scripts/fips_crypto_utils.c

   1 /*
   2  * Utility functions called from fips_crypto_hmac.sh.
   3  *
   4  * executed during Kernel build
   5  *
   6  *
   7  * Author : Rohit Kothari (r.kothari@samsung.com)
   8  * Date   : 11 Feb 2014
   9  *
  10  * Copyright (c) 2014 Samsung Electronics
  11  *
  12  */
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16
  17 int main (int argc, char **argv)
  18 {
  19         if (argc < 2)
  20         {
  21                 printf ("\nUsage : \n");
  22                 printf ("fips_crypto_utils -u vmlinux_file hmac_file offset");
  23                 printf ("fips_crypto_utils -g vmlinux_file section_name offset size out_file");
  24                 printf ("\n");
  25                 return -1;
  26         }
  27
  28         if (!strcmp ("-u", argv[1]))
  29         {
  30                 unsigned long offset = 0;
  31                 unsigned char * vmlinux_file = NULL;
  32                 unsigned char * hmac_file    = NULL;
  33
  34                 if (argc != 5)
  35                 {
  36                         printf ("\nUsage : \n");
  37                         printf ("fips_crypto_utils -u vmlinux_file hmac_file offset");
  38                         printf ("\n");
  39                         return -1;
  40                 }
  41
  42                 vmlinux_file = argv[2];
  43                 hmac_file    = argv[3];
  44                 offset       = atol(argv[4]);
  45
  46                 if (!vmlinux_file || !hmac_file || !offset)
  47                 {
  48                         printf ("./fips_crypto_utils -u vmlinux_file hmac_file offset");
  49                         return -1;
  50                 }
  51
  52                 return update_crypto_hmac (vmlinux_file, hmac_file, offset);
  53         }
  54         else if (!strcmp ("-g", argv[1]))
  55         {
  56                 const char * in_file      = NULL;
  57                 const char * section_name = NULL;
  58                 unsigned long offset      = 0;
  59                 unsigned long size        = 0;
  60                 const char * out_file     = NULL;
  61
  62                 if (argc != 7)
  63                 {
  64                         printf ("\nUsage : \n");
  65                         printf ("./fips_crypto_utils -g vmlinux_file section_name offset size out_file");
  66                         printf ("\n");
  67                         return -1;
  68                 }
  69
  70                 in_file      = argv[2];
  71                 section_name = argv[3];
  72                 offset       = atol(argv[4]);
  73                 size         = atol(argv[5]);
  74                 out_file     = argv[6];
  75
  76                 if (!in_file || !section_name || !offset || !size || !out_file)
  77                 {
  78                         printf ("./fips_crypto_utils -g vmlinux_file section_name offset size out_file");
  79                         return -1;
  80                 }
  81
  82                 return collect_crypto_bytes (in_file, section_name, offset, size, out_file);
  83         }
  84         else
  85         {
  86                 printf ("\nUsage : \n");
  87                 printf ("fips_crypto_utils -u vmlinux_file hmac_file offset");
  88                 printf ("fips_crypto_utils -g vmlinux_file section_name offset size out_file");
  89                 printf ("\n");
  90         }
  91
  92         return -1;
  93 }
  94
  95 /*
  96  * Given a vmlinux file, dumps "size" bytes from given "offset" to output file
  97  * in_file      : absolute path to vmlinux file
  98  * section_name : Used only for printing / debugging
  99  * offset       : offset in file from where to dump bytes
 100  * size         : how many bytes to dump
 101  * out_file     : Output file, where to dump bytes.
 102  *                Open in append mode, to keep previous bytes, if present
 103  *                Caller need to clean up before 1st call
 104  *
 105  * Returns 0, if success
 106  *        -1, if error
 107  */
 108
 109 int
 110 collect_crypto_bytes (const char * in_file, const char * section_name, unsigned long offset,
 111                       unsigned long size, const char * out_file)
 112 {
 113         FILE * in_fp  = NULL;
 114         FILE * out_fp = NULL;
 115         unsigned int i     = 0;
 116         unsigned char data = 0;
 117
 118         if (!in_file || !section_name || !offset || !size || !out_file)
 119         {
 120                 printf ("collect_crypto_bytes : Invalid arguments");
 121                 return -1;
 122         }
 123
 124         printf ("Section : %s\n", section_name);
 125
 126         in_fp = fopen (in_file, "r");
 127         if (!in_fp)
 128         {
 129                 printf ("Unable to open file : %s", in_file);
 130                 return -1;
 131         }
 132
 133         if (fseek (in_fp, offset, SEEK_SET) != 0 )
 134         {
 135                 printf ("Unable to seek file : %s", in_file);
 136                 fclose (in_fp);
 137                 return -1;
 138         }
 139
 140         out_fp = fopen (out_file, "ab");
 141         if (!out_fp)
 142         {
 143                 printf ("Unable to open file : %s", out_file);
 144                 fclose(in_fp);
 145                 return -1;
 146         }
 147
 148         for (i = 1; i <= size; i++)
 149         {
 150                 if ( 1 != fread (&data, sizeof(unsigned char), 1, in_fp))
 151                 {
 152                         printf ("Unable to read 1 byte from  file : %s", in_file);
 153                         fclose (in_fp);
 154                         fclose (out_fp);
 155                         return -1;
 156                 }
 157
 158                 printf ("%02x ", data);
 159
 160                 if (1 != fwrite (&data, 1, 1, out_fp))
 161                 {
 162                         printf ("Unable to write 1 byte to file : %s", out_file);
 163                         fclose (in_fp);
 164                         fclose (out_fp);
 165                         return -1;
 166                 }
 167
 168                 if ( !(i % 16))
 169                         printf ("\n");
 170         }
 171
 172         fclose (in_fp);
 173         fclose (out_fp);
 174
 175         return 0;
 176 }
 177
 178
 179 #define SHA256_DIGEST_SIZE 32
 180
 181 /*
 182  * Given a vmlinux file, overwrites bytes at given offset with hmac bytes, available in
 183  * hmac file.
 184  * Return 0, if Success
 185  *       -1, if Error
 186  */
 187 int
 188 update_crypto_hmac (const char * vmlinux_path, const char * hmac_path, unsigned long offset)
 189 {
 190         FILE * vmlinux_fp = NULL;
 191         FILE * hmac_fp = NULL;
 192         int i = 0, j = 0;
 193         unsigned char hmac[SHA256_DIGEST_SIZE];
 194
 195         if (!vmlinux_path || !hmac_path || !offset)
 196         {
 197                 printf ("FIPS update_crypto_hmac : Invalid Params");
 198                 return -1;
 199         }
 200
 201         vmlinux_fp  = fopen (vmlinux_path, "r+b");
 202         if (!vmlinux_fp)
 203         {
 204                 printf ("Unable to open vmlinux file ");
 205                 return -1;
 206         }
 207
 208         hmac_fp = fopen (hmac_path, "rb");
 209
 210         if (!hmac_fp)
 211         {
 212                 printf ("Unable to open hmac file ");
 213                 fclose (vmlinux_fp);
 214                 return -1;
 215         }
 216
 217         if (SHA256_DIGEST_SIZE != fread (&hmac, sizeof(unsigned char), SHA256_DIGEST_SIZE, hmac_fp))
 218         {
 219                 printf ("Unable to read %d bytes from hmac file", SHA256_DIGEST_SIZE);
 220                 fclose (hmac_fp);
 221                 fclose (vmlinux_fp);
 222                 return -1;
 223         }
 224
 225 #if 0
 226         printf ("Hash : ");
 227         for (i = 0; i < sizeof(hmac); i++)
 228                 printf ("%02x ", hmac[i]);
 229         printf ("\n");
 230
 231         printf ("Offset : %ld", offset);
 232 #endif
 233
 234         if (fseek (vmlinux_fp, offset, SEEK_SET) != 0 )
 235         {
 236                 printf ("Unable to seek into vmlinux file.");
 237                 fclose (hmac_fp);
 238                 fclose (vmlinux_fp);
 239                 return -1;
 240         }
 241
 242         if (SHA256_DIGEST_SIZE !=  fwrite (hmac, sizeof(unsigned char), SHA256_DIGEST_SIZE, vmlinux_fp))
 243         {
 244                 printf ("Unable to write %d byte into vmlinux", SHA256_DIGEST_SIZE);
 245                 fclose (hmac_fp);
 246                 fclose (vmlinux_fp);
 247                 return -1;
 248         }
 249
 250         fclose (vmlinux_fp);
 251         fclose (hmac_fp);
 252
 253         return 0;
 254 }