Initial XCI Support. (WIP, #4).

-Not all pertitent information is printed out. -Extraction is pretty much supported, though. -TODO: CERT stuff, decryption, title ID fetching...
2024-11-10 06:34:14 +00:00 · 2018-02-04 00:21:04 -08:00 · 2018-02-04 00:21:04 -08:00 · 2567d516d5
commit 2567d516d5
parent 910918bbb1
10 changed files with 415 additions and 10 deletions
--- a/7
+++ b/7
@ -17,7 +17,7 @@ all:
 .c.o:
 	$(CC) $(INCLUDE) -c $(CFLAGS) -o $@ $<

-hactool: sha.o aes.o rsa.o npdm.o bktr.o pki.o pfs0.o hfs0.o romfs.o utils.o nca.o main.o filepath.o
+hactool: sha.o aes.o rsa.o npdm.o bktr.o pki.o pfs0.o hfs0.o romfs.o utils.o nca.o xci.o main.o filepath.o
 	$(CC) -o $@ $^ $(LDFLAGS) -L $(LIBDIR)

 aes.o: aes.h types.h
@ -46,8 +46,13 @@ sha.o: sha.h types.h

 utils.o: utils.h types.h

+xci.o: xci.h types.h hfs0.h
+
 clean:
 	rm -f *.o hactool hactool.exe
+    
+clean_full:
+	rm -f *.o hactool hactool.exe
 	cd mbedtls && $(MAKE) clean

 dist:
--- a/README.md
+++ b/README.md
@ -51,6 +51,12 @@ HFS0 options:
  --hfs0dir=dir      Specify HFS0 directory path.
  --outdir=dir       Specify HFS0 directory path. Overrides previous path, if present.
  --exefsdir=dir     Specify HFS0 directory path. Overrides previous paths, if present.
+XCI options:
+  --rootdir=dir      Specify XCI root HFS0 directory path.
+  --updatedir=dir    Specify XCI update HFS0 directory path.
+  --normaldir=dir    Specify XCI update HFS0 directory path.
+  --securedir=dir    Specify XCI update HFS0 directory path.
+  --outdir=dir       Specify XCI directory path. Overrides previous paths, if present.
 ```

 ## Building
--- a/hfs0.c
+++ b/hfs0.c
@ -11,6 +11,7 @@ void hfs0_process(hfs0_ctx_t *ctx) {
    }
    
    if (raw_header.magic != MAGIC_HFS0) {
+        memdump(stdout, "Sanity: ", &raw_header, sizeof(raw_header));
        printf("Error: HFS0 is corrupt!\n");
        exit(EXIT_FAILURE);
    }
@ -34,7 +35,7 @@ void hfs0_process(hfs0_ctx_t *ctx) {
    uint64_t cur_ofs = 0;
    for (unsigned int i = 0; i < ctx->header->num_files; i++) {
        hfs0_file_entry_t *cur_file = hfs0_get_file_entry(ctx->header, i);
-        if (cur_file->offset != cur_ofs) {
+        if (cur_file->offset < cur_ofs) {
            printf("Error: HFS0 is corrupt!\n");
            exit(EXIT_FAILURE);
        }
--- a/hfs0.h
+++ b/hfs0.h
@ -53,5 +53,6 @@ void hfs0_process(hfs0_ctx_t *ctx);
 void hfs0_save(hfs0_ctx_t *ctx);
 void hfs0_print(hfs0_ctx_t *ctx);

+void hfs0_save_file(hfs0_ctx_t *ctx, uint32_t i, filepath_t *dirpath);

 #endif
--- a/main.c
+++ b/main.c
@ -8,7 +8,7 @@
 #include "settings.h"
 #include "pki.h"
 #include "nca.h"
-#include "hfs0.h"
+#include "xci.h"

 static char *prog_name = "hactool";

@ -60,6 +60,12 @@ static void usage(void) {
        "  --hfs0dir=dir      Specify HFS0 directory path.\n"
        "  --outdir=dir       Specify HFS0 directory path. Overrides previous path, if present.\n"
        "  --exefsdir=dir     Specify HFS0 directory path. Overrides previous paths, if present.\n"
+        "XCI options:\n"
+        "  --rootdir=dir      Specify XCI root HFS0 directory path.\n"
+        "  --updatedir=dir    Specify XCI update HFS0 directory path.\n"
+        "  --normaldir=dir    Specify XCI update HFS0 directory path.\n"
+        "  --securedir=dir    Specify XCI update HFS0 directory path.\n"
+        "  --outdir=dir       Specify XCI directory path. Overrides previous paths, if present.\n"
        "\n", __TIME__, __DATE__, prog_name);
    exit(EXIT_FAILURE);
 }
@ -155,6 +161,10 @@ int main(int argc, char **argv) {
            {"header", 1, NULL, 19},
            {"pfs0dir", 1, NULL, 20},
            {"hfs0dir", 1, NULL, 21},
+            {"rootdir", 1, NULL, 22},
+            {"updatedir", 1, NULL, 23},
+            {"normaldir", 1, NULL, 24},
+            {"securedir", 1, NULL, 25},
            {NULL, 0, NULL, 0},
        };

@ -188,11 +198,10 @@ int main(int argc, char **argv) {
                    nca_ctx.tool_ctx->file_type = FILETYPE_ROMFS; 
                } else if (!strcmp(optarg, "hfs0")) {
                    nca_ctx.tool_ctx->file_type = FILETYPE_HFS0;
+                } else if (!strcmp(optarg, "xci") || !strcmp(optarg, "gamecard") || !strcmp(optarg, "gc")) {
+                    nca_ctx.tool_ctx->file_type = FILETYPE_XCI;
                }
-                /* } else if (!strcmp(optarg, "xci") || !strcmp(optarg, "gamecard") || !strcmp(optarg, "gc")) {
-                 *    nca_ctx.tool_ctx->file_type = FILETYPE_XCI;
-                 * }
-                 * } else if (!strcmp(optarg, "package2") || !strcmp(optarg, "pk21")) {
+                /* } else if (!strcmp(optarg, "package2") || !strcmp(optarg, "pk21")) {
                 *    nca_ctx.tool_ctx->file_type = FILETYPE_PACKAGE2;
                 * }
                 * } else if (!strcmp(optarg, "package1") || !strcmp(optarg, "pk11")) {
@ -282,6 +291,18 @@ int main(int argc, char **argv) {
            case 21:
                filepath_set(&tool_ctx.settings.hfs0_dir_path, optarg); 
                break;
+            case 22:
+                filepath_set(&tool_ctx.settings.rootpt_dir_path, optarg); 
+                break;
+            case 23:
+                filepath_set(&tool_ctx.settings.update_dir_path, optarg); 
+                break;
+            case 24:
+                filepath_set(&tool_ctx.settings.normal_dir_path, optarg); 
+                break;
+            case 25:
+                filepath_set(&tool_ctx.settings.secure_dir_path, optarg); 
+                break;
            default:
                usage();
                return EXIT_FAILURE;
@ -371,6 +392,14 @@ int main(int argc, char **argv) {
            }
            break;
        }
+        case FILETYPE_XCI: {
+            xci_ctx_t xci_ctx;
+            memset(&xci_ctx, 0, sizeof(xci_ctx));
+            xci_ctx.file = tool_ctx.file;
+            xci_ctx.tool_ctx = &tool_ctx;
+            xci_process(&xci_ctx);
+            break;
+        }
        default: {
            fprintf(stderr, "Unknown File Type!\n\n");
            usage();
--- a/rsa.c
+++ b/rsa.c
@ -39,8 +39,7 @@ int rsa2048_pss_verify(const void *data, size_t len, const unsigned char *signat
    mbedtls_mpi_free(&e_mpi);
    mbedtls_mpi_free(&message_mpi);

-    /* libgcrypt requires knowledge of the salt to do automated PSS verification as far as I can tell. */
-    /* This is not an option in our case... */
+    /* There's no automated PSS verification as far as I can tell. */
    if (m_buf[RSA_2048_BYTES-1] != 0xBC) {
        return false;
    }
@ -79,4 +78,58 @@ int rsa2048_pss_verify(const void *data, size_t len, const unsigned char *signat
    memcpy(&validate_buf[0x28], &m_buf[RSA_2048_BYTES - 0x20 - 0x20 - 1], 0x20);
    sha256_hash_buffer(validate_hash, validate_buf, 0x48);
    return memcmp(h_buf, validate_hash, 0x20) == 0;
+}
+
+/* Perform an RSA-PKCS1 verify operation on data, with signature and N. */
+int rsa2048_pkcs1_verify(const void *data, size_t len, const unsigned char *signature, const unsigned char *modulus) {
+    mbedtls_mpi signature_mpi;
+    mbedtls_mpi modulus_mpi;
+    mbedtls_mpi e_mpi;
+    mbedtls_mpi message_mpi;
+    
+    mbedtls_mpi_init(&signature_mpi);
+    mbedtls_mpi_init(&modulus_mpi);
+    mbedtls_mpi_init(&e_mpi);
+    mbedtls_mpi_init(&message_mpi);
+    mbedtls_mpi_lset(&message_mpi, RSA_2048_BITS);
+
+    unsigned char m_buf[RSA_2048_BYTES];
+    unsigned char h_buf[0x20];
+    const unsigned char E[3] = {1, 0, 1};
+    
+    mbedtls_mpi_read_binary(&e_mpi, E, 3);
+    mbedtls_mpi_read_binary(&signature_mpi, signature, RSA_2048_BYTES);
+    mbedtls_mpi_read_binary(&modulus_mpi, modulus, RSA_2048_BYTES);
+    mbedtls_mpi_exp_mod(&message_mpi, &signature_mpi, &e_mpi, &modulus_mpi, NULL);
+
+    if (mbedtls_mpi_write_binary(&message_mpi, m_buf, RSA_2048_BYTES) != 0) {
+        FATAL_ERROR("Failed to export exponentiated RSA message!");
+    }
+
+    mbedtls_mpi_free(&signature_mpi);
+    mbedtls_mpi_free(&modulus_mpi);
+    mbedtls_mpi_free(&e_mpi);
+    mbedtls_mpi_free(&message_mpi);
+    
+    /* For RSA-2048, this prefix is just a constant. */
+    const unsigned char pkcs1_hash_prefix[0xE0] = {
+        0x00, 0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 
+        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x30, 0x31, 0x30, 
+        0x0D, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20
+    };
+    
+    sha256_hash_buffer(h_buf, data, len);
+    
+    return memcmp(pkcs1_hash_prefix, m_buf, 0xE0) == 0 && memcmp(&m_buf[0xE0], h_buf, 0x20) == 0;
 }
--- a/rsa.h
+++ b/rsa.h
@ -4,5 +4,6 @@
 #include "mbedtls/rsa.h"

 int rsa2048_pss_verify(const void *data, size_t len, const unsigned char *signature, const unsigned char *modulus);
+int rsa2048_pkcs1_verify(const void *data, size_t len, const unsigned char *signature, const unsigned char *modulus);

 #endif
--- a/settings.h
+++ b/settings.h
@ -53,6 +53,10 @@ typedef struct {
    filepath_t pfs0_dir_path;
    filepath_t hfs0_dir_path;
    filepath_t dec_nca_path;
+    filepath_t rootpt_dir_path;
+    filepath_t update_dir_path;
+    filepath_t normal_dir_path;
+    filepath_t secure_dir_path;
    filepath_t header_path;
 } hactool_settings_t;

@ -62,7 +66,7 @@ enum hactool_file_type
    FILETYPE_PFS0,
    FILETYPE_ROMFS,
    FILETYPE_HFS0,
-    /* FILETYPE_XCI, */
+    FILETYPE_XCI,
    /* FILETYPE_PACKAGE2, */
    /* FILETYPE_PACKAGE1, */
 };
--- a/xci.c
+++ b/xci.c
@ -0,0 +1,241 @@
+#include <string.h>
+#include "rsa.h"
+#include "xci.h"
+
+/* This RSA-PKCS1 public key is only accessible to the gamecard controller. */
+/* However, it (and other XCI keys) can be dumped with a GCD attack on two signatures. */
+/* Contact SciresM for details, if curious. */
+const unsigned char xci_header_pubk[0x100] = {
+    0x98, 0xC7, 0x26, 0xB6, 0x0D, 0x0A, 0x50, 0xA7, 0x39, 0x21, 0x0A, 0xE3, 0x2F, 0xE4, 0x3E, 0x2E, 
+    0x5B, 0xA2, 0x86, 0x75, 0xAA, 0x5C, 0xEE, 0x34, 0xF1, 0xA3, 0x3A, 0x7E, 0xBD, 0x90, 0x4E, 0xF7, 
+    0x8D, 0xFA, 0x17, 0xAA, 0x6B, 0xC6, 0x36, 0x6D, 0x4C, 0x9A, 0x6D, 0x57, 0x2F, 0x80, 0xA2, 0xBC, 
+    0x38, 0x4D, 0xDA, 0x99, 0xA1, 0xD8, 0xC3, 0xE2, 0x99, 0x79, 0x36, 0x71, 0x90, 0x20, 0x25, 0x9D, 
+    0x4D, 0x11, 0xB8, 0x2E, 0x63, 0x6B, 0x5A, 0xFA, 0x1E, 0x9C, 0x04, 0xD1, 0xC5, 0xF0, 0x9C, 0xB1, 
+    0x0F, 0xB8, 0xC1, 0x7B, 0xBF, 0xE8, 0xB0, 0xD2, 0x2B, 0x47, 0x01, 0x22, 0x6B, 0x23, 0xC9, 0xD0, 
+    0xBC, 0xEB, 0x75, 0x6E, 0x41, 0x7D, 0x4C, 0x26, 0xA4, 0x73, 0x21, 0xB4, 0xF0, 0x14, 0xE5, 0xD9, 
+    0x8D, 0xB3, 0x64, 0xEE, 0xA8, 0xFA, 0x84, 0x1B, 0xB8, 0xB8, 0x7C, 0x88, 0x6B, 0xEF, 0xCC, 0x97, 
+    0x04, 0x04, 0x9A, 0x67, 0x2F, 0xDF, 0xEC, 0x0D, 0xB2, 0x5F, 0xB5, 0xB2, 0xBD, 0xB5, 0x4B, 0xDE, 
+    0x0E, 0x88, 0xA3, 0xBA, 0xD1, 0xB4, 0xE0, 0x91, 0x81, 0xA7, 0x84, 0xEB, 0x77, 0x85, 0x8B, 0xEF, 
+    0xA5, 0xE3, 0x27, 0xB2, 0xF2, 0x82, 0x2B, 0x29, 0xF1, 0x75, 0x2D, 0xCE, 0xCC, 0xAE, 0x9B, 0x8D, 
+    0xED, 0x5C, 0xF1, 0x8E, 0xDB, 0x9A, 0xD7, 0xAF, 0x42, 0x14, 0x52, 0xCD, 0xE3, 0xC5, 0xDD, 0xCE, 
+    0x08, 0x12, 0x17, 0xD0, 0x7F, 0x1A, 0xAA, 0x1F, 0x7D, 0xE0, 0x93, 0x54, 0xC8, 0xBC, 0x73, 0x8A, 
+    0xCB, 0xAD, 0x6E, 0x93, 0xE2, 0x19, 0x72, 0x6B, 0xD3, 0x45, 0xF8, 0x73, 0x3D, 0x2B, 0x6A, 0x55, 
+    0xD2, 0x3A, 0x8B, 0xB0, 0x8A, 0x42, 0xE3, 0x3D, 0xF1, 0x92, 0x23, 0x42, 0x2E, 0xBA, 0xCC, 0x9C, 
+    0x9A, 0xC1, 0xDD, 0x62, 0x86, 0x9C, 0x2E, 0xE1, 0x2D, 0x6F, 0x62, 0x67, 0x51, 0x08, 0x0E, 0xCF
+};
+
+void xci_process(xci_ctx_t *ctx) {
+    fseeko64(ctx->file, 0, SEEK_SET);
+    if (fread(&ctx->header, 1, 0x200, ctx->file) != 0x200) {
+        fprintf(stderr, "Failed to read XCI header!\n");
+        return;
+    }
+    
+    if (ctx->header.magic != MAGIC_HEAD) {
+        fprintf(stderr, "Error: XCI header is corrupt!\n");
+        exit(EXIT_FAILURE);
+    }
+    
+    if (ctx->tool_ctx->action & ACTION_VERIFY) {
+        if (rsa2048_pkcs1_verify(&ctx->header.magic, 0x100, ctx->header.header_sig, xci_header_pubk)) {
+            ctx->header_sig_validity = VALIDITY_VALID;
+        } else {
+            ctx->header_sig_validity = VALIDITY_INVALID;
+        }
+    }
+    
+    ctx->hfs0_hash_validity = check_memory_hash_table(ctx->file, ctx->header.hfs0_header_hash, ctx->header.hfs0_offset, ctx->header.hfs0_header_size, ctx->header.hfs0_header_size, 0);
+    if (ctx->hfs0_hash_validity != VALIDITY_VALID) {
+        fprintf(stderr, "Error: XCI partition is corrupt!\n");
+        exit(EXIT_FAILURE);
+    }
+    
+    hactool_ctx_t blank_ctx;
+    memset(&blank_ctx, 0, sizeof(blank_ctx));
+    blank_ctx.action = ctx->tool_ctx->action & ~(ACTION_EXTRACT | ACTION_INFO);
+    
+    ctx->partition_ctx.file = ctx->file;
+    ctx->partition_ctx.offset = ctx->header.hfs0_offset;
+    ctx->partition_ctx.tool_ctx = &blank_ctx;
+    ctx->partition_ctx.name = "rootpt";
+    hfs0_process(&ctx->partition_ctx);
+    
+    if (ctx->partition_ctx.header->num_files != 3) {
+        fprintf(stderr, "Error: Invalid XCI partition!\n");
+        exit(EXIT_FAILURE);    
+    }
+    
+    for (unsigned int i = 0; i < 3; i++)  {
+        hfs0_ctx_t *cur_ctx = NULL;
+        
+        hfs0_file_entry_t *cur_file = hfs0_get_file_entry(ctx->partition_ctx.header, i);
+        char *cur_name = hfs0_get_file_name(ctx->partition_ctx.header, i);
+        if (!strcmp(cur_name, "update") && ctx->update_ctx.file == NULL) {
+            cur_ctx = &ctx->update_ctx;
+        } else if (!strcmp(cur_name, "normal") && ctx->normal_ctx.file == NULL) {
+            cur_ctx = &ctx->normal_ctx;
+        } else if (!strcmp(cur_name, "secure") && ctx->secure_ctx.file == NULL) {
+            cur_ctx = &ctx->secure_ctx;
+        } 
+        
+        if (cur_ctx == NULL) {
+            fprintf(stderr, "Unknown XCI partition: %s\n", cur_name);
+            exit(EXIT_FAILURE);
+        }
+        
+        cur_ctx->name = cur_name;
+        cur_ctx->offset = ctx->partition_ctx.offset + hfs0_get_header_size(ctx->partition_ctx.header) + cur_file->offset;
+        cur_ctx->tool_ctx = &blank_ctx;
+        cur_ctx->file = ctx->file;
+        hfs0_process(cur_ctx);
+    }
+    
+    for (unsigned int i = 0; i < 0x10; i++) {
+        ctx->iv[i] = ctx->header.reversed_iv[0xF-i];
+    }
+
+    if (ctx->tool_ctx->action & ACTION_INFO) {
+        xci_print(ctx);
+    }
+    
+    if (ctx->tool_ctx->action & ACTION_EXTRACT) {
+        xci_save(ctx);
+    }
+}
+
+void xci_save(xci_ctx_t *ctx) {
+    /* Extract to directory. */
+    if (ctx->tool_ctx->settings.out_dir_path.enabled && ctx->tool_ctx->settings.out_dir_path.path.valid == VALIDITY_VALID) {
+        printf("Extracting XCI...\n");
+        filepath_t *dirpath = &ctx->tool_ctx->settings.out_dir_path.path;
+        os_makedir(dirpath->os_path);
+        for (unsigned int i = 0; i < 3; i++) {
+            hfs0_ctx_t *cur_ctx = NULL;
+            
+            char *cur_name = hfs0_get_file_name(ctx->partition_ctx.header, i);
+            if (!strcmp(cur_name, "update")) {
+                cur_ctx = &ctx->update_ctx;
+            } else if (!strcmp(cur_name, "normal")) {
+                cur_ctx = &ctx->normal_ctx;
+            } else if (!strcmp(cur_name, "secure")) {
+                cur_ctx = &ctx->secure_ctx;
+            }
+            if (cur_ctx == NULL) {
+                fprintf(stderr, "Unkown XCI partition found in extraction: %s\n", cur_name);
+                exit(EXIT_FAILURE);
+            }
+            filepath_t partition_dirpath;
+            filepath_copy(&partition_dirpath, dirpath);
+
+            filepath_append(&partition_dirpath, "%s", cur_name);
+            os_makedir(partition_dirpath.os_path);
+            for (uint32_t i = 0; i < cur_ctx->header->num_files; i++) {
+                hfs0_save_file(cur_ctx, i, &partition_dirpath);
+            }
+        }
+    } else {
+        /* Save Root Partition. */
+        if (ctx->tool_ctx->settings.rootpt_dir_path.valid == VALIDITY_VALID) {
+            printf("Saving Root Partition...\n");
+            os_makedir(ctx->tool_ctx->settings.rootpt_dir_path.os_path);
+            for (uint32_t i = 0; i < ctx->partition_ctx.header->num_files; i++) {
+                hfs0_save_file(&ctx->partition_ctx, i, &ctx->tool_ctx->settings.rootpt_dir_path);
+            }
+            printf("\n");
+        }
+        /* Save Update Partition. */
+        if (ctx->tool_ctx->settings.update_dir_path.valid == VALIDITY_VALID) {
+             printf("Saving Update Partition...\n");
+            os_makedir(ctx->tool_ctx->settings.update_dir_path.os_path);
+            for (uint32_t i = 0; i < ctx->update_ctx.header->num_files; i++) {
+                hfs0_save_file(&ctx->update_ctx, i, &ctx->tool_ctx->settings.update_dir_path);
+            }
+            printf("\n");
+        }
+        /* Save Normal Partition. */
+        if (ctx->tool_ctx->settings.normal_dir_path.valid == VALIDITY_VALID) {
+             printf("Saving Normal Partition...\n");
+            os_makedir(ctx->tool_ctx->settings.normal_dir_path.os_path);
+            for (uint32_t i = 0; i < ctx->normal_ctx.header->num_files; i++) {
+                hfs0_save_file(&ctx->normal_ctx, i, &ctx->tool_ctx->settings.normal_dir_path);
+            }
+            printf("\n");
+        }
+        /* Save Secure Partition. */
+        if (ctx->tool_ctx->settings.secure_dir_path.valid == VALIDITY_VALID) {
+             printf("Saving Secure Partition...\n");
+            os_makedir(ctx->tool_ctx->settings.secure_dir_path.os_path);
+            for (uint32_t i = 0; i < ctx->secure_ctx.header->num_files; i++) {
+                hfs0_save_file(&ctx->secure_ctx, i, &ctx->tool_ctx->settings.secure_dir_path);
+            }
+            printf("\n");
+        }        
+    }
+}
+
+char *xci_get_cartridge_type(xci_ctx_t *ctx) {
+    cartridge_type_t cart_type = (cartridge_type_t)ctx->header.cart_type;
+    switch (cart_type) {
+        case CARTSIZE_2GB: return "2GB";
+        case CARTSIZE_4GB: return "4GB";
+        case CARTSIZE_8GB: return "8GB";
+        case CARTSIZE_16GB: return "16GB";
+        default:
+            return "Unknown/Invalid";
+    }
+}
+
+void xci_print_hfs0(hfs0_ctx_t *ctx) {
+    print_magic("    Magic:                          ", ctx->header->magic);
+    printf("    Offset:                         %012"PRIx64"\n", ctx->offset);
+    printf("    Number of files:                %"PRId32"\n", ctx->header->num_files);
+    
+    if (ctx->header->num_files > 0 && (ctx->header->num_files < 100 || ctx->tool_ctx->action & ACTION_VERIFY)) {
+        printf("    Files:");
+        for (unsigned int i = 0; i < ctx->header->num_files; i++) {
+            hfs0_file_entry_t *cur_file = hfs0_get_file_entry(ctx->header, i);
+            if (ctx->tool_ctx->action & ACTION_VERIFY) {
+                validity_t hash_validity = check_memory_hash_table(ctx->file, cur_file->hash, ctx->offset + hfs0_get_header_size(ctx->header) + cur_file->offset, cur_file->hashed_size, cur_file->hashed_size, 0);
+                printf("%s%s:/%-48s %012"PRIx64"-%012"PRIx64" (%s)\n", i == 0 ? "                          " : "                                    ", ctx->name == NULL ? "hfs0" : ctx->name, hfs0_get_file_name(ctx->header, i), cur_file->offset, cur_file->offset + cur_file->size, GET_VALIDITY_STR(hash_validity));
+            } else {
+                printf("%s%s:/%-48s %012"PRIx64"-%012"PRIx64"\n", i == 0 ? "                          " : "                                    ", ctx->name == NULL ? "hfs0" : ctx->name, hfs0_get_file_name(ctx->header, i), cur_file->offset, cur_file->offset + cur_file->size);
+            }
+        }
+    }
+}
+    
+void xci_print(xci_ctx_t *ctx) {
+    printf("\nXCI:\n");
+    print_magic("Magic:                              ", ctx->header.magic);
+
+    if (ctx->tool_ctx->action & ACTION_VERIFY) {
+        if (ctx->header_sig_validity == VALIDITY_VALID) {
+            memdump(stdout, "Header Signature (GOOD):            ", &ctx->header.header_sig, 0x100);
+        } else {
+            memdump(stdout, "Header Signature (FAIL):            ", &ctx->header.header_sig, 0x100);
+        }
+    } else {
+        memdump(stdout, "Header Signature:                   ", &ctx->header.header_sig, 0x100);
+    }
+    
+    printf("Cartridge Type:                     %s\n", xci_get_cartridge_type(ctx));
+    printf("Cartridge Size:                     %012"PRIx64"\n", media_to_real(ctx->header.cart_size + 1));
+    memdump(stdout, "Header IV:                          ", ctx->iv, 0x10);
+    memdump(stdout, "Encrypted Header:                   ", ctx->header.encrypted_data, 0x70);
+
+    if (ctx->tool_ctx->action & ACTION_VERIFY) {
+        printf("Root Partition (%s):\n", GET_VALIDITY_STR(ctx->hfs0_hash_validity));
+    } else {
+        printf("Root Partition:\n");
+    }
+    xci_print_hfs0(&ctx->partition_ctx);
+    
+    printf("Update Partition:\n");
+    xci_print_hfs0(&ctx->update_ctx);
+    
+    printf("Normal Partition:\n");
+    xci_print_hfs0(&ctx->normal_ctx);
+    
+    printf("Secure Partition:\n");
+    xci_print_hfs0(&ctx->secure_ctx);
+}
--- a/xci.h
+++ b/xci.h
@ -0,0 +1,64 @@
+#ifndef HACTOOL_XCI_H
+#define HACTOOL_XCI_H
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "types.h"
+#include "settings.h"
+#include "hfs0.h"
+
+#define MAGIC_HEAD 0x44414548 /* "HEAD" */
+
+typedef enum {
+    CARTSIZE_2GB = 0xF8,
+    CARTSIZE_4GB = 0xF0,
+    CARTSIZE_8GB = 0xE0,
+    CARTSIZE_16GB = 0xE1,
+    /* CARTSIZE_32GB = 0xE2? */
+} cartridge_type_t;
+
+typedef struct {
+    uint8_t header_sig[0x100];
+    uint32_t magic;
+    uint32_t secure_offset;
+    uint32_t _0x108;
+    uint8_t _0x10C;
+    uint8_t cart_type;
+    uint8_t _0x10E;
+    uint8_t _0x10F;
+    uint64_t _0x110;
+    uint64_t cart_size;
+    unsigned char reversed_iv[0x10];
+    uint64_t hfs0_offset;
+    uint64_t hfs0_header_size;
+    unsigned char hfs0_header_hash[0x20];
+    unsigned char crypto_header_hash[0x20];
+    uint32_t _0x180;
+    uint32_t _0x184;
+    uint32_t _0x188;
+    uint32_t _0x18C;
+    unsigned char encrypted_data[0x70];
+} xci_header_t;
+
+typedef struct {
+    FILE *file; /* File for this NCA. */
+    validity_t header_sig_validity;
+    validity_t cert_sig_validity;
+    validity_t hfs0_hash_validity;
+    hfs0_ctx_t partition_ctx;
+    hfs0_ctx_t normal_ctx;
+    hfs0_ctx_t update_ctx;
+    hfs0_ctx_t secure_ctx;
+    hactool_ctx_t *tool_ctx;
+    unsigned char iv[0x10];
+    /* TODO: Header decryption. */
+    /* unsigned char decrypted_header[0x70]; */
+    xci_header_t header;
+} xci_ctx_t;
+
+void xci_process(xci_ctx_t *ctx);
+void xci_save(xci_ctx_t *ctx);
+void xci_print(xci_ctx_t *ctx);
+
+
+#endif