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      1 /* ldbuildid.c - Build Id support routines
      2    Copyright (C) 2013-2016 Free Software Foundation, Inc.
      3 
      4    This file is part of the GNU Binutils.
      5 
      6    This program is free software; you can redistribute it and/or modify
      7    it under the terms of the GNU General Public License as published by
      8    the Free Software Foundation; either version 3 of the License, or
      9    (at your option) any later version.
     10 
     11    This program is distributed in the hope that it will be useful,
     12    but WITHOUT ANY WARRANTY; without even the implied warranty of
     13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     14    GNU General Public License for more details.
     15 
     16    You should have received a copy of the GNU General Public License
     17    along with this program; if not, write to the Free Software
     18    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
     19    MA 02110-1301, USA.  */
     20 
     21 #include "sysdep.h"
     22 #include "bfd.h"
     23 #include "safe-ctype.h"
     24 #include "md5.h"
     25 #include "sha1.h"
     26 #include "ldbuildid.h"
     27 
     28 #define streq(a,b)     strcmp ((a), (b)) == 0
     29 #define strneq(a,b,n)  strncmp ((a), (b), (n)) == 0
     30 
     31 bfd_boolean
     32 validate_build_id_style (const char *style)
     33 {
     34  if ((streq (style, "md5")) || (streq (style, "sha1"))
     35 #ifndef __MINGW32__
     36      || (streq (style, "uuid"))
     37 #endif
     38      || (strneq (style, "0x", 2)))
     39    return TRUE;
     40 
     41  return FALSE;
     42 }
     43 
     44 bfd_size_type
     45 compute_build_id_size (const char *style)
     46 {
     47   if (streq (style, "md5") || streq (style, "uuid"))
     48     return 128 / 8;
     49 
     50   if (streq (style, "sha1"))
     51     return 160 / 8;
     52 
     53   if (strneq (style, "0x", 2))
     54     {
     55       bfd_size_type size = 0;
     56       /* ID is in string form (hex).  Count the bytes.  */
     57       const char *id = style + 2;
     58 
     59       do
     60 	{
     61 	  if (ISXDIGIT (id[0]) && ISXDIGIT (id[1]))
     62 	    {
     63 	      ++size;
     64 	      id += 2;
     65 	    }
     66 	  else if (*id == '-' || *id == ':')
     67 	    ++id;
     68 	  else
     69 	    {
     70 	      size = 0;
     71 	      break;
     72 	    }
     73 	} while (*id != '\0');
     74       return size;
     75     }
     76 
     77   return 0;
     78 }
     79 
     80 static unsigned char
     81 read_hex (const char xdigit)
     82 {
     83   if (ISDIGIT (xdigit))
     84     return xdigit - '0';
     85 
     86   if (ISUPPER (xdigit))
     87     return xdigit - 'A' + 0xa;
     88 
     89   if (ISLOWER (xdigit))
     90     return xdigit - 'a' + 0xa;
     91 
     92   abort ();
     93   return 0;
     94 }
     95 
     96 bfd_boolean
     97 generate_build_id (bfd *abfd,
     98 		   const char *style,
     99 		   checksum_fn checksum_contents,
    100 		   unsigned char *id_bits,
    101 		   int size ATTRIBUTE_UNUSED)
    102 {
    103   if (streq (style, "md5"))
    104     {
    105       struct md5_ctx ctx;
    106 
    107       md5_init_ctx (&ctx);
    108       if (!(*checksum_contents) (abfd, (sum_fn) &md5_process_bytes, &ctx))
    109 	return FALSE;
    110       md5_finish_ctx (&ctx, id_bits);
    111     }
    112   else if (streq (style, "sha1"))
    113     {
    114       struct sha1_ctx ctx;
    115 
    116       sha1_init_ctx (&ctx);
    117       if (!(*checksum_contents) (abfd, (sum_fn) &sha1_process_bytes, &ctx))
    118 	return FALSE;
    119       sha1_finish_ctx (&ctx, id_bits);
    120     }
    121 #ifndef __MINGW32__
    122   else if (streq (style, "uuid"))
    123     {
    124       int n;
    125       int fd = open ("/dev/urandom", O_RDONLY);
    126 
    127       if (fd < 0)
    128 	return FALSE;
    129       n = read (fd, id_bits, size);
    130       close (fd);
    131       if (n < size)
    132 	return FALSE;
    133     }
    134 #endif
    135   else if (strneq (style, "0x", 2))
    136     {
    137       /* ID is in string form (hex).  Convert to bits.  */
    138       const char *id = style + 2;
    139       size_t n = 0;
    140 
    141       do
    142 	{
    143 	  if (ISXDIGIT (id[0]) && ISXDIGIT (id[1]))
    144 	    {
    145 	      id_bits[n] = read_hex (*id++) << 4;
    146 	      id_bits[n++] |= read_hex (*id++);
    147 	    }
    148 	  else if (*id == '-' || *id == ':')
    149 	    ++id;
    150 	  else
    151 	    abort ();		/* Should have been validated earlier.  */
    152 	} while (*id != '\0');
    153     }
    154   else
    155     abort ();			/* Should have been validated earlier.  */
    156 
    157   return TRUE;
    158 }
    159