1 files changed, 118 insertions, 0 deletions
diff --git a/lib/isc/hmacmd5.c b/lib/isc/hmacmd5.c
new file mode 100644
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--- /dev/null
+++ b/lib/isc/hmacmd5.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (C) 2000, 2001  Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: hmacmd5.c,v 1.14 2007/06/19 23:47:17 tbox Exp $ */
+
+/*! \file
+ * This code implements the HMAC-MD5 keyed hash algorithm
+ * described in RFC2104.
+ */
+
+#include "config.h"
+
+#include <isc/assertions.h>
+#include <isc/hmacmd5.h>
+#include <isc/md5.h>
+#include <isc/string.h>
+#include <isc/types.h>
+#include <isc/util.h>
+
+#define PADLEN 64
+#define IPAD 0x36
+#define OPAD 0x5C
+
+/*!
+ * Start HMAC-MD5 process.  Initialize an md5 context and digest the key.
+ */
+void
+isc_hmacmd5_init(isc_hmacmd5_t *ctx, const unsigned char *key,
+		 unsigned int len)
+{
+	unsigned char ipad[PADLEN];
+	int i;
+
+	memset(ctx->key, 0, sizeof(ctx->key));
+	if (len > sizeof(ctx->key)) {
+		isc_md5_t md5ctx;
+		isc_md5_init(&md5ctx);
+		isc_md5_update(&md5ctx, key, len);
+		isc_md5_final(&md5ctx, ctx->key);
+	} else
+		memcpy(ctx->key, key, len);
+
+	isc_md5_init(&ctx->md5ctx);
+	memset(ipad, IPAD, sizeof(ipad));
+	for (i = 0; i < PADLEN; i++)
+		ipad[i] ^= ctx->key[i];
+	isc_md5_update(&ctx->md5ctx, ipad, sizeof(ipad));
+}
+
+void
+isc_hmacmd5_invalidate(isc_hmacmd5_t *ctx) {
+	isc_md5_invalidate(&ctx->md5ctx);
+	memset(ctx->key, 0, sizeof(ctx->key));
+}
+
+/*!
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+void
+isc_hmacmd5_update(isc_hmacmd5_t *ctx, const unsigned char *buf,
+		   unsigned int len)
+{
+	isc_md5_update(&ctx->md5ctx, buf, len);
+}
+
+/*!
+ * Compute signature - finalize MD5 operation and reapply MD5.
+ */
+void
+isc_hmacmd5_sign(isc_hmacmd5_t *ctx, unsigned char *digest) {
+	unsigned char opad[PADLEN];
+	int i;
+
+	isc_md5_final(&ctx->md5ctx, digest);
+
+	memset(opad, OPAD, sizeof(opad));
+	for (i = 0; i < PADLEN; i++)
+		opad[i] ^= ctx->key[i];
+
+	isc_md5_init(&ctx->md5ctx);
+	isc_md5_update(&ctx->md5ctx, opad, sizeof(opad));
+	isc_md5_update(&ctx->md5ctx, digest, ISC_MD5_DIGESTLENGTH);
+	isc_md5_final(&ctx->md5ctx, digest);
+	isc_hmacmd5_invalidate(ctx);
+}
+
+/*!
+ * Verify signature - finalize MD5 operation and reapply MD5, then
+ * compare to the supplied digest.
+ */
+isc_boolean_t
+isc_hmacmd5_verify(isc_hmacmd5_t *ctx, unsigned char *digest) {
+	return (isc_hmacmd5_verify2(ctx, digest, ISC_MD5_DIGESTLENGTH));
+}
+
+isc_boolean_t
+isc_hmacmd5_verify2(isc_hmacmd5_t *ctx, unsigned char *digest, size_t len) {
+	unsigned char newdigest[ISC_MD5_DIGESTLENGTH];
+
+	REQUIRE(len <= ISC_MD5_DIGESTLENGTH);
+	isc_hmacmd5_sign(ctx, newdigest);
+	return (ISC_TF(memcmp(digest, newdigest, len) == 0));
+}