fusee: add untested, not hooked up ips code

fusee/fusee-secondary/src/ips.c

@@ -0,0 +1,291 @@
+/*
+ * Copyright (c) 2018 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+ 
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <dirent.h>
+#include <string.h>
+#include <ctype.h>
+#include "utils.h"
+#include "se.h"
+#include "ips.h"
+
+/* IPS Patching adapted from Luma3DS (https://github.com/AuroraWright/Luma3DS/blob/master/sysmodules/loader/source/patcher.c) */
+
+#define IPS_MAGIC "PATCH"
+#define IPS_TAIL "EOF"
+
+#define IPS32_MAGIC "IPS32"
+#define IPS32_TAIL "EEOF"
+
+/* Applies an IPS/IPS32 patch to memory, disregarding writes to the first prot_size bytes. */
+static void apply_ips_patch(uint8_t *mem, size_t mem_size, size_t prot_size, bool is_ips32, FILE *f_ips) {
+    uint8_t buffer[4];
+    while (fread(buffer, is_ips32 ? 4 : 3, 1, f_ips) == 1) {
+        if (is_ips32 && memcmp(buffer, IPS32_TAIL, 4) == 0) {
+            break;
+        } else if (!is_ips32 && memcmp(buffer, IPS_TAIL, 3) == 0) {
+            break;
+        }
+        
+        /* Offset of patch. */
+        uint32_t patch_offset;
+        if (is_ips32) {
+           patch_offset = (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
+        } else {
+           patch_offset = (buffer[0] << 16) | (buffer[1] << 8) | (buffer[2]);
+        }
+        
+        /* Size of patch. */
+        if (fread(buffer, 2, 1, f_ips) != 1) {
+            break;
+        }
+        uint32_t patch_size = (buffer[0] << 8) | (buffer[1]);
+        
+        /* Check for RLE encoding. */
+        if (patch_size == 0) {
+            /* Size of RLE. */
+            if (fread(buffer, 2, 1, f_ips) != 1) {
+                break;
+            }
+            
+            uint32_t rle_size = (buffer[0] << 8) | (buffer[1]);
+            
+            /* Value for RLE. */
+            if (fread(buffer, 1, 1, f_ips) != 1) {
+                break;
+            }
+            
+            if (patch_offset < prot_size) {
+                if (patch_offset + rle_size > prot_size) {
+                    uint32_t diff = prot_size - patch_offset;
+                    patch_offset += diff;
+                    rle_size -= diff;
+                    goto IPS_RLE_PATCH_OFFSET_WITHIN_BOUNDS;
+                }
+            } else {
+                IPS_RLE_PATCH_OFFSET_WITHIN_BOUNDS:
+                patch_offset -= prot_size;
+                if (patch_offset + rle_size > mem_size) {
+                    rle_size = mem_size - patch_offset;
+                }
+                memset(mem + patch_offset, buffer[0], rle_size);
+            }
+        } else {
+            if (patch_offset < prot_size) {
+                if (patch_offset + patch_size > prot_size) {
+                    uint32_t diff = prot_size - patch_offset;
+                    patch_offset += diff;
+                    patch_size -= diff;
+                    fseek(f_ips, diff, SEEK_CUR);
+                    goto IPS_DATA_PATCH_OFFSET_WITHIN_BOUNDS;
+                } else {
+                    fseek(f_ips, patch_size, SEEK_CUR);
+                }
+            } else {
+                IPS_DATA_PATCH_OFFSET_WITHIN_BOUNDS:
+                patch_offset -= prot_size;
+                uint32_t read_size = patch_size;
+                if (patch_offset + read_size > mem_size) {
+                    read_size = mem_size - patch_offset;
+                }
+                if (fread(mem + patch_offset, read_size, 1, f_ips) != 1) {
+                    break;
+                }
+                if (patch_size > read_size) {
+                    fseek(f_ips, patch_size - read_size, SEEK_CUR);
+                }
+            }
+        }
+    }
+}
+
+
+static inline uint8_t hex_nybble_to_u8(const char nybble) {
+    if ('0' <= nybble && nybble <= '9') {
+        return nybble - '0';
+    } else if ('a' <= nybble && nybble <= 'f') {
+        return nybble - 'a' + 0xa;
+    } else {
+        return nybble - 'A' + 0xA;
+    }
+}
+
+static bool name_matches_hash(const char *name, size_t name_len, const void *hash, size_t hash_size) {
+    /* Validate name is hex build id. */
+    for (unsigned int i = 0; i < name_len - 4; i++) {
+        if (isxdigit(name[i]) == 0) {
+                return false;
+        }
+    }
+
+    /* Read hash from name. */
+    uint8_t hash_from_name[0x20] = {0};
+    for (unsigned int name_ofs = 0, id_ofs = 0; name_ofs < name_len - 4; id_ofs++) {
+        hash_from_name[id_ofs] |= hex_nybble_to_u8(name[name_ofs++]) << 4;
+        hash_from_name[id_ofs] |= hex_nybble_to_u8(name[name_ofs++]);
+    }
+    
+    return memcmp(hash, hash_from_name, hash_size) == 0;
+
+}
+
+static bool apply_ips_patches(const char *dir, void *mem, size_t mem_size, size_t prot_size, const void *hash, size_t hash_size) {
+    bool any_patches = false;
+    char path[0x301] = {0};
+    snprintf(path, sizeof(path) - 1, "%s", dir);
+    DIR *patches_dir = opendir(path);
+    struct dirent *pdir_ent;
+    if (patches_dir != NULL) {
+        /* Iterate over the patches directory to find patch subdirectories. */
+        while ((pdir_ent = readdir(patches_dir)) != NULL) {
+            if (strcmp(pdir_ent->d_name, ".") == 0 || strcmp(pdir_ent->d_name, "..") == 0) {
+                continue;
+            }
+            snprintf(path, sizeof(path) - 1, "%s/%s", dir, pdir_ent->d_name);
+            DIR *patch_dir = opendir(path);
+            struct dirent *ent;
+            if (patch_dir != NULL) {
+                /* Iterate over the patch subdirectory to find .ips patches. */
+                while ((ent = readdir(patch_dir)) != NULL) {
+                    if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) {
+                        continue;
+                    }
+                    size_t name_len = strlen(ent->d_name);
+                    if ((4 < name_len && name_len <= 0x44) && ((name_len & 1) == 0) && strcmp(ent->d_name + name_len - 4, ".ips") == 0 && name_matches_hash(ent->d_name, name_len, hash, hash_size)) {
+                        snprintf(path, sizeof(path) - 1, "%s/%s/%s", dir, pdir_ent->d_name, ent->d_name);
+                        FILE *f_ips = fopen(path, "rb");
+                        if (f_ips != NULL) {
+                            uint8_t header[5];
+                            if (fread(header, 5, 1, f_ips) == 1) {
+                                if (memcmp(header, IPS_MAGIC, 5) == 0) {
+                                    any_patches = true;
+                                    apply_ips_patch(mem, mem_size, prot_size, false, f_ips);
+                                } else if (memcmp(header, IPS32_MAGIC, 5) == 0) {
+                                    any_patches = true;
+                                    apply_ips_patch(mem, mem_size, prot_size, true, f_ips);
+                                }
+                            }
+                            fclose(f_ips);
+                        }
+                    }
+                }
+                closedir(patch_dir);
+            }
+        }
+        closedir(patches_dir);
+    }
+
+    return any_patches;
+} 
+
+void apply_kernel_ips_patches(void *kernel, size_t kernel_size) {
+    uint8_t hash[0x20];
+    se_calculate_sha256(hash, kernel, kernel_size);
+    apply_ips_patches("atmosphere/kernel_patches", kernel, kernel_size, 0, hash, sizeof(hash));
+}
+
+static void kip1_blz_uncompress(void *hdr_end) {
+    uint32_t addl_size = ((uint32_t *)hdr_end)[-1];
+    uint32_t header_size = ((uint32_t *)hdr_end)[-2];
+    uint32_t cmp_and_hdr_size = ((uint32_t *)hdr_end)[-3];
+    
+    unsigned char *cmp_start = (unsigned char *)(((uintptr_t)hdr_end) - cmp_and_hdr_size);
+    uint32_t cmp_ofs = cmp_and_hdr_size - header_size;
+    uint32_t out_ofs = cmp_and_hdr_size + addl_size;
+    
+    while (out_ofs) {
+        unsigned char control = cmp_start[--cmp_ofs];
+        for (unsigned int i = 0; i < 8; i++) {
+            if (control & 0x80) {
+                if (cmp_ofs < 2) {      
+                    fatal_error("KIP1 decompression out of bounds!\n");
+                }
+                cmp_ofs -= 2;
+                uint16_t seg_val = ((unsigned int)cmp_start[cmp_ofs+1] << 8) | cmp_start[cmp_ofs];
+                uint32_t seg_size = ((seg_val >> 12) & 0xF) + 3;
+                uint32_t seg_ofs = (seg_val & 0x0FFF) + 3;
+                if (out_ofs < seg_size) {
+                    /* Kernel restricts segment copy to stay in bounds. */
+                    seg_size = out_ofs;
+                }
+                out_ofs -= seg_size;
+                
+                for (unsigned int j = 0; j < seg_size; j++) {
+                    cmp_start[out_ofs + j] = cmp_start[out_ofs + j + seg_ofs];
+                }
+            } else {
+                /* Copy directly. */
+                if (cmp_ofs < 1) {
+                    fatal_error("KIP1 decompression out of bounds!\n");
+                }
+                cmp_start[--out_ofs] = cmp_start[--cmp_ofs];
+            }
+            control <<= 1;
+            if (out_ofs == 0) {
+                return;
+            }
+        }
+    }
+}
+
+static kip1_header_t *kip1_uncompress(kip1_header_t *kip, size_t *size) {
+    kip1_header_t new_header = *kip;
+    for (unsigned int i = 0; i < 3; i++) {
+        new_header.section_headers[i].compressed_size = new_header.section_headers[i].out_size;
+    }
+    new_header.flags &= 0xF8;
+    
+    *size = kip1_get_size_from_header(&new_header);
+    
+    unsigned char *new_kip = calloc(1, *size);
+    if (new_kip == NULL) {
+        return NULL;
+    }
+    *((kip1_header_t *)new_kip) = new_header;
+    
+    size_t new_offset = 0x100;
+    size_t old_offset = 0x100;
+    for (unsigned int i = 0; i < 3; i++) {
+        memcpy(new_kip + new_offset, (unsigned char *)kip + old_offset, kip->section_headers[i].compressed_size);
+        if (kip->flags & (1 << i)) {
+            kip1_blz_uncompress(new_kip + new_offset + kip->section_headers[i].compressed_size);
+        }
+        new_offset += kip->section_headers[i].out_size;
+        old_offset += kip->section_headers[i].compressed_size;
+    }
+    
+    return (kip1_header_t *)new_kip;
+}
+
+kip1_header_t *apply_kip_ips_patches(kip1_header_t *kip, size_t kip_size) {
+    uint8_t hash[0x20];
+    se_calculate_sha256(hash, kip, kip_size);
+    
+    size_t uncompressed_kip_size;
+    kip1_header_t *uncompressed_kip = kip1_uncompress(kip, &uncompressed_kip_size);
+    if (uncompressed_kip == NULL) {
+        return NULL;
+    }
+    
+    if (apply_ips_patches("atmosphere/kip_patches", uncompressed_kip, uncompressed_kip_size, 0x100, hash, sizeof(hash))) {
+        return uncompressed_kip;
+    } else {
+        free(uncompressed_kip);
+        return NULL;
+    }
+}

fusee/fusee-secondary/src/ips.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2018 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+ 
+#ifndef FUSEE_IPS_H
+#define FUSEE_IPS_H
+
+#include "utils.h"
+#include "kip.h"
+#include <stdint.h>
+
+void apply_kernel_ips_patches(void *kernel, size_t kernel_size);
+kip1_header_t *apply_kip_ips_patches(kip1_header_t *kip, size_t kip_size);
+
+#endif