RFC 4648 base64-encodingv0.2.0

2 files changed, 382 insertions, 1 deletions

diff --git a/src/Encoding.php b/src/Encoding.php
index 81983c2..5a5f648 100644
--- a/src/Encoding.php
+++ b/src/Encoding.php
@@ -25,11 +25,204 @@ namespace ParagonIE\ConstantTime;
 class Encoding
 {
     /**
+     * Decode a Base32-encoded string into raw binary
+     *
+     * @param string $src
+     * @return string
+     */
+    public static function base32Decode($src)
+    {
+        // Remove padding
+        $srcLen = self::safeStrlen($src);
+        if ($srcLen === 0) {
+            return '';
+        }
+        if (($srcLen & 7) === 0) {
+            if ($src[$srcLen - 1] === '=') {
+                $srcLen--;
+                if ($src[$srcLen - 1] === '=') {
+                    $srcLen--;
+                }
+                if ($src[$srcLen - 1] === '=') {
+                    $srcLen--;
+                }
+                if ($src[$srcLen - 1] === '=') {
+                    $srcLen--;
+                }
+                if ($src[$srcLen - 1] === '=') {
+                    $srcLen--;
+                }
+                if ($src[$srcLen - 1] === '=') {
+                    $srcLen--;
+                }
+                if ($src[$srcLen - 1] === '=') {
+                    $srcLen--;
+                }
+            }
+        }
+        if (($srcLen & 7) === 1) {
+            return false;
+        }
+
+        $err = 0;
+        $dest = '';
+        for ($i = 0; $i + 8 <= $srcLen; $i += 8) {
+            $c0 = self::base32Decode5Bits(ord($src[$i]));
+            $c1 = self::base32Decode5Bits(ord($src[$i + 1]));
+            $c2 = self::base32Decode5Bits(ord($src[$i + 2]));
+            $c3 = self::base32Decode5Bits(ord($src[$i + 3]));
+            $c4 = self::base32Decode5Bits(ord($src[$i + 4]));
+            $c5 = self::base32Decode5Bits(ord($src[$i + 5]));
+            $c6 = self::base32Decode5Bits(ord($src[$i + 6]));
+            $c7 = self::base32Decode5Bits(ord($src[$i + 7]));
+
+            $dest .=
+                chr((($c0 << 3) | ($c1 >> 2)             ) & 0xff) .
+                chr((($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff) .
+                chr((($c3 << 4) | ($c4 >> 1)             ) & 0xff) .
+                chr((($c4 << 7) | ($c5 << 2) | ($c6 >> 3)) & 0xff) .
+                chr((($c6 << 5) | ($c7     )             ) & 0xff);
+        }
+        if ($i < $srcLen) {
+            $c0 = self::base32Decode5Bits(ord($src[$i]));
+            if ($i + 6 < $srcLen) {
+                $c1 = self::base32Decode5Bits(ord($src[$i + 1]));
+                $c2 = self::base32Decode5Bits(ord($src[$i + 2]));
+                $c3 = self::base32Decode5Bits(ord($src[$i + 3]));
+                $c4 = self::base32Decode5Bits(ord($src[$i + 4]));
+                $c5 = self::base32Decode5Bits(ord($src[$i + 5]));
+                $c6 = self::base32Decode5Bits(ord($src[$i + 6]));
+
+                $dest .=
+                    chr((($c0 << 3) | ($c1 >> 2)             ) & 0xff) .
+                    chr((($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff) .
+                    chr((($c3 << 4) | ($c4 >> 1)             ) & 0xff) .
+                    chr((($c4 << 7) | ($c5 << 2) | ($c6 >> 3)) & 0xff);
+            } elseif ($i + 5 < $srcLen) {
+                $c1 = self::base32Decode5Bits(ord($src[$i + 1]));
+                $c2 = self::base32Decode5Bits(ord($src[$i + 2]));
+                $c3 = self::base32Decode5Bits(ord($src[$i + 3]));
+                $c4 = self::base32Decode5Bits(ord($src[$i + 4]));
+                $c5 = self::base32Decode5Bits(ord($src[$i + 5]));
+
+                $dest .=
+                    chr((($c0 << 3) | ($c1 >> 2)             ) & 0xff) .
+                    chr((($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff) .
+                    chr((($c3 << 4) | ($c4 >> 1)             ) & 0xff) .
+                    chr((($c4 << 7) | ($c5 << 2)             ) & 0xff);
+            } elseif ($i + 4 < $srcLen) {
+                $c1 = self::base32Decode5Bits(ord($src[$i + 1]));
+                $c2 = self::base32Decode5Bits(ord($src[$i + 2]));
+                $c3 = self::base32Decode5Bits(ord($src[$i + 3]));
+                $c4 = self::base32Decode5Bits(ord($src[$i + 4]));
+
+                $dest .=
+                    chr((($c0 << 3) | ($c1 >> 2)             ) & 0xff) .
+                    chr((($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff) .
+                    chr((($c3 << 4) | ($c4 >> 1)             ) & 0xff);
+            } elseif ($i + 3 < $srcLen) {
+                $c1 = self::base32Decode5Bits(ord($src[$i + 1]));
+                $c2 = self::base32Decode5Bits(ord($src[$i + 2]));
+                $c3 = self::base32Decode5Bits(ord($src[$i + 3]));
+
+                $dest .=
+                    chr((($c0 << 3) | ($c1 >> 2)             ) & 0xff) .
+                    chr((($c1 << 6) | ($c2 << 1) | ($c3 >> 4)) & 0xff) .
+                    ''; //chr((($c3 << 4)                          ) & 0xff);
+            } elseif ($i + 2 < $srcLen) {
+                $c1 = self::base32Decode5Bits(ord($src[$i + 1]));
+                $c2 = self::base32Decode5Bits(ord($src[$i + 2]));
+
+                $dest .=
+                    chr((($c0 << 3) | ($c1 >> 2)             ) & 0xff) .
+                    chr((($c1 << 6) | ($c2 << 1)             ) & 0xff);
+            } elseif ($i + 1 < $srcLen) {
+                $c1 = self::base32Decode5Bits(ord($src[$i + 1]));
+                $dest .=
+                    chr((($c0 << 3) | ($c1 >> 2)             ) & 0xff);
+            } else {
+                $dest .=
+                    chr((($c0 << 3)                          ) & 0xff);
+            }
+        }
+        return $dest;
+    }
+
+    /**
+     * Encode into Base32 (RFC 4648)
+     *
+     * @param string $src
+     * @return string
+     */
+    public static function base32Encode($src)
+    {
+        $dest = '';
+        $srcLen = self::safeStrlen($src);
+        for ($i = 0; $i + 5 <= $srcLen; $i += 5) {
+            $b0 = ord($src[$i]);
+            $b1 = ord($src[$i + 1]);
+            $b2 = ord($src[$i + 2]);
+            $b3 = ord($src[$i + 3]);
+            $b4 = ord($src[$i + 4]);
+            $dest .=
+                self::base32Encode5Bits(              ($b0 >> 3)  & 31) .
+                self::base32Encode5Bits((($b0 << 2) | ($b1 >> 6)) & 31) .
+                self::base32Encode5Bits((($b1 >> 1)             ) & 31) .
+                self::base32Encode5Bits((($b1 << 4) | ($b2 >> 4)) & 31) .
+                self::base32Encode5Bits((($b2 << 1) | ($b3 >> 7)) & 31) .
+                self::base32Encode5Bits((($b3 >> 2)             ) & 31) .
+                self::base32Encode5Bits((($b3 << 3) | ($b4 >> 5)) & 31) .
+                self::base32Encode5Bits(  $b4                     & 31);
+        }
+        if ($i < $srcLen) {
+            $b0 = ord($src[$i]);
+            if ($i + 3 < $srcLen) {
+                $b1 = ord($src[$i + 1]);
+                $b2 = ord($src[$i + 2]);
+                $b3 = ord($src[$i + 3]);
+                $dest .=
+                    self::base32Encode5Bits(              ($b0 >> 3)  & 31) .
+                    self::base32Encode5Bits((($b0 << 2) | ($b1 >> 6)) & 31) .
+                    self::base32Encode5Bits((($b1 >> 1)             ) & 31) .
+                    self::base32Encode5Bits((($b1 << 4) | ($b2 >> 4)) & 31) .
+                    self::base32Encode5Bits((($b2 << 1) | ($b3 >> 7)) & 31) .
+                    self::base32Encode5Bits((($b3 >> 2)             ) & 31) .
+                    self::base32Encode5Bits((($b3 << 3)             ) & 31) .
+                    '=';
+            } elseif ($i + 2 < $srcLen) {
+                $b1 = ord($src[$i + 1]);
+                $b2 = ord($src[$i + 2]);
+                $dest .=
+                    self::base32Encode5Bits(              ($b0 >> 3)  & 31) .
+                    self::base32Encode5Bits((($b0 << 2) | ($b1 >> 6)) & 31) .
+                    self::base32Encode5Bits((($b1 >> 1)             ) & 31) .
+                    self::base32Encode5Bits((($b1 << 4) | ($b2 >> 4)) & 31) .
+                    self::base32Encode5Bits((($b2 << 1)             ) & 31) .
+                    '===';
+            } elseif ($i + 1 < $srcLen) {
+                $b1 = ord($src[$i + 1]);
+                $dest .=
+                    self::base32Encode5Bits(              ($b0 >> 3)  & 31) .
+                    self::base32Encode5Bits((($b0 << 2) | ($b1 >> 6)) & 31) .
+                    self::base32Encode5Bits((($b1 >> 1)             ) & 31) .
+                    self::base32Encode5Bits((($b1 << 4)             ) & 31) .
+                    '====';
+            } else {
+                $dest .=
+                    self::base32Encode5Bits(              ($b0 >> 3)  & 31) .
+                    self::base32Encode5Bits( ($b0 << 2)               & 31) .
+                    '======';
+            }
+        }
+        return $dest;
+    }
+
+    /**
      * Encode into Base64
      *
      * Base64 character set "[A-Z][a-z][0-9]+/"
      *
-     * @param $src
+     * @param string $src
      * @return string
      */
     public static function base64Encode($src)
@@ -366,6 +559,7 @@ class Encoding
     {
         $hex_pos = 0;
         $bin = '';
+        $c_acc = 0;
         $hex_len = self::safeStrlen($hex_string);
         $state = 0;
 
@@ -394,6 +588,38 @@ class Encoding
 
     /**
      *
+     * @param $src
+     * @return int
+     */
+    protected static function base32Decode5Bits($src)
+    {
+        $ret = -1;
+
+        // if ($src > 64 && $src < 91) $ret += $src - 65 + 1; // -64
+        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 64);
+
+        // if ($src > 0x31 && $src < 0x38) $ret += $src - 24 + 1; // -23
+        $ret += (((0x31 - $src) & ($src - 0x38)) >> 8) & ($src - 23);
+
+        return $ret;
+    }
+
+    /**
+     * @param $src
+     * @return string
+     */
+    protected static function base32Encode5Bits($src)
+    {
+        $diff = 0x41;
+
+        // if ($src > 25) $ret -= 40;
+        $diff -= ((25 - $src) >> 8) & 41;
+
+        return chr($src + $diff);
+    }
+
+    /**
+     *
      * Base64 character set:
      * [A-Z]      [a-z]      [0-9]      +     /
      * 0x41-0x5a, 0x61-0x7a, 0x30-0x39, 0x2b, 0x2f
diff --git a/tests/EncodingTest.php b/tests/EncodingTest.php
index 556c5a5..17a7af2 100644
--- a/tests/EncodingTest.php
+++ b/tests/EncodingTest.php
@@ -3,6 +3,152 @@ use \ParagonIE\ConstantTime\Encoding;
 
 class EncodingTest extends PHPUnit_Framework_TestCase
 {
+    /**
+     * Based on test vectors from RFC 4648
+     */
+    public function testBase32Encode()
+    {
+        $this->assertEquals(
+            Encoding::base32Encode("\x00"),
+            'AA======'
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("\x00\x00"),
+            'AAAA===='
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("\x00\x00\x00"),
+            'AAAAA==='
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("\x00\x00\x00\x00"),
+            'AAAAAAA='
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("\x00\x00\x00\x00\x00"),
+            'AAAAAAAA'
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("f"),
+            'MY======'
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("fo"),
+            'MZXQ===='
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("foo"),
+            'MZXW6==='
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("foob"),
+            'MZXW6YQ='
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("fooba"),
+            'MZXW6YTB'
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("foobar"),
+            'MZXW6YTBOI======'
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("\x00\x00\x0F\xFF\xFF"),
+            'AAAA7777'
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("\xFF\xFF\xF0\x00\x00"),
+            '7777AAAA'
+        );
+
+        $this->assertEquals(
+            Encoding::base32Encode("\xce\x73\x9c\xe7\x39"),
+            'ZZZZZZZZ'
+        );
+        $this->assertEquals(
+            Encoding::base32Encode("\xd6\xb5\xad\x6b\x5a"),
+            '22222222'
+        );
+    }
+    /**
+     * Based on test vectors from RFC 4648
+     */
+    public function testBase32Decode()
+    {
+        $this->assertEquals(
+            "\x00\x00\x00\x00\x00\x00",
+            Encoding::base32Decode('AAAAAAAAAA======')
+        );
+        $this->assertEquals(
+            "\x00\x00\x00\x00\x00\x00\x00",
+            Encoding::base32Decode('AAAAAAAAAAAA====')
+        );
+        $this->assertEquals(
+            "\x00\x00\x00\x00\x00\x00\x00\x00",
+            Encoding::base32Decode('AAAAAAAAAAAAA===')
+        );
+        $this->assertEquals(
+            "\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+            Encoding::base32Decode('AAAAAAAAAAAAAAA=')
+        );
+        $this->assertEquals(
+            "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+            Encoding::base32Decode('AAAAAAAAAAAAAAAA')
+        );
+        $this->assertEquals(
+            "\x00",
+            Encoding::base32Decode('AA======')
+        );
+        $this->assertEquals(
+            "\x00\x00",
+            Encoding::base32Decode('AAAA====')
+        );
+        $this->assertEquals(
+            "\x00\x00\x00",
+            Encoding::base32Decode('AAAAA===')
+        );
+        $this->assertEquals(
+            "\x00\x00\x00\x00",
+            Encoding::base32Decode('AAAAAAA=')
+        );
+        $this->assertEquals(
+            "\x00\x00\x00\x00\x00",
+            Encoding::base32Decode('AAAAAAAA')
+        );
+        $this->assertEquals(
+            "\x00\x00\x0F\xFF\xFF",
+            Encoding::base32Decode('AAAA7777')
+        );
+        $this->assertEquals(
+            "\xFF\xFF\xF0\x00\x00",
+            Encoding::base32Decode('7777AAAA')
+        );
+        $this->assertEquals(
+            "\xce\x73\x9c\xe7\x39",
+            Encoding::base32Decode('ZZZZZZZZ')
+        );
+        $this->assertEquals(
+            "\xd6\xb5\xad\x6b\x5a",
+            Encoding::base32Decode('22222222')
+        );
+        $this->assertEquals(
+            'foobar',
+            Encoding::base32Decode('MZXW6YTBOI======')
+        );
+
+        $rand = random_bytes(9);
+        $enc = Encoding::base32Encode($rand);
+
+        $this->assertEquals(
+            Encoding::base32Encode($rand),
+            Encoding::base32Encode(Encoding::base32Decode($enc))
+        );
+        $this->assertEquals(
+            $rand,
+            Encoding::base32Decode($enc)
+        );
+    }
+
     public function testBasicEncoding()
     {
         $str = random_bytes(33);
@@ -11,5 +157,14 @@ class EncodingTest extends PHPUnit_Framework_TestCase
             $str,
             Encoding::base64Decode($enc)
         );
+
+        for ($i = 1; $i < 34; ++$i) {
+            $rand = random_bytes($i);
+            $enc = Encoding::base32Encode($rand);
+            $this->assertEquals(
+                bin2hex($rand),
+                bin2hex(Encoding::base32Decode($enc))
+            );
+        }
     }
 }
\ No newline at end of file