diff options
| -rw-r--r-- | kexec/lzma.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/kexec/lzma.c b/kexec/lzma.c index 5bfccb78..f27cfe24 100644 --- a/kexec/lzma.c +++ b/kexec/lzma.c @@ -155,6 +155,39 @@ ssize_t lzread(LZFILE *lzfile, void *buf, size_t len) } } +int is_lzma_file(const char *filename) +{ + FILE *fp; + int ret = 0; + uint8_t buf[13]; + + if (!filename) + return 0; + + fp = fopen(filename, "r"); + if (fp == NULL) + return 0; + + const size_t size = fread(buf, 1, sizeof(buf), fp); + + if (size != 13) + return 0; + + lzma_filter filter = { .id = LZMA_FILTER_LZMA1 }; + + switch (lzma_properties_decode(&filter, NULL, buf, 5)) { + case LZMA_OK: + ret = 1; + break; + default: + /* It's not a lzma file */ + ret = 0; + } + + fclose(fp); + return ret; +} + char *lzma_decompress_file(const char *filename, off_t *r_size) { LZFILE *fp; @@ -168,6 +201,9 @@ char *lzma_decompress_file(const char *filename, off_t *r_size) if (!filename) return NULL; + if (!is_lzma_file(filename)) + return NULL; + fp = lzopen(filename, "rb"); if (fp == 0) { dbgprintf("Cannot open `%s'\n", filename); |