2G ems initial

include/nettle/base64.h

@@ -0,0 +1,172 @@
+/* base64.h
+   
+   Base-64 encoding and decoding.
+
+   Copyright (C) 2002 Niels Möller, Dan Egnor
+
+   This file is part of GNU Nettle.
+
+   GNU Nettle is free software: you can redistribute it and/or
+   modify it under the terms of either:
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at your
+       option) any later version.
+
+   or
+
+     * 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.
+
+   or both in parallel, as here.
+
+   GNU Nettle 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see http://www.gnu.org/licenses/.
+*/
+ 
+#ifndef NETTLE_BASE64_H_INCLUDED
+#define NETTLE_BASE64_H_INCLUDED
+
+#include "nettle-types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Name mangling */
+#define base64_encode_init nettle_base64_encode_init
+#define base64url_encode_init nettle_base64url_encode_init
+#define base64_encode_single nettle_base64_encode_single
+#define base64_encode_update nettle_base64_encode_update
+#define base64_encode_final nettle_base64_encode_final
+#define base64_encode_raw nettle_base64_encode_raw
+#define base64_encode_group nettle_base64_encode_group
+#define base64_decode_init nettle_base64_decode_init
+#define base64url_decode_init nettle_base64url_decode_init
+#define base64_decode_single nettle_base64_decode_single
+#define base64_decode_update nettle_base64_decode_update
+#define base64_decode_final nettle_base64_decode_final
+
+#define BASE64_BINARY_BLOCK_SIZE 3
+#define BASE64_TEXT_BLOCK_SIZE 4
+
+/* Base64 encoding */
+
+/* Maximum length of output for base64_encode_update. NOTE: Doesn't
+ * include any padding that base64_encode_final may add. */
+/* We have at most 4 buffered bits, and a total of (4 + length * 8) bits. */
+#define BASE64_ENCODE_LENGTH(length) (((length) * 8 + 4)/6)
+
+/* Maximum length of output generated by base64_encode_final. */
+#define BASE64_ENCODE_FINAL_LENGTH 3
+
+/* Exact length of output generated by base64_encode_raw, including
+ * padding. */
+#define BASE64_ENCODE_RAW_LENGTH(length) ((((length) + 2)/3)*4)
+
+struct base64_encode_ctx
+{
+  const char *alphabet;    /* Alphabet to use for encoding */
+  unsigned short word;     /* Leftover bits */
+  unsigned char bits;      /* Number of bits, always 0, 2, or 4. */
+};
+
+/* Initialize encoding context for base-64 */
+void
+base64_encode_init(struct base64_encode_ctx *ctx);
+
+/* Initialize encoding context for URL safe alphabet, RFC 4648. */
+void
+base64url_encode_init(struct base64_encode_ctx *ctx);
+
+/* Encodes a single byte. Returns amount of output (always 1 or 2). */
+size_t
+base64_encode_single(struct base64_encode_ctx *ctx,
+		     char *dst,
+		     uint8_t src);
+
+/* Returns the number of output characters. DST should point to an
+ * area of size at least BASE64_ENCODE_LENGTH(length). */
+size_t
+base64_encode_update(struct base64_encode_ctx *ctx,
+		     char *dst,
+		     size_t length,
+		     const uint8_t *src);
+
+/* DST should point to an area of size at least
+ * BASE64_ENCODE_FINAL_LENGTH */
+size_t
+base64_encode_final(struct base64_encode_ctx *ctx,
+		    char *dst);
+
+/* Lower level functions */
+
+/* Encodes a string in one go, including any padding at the end.
+ * Generates exactly BASE64_ENCODE_RAW_LENGTH(length) bytes of output.
+ * Supports overlapped operation, if src <= dst. FIXME: Use of overlap
+ * is deprecated, if needed there should be a separate public fucntion
+ * to do that.*/
+void
+base64_encode_raw(char *dst, size_t length, const uint8_t *src);
+
+void
+base64_encode_group(char *dst, uint32_t group);
+
+
+/* Base64 decoding */
+
+/* Maximum length of output for base64_decode_update. */
+/* We have at most 6 buffered bits, and a total of (length + 1) * 6 bits. */
+#define BASE64_DECODE_LENGTH(length) ((((length) + 1) * 6) / 8)
+
+struct base64_decode_ctx
+{
+  const signed char *table; /* Decoding table */
+  unsigned short word;      /* Leftover bits */
+  unsigned char bits;       /* Number buffered bits */
+
+  /* Number of padding characters encountered */
+  unsigned char padding;
+};
+
+/* Initialize decoding context for base-64 */
+void
+base64_decode_init(struct base64_decode_ctx *ctx);
+
+/* Initialize encoding context for URL safe alphabet, RFC 4648. */
+void
+base64url_decode_init(struct base64_decode_ctx *ctx);
+
+/* Decodes a single byte. Returns amount of output (0 or 1), or -1 on
+ * errors. */
+int
+base64_decode_single(struct base64_decode_ctx *ctx,
+		     uint8_t *dst,
+		     char src);
+
+/* Returns 1 on success, 0 on error. DST should point to an area of
+ * size at least BASE64_DECODE_LENGTH(length). The amount of data
+ * generated is returned in *DST_LENGTH. */
+int
+base64_decode_update(struct base64_decode_ctx *ctx,
+		     size_t *dst_length,
+		     uint8_t *dst,
+		     size_t src_length,
+		     const char *src);
+
+/* Returns 1 on success. */
+int
+base64_decode_final(struct base64_decode_ctx *ctx);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NETTLE_BASE64_H_INCLUDED */