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
validate_build_id_style(const char * style)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
compute_build_id_size(const char * style)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
read_hex(const char xdigit)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
generate_build_id(bfd * abfd,const char * style,checksum_fn checksum_contents,unsigned char * id_bits,int size ATTRIBUTE_UNUSED)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