scripts/fips_fmp_utils.c

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