Add base64 algorithms from PolarSSL to libalpm

We will need these for GPG functionality (decoding the base64 encoded
signature stored in the databases).

Signed-off-by: Dan McGee <dan@archlinux.org>
Signed-off-by: Allan McRae <allan@archlinux.org>

1 files changed, 190 insertions, 0 deletions

diff --git a/lib/libalpm/base64.c b/lib/libalpm/base64.c
new file mode 100644
index 00000000..fa8bec5c
--- /dev/null
+++ b/lib/libalpm/base64.c
@@ -0,0 +1,190 @@
+/*
+ *  RFC 1521 base64 encoding/decoding
+ *
+ *  Copyright (C) 2006-2010, Brainspark B.V.
+ *
+ *  This file is part of PolarSSL (http://www.polarssl.org)
+ *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ *  All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+/*
+ *  Pacman Notes:
+ *
+ *  Taken from the PolarSSL project at www.polarssl.org under terms of the
+ *  GPL. This is from version 0.14.2 of the library, and has been modified
+ *  as following, which may be helpful for future updates:
+ *  * remove "polarssl/config.h" include
+ *  * change include from "polarssl/base64.h" to "base64.h"
+ *  * removal of SELF_TEST code
+ */
+
+#include "base64.h"
+
+static const unsigned char base64_enc_map[64] =
+{
+    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
+    'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
+    'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
+    'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+    'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
+    'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
+    '8', '9', '+', '/'
+};
+
+static const unsigned char base64_dec_map[128] =
+{
+    127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
+    127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
+    127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
+    127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
+    127, 127, 127,  62, 127, 127, 127,  63,  52,  53,
+     54,  55,  56,  57,  58,  59,  60,  61, 127, 127,
+    127,  64, 127, 127, 127,   0,   1,   2,   3,   4,
+      5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
+     15,  16,  17,  18,  19,  20,  21,  22,  23,  24,
+     25, 127, 127, 127, 127, 127, 127,  26,  27,  28,
+     29,  30,  31,  32,  33,  34,  35,  36,  37,  38,
+     39,  40,  41,  42,  43,  44,  45,  46,  47,  48,
+     49,  50,  51, 127, 127, 127, 127, 127
+};
+
+/*
+ * Encode a buffer into base64 format
+ */
+int base64_encode( unsigned char *dst, int *dlen,
+                   const unsigned char *src, int  slen )
+{
+    int i, n;
+    int C1, C2, C3;
+    unsigned char *p;
+
+    if( slen == 0 )
+        return( 0 );
+
+    n = (slen << 3) / 6;
+
+    switch( (slen << 3) - (n * 6) )
+    {
+        case  2: n += 3; break;
+        case  4: n += 2; break;
+        default: break;
+    }
+
+    if( *dlen < n + 1 )
+    {
+        *dlen = n + 1;
+        return( POLARSSL_ERR_BASE64_BUFFER_TOO_SMALL );
+    }
+
+    n = (slen / 3) * 3;
+
+    for( i = 0, p = dst; i < n; i += 3 )
+    {
+        C1 = *src++;
+        C2 = *src++;
+        C3 = *src++;
+
+        *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
+        *p++ = base64_enc_map[(((C1 &  3) << 4) + (C2 >> 4)) & 0x3F];
+        *p++ = base64_enc_map[(((C2 & 15) << 2) + (C3 >> 6)) & 0x3F];
+        *p++ = base64_enc_map[C3 & 0x3F];
+    }
+
+    if( i < slen )
+    {
+        C1 = *src++;
+        C2 = ((i + 1) < slen) ? *src++ : 0;
+
+        *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
+        *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F];
+
+        if( (i + 1) < slen )
+             *p++ = base64_enc_map[((C2 & 15) << 2) & 0x3F];
+        else *p++ = '=';
+
+        *p++ = '=';
+    }
+
+    *dlen = p - dst;
+    *p = 0;
+
+    return( 0 );
+}
+
+/*
+ * Decode a base64-formatted buffer
+ */
+int base64_decode( unsigned char *dst, int *dlen,
+                   const unsigned char *src, int  slen )
+{
+    int i, j, n;
+    unsigned long x;
+    unsigned char *p;
+
+    for( i = j = n = 0; i < slen; i++ )
+    {
+        if( ( slen - i ) >= 2 &&
+            src[i] == '\r' && src[i + 1] == '\n' )
+            continue;
+
+        if( src[i] == '\n' )
+            continue;
+
+        if( src[i] == '=' && ++j > 2 )
+            return( POLARSSL_ERR_BASE64_INVALID_CHARACTER );
+
+        if( src[i] > 127 || base64_dec_map[src[i]] == 127 )
+            return( POLARSSL_ERR_BASE64_INVALID_CHARACTER );
+
+        if( base64_dec_map[src[i]] < 64 && j != 0 )
+            return( POLARSSL_ERR_BASE64_INVALID_CHARACTER );
+
+        n++;
+    }
+
+    if( n == 0 )
+        return( 0 );
+
+    n = ((n * 6) + 7) >> 3;
+
+    if( *dlen < n )
+    {
+        *dlen = n;
+        return( POLARSSL_ERR_BASE64_BUFFER_TOO_SMALL );
+    }
+
+   for( j = 3, n = x = 0, p = dst; i > 0; i--, src++ )
+   {
+        if( *src == '\r' || *src == '\n' )
+            continue;
+
+        j -= ( base64_dec_map[*src] == 64 );
+        x  = (x << 6) | ( base64_dec_map[*src] & 0x3F );
+
+        if( ++n == 4 )
+        {
+            n = 0;
+            if( j > 0 ) *p++ = (unsigned char)( x >> 16 );
+            if( j > 1 ) *p++ = (unsigned char)( x >>  8 );
+            if( j > 2 ) *p++ = (unsigned char)( x       );
+        }
+    }
+
+    *dlen = p - dst;
+
+    return( 0 );
+}