Filza 27.2 worse_query: public and developer builds

XPF/src/decompress.c

@@ -0,0 +1,132 @@
+// Taken from golb: https://github.com/0x7ff/golb
+// Licensed under Apache 2.0
+// See decompress.LICENSE
+
+#include "decompress.h"
+#include <stdlib.h>
+#include <string.h>
+#include <compression.h>
+
+#define DER_INT (0x2U)
+#define DER_SEQ (0x30U)
+#define LZSS_F (18)
+#define LZSS_N (4096)
+#define LZSS_THRESHOLD (2)
+#define KCOMP_HDR_PAD_SZ (0x16C)
+#define DER_IA5_STR (0x16U)
+#define DER_OCTET_STR (0x4U)
+#define KCOMP_HDR_MAGIC (0x636F6D70U)
+#define KCOMP_HDR_TYPE_LZSS (0x6C7A7373U)
+
+const uint8_t *
+der_decode(uint8_t tag, const uint8_t *der, const uint8_t *der_end, size_t *out_len) {
+    size_t der_len;
+
+    if(der_end - der > 2 && tag == *der++) {
+        if(((der_len = *der++) & 0x80U) != 0) {
+            *out_len = 0;
+            if((der_len &= 0x7FU) <= sizeof(*out_len) && (size_t)(der_end - der) >= der_len) {
+                while(der_len-- != 0) {
+                    *out_len = (*out_len << 8U) | *der++;
+                }
+            }
+        } else {
+            *out_len = der_len;
+        }
+        if(*out_len != 0 && (size_t)(der_end - der) >= *out_len) {
+            return der;
+        }
+    }
+    return NULL;
+}
+
+const uint8_t *
+der_decode_seq(const uint8_t *der, const uint8_t *der_end, const uint8_t **seq_end) {
+    size_t der_len;
+
+    if((der = der_decode(DER_SEQ, der, der_end, &der_len)) != NULL) {
+        *seq_end = der + der_len;
+    }
+    return der;
+}
+
+const uint8_t *
+der_decode_uint64(const uint8_t *der, const uint8_t *der_end, uint64_t *r) {
+    size_t der_len;
+
+    if((der = der_decode(DER_INT, der, der_end, &der_len)) != NULL && (*der & 0x80U) == 0 && (der_len <= sizeof(*r) || (--der_len == sizeof(*r) && *der++ == 0))) {
+        *r = 0;
+        while(der_len-- != 0) {
+            *r = (*r << 8U) | *der++;
+        }
+        return der;
+    }
+    return NULL;
+}
+
+size_t
+decompress_lzss(const uint8_t *src, size_t src_len, uint8_t *dst, size_t dst_len) {
+    const uint8_t *src_end = src + src_len, *dst_start = dst, *dst_end = dst + dst_len;
+    uint16_t i, r = LZSS_N - LZSS_F, flags = 0;
+    uint8_t text_buf[LZSS_N + LZSS_F - 1], j;
+
+    memset(text_buf, ' ', r);
+    while(src != src_end && dst != dst_end) {
+        if(((flags >>= 1U) & 0x100U) == 0) {
+            flags = *src++ | 0xFF00U;
+            if(src == src_end) {
+                break;
+            }
+        }
+        if((flags & 1U) != 0) {
+            text_buf[r++] = *dst++ = *src++;
+            r &= LZSS_N - 1U;
+        } else {
+            i = *src++;
+            if(src == src_end) {
+                break;
+            }
+            j = *src++;
+            i |= (j & 0xF0U) << 4U;
+            j = (j & 0xFU) + LZSS_THRESHOLD;
+            do {
+                *dst++ = text_buf[r++] = text_buf[i++ & (LZSS_N - 1U)];
+                r &= LZSS_N - 1U;
+            } while(j-- != 0 && dst != dst_end);
+        }
+    }
+    return (size_t)(dst - dst_start);
+}
+
+void *
+kdecompress(const void *src, size_t src_len, size_t *dst_len) {
+	const uint8_t *der, *octet, *der_end, *src_end = (const uint8_t *)src + src_len;
+	struct {
+		uint32_t magic, type, adler32, uncomp_sz, comp_sz;
+		uint8_t pad[KCOMP_HDR_PAD_SZ];
+	} kcomp_hdr;
+	size_t der_len;
+	uint64_t r;
+	void *dst;
+
+	if((der = der_decode_seq(src, src_end, &der_end)) != NULL && (der = der_decode(DER_IA5_STR, der, der_end, &der_len)) != NULL && der_len == 4 && (memcmp(der, "IMG4", der_len) != 0 || ((der = der_decode_seq(der + der_len, src_end, &der_end)) != NULL && (der = der_decode(DER_IA5_STR, der, der_end, &der_len)) != NULL && der_len == 4)) && memcmp(der, "IM4P", der_len) == 0 && (der = der_decode(DER_IA5_STR, der + der_len, der_end, &der_len)) != NULL && der_len == 4 && memcmp(der, "krnl", der_len) == 0 && (der = der_decode(DER_IA5_STR, der + der_len, der_end, &der_len)) != NULL && (der = der_decode(DER_OCTET_STR, der + der_len, der_end, &der_len)) != NULL && der_len > sizeof(kcomp_hdr)) {
+		octet = der;
+		memcpy(&kcomp_hdr, octet, sizeof(kcomp_hdr));
+		if(kcomp_hdr.magic == __builtin_bswap32(KCOMP_HDR_MAGIC)) {
+			if(kcomp_hdr.type == __builtin_bswap32(KCOMP_HDR_TYPE_LZSS) && (kcomp_hdr.comp_sz = __builtin_bswap32(kcomp_hdr.comp_sz)) <= der_len - sizeof(kcomp_hdr) && (kcomp_hdr.uncomp_sz = __builtin_bswap32(kcomp_hdr.uncomp_sz)) != 0 && (dst = malloc(kcomp_hdr.uncomp_sz)) != NULL) {
+				if(decompress_lzss(octet + sizeof(kcomp_hdr), kcomp_hdr.comp_sz, dst, kcomp_hdr.uncomp_sz) == kcomp_hdr.uncomp_sz) {
+					*dst_len = kcomp_hdr.uncomp_sz;
+					return dst;
+				}
+				free(dst);
+			}
+		} else if((der = der_decode_seq(der + der_len, src_end, &der_end)) != NULL && (der = der_decode_uint64(der, der_end, &r)) != NULL && r == 1 && der_decode_uint64(der, der_end, &r) != NULL && r != 0 && (dst = malloc(r)) != NULL) {
+			if(compression_decode_buffer(dst, r, octet, der_len, NULL, COMPRESSION_LZFSE) == r) {
+				*dst_len = r;
+				return dst;
+			}
+			free(dst);
+		}
+	}
+	return NULL;
+}