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 static char exitstr[ERRMAX];
  11
  12 typedef struct Sha2 Sha2;
  13 struct Sha2 {
  14         int     bits;
  15         int     dlen;
  16         DigestState* (*func)(uchar *, ulong, uchar *, DigestState *);
  17 };
  18
  19 static Sha2 sha2s[] = {
  20         224,    SHA2_224dlen,   sha2_224,
  21         256,    SHA2_256dlen,   sha2_256,
  22         384,    SHA2_384dlen,   sha2_384,
  23         512,    SHA2_512dlen,   sha2_512,
  24 };
  25
  26 static DigestState* (*shafunc)(uchar *, ulong, uchar *, DigestState *);
  27 static int shadlen;
  28
  29 static int
  30 digestfmt(Fmt *fmt)
  31 {
  32         char buf[SHA2_512dlen*2 + 1];
  33         uchar *p;
  34         int i;
  35
  36         p = va_arg(fmt->args, uchar*);
  37         for(i = 0; i < shadlen; i++)
  38                 sprint(buf + 2*i, "%.2ux", p[i]);
  39         return fmtstrcpy(fmt, buf);
  40 }
  41
  42 static void
  43 sum(int fd, char *name)
  44 {
  45         int n;
  46         uchar buf[8192], digest[SHA2_512dlen];
  47         DigestState *s;
  48
  49         s = (*shafunc)(nil, 0, nil, nil);
  50         while((n = read(fd, buf, sizeof buf)) > 0)
  51                 (*shafunc)(buf, n, nil, s);
  52         if(n < 0){
  53                 snprint(exitstr, sizeof(exitstr), "reading %s: %r\n", name? name: "stdin");
  54                 fprint(2, "%s", exitstr);
  55                 return;
  56         }
  57         (*shafunc)(nil, 0, digest, s);
  58         if(name == nil)
  59                 print("%M\n", digest);
  60         else
  61                 print("%M\t%s\n", digest, name);
  62 }
  63
  64 static void
  65 usage(void)
  66 {
  67         fprint(2, "usage: %s [-2 bits] [file...]\n", argv0);
  68         exits("usage");
  69 }
  70
  71 void
  72 main(int argc, char *argv[])
  73 {
  74         int i, fd, bits;
  75         Sha2 *sha;
  76
  77         shafunc = sha1;
  78         shadlen = SHA1dlen;
  79         ARGBEGIN{
  80         case '2':
  81                 bits = atoi(EARGF(usage()));
  82                 for (sha = sha2s; sha < sha2s + nelem(sha2s); sha++)
  83                         if (sha->bits == bits)
  84                                 break;
  85                 if (sha >= sha2s + nelem(sha2s))
  86                         sysfatal("unknown number of sha2 bits: %d", bits);
  87                 shafunc = sha->func;
  88                 shadlen = sha->dlen;
  89                 break;
  90         default:
  91                 usage();
  92         }ARGEND
  93
  94         fmtinstall('M', digestfmt);
  95
  96         if(argc == 0)
  97                 sum(0, nil);
  98         else
  99                 for(i = 0; i < argc; i++){
 100                         fd = open(argv[i], OREAD);
 101                         if(fd < 0){
 102                                 snprint(exitstr, sizeof(exitstr), "can't open %s: %r", argv[i]);
 103                                 fprint(2, "%s: %s\n", argv0, exitstr);
 104                                 continue;
 105                         }
 106                         sum(fd, argv[i]);
 107                         close(fd);
 108                 }
 109         exits(exitstr);
 110 }