From: Stephan Bosch <stephan.bosch@open-xchange.com>
Date: Tue, 27 Aug 2019 23:21:01 +0000 (+0200)
Subject: lib: base64 - Add BASE64_DECODE_FLAG_IGNORE_PADDING.
X-Git-Tag: 2.3.9~265
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=23a9a74534aa3bdfe4d15bbbe84a02410de657f6;p=thirdparty%2Fdovecot%2Fcore.git

lib: base64 - Add BASE64_DECODE_FLAG_IGNORE_PADDING.

Makes padding optional rather than either disallowed or required.
---

diff --git a/src/lib/base64.c b/src/lib/base64.c
index 35e0a558a1..54f50923a0 100644
--- a/src/lib/base64.c
+++ b/src/lib/base64.c
@@ -672,7 +672,12 @@ int base64_decode_finish(struct base64_decoder *dec)
 		return -1;
 
 	if (HAS_ALL_BITS(dec->flags,
-			 BASE64_DECODE_FLAG_NO_PADDING))
+			 BASE64_DECODE_FLAG_NO_PADDING)) {
+		i_assert(!dec->seen_padding);
+		return 0;
+	}
+	if (HAS_ALL_BITS(dec->flags,
+			 BASE64_DECODE_FLAG_IGNORE_PADDING))
 		return 0;
 	return (dec->sub_pos == 0 ? 0 : -1);
 }
diff --git a/src/lib/base64.h b/src/lib/base64.h
index 28215529eb..3663041ecd 100644
--- a/src/lib/base64.h
+++ b/src/lib/base64.h
@@ -118,6 +118,10 @@ enum base64_decode_flags {
 	BASE64_DECODE_FLAG_NO_WHITESPACE   = BIT(1),
 	/* Require absence of padding at the end of the input. */
 	BASE64_DECODE_FLAG_NO_PADDING      = BIT(2),
+	/* Ignore padding at the end of the input. This flag is ignored when
+	   BASE64_DECODE_FLAG_NO_PADDING is also set. If both of these flags are
+	   absent, padding is required (the default). */
+	BASE64_DECODE_FLAG_IGNORE_PADDING  = BIT(3),
 };
 
 struct base64_decoder {
diff --git a/src/lib/test-base64.c b/src/lib/test-base64.c
index e9e08dcb41..d94500d404 100644
--- a/src/lib/test-base64.c
+++ b/src/lib/test-base64.c
@@ -534,6 +534,22 @@ tests_base64_decode_lowlevel[] = {
 		.ret = 0,
 		.src_pos = 16,
 	},
+	{
+		.scheme = &base64_scheme,
+		.flags = BASE64_DECODE_FLAG_IGNORE_PADDING,
+		.input = "\taGVsbG8gd29ybGQ=",
+		.output = "hello world",
+		.ret = 0,
+		.src_pos = 17,
+	},
+	{
+		.scheme = &base64_scheme,
+		.flags = BASE64_DECODE_FLAG_IGNORE_PADDING,
+		.input = "\taGVsbG8gd29ybGQ",
+		.output = "hello world",
+		.ret = 0,
+		.src_pos = 16,
+	},
 	{
 		.scheme = &base64_scheme,
 		.input = "\nZm9v\n \tIGJh  \t\ncml0cw==",
@@ -585,6 +601,22 @@ tests_base64_decode_lowlevel[] = {
 		.ret = 0,
 		.src_pos = 22,
 	},
+	{
+		.scheme = &base64_scheme,
+		.flags = BASE64_DECODE_FLAG_IGNORE_PADDING,
+		.input = "\nZm9v\n \tIGJh  \t\ncml0cw==",
+		.output = "foo barits",
+		.ret = 0,
+		.src_pos = 24,
+	},
+	{
+		.scheme = &base64_scheme,
+		.flags = BASE64_DECODE_FLAG_IGNORE_PADDING,
+		.input = "\nZm9v\n \tIGJh  \t\ncml0cw",
+		.output = "foo barits",
+		.ret = 0,
+		.src_pos = 22,
+	},
 	{
 		.scheme = &base64_scheme,
 		.input = "  anVzdCBuaWlu  \n",
@@ -607,6 +639,14 @@ tests_base64_decode_lowlevel[] = {
 		.ret = 0,
 		.src_pos = UINT_MAX,
 	},
+	{
+		.scheme = &base64_scheme,
+		.flags = BASE64_DECODE_FLAG_IGNORE_PADDING,
+		.input = "  anVzdCBuaWlu  \n",
+		.output = "just niin",
+		.ret = 0,
+		.src_pos = UINT_MAX,
+	},
 	{
 		.scheme = &base64_scheme,
 		.input = "aGVsb",
@@ -629,6 +669,14 @@ tests_base64_decode_lowlevel[] = {
 		.ret = 0,
 		.src_pos = 5,
 	},
+	{
+		.scheme = &base64_scheme,
+		.flags = BASE64_DECODE_FLAG_IGNORE_PADDING,
+		.input = "aGVsb",
+		.output = "hel",
+		.ret = 0,
+		.src_pos = 5,
+	},
 	{
 		.scheme = &base64_scheme,
 		.input = "aGVsb!!!!!",
@@ -697,6 +745,34 @@ tests_base64_decode_lowlevel[] = {
 		.ret = 0,
 		.src_pos = UINT_MAX,
 	},
+	{
+		.scheme = &base64_scheme,
+		.flags = BASE64_DECODE_FLAG_IGNORE_PADDING,
+		.input =
+			"0JPQvtCy0L7RgNGPzIHRgiwg0YfRgt"
+			"C+INC60YPRgCDQtNC+0Y/MgdGCLg",
+		.output =
+			"\xd0\x93\xd0\xbe\xd0\xb2\xd0\xbe\xd1\x80\xd1\x8f\xcc"
+			"\x81\xd1\x82\x2c\x20\xd1\x87\xd1\x82\xd0\xbe\x20\xd0"
+			"\xba\xd1\x83\xd1\x80\x20\xd0\xb4\xd0\xbe\xd1\x8f\xcc"
+			"\x81\xd1\x82\x2e",
+		.ret = 0,
+		.src_pos = UINT_MAX,
+	},
+	{
+		.scheme = &base64_scheme,
+		.flags = BASE64_DECODE_FLAG_IGNORE_PADDING,
+		.input =
+			"0JPQvtCy0L7RgNGPzIHRgiwg0YfRgt"
+			"C+INC60YPRgCDQtNC+0Y/MgdGCLg==",
+		.output =
+			"\xd0\x93\xd0\xbe\xd0\xb2\xd0\xbe\xd1\x80\xd1\x8f\xcc"
+			"\x81\xd1\x82\x2c\x20\xd1\x87\xd1\x82\xd0\xbe\x20\xd0"
+			"\xba\xd1\x83\xd1\x80\x20\xd0\xb4\xd0\xbe\xd1\x8f\xcc"
+			"\x81\xd1\x82\x2e",
+		.ret = 0,
+		.src_pos = UINT_MAX,
+	},
 };
 
 static void test_base64_decode_lowlevel(void)