EVP_MAC: Add CMAC implementation

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7484)

2 files changed, 165 insertions, 1 deletions

diff --git a/crypto/cmac/build.info b/crypto/cmac/build.info
index c8a4949a07..a00ea2e735 100644
--- a/crypto/cmac/build.info
+++ b/crypto/cmac/build.info
@@ -1,2 +1,2 @@
 LIBS=../../libcrypto
-SOURCE[../../libcrypto]=cmac.c cm_ameth.c cm_pmeth.c
+SOURCE[../../libcrypto]=cmac.c cm_ameth.c cm_pmeth.c cm_meth.c
diff --git a/crypto/cmac/cm_meth.c b/crypto/cmac/cm_meth.c
new file mode 100644
index 0000000000..70899360e2
--- /dev/null
+++ b/crypto/cmac/cm_meth.c
@@ -0,0 +1,164 @@
+/*
+ * 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
+ */
+
+#include <stdio.h>
+#include "internal/cryptlib.h"
+#include <openssl/x509.h>
+#include <openssl/x509v3.h>
+#include <openssl/evp.h>
+#include <openssl/cmac.h>
+#include "internal/evp_int.h"
+
+/* local CMAC pkey structure */
+
+/* typedef EVP_MAC_IMPL */
+struct evp_mac_impl_st {
+    /* tmpcipher and tmpengine are set to NULL after a CMAC_Init call */
+    const EVP_CIPHER *tmpcipher; /* cached CMAC cipher */
+    const ENGINE *tmpengine;     /* cached CMAC cipher engine */
+    CMAC_CTX *ctx;
+};
+
+static EVP_MAC_IMPL *cmac_new(void)
+{
+    EVP_MAC_IMPL *cctx;
+
+    if ((cctx = OPENSSL_zalloc(sizeof(*cctx))) == NULL
+        || (cctx->ctx = CMAC_CTX_new()) == NULL) {
+        OPENSSL_free(cctx);
+        cctx = NULL;
+    }
+
+    return cctx;
+}
+
+static void cmac_free(EVP_MAC_IMPL *cctx)
+{
+    if (cctx != NULL) {
+        CMAC_CTX_free(cctx->ctx);
+        OPENSSL_free(cctx);
+    }
+}
+
+static int cmac_copy(EVP_MAC_IMPL *cdst, EVP_MAC_IMPL *csrc)
+{
+    if (!CMAC_CTX_copy(cdst->ctx, csrc->ctx))
+        return 0;
+
+    cdst->tmpengine = csrc->tmpengine;
+    cdst->tmpcipher = csrc->tmpcipher;
+    return 1;
+}
+
+static size_t cmac_size(EVP_MAC_IMPL *cctx)
+{
+    return EVP_CIPHER_CTX_block_size(CMAC_CTX_get0_cipher_ctx(cctx->ctx));
+}
+
+static int cmac_init(EVP_MAC_IMPL *cctx)
+{
+    int rv = CMAC_Init(cctx->ctx, NULL, 0, cctx->tmpcipher,
+                       (ENGINE *)cctx->tmpengine);
+    cctx->tmpcipher = NULL;
+    cctx->tmpengine = NULL;
+
+    return rv;
+}
+
+static int cmac_update(EVP_MAC_IMPL *cctx, const unsigned char *data,
+                       size_t datalen)
+{
+    return CMAC_Update(cctx->ctx, data, datalen);
+}
+
+static int cmac_final(EVP_MAC_IMPL *cctx, unsigned char *out)
+{
+    size_t hlen;
+
+    return CMAC_Final(cctx->ctx, out, &hlen);
+}
+
+static int cmac_ctrl(EVP_MAC_IMPL *cctx, int cmd, va_list args)
+{
+    switch (cmd) {
+    case EVP_MAC_CTRL_SET_KEY:
+        {
+            const unsigned char *key = va_arg(args, const unsigned char *);
+            size_t keylen = va_arg(args, size_t);
+            int rv = CMAC_Init(cctx->ctx, key, keylen, cctx->tmpcipher,
+                               (ENGINE *)cctx->tmpengine);
+
+            cctx->tmpcipher = NULL;
+            cctx->tmpengine = NULL;
+
+            return rv;
+        }
+        break;
+    case EVP_MAC_CTRL_SET_CIPHER:
+        cctx->tmpcipher = va_arg(args, const EVP_CIPHER *);
+        break;
+    case EVP_MAC_CTRL_SET_ENGINE:
+        cctx->tmpengine = va_arg(args, const ENGINE *);
+        break;
+    default:
+        return -2;
+    }
+    return 1;
+}
+
+static int cmac_ctrl_int(EVP_MAC_IMPL *hctx, int cmd, ...)
+{
+    int rv;
+    va_list args;
+
+    va_start(args, cmd);
+    rv = cmac_ctrl(hctx, cmd, args);
+    va_end(args);
+
+    return rv;
+}
+
+static int cmac_ctrl_str_cb(void *hctx, int cmd, void *buf, size_t buflen)
+{
+    return cmac_ctrl_int(hctx, cmd, buf, buflen);
+}
+
+static int cmac_ctrl_str(EVP_MAC_IMPL *cctx, const char *type,
+                         const char *value)
+{
+    if (!value)
+        return 0;
+    if (strcmp(type, "cipher") == 0) {
+        const EVP_CIPHER *c = EVP_get_cipherbyname(value);
+
+        if (c == NULL)
+            return 0;
+        return cmac_ctrl_int(cctx, EVP_MAC_CTRL_SET_CIPHER, c);
+    }
+    if (strcmp(type, "key") == 0)
+        return EVP_str2ctrl(cmac_ctrl_str_cb, cctx, EVP_MAC_CTRL_SET_KEY,
+                            value);
+    if (strcmp(type, "hexkey") == 0)
+        return EVP_hex2ctrl(cmac_ctrl_str_cb, cctx, EVP_MAC_CTRL_SET_KEY,
+                            value);
+    return -2;
+}
+
+const EVP_MAC cmac_meth = {
+    EVP_MAC_CMAC,
+    cmac_new,
+    cmac_copy,
+    cmac_free,
+    cmac_size,
+    cmac_init,
+    cmac_update,
+    cmac_final,
+    cmac_ctrl,
+    cmac_ctrl_str
+};