diff -r 000000000000 -r df9da0f6b358 MYOID.m
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MYOID.m	Fri Jun 05 08:57:18 2009 -0700
@@ -0,0 +1,152 @@
+//
+//  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));
+}