Open sourcing our SHA1 code

KSSHA1Stream.h

@@ -0,0 +1,41 @@
+//
+//  KSSHA1Stream.h
+//  Sandvox
+//
+//  Created by Mike on 12/03/2011.
+//  Copyright 2011 Karelia Software. All rights reserved.
+//
+
+#import <Cocoa/Cocoa.h>
+#import <CommonCrypto/CommonDigest.h>
+
+
+
+@interface KSSHA1Stream : NSOutputStream
+{
+  @private
+    CC_SHA1_CTX _ctx;
+    NSData      *_digest;
+}
+
+// nil until you call -close
+@property(nonatomic, copy, readonly) NSData *SHA1Digest;
+
+@end
+
+
+@interface KSSHA1Stream (KSURLHashing)
++ (NSData *)SHA1DigestOfContentsOfURL:(NSURL *)URL;
+@end
+
+
+#pragma mark -
+
+
+@interface NSData (KSSHA1Stream)
+
+// Cryptographic hashes
+- (NSData *)ks_SHA1Digest;
+- (NSString *)ks_SHA1DigestString;
+
+@end

KSSHA1Stream.m

@@ -0,0 +1,164 @@
+//
+//  KSSHA1Stream.m
+//  Sandvox
+//
+//  Created by Mike on 12/03/2011.
+//  Copyright 2011 Karelia Software. All rights reserved.
+//
+
+#import "KSSHA1Stream.h"
+
+
+@implementation KSSHA1Stream
+
+- (id)init;
+{
+    [super init];
+    CC_SHA1_Init(&_ctx);
+    return self;
+}
+
+- (void)close;
+{
+    unsigned char digest[CC_SHA1_DIGEST_LENGTH];
+	CC_SHA1_Final(digest, &_ctx);
+
+    _digest = [[NSData alloc] initWithBytes:digest length:CC_SHA1_DIGEST_LENGTH];
+}
+
+- (void)dealloc;
+{
+    [_digest release];
+    [super dealloc];
+}
+
+- (NSInteger)write:(const uint8_t *)buffer maxLength:(NSUInteger)len;
+{
+    CC_SHA1_Update(&_ctx, buffer, len);
+    return len;
+}
+
+@synthesize SHA1Digest = _digest;
+
+@end
+
+
+#pragma mark -
+
+
+@implementation NSData (KSSHA1Stream)
+
+- (NSData *)ks_SHA1Digest
+{
+	KSSHA1Stream *stream = [[KSSHA1Stream alloc] init];
+    [stream write:[self bytes] maxLength:[self length]];
+    [stream close];
+    NSData *result = [[[stream SHA1Digest] copy] autorelease];
+
+    [stream release];
+    return result;
+}
+
+- (NSString *)ks_SHA1DigestString
+{
+	static char sHEHexDigits[] = "0123456789abcdef";
+
+    NSData *digestData = [self ks_SHA1Digest];
+    unsigned char *digest = (unsigned char *)[digestData bytes];
+
+	unsigned char digestString[2 * CC_SHA1_DIGEST_LENGTH];
+    NSUInteger i;
+	for (i=0; i<CC_SHA1_DIGEST_LENGTH; i++)
+	{
+		digestString[2*i]   = sHEHexDigits[digest[i] >> 4];
+		digestString[2*i+1] = sHEHexDigits[digest[i] & 0x0f];
+	}
+
+	return [[[NSString alloc] initWithBytes:(const char *)digestString
+                                     length:2 * CC_SHA1_DIGEST_LENGTH
+                                   encoding:NSASCIIStringEncoding] autorelease];
+}
+
+@end
+
+
+#pragma mark -
+
+
+@implementation KSSHA1Stream (KSURLHashing)
+
++ (NSData *)SHA1DigestOfContentsOfURL:(NSURL *)URL;
+{
+    OBPRECONDITION(URL);
+    KSSHA1Stream *hasher = [[KSSHA1Stream alloc] initWithURL:URL];
+
+    NSData *result;
+    if ([URL isFileURL])
+    {
+        NSInputStream *stream = [[NSInputStream alloc] initWithFileAtPath:[URL path]];
+        [stream open];
+
+#define READ_BUFFER_SIZE 64*CC_SHA1_BLOCK_BYTES
+        uint8_t buffer[READ_BUFFER_SIZE];
+
+        while ([stream streamStatus] < NSStreamStatusAtEnd)
+        {
+            NSInteger length = [stream read:buffer maxLength:READ_BUFFER_SIZE];
+
+            if (length > 0)
+            {
+                NSInteger written = [hasher write:buffer maxLength:length];
+                OBASSERT(written == length);
+            }
+        }
+
+        [stream release];
+
+        [hasher close];
+        result = [hasher SHA1Digest];
+    }
+    else
+    {
+        // Run the runloop until done
+        while (!(result = [hasher SHA1Digest]))
+        {
+            [[NSRunLoop currentRunLoop] runUntilDate:[NSDate distantPast]];
+        }
+
+        // Finish up. Empty hash means load failed
+        if (![result length]) result = nil;
+    }
+
+
+    // Finish up. Empty hash means load failed
+    result = [[result copy] autorelease];
+    [hasher release];
+    return result;
+}
+
+- (id)initWithURL:(NSURL *)URL;
+{
+    [self init];
+
+    [NSURLConnection connectionWithRequest:[NSURLRequest requestWithURL:URL] 
+                                  delegate:self];
+
+    return self;
+}
+
+- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
+{
+    [self write:[data bytes] maxLength:[data length]];
+}
+
+- (void)connectionDidFinishLoading:(NSURLConnection *)connection
+{
+    [self close];
+}
+
+- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
+{
+    _digest = [[NSData alloc] init];
+}
+
+@end