From a4f5a0c1a65c9df239a737c350d4723c2a8cbc55 Mon Sep 17 00:00:00 2001 From: Nikias Bassen Date: Tue, 4 Oct 2022 13:06:20 +0200 Subject: img4: Add support for stitching with additional TBM data --- src/idevicerestore.c | 4 +- src/img4.c | 192 +++++++++++++++++++++++++++++++++++++++++++++++++-- src/img4.h | 2 +- 3 files changed, 191 insertions(+), 7 deletions(-) diff --git a/src/idevicerestore.c b/src/idevicerestore.c index 308c6cb..62fbc09 100644 --- a/src/idevicerestore.c +++ b/src/idevicerestore.c @@ -2566,9 +2566,9 @@ int personalize_component(const char *component_name, const unsigned char* compo unsigned char* stitched_component = NULL; unsigned int stitched_component_size = 0; - if (tss_response && tss_response_get_ap_img4_ticket(tss_response, &component_blob, &component_blob_size) == 0) { + if (tss_response && plist_dict_get_item(tss_response, "ApImg4Ticket")) { /* stitch ApImg4Ticket into IMG4 file */ - img4_stitch_component(component_name, component_data, component_size, component_blob, component_blob_size, &stitched_component, &stitched_component_size); + img4_stitch_component(component_name, component_data, component_size, tss_response, &stitched_component, &stitched_component_size); } else { /* try to get blob for current component from tss response */ if (tss_response && tss_response_get_blob_by_entry(tss_response, component_name, &component_blob) < 0) { diff --git a/src/img4.c b/src/img4.c index 6cff349..3a74c5e 100644 --- a/src/img4.c +++ b/src/img4.c @@ -24,6 +24,7 @@ #include "common.h" #include "img4.h" +#include "tss.h" #define ASN1_PRIVATE 0xc0 #define ASN1_PRIMITIVE_TAG 0x1f @@ -201,7 +202,7 @@ static void asn1_write_element(unsigned char **p, unsigned int *length, unsigned } } break; default: - fprintf(stderr, "ERROR: %s: type %02x is not implemented", __func__, type); + fprintf(stderr, "ERROR: %s: type %02x is not implemented\n", __func__, type); return; } } @@ -393,7 +394,38 @@ static const char *_img4_get_component_tag(const char *compname) return NULL; } -int img4_stitch_component(const char* component_name, const unsigned char* component_data, unsigned int component_size, const unsigned char* blob, unsigned int blob_size, unsigned char** img4_data, unsigned int *img4_size) +static void hexdump(char* data, int length) +{ + int i; + int j; + unsigned char c; + + for (i = 0; i < length; i += 16) { + fprintf(stderr, "%04x: ", i); + for (j = 0; j < 16; j++) { + if (i + j >= length) { + fprintf(stderr, " "); + continue; + } + fprintf(stderr, "%02x ", *(data + i + j) & 0xff); + } + fprintf(stderr, " | "); + for (j = 0; j < 16; j++) { + if (i + j >= length) + break; + c = *(data + i + j); + if ((c < 32) || (c > 127)) { + fprintf(stderr, "."); + continue; + } + fprintf(stderr, "%c", c); + } + fprintf(stderr, "\n"); + } + fprintf(stderr, "\n"); +} + +int img4_stitch_component(const char* component_name, const unsigned char* component_data, unsigned int component_size, plist_t tss_response, unsigned char** img4_data, unsigned int *img4_size) { unsigned char* magic_header = NULL; unsigned int magic_header_size = 0; @@ -404,8 +436,15 @@ int img4_stitch_component(const char* component_name, const unsigned char* compo unsigned int content_size; unsigned char* outbuf; unsigned char* p; + unsigned char* blob = NULL; + unsigned int blob_size = 0; - if (!component_name || !component_data || component_size == 0 || !blob || blob_size == 0 || !img4_data || !img4_size) { + if (!component_name || !component_data || component_size == 0 || !tss_response || !img4_data || !img4_size) { + return -1; + } + + if (tss_response_get_ap_img4_ticket(tss_response, &blob, &blob_size) != 0) { + error("ERROR: %s: Failed to get ApImg4Ticket from TSS response\n", __func__); return -1; } @@ -435,13 +474,152 @@ int img4_stitch_component(const char* component_name, const unsigned char* compo } } + // check if we have a *-TBM entry for the given component + unsigned char *additional_data = NULL; + unsigned int additional_size = 0; + char *tbm_key = malloc(strlen(component_name) + 5); + sprintf(tbm_key, "%s-TBM", component_name); + plist_t tbm_dict = plist_dict_get_item(tss_response, tbm_key); + free(tbm_key); + if (tbm_dict) { + plist_t dt = plist_dict_get_item(tbm_dict, "ucon"); + if (!dt) { + error("ERROR: %s: Missing ucon node in %s-TBM dictionary\n", __func__, component_name); + return -1; + } + uint64_t ucon_size = 0; + const char* ucon_data = plist_get_data_ptr(dt, &ucon_size); + if (!ucon_data) { + error("ERROR: %s: Missing ucon data in %s-TBM dictionary\n", __func__, component_name); + return -1; + } + dt = plist_dict_get_item(tbm_dict, "ucer"); + if (!dt) { + error("ERROR: %s: Missing ucer data node in %s-TBM dictionary\n", __func__, component_name); + return -1; + } + uint64_t ucer_size = 0; + const char* ucer_data = plist_get_data_ptr(dt, &ucer_size); + if (!ucer_data) { + error("ERROR: %s: Missing ucer data in %s-TBM dictionary\n", __func__, component_name); + return -1; + } + + unsigned char *im4rset = (unsigned char*)malloc(16 + 8 + 8 + ucon_size + 16 + 8 + 8 + ucer_size + 16); + unsigned char *p_im4rset = im4rset; + unsigned int im4rlen = 0; + + // ----------- ucon ------------ + // write priv ucon element + asn1_write_priv_element(&p_im4rset, &im4rlen, *(uint32_t*)"nocu"); + + // write ucon IA5STRING and ucon data + unsigned char ucon_seq[16]; + unsigned char *p_ucon_seq = &ucon_seq[0]; + unsigned int ucon_seq_hdr_len = 0; + asn1_write_element(&p_ucon_seq, &ucon_seq_hdr_len, ASN1_IA5_STRING, (void*)"ucon", -1); + asn1_write_element_header(ASN1_OCTET_STRING, ucon_size, &p_ucon_seq, &ucon_seq_hdr_len); + + // write ucon sequence + unsigned char elem_seq[8]; + unsigned char *p = &elem_seq[0]; + unsigned int seq_hdr_len = 0; + asn1_write_element_header(ASN1_SEQUENCE | ASN1_CONSTRUCTED, ucon_seq_hdr_len + ucon_size, &p, &seq_hdr_len); + + // add size to priv ucon element + asn1_write_size(ucon_seq_hdr_len + ucon_size + seq_hdr_len, &p_im4rset, &im4rlen); + + // put it together + memcpy(p_im4rset, elem_seq, seq_hdr_len); + p_im4rset += seq_hdr_len; + im4rlen += seq_hdr_len; + memcpy(p_im4rset, ucon_seq, ucon_seq_hdr_len); + p_im4rset += ucon_seq_hdr_len; + im4rlen += ucon_seq_hdr_len; + memcpy(p_im4rset, ucon_data, ucon_size); + p_im4rset += ucon_size; + im4rlen += ucon_size; + + // ----------- ucer ------------ + // write priv ucer element + asn1_write_priv_element(&p_im4rset, &im4rlen, *(uint32_t*)"recu"); + + // write ucon IA5STRING and ucer data + unsigned char ucer_seq[16]; + unsigned char *p_ucer_seq = &ucer_seq[0]; + unsigned int ucer_seq_hdr_len = 0; + asn1_write_element(&p_ucer_seq, &ucer_seq_hdr_len, ASN1_IA5_STRING, (void*)"ucer", -1); + asn1_write_element_header(ASN1_OCTET_STRING, ucer_size, &p_ucer_seq, &ucer_seq_hdr_len); + + p = &elem_seq[0]; + seq_hdr_len = 0; + asn1_write_element_header(ASN1_SEQUENCE | ASN1_CONSTRUCTED, ucer_seq_hdr_len + ucer_size, &p, &seq_hdr_len); + + // add size to priv ucer element + asn1_write_size(ucer_seq_hdr_len + ucer_size + seq_hdr_len, &p_im4rset, &im4rlen); + + // put it together + memcpy(p_im4rset, elem_seq, seq_hdr_len); + p_im4rset += seq_hdr_len; + im4rlen += seq_hdr_len; + memcpy(p_im4rset, ucer_seq, ucer_seq_hdr_len); + p_im4rset += ucer_seq_hdr_len; + im4rlen += ucer_seq_hdr_len; + memcpy(p_im4rset, ucer_data, ucer_size); + p_im4rset += ucer_size; + im4rlen += ucer_size; + + // now construct IM4R + + /* write inner set */ + unsigned char inner_set_[8]; + unsigned char *inner_set = &inner_set_[0]; + unsigned int inner_set_len = 0; + asn1_write_element_header(ASN1_SET | ASN1_CONSTRUCTED, im4rlen, &inner_set, &inner_set_len); + + /* write header values */ + unsigned char hdrdata_[16]; + unsigned char *hdrdata = &hdrdata_[0]; + unsigned int hdrdata_len = 0; + asn1_write_element(&hdrdata, &hdrdata_len, ASN1_IA5_STRING, (void*)"IM4R", -1); + + /* write sequence now that we know the entire size */ + unsigned char seq_[8]; + unsigned char *seq = &seq_[0]; + unsigned int seq_len = 0; + asn1_write_element_header(ASN1_SEQUENCE | ASN1_CONSTRUCTED, im4rlen + inner_set_len + hdrdata_len, &seq, &seq_len); + + /* write outer cont[1] */ + unsigned char cont_[8]; + unsigned char *cont = &cont_[0]; + unsigned int cont_len = 0; + asn1_write_element_header(ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 1, im4rlen + inner_set_len + hdrdata_len + seq_len, &cont, &cont_len); + + // now put everything together + additional_data = malloc(im4rlen + inner_set_len + hdrdata_len + seq_len + cont_len); + p = additional_data; + memcpy(p, cont_, cont_len); + p += cont_len; + memcpy(p, seq_, seq_len); + p += seq_len; + memcpy(p, hdrdata_, hdrdata_len); + p += hdrdata_len; + memcpy(p, inner_set_, inner_set_len); + p += inner_set_len; + memcpy(p, im4rset, im4rlen); + p += im4rlen; + additional_size = (unsigned int)(p - additional_data); + + free(im4rset); + } + // create element header for the "IMG4" magic asn1_create_element_header(ASN1_IA5_STRING, IMG4_MAGIC_SIZE, &magic_header, &magic_header_size); // create element header for the blob (ApImg4Ticket) asn1_create_element_header(ASN1_CONTEXT_SPECIFIC|ASN1_CONSTRUCTED, blob_size, &blob_header, &blob_header_size); // calculate the size for the final IMG4 file (asn1 sequence) - content_size = magic_header_size + IMG4_MAGIC_SIZE + component_size + blob_header_size + blob_size; + content_size = magic_header_size + IMG4_MAGIC_SIZE + component_size + blob_header_size + blob_size + additional_size; // create element header for the final IMG4 asn1 blob asn1_create_element_header(ASN1_SEQUENCE|ASN1_CONSTRUCTED, content_size, &img4header, &img4header_size); @@ -457,6 +635,7 @@ int img4_stitch_component(const char* component_name, const unsigned char* compo if (img4header) { free(img4header); } + free(additional_data); error("ERROR: out of memory when personalizing IMG4 component %s\n", component_name); return -1; } @@ -475,6 +654,10 @@ int img4_stitch_component(const char* component_name, const unsigned char* compo p += blob_header_size; memcpy(p, blob, blob_size); p += blob_size; + if (additional_size) { + memcpy(p, additional_data, additional_size); + p += additional_size; + } *img4_data = outbuf; *img4_size = (p - outbuf); @@ -488,6 +671,7 @@ int img4_stitch_component(const char* component_name, const unsigned char* compo if (img4header) { free(img4header); } + free(additional_data); return 0; } diff --git a/src/img4.h b/src/img4.h index 37dea56..1056fa6 100644 --- a/src/img4.h +++ b/src/img4.h @@ -26,7 +26,7 @@ extern "C" { #endif -int img4_stitch_component(const char* component_name, const unsigned char* component_data, unsigned int component_size, const unsigned char* blob, unsigned int blob_size, unsigned char** img4_data, unsigned int *img4_size); +int img4_stitch_component(const char* component_name, const unsigned char* component_data, unsigned int component_size, plist_t tss_response, unsigned char** img4_data, unsigned int *img4_size); int img4_create_local_manifest(plist_t request, plist_t build_identity, plist_t* manifest); #ifdef __cplusplus -- cgit v1.1-32-gdbae