1 files changed, 135 insertions, 0 deletions
diff --git a/roms/ipxe/src/core/base16.c b/roms/ipxe/src/core/base16.c
new file mode 100644
index 00000000..bf9cc21b
--- /dev/null
+++ b/roms/ipxe/src/core/base16.c
@@ -0,0 +1,135 @@
+/*
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, 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;
+
+	/* Encode each byte */
+	for ( ; remaining-- ; encoded_bytes += 2 ) {
+		sprintf ( encoded_bytes, "%02x", *(raw_bytes++) );
+	}
+
+	/* Ensure terminating NUL exists even if length was zero */
+	*encoded_bytes = '\0';
+
+	DBG ( "Base16-encoded to \"%s\":\n", encoded );
+	DBG_HDA ( 0, raw, len );
+	assert ( strlen ( encoded ) == base16_encoded_len ( len ) );
+}
+
+/**
+ * Decode hexadecimal string
+ *
+ * @v encoded		Encoded string
+ * @v separator		Byte separator character, or 0 for no separator
+ * @v data		Buffer
+ * @v len		Length of buffer
+ * @ret len		Length of data, or negative error
+ */
+int hex_decode ( const char *encoded, char separator, void *data, size_t len ) {
+	uint8_t *out = data;
+	unsigned int count = 0;
+	unsigned int sixteens;
+	unsigned int units;
+
+	while ( *encoded ) {
+
+		/* Check separator, if applicable */
+		if ( count && separator && ( ( *(encoded++) != separator ) ) )
+			return -EINVAL;
+
+		/* Extract digits.  Note that either digit may be NUL,
+		 * which would be interpreted as an invalid value by
+		 * strtoul_charval(); there is therefore no need for an
+		 * explicit end-of-string check.
+		 */
+		sixteens = strtoul_charval ( *(encoded++) );
+		if ( sixteens >= 16 )
+			return -EINVAL;
+		units = strtoul_charval ( *(encoded++) );
+		if ( units >= 16 )
+			return -EINVAL;
+
+		/* Store result */
+		if ( count < len )
+			out[count] = ( ( sixteens << 4 ) | units );
+		count++;
+
+	}
+	return count;
+}
+
+/**
+ * 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 ) {
+	int len;
+
+	len = hex_decode ( encoded, 0, raw, -1UL );
+	if ( len < 0 )
+		return len;
+
+	DBG ( "Base16-decoded \"%s\" to:\n", encoded );
+	DBG_HDA ( 0, raw, len );
+	assert ( len <= ( int ) base16_decoded_max_len ( encoded ) );
+
+	return len;
+}