sys/src/cmd/sha1sum.c

   1 /*
   2  * sha1sum - compute SHA1 or SHA2 digest
   3  */
   4 #include <u.h>
   5 #include <libc.h>
   6 #include <libsec.h>
   7
   8 #pragma varargck        type    "M"     uchar*
   9
  10 typedef struct Sha2 Sha2;
  11 struct Sha2 {
  12         int     bits;
  13         int     dlen;
  14         DigestState* (*func)(uchar *, ulong, uchar *, DigestState *);
  15 };
  16
  17 static Sha2 sha2s[] = {
  18         224,    SHA2_224dlen,   sha2_224,
  19         256,    SHA2_256dlen,   sha2_256,
  20         384,    SHA2_384dlen,   sha2_384,
  21         512,    SHA2_512dlen,   sha2_512,
  22 };
  23
  24 static DigestState* (*shafunc)(uchar *, ulong, uchar *, DigestState *);
  25 static int shadlen;
  26
  27 static int
  28 digestfmt(Fmt *fmt)
  29 {
  30         char buf[SHA2_512dlen*2 + 1];
  31         uchar *p;
  32         int i;
  33
  34         p = va_arg(fmt->args, uchar*);
  35         for(i = 0; i < shadlen; i++)
  36                 sprint(buf + 2*i, "%.2ux", p[i]);
  37         return fmtstrcpy(fmt, buf);
  38 }
  39
  40 static void
  41 sum(int fd, char *name)
  42 {
  43         int n;
  44         uchar buf[8192], digest[SHA2_512dlen];
  45         DigestState *s;
  46
  47         s = (*shafunc)(nil, 0, nil, nil);
  48         while((n = read(fd, buf, sizeof buf)) > 0)
  49                 (*shafunc)(buf, n, nil, s);
  50         if(n < 0){
  51                 fprint(2, "reading %s: %r\n", name? name: "stdin");
  52                 return;
  53         }
  54         (*shafunc)(nil, 0, digest, s);
  55         if(name == nil)
  56                 print("%M\n", digest);
  57         else
  58                 print("%M\t%s\n", digest, name);
  59 }
  60
  61 static void
  62 usage(void)
  63 {
  64         fprint(2, "usage: %s [-2 bits] [file...]\n", argv0);
  65         exits("usage");
  66 }
  67
  68 void
  69 main(int argc, char *argv[])
  70 {
  71         int i, fd, bits;
  72         Sha2 *sha;
  73
  74         shafunc = sha1;
  75         shadlen = SHA1dlen;
  76         ARGBEGIN{
  77         case '2':
  78                 bits = atoi(EARGF(usage()));
  79                 for (sha = sha2s; sha < sha2s + nelem(sha2s); sha++)
  80                         if (sha->bits == bits)
  81                                 break;
  82                 if (sha >= sha2s + nelem(sha2s))
  83                         sysfatal("unknown number of sha2 bits: %d", bits);
  84                 shafunc = sha->func;
  85                 shadlen = sha->dlen;
  86                 break;
  87         default:
  88                 usage();
  89         }ARGEND
  90
  91         fmtinstall('M', digestfmt);
  92
  93         if(argc == 0)
  94                 sum(0, nil);
  95         else
  96                 for(i = 0; i < argc; i++){
  97                         fd = open(argv[i], OREAD);
  98                         if(fd < 0){
  99                                 fprint(2, "%s: can't open %s: %r\n", argv0, argv[i]);
 100                                 continue;
 101                         }
 102                         sum(fd, argv[i]);
 103                         close(fd);
 104                 }
 105         exits(nil);
 106 }