Add EVP_MAC API

We currently implement EVP MAC methods as EVP_PKEY methods.  This
change creates a separate EVP API for MACs, to replace the current
EVP_PKEY ones.

A note about this EVP API and how it interfaces with underlying MAC
implementations:

Other EVP APIs pass the EVP API context down to implementations, and
it can be observed that the implementations use the pointer to their
own private data almost exclusively.  The EVP_MAC API deviates from
that pattern by passing the pointer to the implementation's private
data directly, and thereby deny the implementations access to the
EVP_MAC context structure.  This change is made to provide a clearer
separation between the EVP library itself and the implementations of
its supported algorithm classes.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7393)

1 files changed, 185 insertions, 0 deletions

diff --git a/crypto/evp/mac_lib.c b/crypto/evp/mac_lib.c
new file mode 100644
index 0000000000..2786a012a5
--- /dev/null
+++ b/crypto/evp/mac_lib.c
@@ -0,0 +1,185 @@
+/*
+ * 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 <string.h>
+#include <stdarg.h>
+#include <openssl/evp.h>
+#include <openssl/err.h>
+#include <openssl/ossl_typ.h>
+#include "internal/nelem.h"
+#include "internal/evp_int.h"
+#include "evp_locl.h"
+
+EVP_MAC_CTX *EVP_MAC_CTX_new_id(int id)
+{
+    const EVP_MAC *mac = EVP_get_macbynid(id);
+
+    if (mac == NULL)
+        return NULL;
+    return EVP_MAC_CTX_new(mac);
+}
+
+EVP_MAC_CTX *EVP_MAC_CTX_new(const EVP_MAC *mac)
+{
+    EVP_MAC_CTX *ctx = OPENSSL_zalloc(sizeof(EVP_MAC_CTX));
+
+    if (ctx == NULL || (ctx->data = mac->new()) == NULL) {
+        EVPerr(EVP_F_EVP_MAC_CTX_NEW, ERR_R_MALLOC_FAILURE);
+        OPENSSL_free(ctx);
+        ctx = NULL;
+    } else {
+        ctx->meth = mac;
+    }
+    return ctx;
+}
+
+void EVP_MAC_CTX_free(EVP_MAC_CTX *ctx)
+{
+    if (ctx != NULL && ctx->data != NULL) {
+        ctx->meth->free(ctx->data);
+        ctx->data = NULL;
+    }
+    OPENSSL_free(ctx);
+}
+
+int EVP_MAC_CTX_copy(EVP_MAC_CTX *dst, EVP_MAC_CTX *src)
+{
+    EVP_MAC_IMPL *macdata;
+
+    if (src->data != NULL && !dst->meth->copy(dst->data, src->data))
+        return 0;
+
+    macdata = dst->data;
+    *dst = *src;
+    dst->data = macdata;
+
+    return 1;
+}
+
+const EVP_MAC *EVP_MAC_CTX_mac(EVP_MAC_CTX *ctx)
+{
+    return ctx->meth;
+}
+
+size_t EVP_MAC_size(EVP_MAC_CTX *ctx)
+{
+    if (ctx->data != NULL)
+        return ctx->meth->size(ctx->data);
+    /* If the MAC hasn't been initialized yet, we return zero */
+    return 0;
+}
+
+int EVP_MAC_init(EVP_MAC_CTX *ctx)
+{
+    return ctx->meth->init(ctx->data);
+}
+
+int EVP_MAC_update(EVP_MAC_CTX *ctx, const unsigned char *data, size_t datalen)
+{
+    return ctx->meth->update(ctx->data, data, datalen);
+}
+
+int EVP_MAC_final(EVP_MAC_CTX *ctx, unsigned char *out, size_t *poutlen)
+{
+    int l = ctx->meth->size(ctx->data);
+
+    if (l < 0)
+        return 0;
+    if (poutlen != NULL)
+        *poutlen = l;
+    if (out == NULL)
+        return 1;
+    return ctx->meth->final(ctx->data, out);
+}
+
+int EVP_MAC_ctrl(EVP_MAC_CTX *ctx, int cmd, ...)
+{
+    int ok = -1;
+    va_list args;
+
+    va_start(args, cmd);
+    ok = EVP_MAC_vctrl(ctx, cmd, args);
+    va_end(args);
+
+    if (ok == -2)
+        EVPerr(EVP_F_EVP_MAC_CTRL, EVP_R_COMMAND_NOT_SUPPORTED);
+
+    return ok;
+}
+
+int EVP_MAC_vctrl(EVP_MAC_CTX *ctx, int cmd, va_list args)
+{
+    int ok = 1;
+
+    if (ctx == NULL || ctx->meth == NULL)
+        return -2;
+
+    switch (cmd) {
+#if 0
+    case ...:
+        /* code */
+        ok = 1;
+        break;
+#endif
+    default:
+        if (ctx->meth->ctrl != NULL)
+            ok = ctx->meth->ctrl(ctx->data, cmd, args);
+        else
+            ok = -2;
+        break;
+    }
+
+    return ok;
+}
+
+int EVP_MAC_ctrl_str(EVP_MAC_CTX *ctx, const char *type, const char *value)
+{
+    int ok = 1;
+
+    if (ctx == NULL || ctx->meth == NULL || ctx->meth->ctrl_str == NULL) {
+        EVPerr(EVP_F_EVP_MAC_CTRL_STR, EVP_R_COMMAND_NOT_SUPPORTED);
+        return -2;
+    }
+
+    ok = ctx->meth->ctrl_str(ctx->data, type, value);
+
+    if (ok == -2)
+        EVPerr(EVP_F_EVP_MAC_CTRL_STR, EVP_R_COMMAND_NOT_SUPPORTED);
+    return ok;
+}
+
+int EVP_MAC_str2ctrl(EVP_MAC_CTX *ctx, int cmd, const char *value)
+{
+    size_t len;
+
+    len = strlen(value);
+    if (len > INT_MAX)
+        return -1;
+    return EVP_MAC_ctrl(ctx, cmd, value, len);
+}
+
+int EVP_MAC_hex2ctrl(EVP_MAC_CTX *ctx, int cmd, const char *hex)
+{
+    unsigned char *bin;
+    long binlen;
+    int rv = -1;
+
+    bin = OPENSSL_hexstr2buf(hex, &binlen);
+    if (bin == NULL)
+        return 0;
+    if (binlen <= INT_MAX)
+        rv = EVP_MAC_ctrl(ctx, cmd, bin, (size_t)binlen);
+    OPENSSL_free(bin);
+    return rv;
+}
+
+int EVP_MAC_nid(const EVP_MAC *mac)
+{
+    return mac->type;
+}