X-Git-Url: https://git.saurik.com/apple/security.git/blobdiff_plain/80e2389990082500d76eb566d4946be3e786c3ef..d8f41ccd20de16f8ebe2ccc84d47bf1cb2b26bbb:/Security/libsecurity_cryptkit/lib/HmacSha1Legacy.c

diff --git a/Security/libsecurity_cryptkit/lib/HmacSha1Legacy.c b/Security/libsecurity_cryptkit/lib/HmacSha1Legacy.c
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+/*
+ * Copyright (c) 2000-2001,2011-2014 Apple Inc. All Rights Reserved.
+ * 
+ * The contents of this file constitute Original Code as defined in and are
+ * subject to the Apple Public Source License Version 1.2 (the 'License').
+ * You may not use this file except in compliance with the License. Please obtain
+ * a copy of the License at http://www.apple.com/publicsource and read it before
+ * using this file.
+ * 
+ * This Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
+ * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
+ * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+ * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
+ * specific language governing rights and limitations under the License.
+ */
+
+
+/*
+ 	File:		HmacSha1Legacy.c
+ 	Contains:	HMAC/SHA1, bug-for-bug compatible with BSAFE 4.0.
+ 	Copyright (c) 2001,2011-2014 Apple Inc. All Rights Reserved.
+*/
+
+#include "ckconfig.h"
+
+#if	CRYPTKIT_HMAC_LEGACY
+
+#include "HmacSha1Legacy.h"
+#include "ckSHA1.h"
+#include <string.h>
+#include <stdlib.h>
+#include <Security/SecBase.h>
+#define kHMACSHA1DigestSize  20
+
+/* XXX These should really be in ckSHA1.h */
+#define kSHA1DigestSize  	20
+#define kSHA1BlockSize  	64
+
+/*
+ * bug-for-bug compatible with BSAFE 4.0. See
+ * BSafe/bsource/algs/ahchhmac.c.
+ *
+ * This implementation, and the BSAFE implementation it emulates, work fine 
+ * when calculating a MAC in a single update (init, update, final). They 
+ * generate nonconforming MACs when performing multiple updates because 
+ * the entire algorithm - both inner and outer digests - are performed 
+ * in the update() step. As a result, if one e.g. calculates a MAC of 
+ * a block of text with one update, and then calculates the MAC over the 
+ * same block of text via two updates, different results will obtain.ÊThe 
+ * incorrect result from the multiple-update scenario is repeatable if and 
+ * only if the same boundaries (same update sizes) are observed on each operation. 
+ *
+ * Because all of the data to be MAC'd is in fact protected by both levels of 
+ * SHA1, and all of the key bits are used, this nonconforming implementation is
+ * believed to be as strong, cryptographically, as a conforming SHA1HMAC
+ * implementation. 
+ */
+struct hmacLegacyContext {
+	sha1Obj sha1Context;
+	UInt8 	k_ipad[kSHA1BlockSize];
+	UInt8 	k_opad[kSHA1BlockSize];
+};
+
+hmacLegacyContextRef hmacLegacyAlloc(void)
+{
+	hmacLegacyContextRef hmac = 
+		(hmacLegacyContextRef)malloc(sizeof(struct hmacLegacyContext));
+	memset(hmac, 0, sizeof(struct hmacLegacyContext));
+	return hmac;
+}
+
+void hmacLegacyFree(
+	hmacLegacyContextRef hmac)
+{
+	if(hmac != NULL) {
+		if(hmac->sha1Context != NULL) {
+			sha1Free (hmac->sha1Context);
+		}
+		memset(hmac, 0, sizeof(struct hmacLegacyContext));
+		free(hmac);
+	}
+}
+
+/* reusable init */
+OSStatus hmacLegacyInit(
+	hmacLegacyContextRef hmac,
+	const void *keyPtr,
+	UInt32 keyLen)
+{	
+	UInt8 	*key;
+	UInt32 	byte;
+
+	if(hmac->sha1Context == NULL) {
+		hmac->sha1Context = sha1Alloc();
+		if(hmac->sha1Context == NULL) {
+			return errSecAllocate;
+		}
+	}
+	else {
+		sha1Reinit(hmac->sha1Context);
+	}
+	/* this implementation requires a 20-byte key */
+	if (keyLen != kSHA1DigestSize) {
+		/* FIXME */
+		return errSecParam;
+	}
+	key = (UInt8*)keyPtr;
+	
+	/* The HMAC_SHA_1 transform looks like:
+	   SHA1 (K XOR opad || SHA1 (K XOR ipad || text))
+	   Where K is a n byte key
+	   ipad is the byte 0x36 repeated 64 times.
+	   opad is the byte 0x5c repeated 64 times.
+	   text is the data being protected.
+	  */
+	/* Copy the key into k_ipad and k_opad while doing the XOR. */
+	for (byte = 0; byte < keyLen; byte++)
+	{
+		hmac->k_ipad[byte] = key[byte] ^ 0x36;
+		hmac->k_opad[byte] = key[byte] ^ 0x5c;
+	}
+
+	/* Fill the remainder of k_ipad and k_opad with 0 XORed with 
+	 * appropriate value. */
+	memset (hmac->k_ipad + keyLen, 0x36, kSHA1BlockSize - keyLen);
+	memset (hmac->k_opad + keyLen, 0x5c, kSHA1BlockSize - keyLen);
+	
+	/* remainder happens in update */
+	return errSecSuccess;
+}
+
+OSStatus hmacLegacyUpdate(
+	hmacLegacyContextRef hmac,
+	const void *textPtr,
+	UInt32 textLen)
+{
+	UInt8 innerDigest[kSHA1DigestSize];
+	
+	/* compute SHA1(k_ipad || data) ==> innerDigest */
+	sha1AddData (hmac->sha1Context, hmac->k_ipad, kSHA1BlockSize);
+	sha1AddData (hmac->sha1Context, (UInt8*)textPtr, textLen);
+	memcpy (innerDigest, sha1Digest(hmac->sha1Context), kSHA1DigestSize);
+	
+	/* reset context (BSAFE does this implicitly in a final() call) */
+	sha1Reinit(hmac->sha1Context);
+	
+	/* compute SHA1(k_opad || innerDigest) */
+	sha1AddData (hmac->sha1Context, hmac->k_opad, kSHA1BlockSize);
+	sha1AddData (hmac->sha1Context, innerDigest, kSHA1DigestSize);
+	
+	/* if there is another update coming, it gets added in to existing 
+	 * context; if the next step is a final, the current digest state is used. */
+	return errSecSuccess;
+}
+
+OSStatus hmacLegacyFinal(
+	hmacLegacyContextRef hmac,
+	void *resultPtr)		// caller mallocs, must be HMACSHA1_OUT_SIZE bytes
+{
+	memcpy (resultPtr, sha1Digest (hmac->sha1Context), kSHA1DigestSize);
+	return errSecSuccess;
+}
+
+#endif	/* CRYPTKIT_HMAC_LEGACY */