1.1 --- a/MYPublicKey.m	Wed Jun 03 17:20:53 2009 -0700
     1.2 +++ b/MYPublicKey.m	Sat Jun 06 15:36:35 2009 -0700
     1.3 @@ -9,6 +9,9 @@
     1.4  #import "MYPublicKey.h"
     1.5  #import "MYCrypto_Private.h"
     1.6  #import "MYDigest.h"
     1.7 +#import "MYASN1Object.h"
     1.8 +#import "MYDEREncoder.h"
     1.9 +#import "MYBERParser.h"
    1.10  #import "MYErrorUtils.h"
    1.11  #import <CommonCrypto/CommonDigest.h>
    1.12  
    1.13 @@ -17,6 +20,16 @@
    1.14  @implementation MYPublicKey
    1.15  
    1.16  
    1.17 +- (id) initWithModulus: (NSData*)modulus exponent: (unsigned)exponent {
    1.18 +    // An RSA key is encoded in ASN.1 as a sequence of modulus and exponent, both as integers.
    1.19 +    MYASN1BigInteger *modulusInt = [[MYASN1BigInteger alloc] initWithUnsignedData: modulus];
    1.20 +    id asn1 = $array( modulusInt, $object(exponent) );
    1.21 +    [modulusInt release];
    1.22 +    NSData *keyData = [MYDEREncoder encodeRootObject: asn1 error: nil];
    1.23 +    return [self initWithKeyData: keyData];
    1.24 +}
    1.25 +
    1.26 +
    1.27  - (void) dealloc
    1.28  {
    1.29      [_digest release];
    1.30 @@ -52,6 +65,18 @@
    1.31  #endif
    1.32  
    1.33  
    1.34 +- (BOOL) getModulus: (NSData**)outModulus exponent: (unsigned*)outExponent {
    1.35 +    Assert(outModulus!=nil);
    1.36 +    Assert(outExponent!=nil);
    1.37 +    NSArray *asn1 = $castIf(NSArray, MYBERParse(self.keyData, nil));
    1.38 +    if (!asn1 || asn1.count != 2)
    1.39 +        return NO;
    1.40 +    *outModulus = $castIf(MYASN1BigInteger, [asn1 objectAtIndex: 0]).unsignedData;
    1.41 +    *outExponent = $castIf(NSNumber, [asn1 objectAtIndex: 1]).unsignedIntValue;
    1.42 +    return (*outModulus!=nil && *outExponent>=3);
    1.43 +}
    1.44 +
    1.45 +
    1.46  - (NSData*) rawEncryptData: (NSData*)data {
    1.47      return [self _crypt: data operation: YES];
    1.48  }