Index: src/OFMD5Hash.m
==================================================================
--- src/OFMD5Hash.m
+++ src/OFMD5Hash.m
@@ -153,11 +153,12 @@
 
 	if (size == 0)
 		return;
 
 	if (isCalculated)
-		@throw [OFHashAlreadyCalculatedException newWithClass: isa];
+		@throw [OFHashAlreadyCalculatedException newWithClass: isa
+								 hash: self];
 
 	/* Update bitcount */
 	t = bits[0];
 	if ((bits[0] = t + ((uint32_t)size << 3)) < t)
 		/* Carry from low to high */

Index: src/OFSHA1Hash.m
==================================================================
--- src/OFSHA1Hash.m
+++ src/OFSHA1Hash.m
@@ -162,11 +162,12 @@
 {
 	if (size == 0)
 		return;
 
 	if (isCalculated)
-		@throw [OFHashAlreadyCalculatedException newWithClass: isa];
+		@throw [OFHashAlreadyCalculatedException newWithClass: isa
+								 hash: self];
 
 	sha1_update(state, &count, buffer, buf, size);
 }
 
 - (uint8_t*)digest

Index: src/exceptions/OFHashAlreadyCalculatedException.h
==================================================================
--- src/exceptions/OFHashAlreadyCalculatedException.h
+++ src/exceptions/OFHashAlreadyCalculatedException.h
@@ -14,10 +14,40 @@
  * file.
  */
 
 #import "OFException.h"
 
+@class OFHash;
+
 /**
  * \brief An exception indicating that the hash has already been calculated.
  */
 @interface OFHashAlreadyCalculatedException: OFException
+{
+	OFHash *hash;
+}
+
+#ifdef OF_HAVE_PROPERTIES
+@property (readonly, nonatomic) OFHash *hash;
+#endif
+
+/**
+ * \param hash The hash which has already been calculated
+ * \return A new hash already calculated exception
+ */
++ newWithClass: (Class)class_
+	  hash: (OFHash*)hash;
+
+/**
+ * Initializes an already allocated hash already calculated exception.
+ *
+ * \param hash The hash which has already been calculated
+ * \return An initialized hash already calculated exception
+ */
+- initWithClass: (Class)class_
+	   hash: (OFHash*)hash;
+
+/**
+ * \return The hash which has already been calculated
+ */
+- (OFHash*)hash;
 @end

Index: src/exceptions/OFHashAlreadyCalculatedException.m
==================================================================
--- src/exceptions/OFHashAlreadyCalculatedException.m
+++ src/exceptions/OFHashAlreadyCalculatedException.m
@@ -16,12 +16,51 @@
 
 #include "config.h"
 
 #import "OFHashAlreadyCalculatedException.h"
 #import "OFString.h"
+
+#import "OFNotImplementedException.h"
 
 @implementation OFHashAlreadyCalculatedException
++ newWithClass: (Class)class_
+	  hash: (OFHash*)hash
+{
+	return [[self alloc] initWithClass: class_
+				      hash: hash];
+}
+
+- initWithClass: (Class)class_
+{
+	Class c = isa;
+	[self release];
+	@throw [OFNotImplementedException newWithClass: c
+					      selector: _cmd];
+}
+
+- initWithClass: (Class)class_
+	   hash: (OFHash*)hash_
+{
+	self = [super initWithClass: class_];
+
+	@try {
+		hash = [hash_ retain];
+	} @catch (id e) {
+		[self release];
+		@throw e;
+	}
+
+	return self;
+}
+
+- (void)dealloc
+{
+	[hash release];
+
+	[super dealloc];
+}
+
 - (OFString*)description
 {
 	if (description != nil)
 		return description;
 
@@ -29,6 +68,11 @@
 	    @"The hash has already been calculated in class %@ and thus no new "
 	    @"data can be added", inClass];
 
 	return description;
 }
+
+- (OFHash*)hash
+{
+	return hash;
+}
 @end