decrypt md5 iphone - iphone

I'm using the following code to encrypt a string using md5
const char* str = [#"123456" UTF8String];
unsigned char result[CC_MD5_DIGEST_LENGTH];
CC_MD5(str, strlen(str), result);
NSMutableString *ret = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH*2];
for(int i = 0; i<CC_MD5_DIGEST_LENGTH; i++) {
[ret appendFormat:#"%02x",result[i]];
}
NSLog(#"%#", ret);
now I want a source code to decrypt the coded string, Any Help?

You can't decrypt an MD5 HASH, it is a oneway encryption.

MD5 is not an Encryption.
It is a hash function.
Finding the original value from a hash function is in general not possible.

Related

PKCS#11 C_Encrypt fails with Bad Arguments for 128 bit AES key

I generate a 128-bit AES object using "C_CreateObject".
I then do the following to encrypt a piece of data and get a "Bad Argumnents" error on the call to "C_Encrypt" to get the encrypted data length.
char clear[] = "My name is Eric!";
buf_len = sizeof(clear) -1;
rv = pfunc11->C_EncryptInit(session, pMechanism, hObject);
if (rv != CKR_OK)
{
printf("ERROR: rv=0x%08X: initializing encryption:\n", (unsigned int)rv);
return false;
}
rv = pfunc11->C_Encrypt(session, (CK_BYTE_PTR)clear, (CK_ULONG)buf_len, NULL, pulEncryptedDataLen);
if (rv != CKR_OK)
{
printf("ERROR: rv=0x%08X: derror getting encryption data buffer length:\n", (unsigned int)rv);
return false;
}
What am I doing wrong here ?
Here is my mechanism definition -
CK_MECHANISM myMechanism = {CKM_AES_CBC_PAD, (CK_VOID_PTR)"01020304050607081122334455667788", (CK_ULONG)16};
CK_MECHANISM_PTR pMechanism = &myMechanism;
Your pulEncryptedDataLen is probably NULL which causes CKR_ARGUMENTS_BAD.
It is better to use e.g.:
CK_ULONG ulEncryptedDataLen;
...
rv = pfunc11->C_Encrypt(session, (CK_BYTE_PTR)clear, (CK_ULONG)buf_len, NULL, &ulEncryptedDataLen);
The number of bytes sufficient to store encryption result of a single-part encryption gets stored into ulEncryptedDataLen.
Also please note that your way of passing IV value is not correct as "01020304050607081122334455667788" results in an ASCII string (giving IV as 30313032303330343035303630373038 -- which is probably not what you want).
To get correct IV use "\x01\x02\x03\x04\x05\x06\x07\x08\x11\x22\x33\x44\x55\x66\x77\x88" instead.
Good luck!

iOS: RSA Encrypt using public key (with modulus and exponent)

I'm trying to RSA encrypt an NSData using a public key. The public key is in this format:
<RSAKeyValue>
<Modulus>yOTe0L1/NcbXdZYwliS82MiTE8VD5WD23S4RDsdbJOFzCLbsyb4d+K1M5fC+xDfCkji1zQjPiiiToZ7JSj/2ww==</Modulus>
<Exponent>AWAB</Exponent>
</RSAKeyValue>
After extracting the modulus and exponent from the XML string, how do I get a SecKeyRef out of those to be used as publicKey in the method below?
+ (NSString *)encryptRSA:(NSString *)plainTextString key:(SecKeyRef)publicKey
{
size_t cipherBufferSize = SecKeyGetBlockSize(publicKey);
uint8_t *cipherBuffer = malloc(cipherBufferSize);
uint8_t *nonce = (uint8_t *)[plainTextString UTF8String];
SecKeyEncrypt(publicKey,
kSecPaddingOAEP,
nonce,
strlen( (char*)nonce ),
&cipherBuffer[0],
&cipherBufferSize);
NSData *encryptedData = [NSData dataWithBytes:cipherBuffer length:cipherBufferSize];
return [encryptedData base64EncodedString];
}
I can't seem to find a definite answer anywhere.
Wow, no wonder it's so hard to find an answer to this. I spent 2 days down the crypto-rabbit hole, and it's not pretty.
The easy way
Use Chilkat iOS RSA Library. One major downside: cost $189! :O
The hard way
Parse the XML, use SCZ-BasicEncodingRules-iOS to generate a public key data out of the modulus and exponent. If that works, create a dummy keychain using that public key (follow sample code here), extract the public key now in SecKeyRef format and pass it to the encryptRSA method in the question. Finally, cleanup, remove the dummy keychain. Sounds good in theory, but I have never tested this thoroughly, if you do, let me know!
I have used the below method for encryption using public key without using any third party libs, guess it may help who is looking for the same after they implemented it just as I did :D
+(NSString *)encryptRSA:(NSString *)plainTextString key:(SecKeyRef)publicKey
{
size_t cipherBufferSize = SecKeyGetBlockSize(publicKey);
uint8_t *cipherBuffer = malloc(cipherBufferSize);
uint8_t *nonce = (uint8_t *)[plainTextString UTF8String];
SecKeyEncrypt(publicKey,
kSecPaddingPKCS1,
nonce,
strlen( (char*)nonce ),
&cipherBuffer[0],
&cipherBufferSize);
NSData *encryptedData = [NSData dataWithBytes:cipherBuffer length:cipherBufferSize];
return [encryptedData base64EncodedStringWithOptions:0];
}
I think this will help u!
you can create a java file like fellow:
this java funtion will generate a public key to base64String
public static RSAPublicKey getPublicKey(String modulus, String exponent) {
try {
BigInteger b1 = new BigInteger(modulus,16);
BigInteger b2 = new BigInteger(exponent,16);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
RSAPublicKeySpec keySpec = new RSAPublicKeySpec(b1, b2);
return (RSAPublicKey) keyFactory.generatePublic(keySpec);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public static String encodePublicKey(byte[] encoded) throws Exception{
BASE64Encoder base64Encoder= new BASE64Encoder();
String s=base64Encoder.encode(encoded);
return s;
u should use like :encodePublicKey(publicKey.getEncoded());
Got it!

how to add FileAttachment annotations of pdf

Hello i am using this library for implementation of annotation but facing one issue of attachment of image it provide PdfFileSpec objective c++ function i tried to convert this function to objective c but getting error in below image
class PODOFO_DOC_API PdfFileSpec : public PdfElement {
public:
PdfFileSpec( const char* pszFilename, bool bEmbedd, PdfDocument* pParent );
PdfFileSpec( const char* pszFilename, bool bEmbedd, PdfVecObjects* pParent );
/* Petr P. Petrov 17 September 2009*/
/** Embeds the file in memory from "data" buffer under "pszFileName" fie name.
*/
PdfFileSpec( const char* pszFilename, const unsigned char* data, ptrdiff_t size, PdfVecObjects* pParent);
PdfFileSpec( PdfObject* pObject );
/** \returns the filename of this file specification.
* if no general name is available
* it will try the Unix, Mac and DOS keys too.
*/
const PdfString & GetFilename() const;
+(void)createFreeTextAnnotationOnPage:(NSInteger)pageIndex doc:(PdfMemDocument*)aDoc rect:(CGRect)aRect borderWidth:(double)bWidth title:(NSString*)title content:(NSString*)content bOpen:(Boolean)bOpen color:(UIColor*)color {
PoDoFo::PdfMemDocument *doc = (PoDoFo::PdfMemDocument *) aDoc;
PoDoFo::PdfPage* pPage = doc->GetPage(pageIndex);
if (! pPage) {
// couldn't get that page
return;
}
PoDoFo::PdfAnnotation* anno;
PoDoFo::EPdfAnnotation type= PoDoFo::ePdfAnnotation_Text;
PoDoFo::PdfRect rect;
rect.SetBottom(aRect.origin.y);
rect.SetLeft(aRect.origin.x);
rect.SetHeight(aRect.size.height);
rect.SetWidth(aRect.size.width);
NSData *data=UIImagePNGRepresentation([UIImage imageNamed:#"Add_button.png"]);
anno = pPage->CreateAnnotation(type , rect);
NSString *myString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
PoDoFo::PdfString sTitle([title UTF8String]);
PoDoFo::PdfString sContent([content UTF8String]);
PoDoFo::PdfFileSpec data1([myString UTF8String], true, doc);
}
I don't see why you are using reinterpret_cast, and it's certainly being misused in the construction of data1.
Have you simply tried:
PoDoFo::PdfString sTitle([title UTF8String]);
PoDoFo::PdfString sContent([content UTF8String]);
PoDoFo::PdfFileSpec data1([myString UTF8String], true, doc);

SecCertificateRef: How to get the certificate information?

I have a certificate (SecCertificateRef), I can check if it's valid and I can extract a "summary" using SecCertificateCopySubjectSummary.
What is the "summary" exactly? I don't understand the term "A string that contains a human-readable summary of the contents of the certificate." in the Apple documentation. I think, they mean the "CN" in the certificate, correct?
Is there any method to get the clear X509-information out of SecCertificateRef? Does a cast to a keychain-object help?
I want to have something like this and I am especially focussed on the "CN" to compare it with the URL I submitted to avoid man-in-the-middle attacks. (Or any better ideas?)
That is what I want to have:
Version: 3 (0x2)
Serial Number: 1 (0x1)
Signature Algorithm: md5WithRSAEncryption
Issuer: C=XY, ST=Austria, L=Graz, O=TrustMe Ltd, OU=Certificate Authority, CN=CA/Email=ca#trustme.dom
Validity
Not Before: Oct 29 17:39:10 2000 GMT
Not After : Oct 29 17:39:10 2001 GMT
Subject: C=DE, ST=Austria, L=Vienna, O=Home, OU=Web Lab, CN=anywhere.com/Email=xyz#anywhere.com
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
RSA Public Key: (1024 bit)
Modulus (1024 bit):
00:c4:40:4c:6e:14:1b:61:36:84:24:b2:61:c0:b5:
d7:e4:7a:a5:4b:94:ef:d9:5e:43:7f:c1:64:80:fd:
9f:50:41:6b:70:73:80:48:90:f3:58:bf:f0:4c:b9:
90:32:81:59:18:16:3f:19:f4:5f:11:68:36:85:f6:
1c:a9:af:fa:a9:a8:7b:44:85:79:b5:f1:20:d3:25:
7d:1c:de:68:15:0c:b6:bc:59:46:0a:d8:99:4e:07:
50:0a:5d:83:61:d4:db:c9:7d:c3:2e:eb:0a:8f:62:
8f:7e:00:e1:37:67:3f:36:d5:04:38:44:44:77:e9:
f0:b4:95:f5:f9:34:9f:f8:43
Exponent: 65537 (0x10001)
X509v3 extensions:
X509v3 Subject Alternative Name:
email:xyz#anywhere.com
Netscape Comment:
mod_ssl generated test server certificate
Netscape Cert Type:
SSL Server
Signature Algorithm: md5WithRSAEncryption
12:ed:f7:b3:5e:a0:93:3f:a0:1d:60:cb:47:19:7d:15:59:9b:
3b:2c:a8:a3:6a:03:43:d0:85:d3:86:86:2f:e3:aa:79:39:e7:
82:20:ed:f4:11:85:a3:41:5e:5c:8d:36:a2:71:b6:6a:08:f9:
cc:1e:da:c4:78:05:75:8f:9b:10:f0:15:f0:9e:67:a0:4e:a1:
4d:3f:16:4c:9b:19:56:6a:f2:af:89:54:52:4a:06:34:42:0d:
d5:40:25:6b:b0:c0:a2:03:18:cd:d1:07:20:b6:e5:c5:1e:21:
44:e7:c5:09:d2:d5:94:9d:6c:13:07:2f:3b:7c:4c:64:90:bf:
ff:8e
I couldn't wait for an answer to the bounty, so I found a solution myself. As others said, Security.framework doesn't give you a way to get this information, so you need to ask OpenSSL to parse the certificate data for you:
#import <openssl/x509.h>
// ...
NSData *certificateData = (NSData *) SecCertificateCopyData(certificate);
const unsigned char *certificateDataBytes = (const unsigned char *)[certificateData bytes];
X509 *certificateX509 = d2i_X509(NULL, &certificateDataBytes, [certificateData length]);
NSString *issuer = CertificateGetIssuerName(certificateX509);
NSDate *expiryDate = CertificateGetExpiryDate(certificateX509);
Where CertificateGetIssuerName and CertificateGetExpiryDate are as follows:
static NSString * CertificateGetIssuerName(X509 *certificateX509)
{
NSString *issuer = nil;
if (certificateX509 != NULL) {
X509_NAME *issuerX509Name = X509_get_issuer_name(certificateX509);
if (issuerX509Name != NULL) {
int nid = OBJ_txt2nid("O"); // organization
int index = X509_NAME_get_index_by_NID(issuerX509Name, nid, -1);
X509_NAME_ENTRY *issuerNameEntry = X509_NAME_get_entry(issuerX509Name, index);
if (issuerNameEntry) {
ASN1_STRING *issuerNameASN1 = X509_NAME_ENTRY_get_data(issuerNameEntry);
if (issuerNameASN1 != NULL) {
unsigned char *issuerName = ASN1_STRING_data(issuerNameASN1);
issuer = [NSString stringWithUTF8String:(char *)issuerName];
}
}
}
}
return issuer;
}
static NSDate *CertificateGetExpiryDate(X509 *certificateX509)
{
NSDate *expiryDate = nil;
if (certificateX509 != NULL) {
ASN1_TIME *certificateExpiryASN1 = X509_get_notAfter(certificateX509);
if (certificateExpiryASN1 != NULL) {
ASN1_GENERALIZEDTIME *certificateExpiryASN1Generalized = ASN1_TIME_to_generalizedtime(certificateExpiryASN1, NULL);
if (certificateExpiryASN1Generalized != NULL) {
unsigned char *certificateExpiryData = ASN1_STRING_data(certificateExpiryASN1Generalized);
// ASN1 generalized times look like this: "20131114230046Z"
// format: YYYYMMDDHHMMSS
// indices: 01234567890123
// 1111
// There are other formats (e.g. specifying partial seconds or
// time zones) but this is good enough for our purposes since
// we only use the date and not the time.
//
// (Source: http://www.obj-sys.com/asn1tutorial/node14.html)
NSString *expiryTimeStr = [NSString stringWithUTF8String:(char *)certificateExpiryData];
NSDateComponents *expiryDateComponents = [[NSDateComponents alloc] init];
expiryDateComponents.year = [[expiryTimeStr substringWithRange:NSMakeRange(0, 4)] intValue];
expiryDateComponents.month = [[expiryTimeStr substringWithRange:NSMakeRange(4, 2)] intValue];
expiryDateComponents.day = [[expiryTimeStr substringWithRange:NSMakeRange(6, 2)] intValue];
expiryDateComponents.hour = [[expiryTimeStr substringWithRange:NSMakeRange(8, 2)] intValue];
expiryDateComponents.minute = [[expiryTimeStr substringWithRange:NSMakeRange(10, 2)] intValue];
expiryDateComponents.second = [[expiryTimeStr substringWithRange:NSMakeRange(12, 2)] intValue];
NSCalendar *calendar = [NSCalendar currentCalendar];
expiryDate = [calendar dateFromComponents:expiryDateComponents];
[expiryDateComponents release];
}
}
}
return expiryDate;
}
I only actually needed the issuer's organization name and the expiry date for my purposes, so that's all the code I've included below. But, based on this you should be able to figure out the rest by reading the x509.h header file.
Edit:
Here's how to get the certificate. I haven't put any error handling, etc. You'll want to check trustResult, err, etc., for example.
NSURLAuthenticationChallenge *challenge;
SecTrustResultType trustResult;
SecTrustRef trust = challenge.protectionSpace.serverTrust;
OSStatus err = SecTrustEvaluate(trust, &trustResult);
SecCertificateRef certificate = SecGetLeafCertificate(trust); // See Apple docs for implementation of SecGetLeafCertificate
better just use SecCertificateCopyCommonName to get CN to compare to your required hostname.
You were right Michael, iOS won't give you the API to do a full job on a X.509 certificates. Thankfully it will give you access to the actual (ASN.1) encoded certificate data. From there you can do your own decoding (not much fun) or delegate it to an existing library, like you did with OpenSSL.
Here's my version that uses the .NET framework. It's mean to be used by MonoTouch developers (and MonoMac developers too) who needs to interoperate with SecCertificateRef within their applications.
public void Show (SecCertificate sc)
{
// get the SecCertificate "raw", i.e. ASN.1 encoded, data
byte[] data = sc.DerData.ToArray<byte> ();
// the build the managed X509Certificate2 from it
X509Certificate2 cer = new X509Certificate2 (data);
// to get all properties / methods available in .NET (pretty exhaustive)
Console.WriteLine ("SubjectName: {0}", cer.Subject);
Console.WriteLine ("IssuerName: {0}", cer.Issuer);
Console.WriteLine ("NotBefore: {0}", cer.NotBefore);
Console.WriteLine ("NotAfter: {0}", cer.NotAfter);
Console.WriteLine ("SerialNumber: {0}", cer.SerialNumber);
// ...
}
If for some reason you want to do this without OpenSSL one can use the apple extraction keys. The first one will extract (just) the Subject and Issuer (there are more kSecOIDX509's for most other things, like expiry dates) and pass them for printing.
+(NSString*)stringFromCerificateWithLongwindedDescription:(SecCertificateRef) certificateRef {
if (certificateRef == NULL)
return #"";
CFStringRef commonNameRef;
OSStatus status;
if ((status=SecCertificateCopyCommonName(certificateRef, &commonNameRef)) != errSecSuccess) {
NSLog(#"Could not extract name from cert: %#",
SecCopyErrorMessageString(status, NULL));
return #"Unreadable cert";
};
CFStringRef summaryRef = SecCertificateCopySubjectSummary(certificateRef);
if (summaryRef == NULL)
summaryRef = CFRetain(commonNameRef);
CFErrorRef error;
const void *keys[] = { kSecOIDX509V1SubjectName, kSecOIDX509V1IssuerName };
const void *labels[] = { "Subject", "Issuer" };
CFArrayRef keySelection = CFArrayCreate(NULL, keys , sizeof(keys)/sizeof(keys[0]), &kCFTypeArrayCallBacks);
CFDictionaryRef vals = SecCertificateCopyValues(certificateRef, keySelection,&error);
NSMutableString *longDesc = [[NSMutableString alloc] init];
for(int i = 0; i < sizeof(keys)/sizeof(keys[0]); i++) {
CFDictionaryRef dict = CFDictionaryGetValue(vals, keys[i]);
CFArrayRef values = CFDictionaryGetValue(dict, kSecPropertyKeyValue);
if (values == NULL)
continue;
[longDesc appendFormat:#"%s:%#\n\n", labels[i], [NSString stringFromDNwithSubjectName:values]];
}
CFRelease(vals);
CFRelease(summaryRef);
CFRelease(commonNameRef);
return longDesc;
}
The second function is an over the top try to extract anything you can get your mittens on:
+(NSString *)stringFromDNwithSubjectName:(CFArrayRef)array {
NSMutableString * out = [[NSMutableString alloc] init];
const void *keys[] = { kSecOIDCommonName, kSecOIDEmailAddress, kSecOIDOrganizationalUnitName, kSecOIDOrganizationName, kSecOIDLocalityName, kSecOIDStateProvinceName, kSecOIDCountryName };
const void *labels[] = { "CN", "E", "OU", "O", "L", "S", "C", "E" };
for(int i = 0; i < NVOID(keys); i++) {
for (CFIndex n = 0 ; n < CFArrayGetCount(array); n++) {
CFDictionaryRef dict = CFArrayGetValueAtIndex(array, n);
if (CFGetTypeID(dict) != CFDictionaryGetTypeID())
continue;
CFTypeRef dictkey = CFDictionaryGetValue(dict, kSecPropertyKeyLabel);
if (!CFEqual(dictkey, keys[i]))
continue;
CFStringRef str = (CFStringRef) CFDictionaryGetValue(dict, kSecPropertyKeyValue);
[out appendFormat:#"%s=%# ", labels[i], (__bridge NSString*)str];
}
}
return [NSString stringWithString:out];
}
I don't believe there is a public API to do this on iOS. On OSX there are a number of SecCertificate APIs to pick apart the X.509 information.
FYI, assuming you're using HTTPS, checking the CN yourself is mostly useless, because the OS already checks to make sure the name is present in the cert. You're more likely to want to check the public key (for key pinning), which you can get from the trust object without touching the certificate directly.
If the public key matches the previous key, then either the site is legit or somebody has thoroughly compromised the site.

Decrypt NSString with AES128 encryption

I hope a smart guy will help me :)
I receive a encrypted text from a C# server and i'm unable to decrypt it correctly:
I always have an empty string. Normally the decrypted key should be
1111111111111111
(16time)
I use the AES128 algorithm for the decryption and the settings given by the back end (the guys who encrypted this text) are as follow :
Padding: PKCS7Padding
KeySize: 128
InitVector: null
Mode: CBC
text to decrypt (base64 encoded) : 1vycDn3ktoyaUkPlRAIlsA==
the key: 3a139b187647a66d
Here is the code i use for the decryption
- (NSData *)AES256DecryptWithKey:(NSString *)key {
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
char keyPtr[kCCKeySizeAES2128+1]; // room for terminator (unused)
bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)
// fetch key data
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [self length];
//See the doc: For block ciphers, the output size will always be less than or
//equal to the input size plus the size of one block.
//That's why we need to add the size of one block here
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc(bufferSize);
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES128,
NULL /* initialization vector (optional) */,
[self bytes], dataLength, /* input */
buffer, bufferSize, /* output */
&numBytesDecrypted);
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); //free the buffer;
return nil;
}
Thanx alot in advance for your help. I'm on this probleme since a long time with no answer in front of me...
The test input you're using doesn't appear to be using PKCS7 padding -- it's using no padding. I was able to get a successful decrypt using:
echo 1vycDn3ktoyaUkPlRAIlsA== | openssl enc -aes-128-cbc -d -a -K `echo 3a139b187647a66d | xxd -ps` -iv 0 -nosalt -nopad