GMAC implementation

[openssl.git] / crypto / gmac / gmac.c

diff --git a/crypto/gmac/gmac.c b/crypto/gmac/gmac.c
new file mode 100644 (file)
index 0000000..929d9a8
--- /dev/null
+++ b/crypto/gmac/gmac.c
@@ -0,0 +1,183 @@
+/*
+ * 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 <stdlib.h>
+#include <openssl/evp.h>
+#include "internal/cryptlib.h"
+#include "internal/evp_int.h"
+
+/* typedef EVP_MAC_IMPL */
+struct evp_mac_impl_st {
+    EVP_CIPHER *cipher;      /* Cache GCM cipher */
+    EVP_CIPHER_CTX *ctx;    /* Cipher context */
+    ENGINE *engine;         /* Engine implementating the algorithm */
+};
+
+static void gmac_free(EVP_MAC_IMPL *gctx)
+{
+    if (gctx != NULL) {
+        EVP_CIPHER_CTX_free(gctx->ctx);
+        OPENSSL_free(gctx);
+    }
+}
+
+static EVP_MAC_IMPL *gmac_new(void)
+{
+    EVP_MAC_IMPL *gctx;
+
+    if ((gctx = OPENSSL_zalloc(sizeof(*gctx))) == NULL
+        || (gctx->ctx = EVP_CIPHER_CTX_new()) == NULL) {
+        gmac_free(gctx);
+        return NULL;
+    }
+    return gctx;
+}
+
+static int gmac_copy(EVP_MAC_IMPL *gdst, EVP_MAC_IMPL *gsrc)
+{
+    gdst->cipher = gsrc->cipher;
+    gdst->engine = gsrc->engine;
+    return EVP_CIPHER_CTX_copy(gdst->ctx, gsrc->ctx);
+}
+
+static size_t gmac_size(EVP_MAC_IMPL *gctx)
+{
+    return EVP_GCM_TLS_TAG_LEN;
+}
+
+static int gmac_init(EVP_MAC_IMPL *gctx)
+{
+    return 1;
+}
+
+static int gmac_update(EVP_MAC_IMPL *gctx, const unsigned char *data,
+                       size_t datalen)
+{
+    EVP_CIPHER_CTX *ctx = gctx->ctx;
+    int outlen;
+
+    while (datalen > INT_MAX) {
+        if (!EVP_EncryptUpdate(ctx, NULL, &outlen, data, INT_MAX))
+            return 0;
+        data += INT_MAX;
+        datalen -= INT_MAX;
+    }
+    return EVP_EncryptUpdate(ctx, NULL, &outlen, data, datalen);
+}
+
+static int gmac_final(EVP_MAC_IMPL *gctx, unsigned char *out)
+{
+    int hlen;
+
+    if (!EVP_EncryptFinal_ex(gctx->ctx, out, &hlen)
+        || !EVP_CIPHER_CTX_ctrl(gctx->ctx, EVP_CTRL_AEAD_GET_TAG,
+                                gmac_size(gctx), out))
+        return 0;
+    return 1;
+}
+
+static int gmac_ctrl(EVP_MAC_IMPL *gctx, int cmd, va_list args)
+{
+    const unsigned char *p;
+    size_t len;
+    EVP_CIPHER_CTX *ctx = gctx->ctx;
+    const EVP_CIPHER *cipher;
+    ENGINE *engine;
+
+    switch (cmd) {
+    case EVP_MAC_CTRL_SET_CIPHER:
+        cipher = va_arg(args, const EVP_CIPHER *);
+        if (cipher == NULL)
+            return 0;
+        if (EVP_CIPHER_mode(cipher) != EVP_CIPH_GCM_MODE) {
+            EVPerr(EVP_F_GMAC_CTRL, EVP_R_CIPHER_NOT_GCM_MODE);
+            return 0;
+        }
+        return EVP_EncryptInit_ex(ctx, cipher, NULL, NULL, NULL);
+
+    case EVP_MAC_CTRL_SET_KEY:
+        p = va_arg(args, const unsigned char *);
+        len = va_arg(args, size_t);
+        if (len != (size_t)EVP_CIPHER_CTX_key_length(ctx)) {
+            EVPerr(EVP_F_GMAC_CTRL, EVP_R_INVALID_KEY_LENGTH);
+            return 0;
+        }
+        return EVP_EncryptInit_ex(ctx, NULL, NULL, p, NULL);
+
+    case EVP_MAC_CTRL_SET_IV:
+        p = va_arg(args, const unsigned char *);
+        len = va_arg(args, size_t);
+        return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, len, NULL)
+               && EVP_EncryptInit_ex(ctx, NULL, NULL, NULL, p);
+
+    case EVP_MAC_CTRL_SET_ENGINE:
+        engine = va_arg(args, ENGINE *);
+        return EVP_EncryptInit_ex(ctx, NULL, engine, NULL, NULL);
+
+    default:
+        return -2;
+    }
+}
+
+static int gmac_ctrl_int(EVP_MAC_IMPL *gctx, int cmd, ...)
+{
+    int rv;
+    va_list args;
+
+    va_start(args, cmd);
+    rv = gmac_ctrl(gctx, cmd, args);
+    va_end(args);
+
+    return rv;
+}
+
+static int gmac_ctrl_str_cb(void *gctx, int cmd, void *buf, size_t buflen)
+{
+    return gmac_ctrl_int(gctx, cmd, buf, buflen);
+}
+
+static int gmac_ctrl_str(EVP_MAC_IMPL *gctx, 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 gmac_ctrl_int(gctx, EVP_MAC_CTRL_SET_CIPHER, c);
+    }
+    if (strcmp(type, "key") == 0)
+        return EVP_str2ctrl(gmac_ctrl_str_cb, gctx, EVP_MAC_CTRL_SET_KEY,
+                            value);
+    if (strcmp(type, "hexkey") == 0)
+        return EVP_hex2ctrl(gmac_ctrl_str_cb, gctx, EVP_MAC_CTRL_SET_KEY,
+                            value);
+    if (strcmp(type, "iv") == 0)
+        return EVP_str2ctrl(gmac_ctrl_str_cb, gctx, EVP_MAC_CTRL_SET_IV,
+                            value);
+    if (strcmp(type, "hexiv") == 0)
+        return EVP_hex2ctrl(gmac_ctrl_str_cb, gctx, EVP_MAC_CTRL_SET_IV,
+                            value);
+    return -2;
+}
+
+const EVP_MAC gmac_meth = {
+    EVP_MAC_GMAC,
+    gmac_new,
+    gmac_copy,
+    gmac_free,
+    gmac_size,
+    gmac_init,
+    gmac_update,
+    gmac_final,
+    gmac_ctrl,
+    gmac_ctrl_str
+};