* gcm.c: New file.

* gcm.h: New file.

Rev: nettle/gcm.c:1.1
Rev: nettle/gcm.h:1.1

1 files changed, 157 insertions, 0 deletions

diff --git a/gcm.h b/gcm.h
new file mode 100644
index 00000000..ad34d702
--- /dev/null
+++ b/gcm.h
@@ -0,0 +1,157 @@
+/* gcm.h
+ *
+ * Galois counter mode, specified by NIST,
+ * http://csrc.nist.gov/publications/nistpubs/800-38D/SP-800-38D.pdf
+ *
+ */
+
+/* NOTE: Tentative interface, subject to change. No effort will be
+   made to avoid incompatible changes. */
+
+/* nettle, low-level cryptographics library
+ *
+ * Copyright (C) 2011 Niels Möller
+ * Copyright (C) 2011 Katholieke Universiteit Leuven
+ * 
+ * Contributed by Nikos Mavrogiannopoulos
+ *
+ * The nettle library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * The nettle library 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 Lesser General Public
+ * License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the nettle library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#ifndef NETTLE_GCM_H_INCLUDED
+#define NETTLE_GCM_H_INCLUDED
+
+#include "nettle-types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Name mangling */
+#define gcm_set_key nettle_gcm_set_key
+#define gcm_set_iv nettle_gcm_set_iv
+#define gcm_auth nettle_gcm_auth
+#define gcm_encrypt nettle_gcm_encrypt
+#define gcm_decrypt nettle_gcm_decrypt
+#define gcm_digest nettle_gcm_digest
+
+#define GCM_BLOCK_SIZE 16
+#define GCM_IV_SIZE (GCM_BLOCK_SIZE - 4)
+
+#define GCM_TABLE_BITS 0
+
+struct gcm_ctx {
+  /* Key-dependent state. */
+  /* Hashing subkey */
+  uint8_t h[GCM_BLOCK_SIZE];
+#if GCM_TABLE_BITS
+  uint8_t h[1 << GCM_TABLE_BITS][GCM_BLOCK_SIZE];
+#endif
+  /* Per-message state, depending on the iv */
+  /* Original counter block */
+  uint8_t iv[GCM_BLOCK_SIZE];
+  /* Updated for each block. */
+  uint8_t ctr[GCM_BLOCK_SIZE];
+  /* Hashing state */
+  uint8_t x[GCM_BLOCK_SIZE];
+  uint64_t auth_size;
+  uint64_t data_size;
+};
+
+/* FIXME: Should use const for the cipher context. Then needs const for
+   nettle_crypt_func, which also rules out using that abstraction for
+   arcfour. */
+void
+gcm_set_key(struct gcm_ctx *ctx,
+	    void *cipher, nettle_crypt_func *f);
+
+void
+gcm_set_iv(struct gcm_ctx *ctx, unsigned length, const uint8_t *iv);
+
+void
+gcm_auth(struct gcm_ctx *ctx, unsigned length, const uint8_t *data);
+
+void
+gcm_encrypt(struct gcm_ctx *ctx, void *cipher, nettle_crypt_func *f,
+	    unsigned length, uint8_t *dst, const uint8_t *src);
+
+void
+gcm_decrypt(struct gcm_ctx *ctx, void *cipher, nettle_crypt_func *f,
+	    unsigned length, uint8_t *dst, const uint8_t *src);
+
+void
+gcm_digest(struct gcm_ctx *ctx, void *cipher, nettle_crypt_func *f,
+	   unsigned length, uint8_t *digest);
+
+#if 0
+/* FIXME: IS this macrology useful? */
+#define GCM_KEY(type) \
+{ type cipher; struct gcm_ctx gcm; }
+
+#define GCM_SET_KEY(ctx, set_key, encrypt, length, data)	\
+  do {								\
+    (set_key)(&(ctx)->cipher, (length), (data));		\
+    gcm_set_key(&(ctx)->gcm, &(ctx)->cipher, (encrypt));	\
+  } while (0)
+
+#define GCM_AUTH(ctx, encrypt, length, data)	    \
+  gcm_auth((ctx)->gcm, &(ctx)->cipher, (encrypt),   \
+	   (length), (data))
+
+#define GCM_ENCRYPT(ctx, encrypt, length, dst, src)       \
+  gcm_encrypt((ctx)->gcm, &(ctx)->cipher, (encrypt),	  \
+	      (length), (dst), (src))
+
+#define GCM_DECRYPT(ctx, key, encrypt, length, dst, src)       \
+  gcm_decrypt((ctx)->gcm, &(ctx)->cipher, (encrypt),	       \
+	      (length), (dst), (src))
+
+#define GCM_DIGEST(ctx, key, encrypt, length, digest)		\
+  gcm_digest((ctx)->gcm, &(ctx)->cipher, (encrypt),		\
+	     (length), (digest))
+
+struct gcm_aes_ctx GCM_CTX(struct aes_ctx);
+
+void
+gcm_aes_set_key(struct gcm_aes_ctx *ctx,
+		unsigned length, const uint8_t *key);
+
+void
+gcm_aes_set_iv(struct gcm_aes_ctx *ctx,
+	       unsigned length, const uint8_t *iv);
+
+void
+gcm_aes_auth(struct gcm_aes_ctx *ctx,
+	     unsigned length, const uint8_t *data);
+
+void
+gcm_aes_encrypt(struct gcm_aes_ctx *ctx,
+		unsigned length, uint8_t *dst, const uint8_t *src);
+
+void
+gcm_aes_decrypt(struct gcm_aes_ctx *ctx,
+		unsigned length, uint8_t *dst, const uint8_t *src);
+
+void
+gcm_aes_digest(struct gcm_aes_ctx *ctx,
+	       unsigned length, uint8_t *digest);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NETTLE_GCM_H_INCLUDED */