Diff: include/polarssl/gcm.h

Revision:

0:137634ff4186

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/polarssl/gcm.h	Thu Jun 11 03:27:03 2015 +0000
@@ -0,0 +1,217 @@
+/**
+ * \file gcm.h
+ *
+ * \brief Galois/Counter mode for 128-bit block ciphers
+ *
+ *  Copyright (C) 2006-2013, ARM Limited, All Rights Reserved
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef POLARSSL_GCM_H
+#define POLARSSL_GCM_H
+
+#include "cipher.h"
+
+#if defined(_MSC_VER) && !defined(EFIX64) && !defined(EFI32)
+#include <basetsd.h>
+typedef UINT32 uint32_t;
+typedef UINT64 uint64_t;
+#else
+#include <stdint.h>
+#endif
+
+#define GCM_ENCRYPT     1
+#define GCM_DECRYPT     0
+
+#define POLARSSL_ERR_GCM_AUTH_FAILED                       -0x0012  /**< Authenticated decryption failed. */
+#define POLARSSL_ERR_GCM_BAD_INPUT                         -0x0014  /**< Bad input parameters to function. */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief          GCM context structure
+ */
+typedef struct {
+    cipher_context_t cipher_ctx;/*!< cipher context used */
+    uint64_t HL[16];            /*!< Precalculated HTable */
+    uint64_t HH[16];            /*!< Precalculated HTable */
+    uint64_t len;               /*!< Total data length */
+    uint64_t add_len;           /*!< Total add length */
+    unsigned char base_ectr[16];/*!< First ECTR for tag */
+    unsigned char y[16];        /*!< Y working value */
+    unsigned char buf[16];      /*!< buf working value */
+    int mode;                   /*!< Encrypt or Decrypt */
+}
+gcm_context;
+
+/**
+ * \brief           GCM initialization (encryption)
+ *
+ * \param ctx       GCM context to be initialized
+ * \param cipher    cipher to use (a 128-bit block cipher)
+ * \param key       encryption key
+ * \param keysize   must be 128, 192 or 256
+ *
+ * \return          0 if successful, or a cipher specific error code
+ */
+int gcm_init( gcm_context *ctx, cipher_id_t cipher, const unsigned char *key,
+              unsigned int keysize );
+
+/**
+ * \brief           GCM buffer encryption/decryption using a block cipher
+ *
+ * \note On encryption, the output buffer can be the same as the input buffer.
+ *       On decryption, the output buffer cannot be the same as input buffer.
+ *       If buffers overlap, the output buffer must trail at least 8 bytes
+ *       behind the input buffer.
+ *
+ * \param ctx       GCM context
+ * \param mode      GCM_ENCRYPT or GCM_DECRYPT
+ * \param length    length of the input data
+ * \param iv        initialization vector
+ * \param iv_len    length of IV
+ * \param add       additional data
+ * \param add_len   length of additional data
+ * \param input     buffer holding the input data
+ * \param output    buffer for holding the output data
+ * \param tag_len   length of the tag to generate
+ * \param tag       buffer for holding the tag
+ *
+ * \return         0 if successful
+ */
+int gcm_crypt_and_tag( gcm_context *ctx,
+                       int mode,
+                       size_t length,
+                       const unsigned char *iv,
+                       size_t iv_len,
+                       const unsigned char *add,
+                       size_t add_len,
+                       const unsigned char *input,
+                       unsigned char *output,
+                       size_t tag_len,
+                       unsigned char *tag );
+
+/**
+ * \brief           GCM buffer authenticated decryption using a block cipher
+ *
+ * \note On decryption, the output buffer cannot be the same as input buffer.
+ *       If buffers overlap, the output buffer must trail at least 8 bytes
+ *       behind the input buffer.
+ *
+ * \param ctx       GCM context
+ * \param length    length of the input data
+ * \param iv        initialization vector
+ * \param iv_len    length of IV
+ * \param add       additional data
+ * \param add_len   length of additional data
+ * \param tag       buffer holding the tag
+ * \param tag_len   length of the tag
+ * \param input     buffer holding the input data
+ * \param output    buffer for holding the output data
+ *
+ * \return         0 if successful and authenticated,
+ *                 POLARSSL_ERR_GCM_AUTH_FAILED if tag does not match
+ */
+int gcm_auth_decrypt( gcm_context *ctx,
+                      size_t length,
+                      const unsigned char *iv,
+                      size_t iv_len,
+                      const unsigned char *add,
+                      size_t add_len,
+                      const unsigned char *tag,
+                      size_t tag_len,
+                      const unsigned char *input,
+                      unsigned char *output );
+
+/**
+ * \brief           Generic GCM stream start function
+ *
+ * \param ctx       GCM context
+ * \param mode      GCM_ENCRYPT or GCM_DECRYPT
+ * \param iv        initialization vector
+ * \param iv_len    length of IV
+ * \param add       additional data (or NULL if length is 0)
+ * \param add_len   length of additional data
+ *
+ * \return         0 if successful
+ */
+int gcm_starts( gcm_context *ctx,
+                int mode,
+                const unsigned char *iv,
+                size_t iv_len,
+                const unsigned char *add,
+                size_t add_len );
+
+/**
+ * \brief           Generic GCM update function. Encrypts/decrypts using the
+ *                  given GCM context. Expects input to be a multiple of 16
+ *                  bytes! Only the last call before gcm_finish() can be less
+ *                  than 16 bytes!
+ *
+ * \note On decryption, the output buffer cannot be the same as input buffer.
+ *       If buffers overlap, the output buffer must trail at least 8 bytes
+ *       behind the input buffer.
+ *
+ * \param ctx       GCM context
+ * \param length    length of the input data
+ * \param input     buffer holding the input data
+ * \param output    buffer for holding the output data
+ *
+ * \return         0 if successful or POLARSSL_ERR_GCM_BAD_INPUT
+ */
+int gcm_update( gcm_context *ctx,
+                size_t length,
+                const unsigned char *input,
+                unsigned char *output );
+
+/**
+ * \brief           Generic GCM finalisation function. Wraps up the GCM stream
+ *                  and generates the tag. The tag can have a maximum length of
+ *                  16 bytes.
+ *
+ * \param ctx       GCM context
+ * \param tag       buffer for holding the tag (may be NULL if tag_len is 0)
+ * \param tag_len   length of the tag to generate
+ *
+ * \return          0 if successful or POLARSSL_ERR_GCM_BAD_INPUT
+ */
+int gcm_finish( gcm_context *ctx,
+                unsigned char *tag,
+                size_t tag_len );
+
+/**
+ * \brief           Free a GCM context and underlying cipher sub-context
+ *
+ * \param ctx       GCM context to free
+ */
+void gcm_free( gcm_context *ctx );
+
+/**
+ * \brief          Checkup routine
+ *
+ * \return         0 if successful, or 1 if the test failed
+ */
+int gcm_self_test( int verbose );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* gcm.h */
+