIPAddress {
	Boolean result;
	CFHostRef hostRef;
	CFArrayRef addresses;
	NSString *hostname = @"www.google.com"; /*change to required host name */
	NSString *ipAddress = @"";
	hostRef = CFHostCreateWithName(kCFAllocatorDefault, (CFStringRef)hostname);
	if (hostRef) {
	result = CFHostStartInfoResolution(hostRef, kCFHostAddresses, NULL);
	if (result == TRUE) {
	addresses = CFHostGetAddressing(hostRef, &result);
	}
	}
	if (result == TRUE) {
	CFIndex index = 0;
	CFDataRef ref = (CFDataRef) CFArrayGetValueAtIndex(addresses, index);
	struct sockaddr_in* remoteAddr;
	char *ip_address;
	remoteAddr = (struct sockaddr_in*) CFDataGetBytePtr(ref);
	if (remoteAddr != NULL) {
	ip_address = inet_ntoa(remoteAddr->sin_addr);
	}
	ipAddress = [NSString stringWithCString:ip_address encoding:NSUTF8StringEncoding];
	}
	return ipAddress;
	}

The Best Way to Answer Salary Interview Questions

1. Q: “What are Your Salary Expectations?”

A: #1 - “I was making $60,000 at my last job, plus bonuses. I would be expecting at least that and a 15 to 20 percent increase. (This is not a good answer) 

A: #2 - “I’m sure whatever you offer will be a fair amount for a person with my qualifications. Salary is not the most important factor to me. I’m looking for opportunity.” (This is a somewhat weak answer) 

A: #3 - “I really need more information about the job before we start to discuss salary. I’d like to postpone that discussion until later. Maybe you could tell me what is budgeted for the position, and how your commission structure works.” (This is the best answer) 

2. Q: “What Do You Expect in the Way of Salary?”

A: #1 - “Before I answer that question, I’d like to ask what you typically pay someone with my experience and education in this type of position?” (Good Answer) 

A: #2 - I’m sure when the time comes and I know more about the facts of the position and how it fits into the bigger picture, we can come to a mutually agreeable figure.” (Good answer) 

A: #3 - “I really need more information about the position before I can begin to discuss salary. Can you tell me the range budgeted for this position?” (Good answer) 

3. Q: “What Salary Range Would You Require to Take This Job?”

A: #1 - “From the research that I have done, it appears to be in the $60–$70,000 range. Is that the range you had in mind?” (This is a good answer if they insist on a figure from you.) 

A: #2 - “Based on my previous experience and education and the ‘going rate’ for this type of position, I would like to be in the mid to high 70s. Is that a range that fits with your compensation structure?” (Good answer if pushed for a figure – give an acceptable range.) 

A: #3 - “I would need to know more about your salary structure and how often you review salaries as well as your entire package before I could discuss salary ranges. Could you provide me with more information before we discuss this subject?” (Good answer to push back the discussion to them.) 

4. Q: “What Salary are You/Were You aking at Your Last Job?”

A: #1 - “It would be very difficult for me to compare my last salary with this position for various reasons—primarily because I don’t have enough information about your whole package. I’m sure we can discuss this subject and your entire package before an offer is made.” (Good answer) 

A: #2 - “That would be like comparing two jobs that are entirely different in responsibilities and in the base and bonus structure. I would be more interested in hearing what the package you offer is, before I compare the two jobs. I hope we can postpone this subject until we both have more information to discuss salary and benefit comparisons.” (Good answer) 

A: #3 - “I had an unusual situation at my last job where I took less salary to own a share of the company. I also had a bonus structure that I was receiving. I would have to look at the entire package that you offer before comparing the two jobs or salaries.” (Good answer) 

5. Q: “Would You Consider Taking Less Pay Than You Made in Your Last Job?”

A: #1 - “I would really need to know more about the opportunity and your whole package before I can give you an answer to that question. You may offer extra perks that my last job may not have had—or vice versa. Basically, I need more information before I decide.” (Good answer) 

A: # 2 - “While my highest career value is not money, it is important to me that I be fairly compensated for the work I do. I would be willing to listen to a fair offer based on what I bring to the position in the way of experience and education.” (Good answer) 

A: #3 - “Opportunity is valuable to me. I am always willing to look at the bigger picture. I would want to be paid according to what I bring to the position, but would be willing to be somewhat flexible.” (Good answer) 

You will notice that most of these examples attempt to defer the subject until you have more information and a better idea of whether this is the right job for you. When you have that information, you will be able to assess whether this is a job where you have something to offer and what the value should be. In other words, what you deserve to be paid. 

Never try to negotiate anything—until there's an offer. 

AES 256 Encryption and Decryption in iOS, OPENSSL

Required things for AES 256 Encryption and Decryption

• Key Should be 64Characters of base64 for 256 AES Encryption
• IV Should be 32Characters of base64 for 256 AES Encryption
• for example key = "3034F6E32958647FDFF75D265B455EBF40C80E6D597092B3A802B3E5863F878E" 
• and iv = "00000000000000000000000000000000"
• key and iv can be any charaters with base64 characters like 0 to 9 and ABCDEF

openssl Requires help key words for AES Encryption and Decryption

usage: enc -ciphername [-AadePp] [-base64] [-bufsize number] [-debug]

    [-engine id] [-in file] [-iv IV] [-K key] [-k password]

    [-kfile file] [-md digest] [-none] [-nopad] [-nosalt]

    [-out file] [-pass arg] [-S salt] [-salt]

 -A                 Process base64 data on one line (requires -a)

 -a                 Perform base64 encoding/decoding (alias -base64)

 -bufsize size      Specify the buffer size to use for I/O

 -d                 Decrypt the input data

 -debug             Print debugging information

 -e                 Encrypt the input data (default)

 -engine id         Use the engine specified by the given identifier

 -in file           Input file to read from (default stdin)

 -iv IV             IV to use, specified as a hexidecimal string

 -K key             Key to use, specified as a hexidecimal string

 -md digest         Digest to use to create a key from the passphrase

 -none              Use NULL cipher (no encryption or decryption)

 -nopad             Disable standard block padding

 -out file          Output file to write to (default stdout)

 -P                 Print out the salt, key and IV used, then exit

                      (no encryption or decryption is performed)

 -p                 Print out the salt, key and IV used

 -pass source       Password source

 -S salt            Salt to use, specified as a hexidecimal string

 -salt              Use a salt in the key derivation routines (default)

 -v                 Verbose

Valid ciphername values:

 -aes-128-cbc              -aes-128-cfb              -aes-128-cfb1            

 -aes-128-cfb8             -aes-128-ctr              -aes-128-ecb             

 -aes-128-gcm              -aes-128-ofb              -aes-128-xts             

 -aes-192-cbc              -aes-192-cfb              -aes-192-cfb1            

 -aes-192-cfb8             -aes-192-ctr              -aes-192-ecb             

 -aes-192-gcm              -aes-192-ofb              -aes-256-cbc             

 -aes-256-cfb              -aes-256-cfb1             -aes-256-cfb8            

 -aes-256-ctr              -aes-256-ecb              -aes-256-gcm             

 -aes-256-ofb              -aes-256-xts              -aes128                  

 -aes192                   -aes256                   -bf                      

 -bf-cbc                   -bf-cfb                   -bf-ecb                  

 -bf-ofb                   -blowfish                 -camellia-128-cbc        

 -camellia-128-cfb         -camellia-128-cfb1        -camellia-128-cfb8       

 -camellia-128-ecb         -camellia-128-ofb         -camellia-192-cbc        

 -camellia-192-cfb         -camellia-192-cfb1        -camellia-192-cfb8       

 -camellia-192-ecb         -camellia-192-ofb         -camellia-256-cbc        

 -camellia-256-cfb         -camellia-256-cfb1        -camellia-256-cfb8       

 -camellia-256-ecb         -camellia-256-ofb         -camellia128             

 -camellia192              -camellia256              -cast                    

 -cast-cbc                 -cast5-cbc                -cast5-cfb               

 -cast5-ecb                -cast5-ofb                -chacha                  

 -des                      -des-cbc                  -des-cfb                 

 -des-cfb1                 -des-cfb8                 -des-ecb                 

 -des-ede                  -des-ede-cbc              -des-ede-cfb             

 -des-ede-ofb              -des-ede3                 -des-ede3-cbc            

 -des-ede3-cfb             -des-ede3-cfb1            -des-ede3-cfb8           

 -des-ede3-ofb             -des-ofb                  -des3                    

 -desx                     -desx-cbc                 -gost89                  

 -gost89-cnt               -gost89-ecb               -id-aes128-GCM           

 -id-aes192-GCM            -id-aes256-GCM            -rc2                     

 -rc2-40-cbc               -rc2-64-cbc               -rc2-cbc                 

 -rc2-cfb                  -rc2-ecb                  -rc2-ofb                 

 -rc4                      -rc4-40                   -rc4-hmac-md5 

AES 256 Encryption and Decryption in OPENSSL in Command Prompt/Terminal

Create File name "testPlainText.enc" write any text required for example "My Name is Vishnu"

Encryption:

Write the below Command in terminal 

openssl enc -aes256 -A -a -p -K 3034F6E32958647FDFF75D265B455EBF40C80E6D597092B3A802B3E5863F878E -iv 00000000000000000000000000000000 -nosalt -in testPlainText.enc -out testEncBas64.enc

The out put will be like shown in below screen shots

1) Terminal Screen Shots

2) below screen shot is "testEncBas64.enc"

The "testEncBas64.enc" file contains encrypted base64 code. Now Decrypt this in terminal itself 

Please follow below command and screenshots of terminal

openssl enc -aes256 -A -p -K 3034F6E32958647FDFF75D265B455EBF40C80E6D597092B3A802B3E5863F878E -iv 00000000000000000000000000000000 -nosalt -base64 -d -in testEncBas64.enc

AES 256 Encryption and Decryption in OPENSSL in iOS Objective C

create files with name "aes.h" & "aes.m" and testViewController.h & testViewController.h

aes.h

#import <Foundation/Foundation.h>

#import <CommonCrypto/CommonDigest.h>

#import <CommonCrypto/CommonCryptor.h>

@interface NSData (AES)

- (NSData *)encryptedDataWithHexKey:(NSString*)hexKey hexIV:(NSString *)hexIV;

- (NSData *)decryptDataWithHexKey:(NSString*)hexKey hexIV:(NSString *)hexIV;

@end

aes.m

#import "aes.h"

@implementation NSData (AES)

+ (NSData *)dataFromHexString:(NSString *)string

{

    string = string.lowercaseString;

    NSMutableData *data = [[NSMutableData alloc] initWithCapacity:string.length/2];

    unsigned char whole_byte;

    char byte_chars[3] = {'\0','\0','\0'};

    int i = 0;

    NSUInteger length = string.length;

    while (i < length-1) {

        char c = [string characterAtIndex:i++];

        if (c < '0' || (c > '9' && c < 'a') || c > 'f')

            continue;

        byte_chars[0] = c;

        byte_chars[1] = [string characterAtIndex:i++];

        whole_byte = strtol(byte_chars, NULL, 16);

        [data appendBytes:&whole_byte length:1];

    }

    return data;

}

+ (void)fillDataArray:(char **)dataPtr length:(NSUInteger)length usingHexString:(NSString *)hexString

{

    NSData *data = [NSData dataFromHexString:hexString];

    NSAssert((data.length + 1) == length, @"The hex provided didn't decode to match length");

    

    unsigned long total_bytes = (length + 1) * sizeof(char);

    

    *dataPtr = malloc(total_bytes);

    bzero(*dataPtr, total_bytes);

    NSLog(@"total_bytes : %lu",total_bytes);

    memcpy(*dataPtr, data.bytes, data.length);

    NSLog(@"data.length : %lu",data.length);

}

- (NSData *)encryptedDataWithHexKey:(NSString*)hexKey hexIV:(NSString *)hexIV

{

    // Fetch key data and put into C string array padded with \0

    char *keyPtr;

    [NSData fillDataArray:&keyPtr length:kCCKeySizeAES256+1 usingHexString:hexKey];

    

    // Fetch iv data and put into C string array padded with \0

    char *ivPtr;

    [NSData fillDataArray:&ivPtr length:kCCKeySizeAES128+1 usingHexString:hexIV];

    

    // For block ciphers, the output size will always be less than or equal to the input size plus the size of one block because we add padding.

    // That's why we need to add the size of one block here

    NSUInteger dataLength = self.length;

    size_t bufferSize = dataLength + kCCBlockSizeAES128;

    void *buffer = malloc( bufferSize );

    

    size_t numBytesEncrypted = 0;

    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES, kCCOptionPKCS7Padding,

                                          keyPtr, kCCKeySizeAES256,

                                          ivPtr /* initialization vector */,

                                          [self bytes], dataLength, /* input */

                                          buffer, bufferSize, /* output */

                                          &numBytesEncrypted);

    

    

    free(keyPtr);

    free(ivPtr);

    

    if(cryptStatus == kCCSuccess) {

        return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];

    }

    

    free(buffer);

    return nil;

}

- (NSData *)decryptDataWithHexKey:(NSString*)hexKey hexIV:(NSString *)hexIV

{

    // Fetch key data and put into C string array padded with \0

    char *keyPtr;

    [NSData fillDataArray:&keyPtr length:kCCKeySizeAES256+1 usingHexString:hexKey];

    

    // Fetch iv data and put into C string array padded with \0

    char *ivPtr;

    [NSData fillDataArray:&ivPtr length:kCCKeySizeAES128+1 usingHexString:hexIV];

    

    // For block ciphers, the output size will always be less than or equal to the input size plus the size of one block because we add padding.

    // That's why we need to add the size of one block here

    NSUInteger dataLength = self.length;

    size_t bufferSize = dataLength + kCCBlockSizeAES128;

    void *buffer = malloc( bufferSize );

    

    size_t numBytesDecrypted = 0;

    CCCryptorStatus cryptStatus = CCCrypt( kCCDecrypt, kCCAlgorithmAES, kCCOptionPKCS7Padding,

                                          keyPtr, kCCKeySizeAES256,

                                          ivPtr,

                                          [self bytes], dataLength, /* input */

                                          buffer, bufferSize, /* output */

                                          &numBytesDecrypted );

    free(keyPtr);

    free(ivPtr);

    

    if( cryptStatus == kCCSuccess )

    {

        // The returned NSData takes ownership of the buffer and will free it on deallocation

        return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];

    }

    

    free(buffer);

    return nil;

}

@end

testViewController.h

#import "aes.h"

#import <UIKit/UIKit.h>

@interface testViewController : UIViewController

@end

testViewController.m

- (Void)testFunction {

    /*hexKey Should be 64Characters of base64 for 256 AES Encryption*/

    NSString *hexKey = @"3034F6E32958647FDFF75D265B455EBF40C80E6D597092B3A802B3E5863F878E";

    NSString *hexIV = nil;

    /*hexIV Should be 32Characters of base64 for 256 AES Encryption*/

    hexIV = @"00000000000000000000000000000000";

    NSString *cipherText = nil;

    

    

    /* AES 256 Encryption*/

    NSString *encryptText = @"Testing123_Test123_End";

    NSData *data = [encryptText dataUsingEncoding:NSUTF8StringEncoding];

    NSData *encryptedPayload = [data encryptedDataWithHexKey:hexKey

                                                       hexIV:hexIV];

    if (encryptedPayload) {

        cipherText = [encryptedPayload base64EncodedStringWithOptions:0];

        NSLog(@"Encryped Result: %@", cipherText);

    }

    

    /* AES 256 Decryption*/

    if(cipherText){

        NSData *data = [[NSData alloc] initWithBase64EncodedString:cipherText options:0];

        NSAssert(data != nil, @"Couldn't base64 decode cipher text");

        

        NSData *decryptedPayload = [data decryptDataWithHexKey:hexKey

                                                         hexIV:hexIV];

        if (decryptedPayload) {

            NSString *decryptText = [[NSString alloc] initWithData:decryptedPayload encoding:NSUTF8StringEncoding];

            NSLog(@"Decrypted Result: %@", decryptText);

        }

    }

}

Any doubts: vishnu.lucky1991@gmail.com