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jpeginfo: clean up

This commit is contained in:
Přemysl Eric Janouch 2021-12-03 14:19:01 +01:00
parent 38427ff88e
commit 46c46ac093
Signed by: p
GPG Key ID: A0420B94F92B9493
1 changed files with 50 additions and 44 deletions
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94
tools/jpeginfo.c
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@ -23,14 +23,7 @@
#include <stdbool.h>
#include <stdarg.h>
// --- TIFF --------------------------------------------------------------------
// https://www.adobe.io/content/dam/udp/en/open/standards/tiff/TIFF6.pdf
// https://www.adobe.io/content/dam/udp/en/open/standards/tiff/TIFFPM6.pdf
// https://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf
//
// libtiff is a mess, and the format is not particularly complicated.
// Also, we'd still want to duplicate its tag tables.
// Exif libraries are senselessly copylefted.
// --- Utilities ---------------------------------------------------------------
static uint32_t
u32be(const uint8_t *p)
@ -56,13 +49,20 @@ u16le(const uint8_t *p)
return (uint16_t) p[1] << 8 | p[0];
}
// --- TIFF --------------------------------------------------------------------
// https://www.adobe.io/content/dam/udp/en/open/standards/tiff/TIFF6.pdf
// https://www.adobe.io/content/dam/udp/en/open/standards/tiff/TIFFPM6.pdf
// https://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf
//
// libtiff is a mess, and the format is not particularly complicated.
// Also, we'd still want to duplicate its tag tables.
// Exif libraries are senselessly copylefted.
static struct un {
uint32_t (*u32) (const uint8_t *);
uint16_t (*u16) (const uint8_t *);
} unbe = {u32be, u16be}, unle = {u32le, u16le};
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
struct tiffer {
struct un *un;
const uint8_t *begin, *p, *end;
@ -467,7 +467,7 @@ parse_icc(jv o, const uint8_t *profile, size_t profile_len)
// https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/
static jv
parse_psir_block(jv o, uint16_t resource_id, const char *name,
process_psir(jv o, uint16_t resource_id, const char *name,
const uint8_t *data, size_t len)
{
// TODO(p): These is more to extract here. The name is most often empty.
@ -477,45 +477,51 @@ parse_psir_block(jv o, uint16_t resource_id, const char *name,
return add_to_subarray(o, "PSIR", jv_number(resource_id));
}
static jv
parse_psir_block(jv o, const uint8_t *p, size_t len, size_t *advance)
{
*advance = 0;
if (len < 8 || memcmp(p, "8BIM", 4))
return add_warning(o, "bad PSIR block header");
uint16_t resource_id = u16be(p + 4);
uint8_t name_len = p[6];
const uint8_t *name = &p[7];
// Add one byte for the Pascal-ish string length prefix,
// then another one for padding to make the length even.
size_t name_len_full = (name_len + 2) & ~1U;
size_t resource_len_offset = 6 + name_len_full,
header_len = resource_len_offset + 4;
if (len < header_len)
return add_warning(o, "bad PSIR block header");
uint32_t resource_len = u32be(p + resource_len_offset);
size_t resource_len_padded = (resource_len + 1) & ~1U;
if (resource_len_padded < resource_len ||
len < header_len + resource_len_padded)
return add_warning(o, "runaway PSIR block");
char *cname = calloc(1, name_len_full);
strncpy(cname, (const char *) name, name_len);
o = process_psir(o, resource_id, cname, p + header_len, resource_len);
free(cname);
*advance = header_len + resource_len_padded;
return o;
}
static jv
parse_psir(jv o, const uint8_t *p, size_t len)
{
if (len == 0)
return add_warning(o, "empty PSIR data");
while (len) {
if (len < 8 || memcmp(p, "8BIM", 4))
return add_warning(o, "bad PSIR block header");
uint16_t resource_id = u16be(p + 4);
uint8_t name_len = p[6];
const uint8_t *name = &p[7];
// Add one byte for the Pascal-ish string length prefix,
// then another one for padding to make the length even.
size_t name_len_full = (name_len + 2) & ~1U;
size_t resource_len_offset = 6 + name_len_full,
header_len = resource_len_offset + 4;
if (len < header_len)
return add_warning(o, "bad PSIR block header");
uint32_t resource_len = u32be(p + resource_len_offset);
size_t resource_len_padded = (resource_len + 1) & ~1U;
if (resource_len_padded < resource_len ||
len < header_len + resource_len_padded)
return add_warning(o, "runaway PSIR block");
p += header_len;
len -= header_len;
char *cname = calloc(1, name_len_full);
strncpy(cname, (const char *) name, name_len);
o = parse_psir_block(o, resource_id, cname, p, resource_len);
free(cname);
p += resource_len_padded;
len -= resource_len_padded;
size_t advance = 0;
while (len && (o = parse_psir_block(o, p, len, &advance), advance)) {
p += advance;
len -= advance;
}
return o;
}