From: compmaniak <6314398+compmaniak@users.noreply.github.com>
Date: Wed, 30 Aug 2017 22:25:22 +0000 (+0300)
Subject: lib: Reduced conditional logic in base64_encode
X-Git-Tag: 2.3.0.rc1~1120
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f117e2804941e1bf8bb0392cbd066218ffdbfa44;p=thirdparty%2Fdovecot%2Fcore.git

lib: Reduced conditional logic in base64_encode
---

diff --git a/src/lib/base64.c b/src/lib/base64.c
index a645dd2fbe..d84014b7b2 100644
--- a/src/lib/base64.c
+++ b/src/lib/base64.c
@@ -49,32 +49,35 @@ void base64_encode(const void *src, size_t src_size, buffer_t *dest)
 	unsigned char tmp[4];
 	size_t src_pos;
 
-	for (src_pos = 0; src_pos < src_size; ) {
+	for (src_pos = 0; src_size - src_pos > 2; src_pos += 3) {
 		tmp[0] = b64enc[src_c[src_pos] >> 2];
-		switch (src_size - src_pos) {
-		case 1:
-			tmp[1] = b64enc[(src_c[src_pos] & 0x03) << 4];
-			tmp[2] = '=';
-			tmp[3] = '=';
-			src_pos++;
-			break;
-		case 2:
-			tmp[1] = b64enc[((src_c[src_pos] & 0x03) << 4) |
-					(src_c[src_pos+1] >> 4)];
-			tmp[2] = b64enc[((src_c[src_pos+1] & 0x0f) << 2)];
-			tmp[3] = '=';
-			src_pos += 2;
-			break;
-		default:
-			tmp[1] = b64enc[((src_c[src_pos] & 0x03) << 4) |
-					(src_c[src_pos+1] >> 4)];
-			tmp[2] = b64enc[((src_c[src_pos+1] & 0x0f) << 2) |
-					((src_c[src_pos+2] & 0xc0) >> 6)];
-			tmp[3] = b64enc[src_c[src_pos+2] & 0x3f];
-			src_pos += 3;
-			break;
-		}
+		tmp[1] = b64enc[((src_c[src_pos] & 0x03) << 4) |
+				(src_c[src_pos+1] >> 4)];
+		tmp[2] = b64enc[((src_c[src_pos+1] & 0x0f) << 2) |
+				((src_c[src_pos+2] & 0xc0) >> 6)];
+		tmp[3] = b64enc[src_c[src_pos+2] & 0x3f];
+		buffer_append(dest, tmp, 4);
+	}
+	switch (src_size - src_pos) {
+	case 0:
+		break;
+	case 1:
+		tmp[0] = b64enc[src_c[src_pos] >> 2];
+		tmp[1] = b64enc[(src_c[src_pos] & 0x03) << 4];
+		tmp[2] = '=';
+		tmp[3] = '=';
+		buffer_append(dest, tmp, 4);
+		break;
+	case 2:
+		tmp[0] = b64enc[src_c[src_pos] >> 2];
+		tmp[1] = b64enc[((src_c[src_pos] & 0x03) << 4) |
+				(src_c[src_pos+1] >> 4)];
+		tmp[2] = b64enc[((src_c[src_pos+1] & 0x0f) << 2)];
+		tmp[3] = '=';
 		buffer_append(dest, tmp, 4);
+		break;
+	default:
+		i_unreached();
 	}
 }