[base16] Add generic base16 encoding and decoding routines

Base16 encoding is currently implemented in both iSCSI and SRP.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/core/base16.c b/src/core/base16.c
new file mode 100644 (file)
index 0000000..14de795
--- /dev/null
+++ b/src/core/base16.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <ipxe/base16.h>
+
+/** @file
+ *
+ * Base16 encoding
+ *
+ */
+
+/**
+ * Base16-encode data
+ *
+ * @v raw              Raw data
+ * @v len              Length of raw data
+ * @v encoded          Buffer for encoded string
+ *
+ * The buffer must be the correct length for the encoded string.  Use
+ * something like
+ *
+ *     char buf[ base16_encoded_len ( len ) + 1 ];
+ *
+ * (the +1 is for the terminating NUL) to provide a buffer of the
+ * correct size.
+ */
+void base16_encode ( const uint8_t *raw, size_t len, char *encoded ) {
+       const uint8_t *raw_bytes = raw;
+       char *encoded_bytes = encoded;
+       size_t remaining = len;
+
+       for ( ; remaining-- ; encoded_bytes += 2 ) {
+               sprintf ( encoded_bytes, "%02x", *(raw_bytes++) );
+       }
+
+       DBG ( "Base16-encoded to \"%s\":\n", encoded );
+       DBG_HDA ( 0, raw, len );
+       assert ( strlen ( encoded ) == base16_encoded_len ( len ) );
+}
+
+/**
+ * Base16-decode data
+ *
+ * @v encoded          Encoded string
+ * @v raw              Raw data
+ * @ret len            Length of raw data, or negative error
+ *
+ * The buffer must be large enough to contain the decoded data.  Use
+ * something like
+ *
+ *     char buf[ base16_decoded_max_len ( encoded ) ];
+ *
+ * to provide a buffer of the correct size.
+ */
+int base16_decode ( const char *encoded, uint8_t *raw ) {
+       const char *encoded_bytes = encoded;
+       uint8_t *raw_bytes = raw;
+       char buf[3];
+       char *endp;
+       size_t len;
+
+       while ( encoded_bytes[0] ) {
+               if ( ! encoded_bytes[1] ) {
+                       DBG ( "Base16-encoded string \"%s\" has invalid "
+                             "length\n", encoded );
+                       return -EINVAL;
+               }
+               memcpy ( buf, encoded_bytes, 2 );
+               buf[2] = '\0';
+               *(raw_bytes++) = strtoul ( buf, &endp, 16 );
+               if ( *endp != '\0' ) {
+                       DBG ( "Base16-encoded string \"%s\" has invalid "
+                             "byte \"%s\"\n", encoded, buf );
+                       return -EINVAL;
+               }
+               encoded_bytes += 2;
+       }
+       len = ( raw_bytes - raw );
+
+       DBG ( "Base16-decoded \"%s\" to:\n", encoded );
+       DBG_HDA ( 0, raw, len );
+       assert ( len <= base16_decoded_max_len ( encoded ) );
+
+       return ( len );
+}

diff --git a/src/include/ipxe/base16.h b/src/include/ipxe/base16.h
new file mode 100644 (file)
index 0000000..f0c9842
--- /dev/null
+++ b/src/include/ipxe/base16.h
@@ -0,0 +1,38 @@
+#ifndef _IPXE_BASE16_H
+#define _IPXE_BASE16_H
+
+/** @file
+ *
+ * Base16 encoding
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <string.h>
+
+/**
+ * Calculate length of base16-encoded data
+ *
+ * @v raw_len          Raw data length
+ * @ret encoded_len    Encoded string length (excluding NUL)
+ */
+static inline size_t base16_encoded_len ( size_t raw_len ) {
+       return ( 2 * raw_len );
+}
+
+/**
+ * Calculate maximum length of base16-decoded string
+ *
+ * @v encoded          Encoded string
+ * @v max_raw_len      Maximum length of raw data
+ */
+static inline size_t base16_decoded_max_len ( const char *encoded ) {
+       return ( ( strlen ( encoded ) + 1 ) / 2 );
+}
+
+extern void base16_encode ( const uint8_t *raw, size_t len, char *encoded );
+extern int base16_decode ( const char *encoded, uint8_t *raw );
+
+#endif /* _IPXE_BASE16_H */

diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
index c62a5b7d3fab86a2ee0ac34d282851be9f92ddd1..2bb655fd7ecef45994c24b71f67575ec7d130ba3 100644 (file)
--- a/src/include/ipxe/errfile.h
+++ b/src/include/ipxe/errfile.h
@@ -54,6 +54,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define ERRFILE_xfer                  ( ERRFILE_CORE | 0x000e0000 )
 #define ERRFILE_bitmap                ( ERRFILE_CORE | 0x000f0000 )
 #define ERRFILE_base64                ( ERRFILE_CORE | 0x00100000 )
+#define ERRFILE_base16                ( ERRFILE_CORE | 0x00110000 )
 
 #define ERRFILE_eisa                ( ERRFILE_DRIVER | 0x00000000 )
 #define ERRFILE_isa                 ( ERRFILE_DRIVER | 0x00010000 )