From 0db957dbbcf6a432086ab913378c23636d8c374c Mon Sep 17 00:00:00 2001
From: Pauli <paul.dale@oracle.com>
Date: Tue, 18 Sep 2018 11:44:43 +1000
Subject: [PATCH] Add a GMAC demonstration program.

Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/7249)
---
 demos/evp/Makefile |   8 ++--
 demos/evp/gmac.c   | 103 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 108 insertions(+), 3 deletions(-)
 create mode 100644 demos/evp/gmac.c

diff --git a/demos/evp/Makefile b/demos/evp/Makefile
index c2e10a1ded..1fb0f39c77 100644
--- a/demos/evp/Makefile
+++ b/demos/evp/Makefile
@@ -7,17 +7,19 @@
 #
 #    LD_LIBRARY_PATH=../.. ./aesccm
 #    LD_LIBRARY_PATH=../.. ./aesgcm
+#    LD_LIBRARY_PATH=../.. ./gmac
 
 CFLAGS = $(OPENSSL_INCS_LOCATION)
 LDFLAGS = $(OPENSSL_LIBS_LOCATION) -lssl -lcrypto
 
-all: aesccm aesgcm
+all: aesccm aesgcm gmac
 
 aesccm: aesccm.o
 aesgcm: aesgcm.o
+gmac: gmac.o
 
-aesccm aesgcm:
+aesccm aesgcm gmac:
 	$(CC) $(CFLAGS) -o $@ $< $(LDFLAGS)
 
 clean:
-	$(RM) aesccm aesgcm *.o
+	$(RM) aesccm aesgcm gmac *.o
diff --git a/demos/evp/gmac.c b/demos/evp/gmac.c
new file mode 100644
index 0000000000..0b2231b368
--- /dev/null
+++ b/demos/evp/gmac.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/*
+ * Simple AES GMAC test program, uses the same NIST data used for the FIPS
+ * self test but uses the application level EVP APIs.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <openssl/bio.h>
+#include <openssl/evp.h>
+
+/* AES-GMAC test data from NIST public test vectors */
+
+static const unsigned char gmac_key[] = { 0x77, 0xbe, 0x63, 0x70, 0x89, 0x71, 0xc4, 0xe2,
+               0x40, 0xd1, 0xcb, 0x79, 0xe8, 0xd7, 0x7f, 0xeb };
+static const unsigned char gmac_iv[] = { 0xe0, 0xe0, 0x0f, 0x19, 0xfe, 0xd7, 0xba, 0x01,
+              0x36, 0xa7, 0x97, 0xf3 };
+static const unsigned char gmac_aad[] = { 0x7a, 0x43, 0xec, 0x1d, 0x9c, 0x0a, 0x5a, 0x78,
+               0xa0, 0xb1, 0x65, 0x33, 0xa6, 0x21, 0x3c, 0xab };
+
+static const unsigned char gmac_tag[] = { 0x20, 0x9f, 0xcc, 0x8d, 0x36, 0x75, 0xed, 0x93,
+               0x8e, 0x9c, 0x71, 0x66, 0x70, 0x9d, 0xd9, 0x46 };
+
+static int aes_gmac(void)
+{
+    EVP_CIPHER_CTX *ctx;
+    int outlen, tmplen;
+    unsigned char outbuf[1024];
+    int ret = 0;
+
+    printf("AES GMAC:\n");
+    printf("Authenticated Data:\n");
+    BIO_dump_fp(stdout, gmac_aad, sizeof(gmac_aad));
+
+    if ((ctx = EVP_CIPHER_CTX_new()) == NULL) {
+        printf("EVP_CIPHER_CTX_new: failed\n");
+        goto err;
+    }
+
+    /* Set cipher type and mode */
+    if (!EVP_EncryptInit_ex(ctx, EVP_aes_128_gcm(), NULL, NULL, NULL)) {
+        printf("EVP_EncryptInit_ex: failed\n");
+        goto err;
+    }
+
+    /* Set IV length if default 96 bits is not appropriate */
+    if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, sizeof(gmac_iv),
+                             NULL)) {
+        printf("EVP_CIPHER_CTX_ctrl: set IV length failed\n");
+        goto err;
+    }
+
+    /* Initialise key and IV */
+    if (!EVP_EncryptInit_ex(ctx, NULL, NULL, gmac_key, gmac_iv)) {
+        printf("EVP_EncryptInit_ex: set key and IV failed\n");
+        goto err;
+    }
+
+    /* Zero or more calls to specify any AAD */
+    if (!EVP_EncryptUpdate(ctx, NULL, &outlen, gmac_aad, sizeof(gmac_aad))) {
+        printf("EVP_EncryptUpdate: setting AAD failed\n");
+        goto err;
+    }
+
+    /* Finalise: note get no output for GMAC */
+    if (!EVP_EncryptFinal_ex(ctx, outbuf, &outlen)) {
+        printf("EVP_EncryptFinal_ex: failed\n");
+        goto err;
+    }
+
+    /* Get tag */
+    if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, 16, outbuf)) {
+        printf("EVP_CIPHER_CTX_ctrl: failed\n");
+        goto err;
+    }
+
+    /* Output tag */
+    printf("Tag:\n");
+    BIO_dump_fp(stdout, outbuf, 16);
+
+    /* Is the tag correct? */
+    if (memcmp(outbuf, gmac_tag, sizeof(gmac_tag)) != 0) {
+        printf("Expected:\n");
+        BIO_dump_fp(stdout, gmac_tag, sizeof(gmac_tag));
+    } else 
+        ret = 1;
+err:
+    EVP_CIPHER_CTX_free(ctx);
+    return ret;
+}
+
+int main(int argc, char **argv)
+{
+    return aes_gmac() ? EXIT_SUCCESS : EXIT_FAILURE;
+}
-- 
2.25.1