1 files changed, 153 insertions, 0 deletions
diff --git a/src/util/hex_quote.c b/src/util/hex_quote.c
new file mode 100644
index 0000000..7089385
--- /dev/null
+++ b/src/util/hex_quote.c
@@ -0,0 +1,153 @@
+/*++
+/* NAME
+/*	hex_quote 3
+/* SUMMARY
+/*	quote/unquote text, HTTP style.
+/* SYNOPSIS
+/*	#include <hex_quote.h>
+/*
+/*	VSTRING	*hex_quote(hex, raw)
+/*	VSTRING	*hex;
+/*	const char *raw;
+/*
+/*	VSTRING	*hex_unquote(raw, hex)
+/*	VSTRING	*raw;
+/*	const char *hex;
+/* DESCRIPTION
+/*	hex_quote() takes a null-terminated string and replaces non-printable
+/*	and whitespace characters and the % by %XX, XX being the two-digit
+/*	hexadecimal equivalent.
+/*	The hexadecimal codes are produced as upper-case characters. The result
+/*	value is the hex argument.
+/*
+/*	hex_unquote() performs the opposite transformation. This function
+/*	understands lowercase, uppercase, and mixed case %XX sequences. The
+/*	result value is the raw argument in case of success, a null pointer
+/*	otherwise.
+/* BUGS
+/*	hex_quote() cannot process null characters in data.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include "sys_defs.h"
+#include <ctype.h>
+
+/* Utility library. */
+
+#include "msg.h"
+#include "vstring.h"
+#include "hex_quote.h"
+
+/* Application-specific. */
+
+#define STR(x)	vstring_str(x)
+#define LEN(x)	VSTRING_LEN(x)
+
+/* hex_quote - raw data to quoted */
+
+VSTRING *hex_quote(VSTRING *hex, const char *raw)
+{
+    const char *cp;
+    int     ch;
+
+    VSTRING_RESET(hex);
+    for (cp = raw; (ch = *(unsigned const char *) cp) != 0; cp++) {
+	if (ch != '%' && !ISSPACE(ch) && ISPRINT(ch)) {
+	    VSTRING_ADDCH(hex, ch);
+	} else {
+	    vstring_sprintf_append(hex, "%%%02X", ch);
+	}
+    }
+    VSTRING_TERMINATE(hex);
+    return (hex);
+}
+
+/* hex_unquote - quoted data to raw */
+
+VSTRING *hex_unquote(VSTRING *raw, const char *hex)
+{
+    const char *cp;
+    int     ch;
+
+    VSTRING_RESET(raw);
+    for (cp = hex; (ch = *cp) != 0; cp++) {
+	if (ch == '%') {
+	    if (ISDIGIT(cp[1]))
+		ch = (cp[1] - '0') << 4;
+	    else if (cp[1] >= 'a' && cp[1] <= 'f')
+		ch = (cp[1] - 'a' + 10) << 4;
+	    else if (cp[1] >= 'A' && cp[1] <= 'F')
+		ch = (cp[1] - 'A' + 10) << 4;
+	    else
+		return (0);
+	    if (ISDIGIT(cp[2]))
+		ch |= (cp[2] - '0');
+	    else if (cp[2] >= 'a' && cp[2] <= 'f')
+		ch |= (cp[2] - 'a' + 10);
+	    else if (cp[2] >= 'A' && cp[2] <= 'F')
+		ch |= (cp[2] - 'A' + 10);
+	    else
+		return (0);
+	    cp += 2;
+	}
+	VSTRING_ADDCH(raw, ch);
+    }
+    VSTRING_TERMINATE(raw);
+    return (raw);
+}
+
+#ifdef TEST
+
+ /*
+  * Proof-of-concept test program: convert to hex and back.
+  */
+#include <vstream.h>
+
+#define BUFLEN 1024
+
+static ssize_t read_buf(VSTREAM *fp, VSTRING *buf)
+{
+    ssize_t len;
+
+    len = vstream_fread_buf(fp, buf, BUFLEN);
+    VSTRING_TERMINATE(buf);
+    return (len);
+}
+
+int     main(int unused_argc, char **unused_argv)
+{
+    VSTRING *raw = vstring_alloc(BUFLEN);
+    VSTRING *hex = vstring_alloc(100);
+    ssize_t len;
+
+    while ((len = read_buf(VSTREAM_IN, raw)) > 0) {
+	hex_quote(hex, STR(raw));
+	if (hex_unquote(raw, STR(hex)) == 0)
+	    msg_fatal("bad input: %.100s", STR(hex));
+	if (LEN(raw) != len)
+	    msg_fatal("len %ld != raw len %ld", (long) len, (long) LEN(raw));
+	if (vstream_fwrite(VSTREAM_OUT, STR(raw), LEN(raw)) != LEN(raw))
+	    msg_fatal("write error: %m");
+    }
+    vstream_fflush(VSTREAM_OUT);
+    vstring_free(raw);
+    vstring_free(hex);
+    return (0);
+}
+
+#endif