url: Prefer upper-case letters in hex characters when encoding

This makes it more compliant with RFC 3986, where the use of
upper-case letters is recommended (as "SHOULD").

Suggested by Sumit Bose.

3 files changed, 46 insertions, 8 deletions

diff --git a/common/test-path.c b/common/test-path.c
index c77acf2..2eb5444 100644
--- a/common/test-path.c
+++ b/common/test-path.c
@@ -206,7 +206,7 @@ test_encode (void)
 	char *test;
 
 	test = p11_path_encode ("2309haonutb;/AOE@#$O ");
-	assert_str_eq (test, "2309haonutb%3b/AOE%40%23%24O%20");
+	assert_str_eq (test, "2309haonutb%3B/AOE%40%23%24O%20");
 	free (test);
 }
 
diff --git a/common/test-url.c b/common/test-url.c
index 892bf3c..4f10cb4 100644
--- a/common/test-url.c
+++ b/common/test-url.c
@@ -150,6 +150,33 @@ test_encode_verbatim (void)
 	p11_buffer_uninit (&buf);
 }
 
+static void
+test_encode_lower (void)
+{
+	const unsigned char *input = (unsigned char *)",.:;";
+	p11_buffer buf;
+
+	if (!p11_buffer_init_null (&buf, 5))
+		assert_not_reached ();
+
+	p11_url_encode (input, input + 5, "", &buf);
+	assert (p11_buffer_ok (&buf));
+	assert_str_eq ("%2C%2E%3A%3B%00", (char *)buf.data);
+	assert_num_eq (15, buf.len);
+
+	if (!p11_buffer_reset (&buf, 5))
+		assert_not_reached ();
+
+	setenv ("P11_KIT_URI_LOWERCASE", "1", 1);
+
+	p11_url_encode (input, input + 5, "", &buf);
+	assert (p11_buffer_ok (&buf));
+	assert_str_eq ("%2c%2e%3a%3b%00", (char *)buf.data);
+	assert_num_eq (15, buf.len);
+
+	p11_buffer_uninit (&buf);
+}
+
 int
 main (int argc,
       char *argv[])
@@ -160,5 +187,6 @@ main (int argc,
 
 	p11_test (test_encode, "/url/encode");
 	p11_test (test_encode_verbatim, "/url/encode-verbatim");
+	p11_test (test_encode_lower, "/url/encode-lower");
 	return p11_test_run (argc, argv);
 }
diff --git a/common/url.c b/common/url.c
index 344d971..903c58b 100644
--- a/common/url.c
+++ b/common/url.c
@@ -44,7 +44,8 @@
 #include <stdio.h>
 #include <string.h>
 
-const static char HEX_CHARS[] = "0123456789abcdef";
+const static char HEX_CHARS_UPPER[] = "0123456789ABCDEF";
+const static char HEX_CHARS_LOWER[] = "0123456789abcdef";
 
 unsigned char *
 p11_url_decode (const char *value,
@@ -75,14 +76,14 @@ p11_url_decode (const char *value,
 				free (result);
 				return NULL;
 			}
-			a = strchr (HEX_CHARS, p11_ascii_tolower (value[0]));
-			b = strchr (HEX_CHARS, p11_ascii_tolower (value[1]));
+			a = strchr (HEX_CHARS_UPPER, p11_ascii_toupper (value[0]));
+			b = strchr (HEX_CHARS_UPPER, p11_ascii_toupper (value[1]));
 			if (!a || !b) {
 				free (result);
 				return NULL;
 			}
-			*p = (a - HEX_CHARS) << 4;
-			*(p++) |= (b - HEX_CHARS);
+			*p = (a - HEX_CHARS_UPPER) << 4;
+			*(p++) |= (b - HEX_CHARS_UPPER);
 			value += 2;
 
 		/* Ignore whitespace characters */
@@ -110,9 +111,18 @@ p11_url_encode (const unsigned char *value,
                 p11_buffer *buf)
 {
 	char hex[3];
+	const char *env;
+	const char *hex_chars;
 
 	assert (value <= end);
 
+	/* Opt to output lowercase hex-digits for compatibility */
+	env = secure_getenv ("P11_KIT_URI_LOWERCASE");
+	if (env && *env != '\0')
+		hex_chars = HEX_CHARS_LOWER;
+	else
+		hex_chars = HEX_CHARS_UPPER;
+
 	/* Now loop through looking for escapes */
 	while (value != end) {
 
@@ -123,8 +133,8 @@ p11_url_encode (const unsigned char *value,
 		/* All others get encoded */
 		} else {
 			hex[0] = '%';
-			hex[1] = HEX_CHARS[((unsigned char)*value) >> 4];
-			hex[2] = HEX_CHARS[((unsigned char)*value) & 0x0F];
+			hex[1] = hex_chars[((unsigned char)*value) >> 4];
+			hex[2] = hex_chars[((unsigned char)*value) & 0x0F];
 			p11_buffer_add (buf, hex, 3);
 		}