* base64-encode.c: New file. New supporting both encode-at-once

and streamed operation.

* base64-decode.c: New file.

Rev: src/nettle/base64-decode.c:1.1
Rev: src/nettle/base64-encode.c:1.1

1 files changed, 135 insertions, 0 deletions

diff --git a/base64-decode.c b/base64-decode.c
new file mode 100644
index 00000000..e1e614de
--- /dev/null
+++ b/base64-decode.c
@@ -0,0 +1,135 @@
+/* base64-encode.c
+ *
+ */
+
+/* nettle, low-level cryptographics library
+ *
+ * Copyright (C) 2002 Niels Möller
+ *  
+ * 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.
+ */
+
+#include "base64.h"
+
+#include <assert.h>
+#include <stdlib.h>
+
+#define TABLE_INVALID -1
+#define TABLE_SPACE -2
+#define TABLE_END -3
+
+static const signed char
+decode_table[0x100] =
+{
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -1, -1, -2, -1, -1, 
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+  -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
+  52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -3, -1, -1,
+  -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
+  15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
+  -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+  41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+};
+
+void
+base64_decode_init(struct base64_decode_ctx *ctx)
+{
+  ctx->word = ctx->bits = 0;
+  ctx->status = BASE64_DECODE_OK;
+}
+
+unsigned
+base64_decode_update(struct base64_decode_ctx *ctx,
+		     uint8_t *dst,
+		     unsigned length,
+		     const uint8_t *src)
+{
+  unsigned done = 0;
+  unsigned i;
+  
+  if (ctx->status == BASE64_DECODE_ERROR)
+    return 0;
+
+  for (i = 0; i<length; i++)
+    {
+      int data = decode_table[src[i]];
+
+      switch(data)
+	{
+	default:
+	  assert(data >= 0 && data < 0x40);
+	  
+	  if (ctx->status != BASE64_DECODE_OK)
+	    goto invalid;
+	  
+	  ctx->word = ctx->word << 6 | data;
+	  ctx->bits += 6;
+
+	  if (ctx->bits >= 8)
+	    {
+	      ctx->bits -= 8;
+	      dst[done++] = ctx->word >> ctx->bits;
+	    }
+	  break;
+
+	case TABLE_INVALID:
+	invalid:
+	  ctx->status = BASE64_DECODE_ERROR;
+	  return done;
+
+	case TABLE_SPACE:
+	  /* Ignore */
+	  break;
+
+	case TABLE_END:
+	  if (!ctx->bits)
+	    goto invalid;
+	  if (ctx->word & ( (1<<ctx->bits) - 1))
+	    /* We shouldn't have any leftover bits */
+	    goto invalid;
+	  
+	  ctx->status = BASE64_DECODE_END;
+	  ctx->bits -= 2;
+	  break;
+	}
+    }
+
+  assert(done <= BASE64_DECODE_LENGTH(length));
+  
+  return done;
+}
+
+int
+base64_decode_status(struct base64_decode_ctx *ctx)
+{
+  switch (ctx->status)
+    {
+    case BASE64_DECODE_END:
+    case BASE64_DECODE_OK:
+      return ctx->bits == 0;
+    case BASE64_DECODE_ERROR:
+      return 0;
+    }
+  abort();
+}