diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/jpeginfo.c | 86 |
1 files changed, 46 insertions, 40 deletions
diff --git a/tools/jpeginfo.c b/tools/jpeginfo.c index 7d6ea66..0a5f2ae 100644 --- a/tools/jpeginfo.c +++ b/tools/jpeginfo.c @@ -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. @@ -478,44 +478,50 @@ parse_psir_block(jv o, uint16_t resource_id, const char *name, } static jv -parse_psir(jv o, const uint8_t *p, size_t len) +parse_psir_block(jv o, const uint8_t *p, size_t len, size_t *advance) { - if (len == 0) - return add_warning(o, "empty PSIR data"); + *advance = 0; + if (len < 8 || memcmp(p, "8BIM", 4)) + return add_warning(o, "bad PSIR block header"); - 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]; - 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; - // 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"); - 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"); - 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); - p += header_len; - len -= header_len; + *advance = header_len + resource_len_padded; + return o; +} - 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); +static jv +parse_psir(jv o, const uint8_t *p, size_t len) +{ + if (len == 0) + return add_warning(o, "empty PSIR data"); - 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; } |