sys/src/cmd/sha1sum.c

   1 /*
   2  * sha1sum - compute SHA1 or SHA2 digest
   3  */
   4 #include <u.h>
   5 #include <libc.h>
   6 #include <bio.h>
   7 #include <libsec.h>
   8
   9 #pragma varargck        type    "M"     uchar*
  10
  11 typedef struct Sha2 Sha2;
  12 struct Sha2 {
  13         int     bits;
  14         int     dlen;
  15         DigestState* (*func)(uchar *, ulong, uchar *, DigestState *);
  16 };
  17
  18 static Sha2 sha2s[] = {
  19         224,    SHA2_224dlen,   sha2_224,
  20         256,    SHA2_256dlen,   sha2_256,
  21         384,    SHA2_384dlen,   sha2_384,
  22         512,    SHA2_512dlen,   sha2_512,
  23 };
  24
  25 static DigestState* (*shafunc)(uchar *, ulong, uchar *, DigestState *);
  26 static int shadlen;
  27
  28 static int
  29 digestfmt(Fmt *fmt)
  30 {
  31         char buf[SHA2_512dlen*2 + 1];
  32         uchar *p;
  33         int i;
  34
  35         p = va_arg(fmt->args, uchar*);
  36         for(i = 0; i < shadlen; i++)
  37                 sprint(buf + 2*i, "%.2ux", p[i]);
  38         return fmtstrcpy(fmt, buf);
  39 }
  40
  41 static void
  42 sum(int fd, char *name)
  43 {
  44         int n;
  45         uchar buf[8192], digest[SHA2_512dlen];
  46         DigestState *s;
  47
  48         s = (*shafunc)(nil, 0, nil, nil);
  49         while((n = read(fd, buf, sizeof buf)) > 0)
  50                 (*shafunc)(buf, n, nil, s);
  51         if(n < 0){
  52                 fprint(2, "reading %s: %r\n", name? name: "stdin");
  53                 return;
  54         }
  55         (*shafunc)(nil, 0, digest, s);
  56         if(name == nil)
  57                 print("%M\n", digest);
  58         else
  59                 print("%M\t%s\n", digest, name);
  60 }
  61
  62 static void
  63 usage(void)
  64 {
  65         fprint(2, "usage: %s [-2 bits] [file...]\n", argv0);
  66         exits("usage");
  67 }
  68
  69 void
  70 main(int argc, char *argv[])
  71 {
  72         int i, fd, bits;
  73         Sha2 *sha;
  74
  75         shafunc = sha1;
  76         shadlen = SHA1dlen;
  77         ARGBEGIN{
  78         case '2':
  79                 bits = atoi(EARGF(usage()));
  80                 for (sha = sha2s; sha < sha2s + nelem(sha2s); sha++)
  81                         if (sha->bits == bits)
  82                                 break;
  83                 if (sha >= sha2s + nelem(sha2s))
  84                         sysfatal("unknown number of sha2 bits: %d", bits);
  85                 shafunc = sha->func;
  86                 shadlen = sha->dlen;
  87                 break;
  88         default:
  89                 usage();
  90         }ARGEND
  91
  92         fmtinstall('M', digestfmt);
  93
  94         if(argc == 0)
  95                 sum(0, nil);
  96         else
  97                 for(i = 0; i < argc; i++){
  98                         fd = open(argv[i], OREAD);
  99                         if(fd < 0){
 100                                 fprint(2, "%s: can't open %s: %r\n", argv0, argv[i]);
 101                                 continue;
 102                         }
 103                         sum(fd, argv[i]);
 104                         close(fd);
 105                 }
 106         exits(nil);
 107 }