//

 //  MYOID.m

 //  MYCrypto

 //

 //  Created by Jens Alfke on 5/28/09.

 //  Copyright 2009 Jens Alfke. All rights reserved.

 //

 #import "MYOID.h"

 @implementation MYOID

 - (id) initWithComponents: (const UInt32*)components count: (unsigned)count

 {

     self = [super init];

     if (self != nil) {

         _data = [[NSData alloc] initWithBytes: components length: count*sizeof(UInt32)];

     }

     return self;

 }

 - (id) initWithBEREncoding: (NSData*)encoding

 {

     self = [super init];

     if (self != nil) {

         size_t len = encoding.length;

         const UInt8 *src = encoding.bytes;

         const UInt8 *end = src+len;

         NSMutableData *data = [NSMutableData dataWithLength: (len+1)*sizeof(UInt32)];

         UInt32* dst = data.mutableBytes;

         if (len >= 2) {

             *dst++ = *src / 40;

             *dst++ = *src % 40;

             src++; 

         }

         while (src < end) {

             UInt32 component = 0;

             UInt8 byte;

             do{

                 if (src >= end) {

                     [self release];

                     return nil;

                 }

                 byte = *src++;

                 component = (component << 7) | (byte & 0x7F);

             }while (byte & 0x80);

             *dst++ = component;

         }

         data.length = (UInt8*)dst - (UInt8*)data.mutableBytes;

         _data = [data copy];

     }

     return self;

 }

 + (MYOID*) OIDWithEncoding: (NSData*)encoding {

     return [[[self alloc] initWithBEREncoding: encoding] autorelease];

 }

 - (id) copyWithZone: (NSZone*)zone {

     return [self retain];

 }

 - (void) dealloc

 {

     [_data release];

     [super dealloc];

 }

 - (NSString*) description {

     NSMutableString *desc = [NSMutableString stringWithString: @"{"];

     const UInt32* components = self.components;

     unsigned count = self.componentCount;

     for (unsigned i=0; i<count; i++) {

         if (i>0)

             [desc appendString: @" "];

         [desc appendFormat: @"%u", components[i]];

     }

     [desc appendString: @"}"];

     return desc;

 }

 - (NSData*) componentData       {return _data;}

 - (const UInt32*) components    {return (const UInt32*)_data.bytes;}

 - (unsigned) componentCount     {return _data.length / sizeof(UInt32);}

 - (NSUInteger)hash {

     return _data.hash;

 }

 - (BOOL)isEqual:(id)object {

     return [object isKindOfClass: [MYOID class]] && [_data isEqual: [object componentData]];

 }

 - (NSData*) DEREncoding {

     unsigned count = self.componentCount;

     UInt8 encoding[5*count]; // worst-case size

     const UInt32 *src=self.components, *end=src+count;

     UInt8 *dst = encoding;

     if (count >= 2 && src[0]<=3 && src[1]<40) {

         // Weird collapsing of 1st two components into one byte:

         *dst++ = src[0]*40 + src[1];

         src += 2;

     }

     while (src<end) {

         UInt32 component = *src++;

         // Write the component in 7-bit groups, most significant first:

         BOOL any = NO;

         for (int shift=28; shift>=0; shift -= 7) {

             UInt8 byte = (component >> shift) & 0x7F;

             if (byte || any) {

                 if (any)

                     dst[-1] |= 0x80;

                 *dst++ = byte;

                 any = YES;

             }

         }

     }

     return [NSData dataWithBytes: encoding length: dst-encoding];

 }

 @end

 #define $data(BYTES...)    ({const uint8_t bytes[] = {BYTES}; [NSData dataWithBytes: bytes length: sizeof(bytes)];})

 #define $components(INTS...)    ({const UInt32 components[] = {INTS}; components;})

 TestCase(OID) {

     CAssertEqual([[MYOID OIDWithEncoding: $data(0x2a,0x86,0x48,0x86,0xf7,0x0d,0x01,0x01,0x01)] description],

                  @"{1 2 840 113549 1 1 1}");

     CAssertEqual([[MYOID OIDWithEncoding: $data(0x55,0x04,0x04)] description],

                  @"{2 5 4 4}");

     CAssertEqual([[MYOID OIDWithEncoding: $data(0x2a,0x86,0x48,0x86,0xf7,0x0d,0x01,0x09,0x01)] description],

                  @"{1 2 840 113549 1 9 1}");

     CAssertEqual([[[MYOID alloc] initWithComponents: $components(1,2,840,113549,1,1,1) count: 7] description],

                  @"{1 2 840 113549 1 1 1}");

     CAssertEqual([[[MYOID alloc] initWithComponents: $components(1,2,840,113549,1,1,1) count: 7] DEREncoding],

                  $data(0x2a, 0x86, 0x48, 0x86,  0xf7, 0x0d, 0x01, 0x01,  0x01));

     CAssertEqual([[[MYOID alloc] initWithComponents: $components(2,5,4,4) count: 4] DEREncoding],

                  $data(0x55,0x04,0x04));

 }