/*- mdXhl.c
 * SPDX-License-Identifier: Beerware
 *
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
 * ----------------------------------------------------------------------------
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

#include "mdX.h"

char *
MDXEnd(MDX_CTX *ctx, char *buf)
{
        int i;
        unsigned char digest[LENGTH];
        static const char hex[]="0123456789abcdef";

        if (!buf)
                buf = malloc(2*LENGTH + 1);
        if (!buf)
                return 0;
        MDXFinal(digest, ctx);
        for (i = 0; i < LENGTH; i++) {
                buf[i+i] = hex[digest[i] >> 4];
                buf[i+i+1] = hex[digest[i] & 0x0f];
        }
        buf[i+i] = '\0';
        return buf;
}

char *
MDXFd(int fd, char *buf)
{
        return MDXFdChunk(fd, buf, 0, 0);
}

char *
MDXFdChunk(int fd, char *buf, off_t ofs, off_t len)
{
        unsigned char buffer[16*1024];
        MDX_CTX ctx;
        struct stat stbuf;
        int readrv, e;
        off_t remain;

        if (len < 0) {
                errno = EINVAL;
                return NULL;
        }

        MDXInit(&ctx);
        if (ofs != 0) {
                errno = 0;
                if (lseek(fd, ofs, SEEK_SET) != ofs ||
                    (ofs == -1 && errno != 0)) {
                        readrv = -1;
                        goto error;
                }
        }
        remain = len;
        readrv = 0;
        while (len == 0 || remain > 0) {
                if (len == 0 || remain > sizeof(buffer))
                        readrv = read(fd, buffer, sizeof(buffer));
                else
                        readrv = read(fd, buffer, remain);
                if (readrv <= 0)
                        break;
                MDXUpdate(&ctx, buffer, readrv);
                remain -= readrv;
        }
error:
        if (readrv < 0)
                return NULL;
        return (MDXEnd(&ctx, buf));
}

char *
MDXFile(const char *filename, char *buf)
{
        return (MDXFileChunk(filename, buf, 0, 0));
}

char *
MDXFileChunk(const char *filename, char *buf, off_t ofs, off_t len)
{
        char *ret;
        int e, fd;

        fd = open(filename, O_RDONLY);
        if (fd < 0)
                return NULL;
        ret = MDXFdChunk(fd, buf, ofs, len);
        e = errno;
        close (fd);
        errno = e;
        return ret;
}

char *
MDXData (const void *data, unsigned int len, char *buf)
{
        MDX_CTX ctx;

        MDXInit(&ctx);
        MDXUpdate(&ctx,data,len);
        return (MDXEnd(&ctx, buf));
}

#ifdef WEAK_REFS
/* When building libmd, provide weak references. Note: this is not
   activated in the context of compiling these sources for internal
   use in libcrypt.
 */
#undef MDXEnd
__weak_reference(_libmd_MDXEnd, MDXEnd);
#undef MDXFile
__weak_reference(_libmd_MDXFile, MDXFile);
#undef MDXFileChunk
__weak_reference(_libmd_MDXFileChunk, MDXFileChunk);
#undef MDXFd
__weak_reference(_libmd_MDXFd, MDXFd);
#undef MDXFdChunk
__weak_reference(_libmd_MDXFdChunk, MDXFdChunk);
#undef MDXData
__weak_reference(_libmd_MDXData, MDXData);
#endif