avutil/uuid: add utility library for manipulating UUIDs as specified in RFC 4122

Co-authored-by: Pierre-Anthony Lemieux <pal@palemieux.com>
Signed-off-by: Zane van Iperen <zane@zanevaniperen.com>

3 files changed, 290 insertions, 0 deletions

diff --git a/libavutil/Makefile b/libavutil/Makefile
index 74d21a8103..b71fb395b4 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -83,6 +83,7 @@ HEADERS = adler32.h                                                     \
           timestamp.h                                                   \
           tree.h                                                        \
           twofish.h                                                     \
+          uuid.h                                                        \
           version.h                                                     \
           video_enc_params.h                                            \
           xtea.h                                                        \
@@ -176,6 +177,7 @@ OBJS = adler32.o                                                        \
        tx_float.o                                                       \
        tx_double.o                                                      \
        tx_int32.o                                                       \
+       uuid.o                                                           \
        version.o                                                        \
        video_enc_params.o                                               \
        film_grain_params.o                                              \
diff --git a/libavutil/uuid.c b/libavutil/uuid.c
new file mode 100644
index 0000000000..062e28736b
--- /dev/null
+++ b/libavutil/uuid.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2022 Pierre-Anthony Lemieux <pal@palemieux.com>
+ *                    Zane van Iperen <zane@zanevaniperen.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * Copyright (C) 1996, 1997 Theodore Ts'o.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
+ * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ */
+
+/**
+ * @file
+ * UUID parsing and serialization utilities.
+ * The library treat the UUID as an opaque sequence of 16 unsigned bytes,
+ * i.e. ignoring the internal layout of the UUID, which depends on the type
+ * of the UUID.
+ *
+ * @author Pierre-Anthony Lemieux <pal@palemieux.com>
+ * @author Zane van Iperen <zane@zanevaniperen.com>
+ */
+
+#include "uuid.h"
+#include "error.h"
+#include "avstring.h"
+
+int av_uuid_parse(const char *in, AVUUID uu)
+{
+    if (strlen(in) != 36)
+        return AVERROR(EINVAL);
+
+    return av_uuid_parse_range(in, in + 36, uu);
+}
+
+static int xdigit_to_int(char c)
+{
+    c = av_tolower(c);
+
+    if (c >= 'a' && c <= 'f')
+        return c - 'a' + 10;
+
+    if (c >= '0' && c <= '9')
+        return c - '0';
+
+    return -1;
+}
+
+int av_uuid_parse_range(const char *in_start, const char *in_end, AVUUID uu)
+{
+    int i;
+    const char *cp;
+
+    if ((in_end - in_start) != 36)
+        return AVERROR(EINVAL);
+
+    for (i = 0, cp = in_start; i < 16; i++) {
+        int hi;
+        int lo;
+
+        if (i == 4 || i == 6 || i == 8 || i == 10)
+            cp++;
+
+        hi = xdigit_to_int(*cp++);
+        lo = xdigit_to_int(*cp++);
+
+        if (hi == -1 || lo == -1)
+            return AVERROR(EINVAL);
+
+        uu[i] = (hi << 4) + lo;
+    }
+
+    return 0;
+}
+
+static const char hexdigits_lower[16] = "0123456789abcdef";
+
+void av_uuid_unparse(const AVUUID uuid, char *out)
+{
+    char *p = out;
+
+    for (int i = 0; i < 16; i++) {
+        uint8_t tmp;
+
+        if (i == 4 || i == 6 || i == 8 || i == 10)
+            *p++ = '-';
+
+        tmp = uuid[i];
+        *p++ = hexdigits_lower[tmp >> 4];
+        *p++ = hexdigits_lower[tmp & 15];
+    }
+
+    *p = '\0';
+}
+
+int av_uuid_urn_parse(const char *in, AVUUID uu)
+{
+    if (av_stristr(in, "urn:uuid:") != in)
+        return AVERROR(EINVAL);
+
+    return av_uuid_parse(in + 9, uu);
+}
diff --git a/libavutil/uuid.h b/libavutil/uuid.h
new file mode 100644
index 0000000000..4b5088911c
--- /dev/null
+++ b/libavutil/uuid.h
@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2022 Pierre-Anthony Lemieux <pal@palemieux.com>
+ *                    Zane van Iperen <zane@zanevaniperen.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * UUID parsing and serialization utilities.
+ * The library treats the UUID as an opaque sequence of 16 unsigned bytes,
+ * i.e. ignoring the internal layout of the UUID, which depends on the type
+ * of the UUID.
+ *
+ * @author Pierre-Anthony Lemieux <pal@palemieux.com>
+ * @author Zane van Iperen <zane@zanevaniperen.com>
+ */
+
+#ifndef AVUTIL_UUID_H
+#define AVUTIL_UUID_H
+
+#include <stdint.h>
+#include <string.h>
+
+#define AV_PRI_UUID                          \
+    "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-" \
+    "%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
+
+#define AV_PRI_URN_UUID                               \
+    "urn:uuid:%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-" \
+    "%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
+
+/* AV_UUID_ARG() is used together with AV_PRI_UUID() or AV_PRI_URN_UUID
+ * to print UUIDs, e.g.
+ * av_log(NULL, AV_LOG_DEBUG, "UUID: " AV_PRI_UUID, AV_UUID_ARG(uuid));
+ */
+#define AV_UUID_ARG(x)                  \
+    (x)[ 0], (x)[ 1], (x)[ 2], (x)[ 3], \
+    (x)[ 4], (x)[ 5], (x)[ 6], (x)[ 7], \
+    (x)[ 8], (x)[ 9], (x)[10], (x)[11], \
+    (x)[12], (x)[13], (x)[14], (x)[15]
+
+#define AV_UUID_LEN 16
+
+/* Binary representation of a UUID */
+typedef uint8_t AVUUID[AV_UUID_LEN];
+
+/**
+ * Parses a string representation of a UUID formatted according to IETF RFC 4122
+ * into an AVUUID. The parsing is case-insensitive. The string must be 37
+ * characters long, including the terminating NUL character.
+ *
+ * Example string representation: "2fceebd0-7017-433d-bafb-d073a7116696"
+ *
+ * @param[in]  in  String representation of a UUID,
+ *                 e.g. 2fceebd0-7017-433d-bafb-d073a7116696
+ * @param[out] uu  AVUUID
+ * @return         A non-zero value in case of an error.
+ */
+int av_uuid_parse(const char *in, AVUUID uu);
+
+/**
+ * Parses a URN representation of a UUID, as specified at IETF RFC 4122,
+ * into an AVUUID. The parsing is case-insensitive. The string must be 46
+ * characters long, including the terminating NUL character.
+ *
+ * Example string representation: "urn:uuid:2fceebd0-7017-433d-bafb-d073a7116696"
+ *
+ * @param[in]  in  URN UUID
+ * @param[out] uu  AVUUID
+ * @return         A non-zero value in case of an error.
+ */
+int av_uuid_urn_parse(const char *in, AVUUID uu);
+
+/**
+ * Parses a string representation of a UUID formatted according to IETF RFC 4122
+ * into an AVUUID. The parsing is case-insensitive.
+ *
+ * @param[in]  in_start Pointer to the first character of the string representation
+ * @param[in]  in_end   Pointer to the character after the last character of the
+ *                      string representation. That memory location is never
+ *                      accessed. It is an error if `in_end - in_start != 36`.
+ * @param[out] uu       AVUUID
+ * @return              A non-zero value in case of an error.
+ */
+int av_uuid_parse_range(const char *in_start, const char *in_end, AVUUID uu);
+
+/**
+ * Serializes a AVUUID into a string representation according to IETF RFC 4122.
+ * The string is lowercase and always 37 characters long, including the
+ * terminating NUL character.
+ *
+ * @param[in]  uu  AVUUID
+ * @param[out] out Pointer to an array of no less than 37 characters.
+ * @return         A non-zero value in case of an error.
+ */
+void av_uuid_unparse(const AVUUID uu, char *out);
+
+/**
+ * Compares two UUIDs for equality.
+ *
+ * @param[in]  uu1  AVUUID
+ * @param[in]  uu2  AVUUID
+ * @return          Nonzero if uu1 and uu2 are identical, 0 otherwise
+ */
+static inline int av_uuid_equal(const AVUUID uu1, const AVUUID uu2)
+{
+    return memcmp(uu1, uu2, AV_UUID_LEN) == 0;
+}
+
+/**
+ * Copies the bytes of src into dest.
+ *
+ * @param[out]  dest  AVUUID
+ * @param[in]   src   AVUUID
+ */
+static inline void av_uuid_copy(AVUUID dest, const AVUUID src)
+{
+    memcpy(dest, src, AV_UUID_LEN);
+}
+
+/**
+ * Sets a UUID to the nil UUID, i.e. a UUID with have all
+ * its 128 bits set to zero.
+ *
+ * @param[in,out]  uu  UUID to be set to the nil UUID
+ */
+static inline void av_uuid_nil(AVUUID uu)
+{
+    memset(uu, 0, AV_UUID_LEN);
+}
+
+#endif /* AVUTIL_UUID_H */