libavutil/uuid.c

   1 /*
   2  * Copyright (c) 2022 Pierre-Anthony Lemieux <pal@palemieux.com>
   3  *                    Zane van Iperen <zane@zanevaniperen.com>
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /*
  23  * Copyright (C) 1996, 1997 Theodore Ts'o.
  24  *
  25  * Redistribution and use in source and binary forms, with or without
  26  * modification, are permitted provided that the following conditions
  27  * are met:
  28  * 1. Redistributions of source code must retain the above copyright
  29  *    notice, and the entire permission notice in its entirety,
  30  *    including the disclaimer of warranties.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. The name of the author may not be used to endorse or promote
  35  *    products derived from this software without specific prior
  36  *    written permission.
  37  *
  38  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  39  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  40  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
  41  * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
  42  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  43  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  44  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  45  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  46  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  47  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  48  * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
  49  * DAMAGE.
  50  */
  51
  52 /**
  53  * @file
  54  * UUID parsing and serialization utilities.
  55  * The library treat the UUID as an opaque sequence of 16 unsigned bytes,
  56  * i.e. ignoring the internal layout of the UUID, which depends on the type
  57  * of the UUID.
  58  *
  59  * @author Pierre-Anthony Lemieux <pal@palemieux.com>
  60  * @author Zane van Iperen <zane@zanevaniperen.com>
  61  */
  62
  63 #include "uuid.h"
  64 #include "error.h"
  65 #include "avstring.h"
  66
  67 int av_uuid_parse(const char *in, AVUUID uu)
  68 {
  69     if (strlen(in) != 36)
  70         return AVERROR(EINVAL);
  71
  72     return av_uuid_parse_range(in, in + 36, uu);
  73 }
  74
  75 static int xdigit_to_int(char c)
  76 {
  77     c = av_tolower(c);
  78
  79     if (c >= 'a' && c <= 'f')
  80         return c - 'a' + 10;
  81
  82     if (c >= '0' && c <= '9')
  83         return c - '0';
  84
  85     return -1;
  86 }
  87
  88 int av_uuid_parse_range(const char *in_start, const char *in_end, AVUUID uu)
  89 {
  90     int i;
  91     const char *cp;
  92
  93     if ((in_end - in_start) != 36)
  94         return AVERROR(EINVAL);
  95
  96     for (i = 0, cp = in_start; i < 16; i++) {
  97         int hi;
  98         int lo;
  99
 100         if (i == 4 || i == 6 || i == 8 || i == 10)
 101             cp++;
 102
 103         hi = xdigit_to_int(*cp++);
 104         lo = xdigit_to_int(*cp++);
 105
 106         if (hi == -1 || lo == -1)
 107             return AVERROR(EINVAL);
 108
 109         uu[i] = (hi << 4) + lo;
 110     }
 111
 112     return 0;
 113 }
 114
 115 static const char hexdigits_lower[16] = "0123456789abcdef";
 116
 117 void av_uuid_unparse(const AVUUID uuid, char *out)
 118 {
 119     char *p = out;
 120
 121     for (int i = 0; i < 16; i++) {
 122         uint8_t tmp;
 123
 124         if (i == 4 || i == 6 || i == 8 || i == 10)
 125             *p++ = '-';
 126
 127         tmp = uuid[i];
 128         *p++ = hexdigits_lower[tmp >> 4];
 129         *p++ = hexdigits_lower[tmp & 15];
 130     }
 131
 132     *p = '\0';
 133 }
 134
 135 int av_uuid_urn_parse(const char *in, AVUUID uu)
 136 {
 137     if (av_stristr(in, "urn:uuid:") != in)
 138         return AVERROR(EINVAL);
 139
 140     return av_uuid_parse(in + 9, uu);
 141 }