1 files changed, 55 insertions, 0 deletions
diff --git a/compat/crypt_openssl/hmac.c b/compat/crypt_openssl/hmac.c
new file mode 100644
index 000000000000..5f55cc30b105
--- /dev/null
+++ b/compat/crypt_openssl/hmac.c
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (c) 2023 Canonical Ltd.
+ *
+ * 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 AUTHOR 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 AUTHOR 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"
+
+#include "openssl/hmac.h"
+
+ssize_t
+hmac(const char *name,
+    const void *key, size_t klen,
+    const void *text, size_t tlen,
+    void *digest, size_t dlen)
+{
+	const EVP_MD	*md;
+	unsigned int	 outlen;
+
+	if (strcmp(name, "md5") == 0)
+		md = EVP_md5();
+	else if (strcmp(name, "sha256") == 0)
+		md = EVP_sha1();
+	else
+		return -1;
+
+	HMAC(md, key, (int)klen, text, tlen, digest, &outlen);
+	if (dlen != outlen)
+		return -1;
+
+	return (ssize_t)outlen;
+}