Detect hmac(3) in libc or the library containing MD5.

If not found, a compat function is provided, taken from NetBSD.

2 files changed, 222 insertions, 0 deletions

diff --git a/compat/crypt/hmac.c b/compat/crypt/hmac.c
new file mode 100644
index 00000000..7e762326
--- /dev/null
+++ b/compat/crypt/hmac.c
@@ -0,0 +1,182 @@
+/*	$NetBSD: hmac.c,v 1.5 2017/10/05 09:59:04 roy Exp $	*/
+
+/*-
+ * Copyright (c) 2016 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Christos Zoulas.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+
+#include "config.h"
+
+#ifdef HAVE_MD5_H
+#  ifndef DEPGEN
+#    include <md5.h>
+#  endif
+#endif
+
+#ifdef SHA2_H
+#  include SHA2_H
+#endif
+
+#if 0
+#include <md2.h>
+#include <md4.h>
+#include <md5.h>
+#include <rmd160.h>
+#include <sha1.h>
+#include <sha2.h>
+#endif
+
+#define HMAC_SIZE	128
+#define HMAC_IPAD	0x36
+#define HMAC_OPAD	0x5C
+
+static const struct hmac {
+	const char *name;
+	size_t ctxsize;
+	size_t digsize;
+	size_t blocksize;
+	void (*init)(void *);
+	void (*update)(void *, const uint8_t *, unsigned int);
+	void (*final)(uint8_t *, void *);
+} hmacs[] = {
+#if 0
+	{
+		"md2", sizeof(MD2_CTX), MD2_DIGEST_LENGTH, MD2_BLOCK_LENGTH,
+		(void *)MD2Init, (void *)MD2Update, (void *)MD2Final,
+	},
+	{
+		"md4", sizeof(MD4_CTX), MD4_DIGEST_LENGTH, MD4_BLOCK_LENGTH,
+		(void *)MD4Init, (void *)MD4Update, (void *)MD4Final,
+	},
+#endif
+	{
+		"md5", sizeof(MD5_CTX), MD5_DIGEST_LENGTH, MD5_BLOCK_LENGTH,
+		(void *)MD5Init, (void *)MD5Update, (void *)MD5Final,
+	},
+#if 0
+	{
+		"rmd160", sizeof(RMD160_CTX), RMD160_DIGEST_LENGTH,
+		RMD160_BLOCK_LENGTH,
+		(void *)RMD160Init, (void *)RMD160Update, (void *)RMD160Final,
+	},
+	{
+		"sha1", sizeof(SHA1_CTX), SHA1_DIGEST_LENGTH, SHA1_BLOCK_LENGTH,
+		(void *)SHA1Init, (void *)SHA1Update, (void *)SHA1Final,
+	},
+	{
+		"sha224", sizeof(SHA224_CTX), SHA224_DIGEST_LENGTH,
+		SHA224_BLOCK_LENGTH,
+		(void *)SHA224_Init, (void *)SHA224_Update,
+		(void *)SHA224_Final,
+	},
+#endif
+	{
+		"sha256", sizeof(SHA256_CTX), SHA256_DIGEST_LENGTH,
+		SHA256_BLOCK_LENGTH,
+		(void *)SHA256_Init, (void *)SHA256_Update,
+		(void *)SHA256_Final,
+	},
+#if 0
+	{
+		"sha384", sizeof(SHA384_CTX), SHA384_DIGEST_LENGTH,
+		SHA384_BLOCK_LENGTH,
+		(void *)SHA384_Init, (void *)SHA384_Update,
+		(void *)SHA384_Final,
+	},
+	{
+		"sha512", sizeof(SHA512_CTX), SHA512_DIGEST_LENGTH,
+		SHA512_BLOCK_LENGTH,
+		(void *)SHA512_Init, (void *)SHA512_Update,
+		(void *)SHA512_Final,
+	},
+#endif
+};
+
+static const struct hmac *
+hmac_find(const char *name)
+{
+	for (size_t i = 0; i < __arraycount(hmacs); i++) {
+		if (strcmp(hmacs[i].name, name) != 0)
+			continue;
+		return &hmacs[i];
+	}
+	return NULL;
+}
+
+ssize_t
+hmac(const char *name,
+    const void *key, size_t klen,
+    const void *text, size_t tlen,
+    void *digest, size_t dlen)
+{
+	uint8_t ipad[HMAC_SIZE], opad[HMAC_SIZE], d[HMAC_SIZE];
+	const uint8_t *k = key;
+	const struct hmac *h;
+	uint64_t c[32];
+	void *p;
+
+	if ((h = hmac_find(name)) == NULL)
+		return -1;
+
+
+	if (klen > h->blocksize) {
+		(*h->init)(c);
+		(*h->update)(c, k, (unsigned int)klen);
+		(*h->final)(d, c);
+		k = (void *)d;
+		klen = h->digsize;
+	}
+
+	/* Form input and output pads for the digests */
+	for (size_t i = 0; i < sizeof(ipad); i++) {
+		ipad[i] = (i < klen ? k[i] : 0) ^ HMAC_IPAD;
+		opad[i] = (i < klen ? k[i] : 0) ^ HMAC_OPAD;
+	}
+
+	p = dlen >= h->digsize ? digest : d;
+	if (p != digest) {
+		memcpy(p, digest, dlen);
+		memset((char *)p + dlen, 0, h->digsize - dlen);
+	}
+	(*h->init)(c);
+	(*h->update)(c, ipad, (unsigned int)h->blocksize);
+	(*h->update)(c, text, (unsigned int)tlen);
+	(*h->final)(p, c);
+
+	(*h->init)(c);
+	(*h->update)(c, opad, (unsigned int)h->blocksize);
+	(*h->update)(c, digest, (unsigned int)h->digsize);
+	(*h->final)(p, c);
+
+	if (p != digest)
+		memcpy(digest, p, dlen);
+
+	return (ssize_t)h->digsize;
+}
diff --git a/compat/crypt/hmac.h b/compat/crypt/hmac.h
new file mode 100644
index 00000000..af3f77ad
--- /dev/null
+++ b/compat/crypt/hmac.h
@@ -0,0 +1,40 @@
+/*	$NetBSD: hmac.c,v 1.5 2017/10/05 09:59:04 roy Exp $	*/
+
+/*-
+ * Copyright (c) 2016 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Christos Zoulas.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef HMAC_H
+#define HMAC_H
+
+#include <sys/types.h>
+
+ssize_t	 hmac(const char *, const void *, size_t, const void *, size_t, void *,
+   size_t);
+
+#endif