Subversion Repositories planix.SVN

/*
 * sha1sum - compute SHA1 or SHA2 digest
 */
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <libsec.h>

#pragma varargck        type    "M"     uchar*

typedef struct Sha2 Sha2;
struct Sha2 {
        int     bits;
        int     dlen;
        DigestState* (*func)(uchar *, ulong, uchar *, DigestState *);
};

static Sha2 sha2s[] = {
        224,    SHA2_224dlen,   sha2_224,
        256,    SHA2_256dlen,   sha2_256,
        384,    SHA2_384dlen,   sha2_384,
        512,    SHA2_512dlen,   sha2_512,
};

static DigestState* (*shafunc)(uchar *, ulong, uchar *, DigestState *);
static int shadlen;

static int
digestfmt(Fmt *fmt)
{
        char buf[SHA2_512dlen*2 + 1];
        uchar *p;
        int i;

        p = va_arg(fmt->args, uchar*);
        for(i = 0; i < shadlen; i++)
                sprint(buf + 2*i, "%.2ux", p[i]);
        return fmtstrcpy(fmt, buf);
}

static void
sum(int fd, char *name)
{
        int n;
        uchar buf[8192], digest[SHA2_512dlen];
        DigestState *s;

        s = (*shafunc)(nil, 0, nil, nil);
        while((n = read(fd, buf, sizeof buf)) > 0)
                (*shafunc)(buf, n, nil, s);
        if(n < 0){
                fprint(2, "reading %s: %r\n", name? name: "stdin");
                return;
        }
        (*shafunc)(nil, 0, digest, s);
        if(name == nil)
                print("%M\n", digest);
        else
                print("%M\t%s\n", digest, name);
}

static void
usage(void)
{
        fprint(2, "usage: %s [-2 bits] [file...]\n", argv0);
        exits("usage");
}

void
main(int argc, char *argv[])
{
        int i, fd, bits;
        Sha2 *sha;

        shafunc = sha1;
        shadlen = SHA1dlen;
        ARGBEGIN{
        case '2':
                bits = atoi(EARGF(usage()));
                for (sha = sha2s; sha < sha2s + nelem(sha2s); sha++)
                        if (sha->bits == bits)
                                break;
                if (sha >= sha2s + nelem(sha2s))
                        sysfatal("unknown number of sha2 bits: %d", bits);
                shafunc = sha->func;
                shadlen = sha->dlen;
                break;
        default:
                usage();
        }ARGEND

        fmtinstall('M', digestfmt);

        if(argc == 0)
                sum(0, nil);
        else
                for(i = 0; i < argc; i++){
                        fd = open(argv[i], OREAD);
                        if(fd < 0){
                                fprint(2, "%s: can't open %s: %r\n", argv0, argv[i]);
                                continue;
                        }
                        sum(fd, argv[i]);
                        close(fd);
                }
        exits(nil);
}