move ipsw on-demand download to ipsw.c

1 files changed, 235 insertions, 0 deletions

diff --git a/src/ipsw.c b/src/ipsw.c
index b9ebdff..033b894 100644
--- a/src/ipsw.c
+++ b/src/ipsw.c
@@ -23,6 +23,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <openssl/sha.h>
 
 #include "ipsw.h"
 #include "idevicerestore.h"
@@ -219,3 +220,237 @@ void ipsw_close(ipsw_archive* archive) {
 		free(archive);
 	}
 }
+
+static int get_latest_fw(plist_t version_data, const char* product, char** fwurl, unsigned char* sha1buf)
+{
+	*fwurl = NULL;
+	memset(sha1buf, '\0', 20);
+
+	plist_t n1 = plist_access_path(version_data, 2, "MobileDeviceMajorVersionsByProductType", product);
+	if (!n1 || (plist_dict_get_size(n1) == 0)) {
+		error("%s: ERROR: Can't find MobileDeviceMajorVersionsByProductType/%s dict in version data\n", __func__, product);
+		return -1;
+	}
+
+	char* strval = NULL;
+	plist_t n2 = plist_dict_get_item(n1, "SameAs");
+	if (n2) {
+		plist_get_string_val(n2, &strval);
+	}
+	if (strval) {
+		n1 = plist_access_path(version_data, 2, "MobileDeviceMajorVersionsByProductType", strval);
+		free(strval);
+		strval = NULL;
+		if (!n1 || (plist_dict_get_size(n1) == 0)) {
+			error("%s: ERROR: Can't find MobileDeviceMajorVersionsByProductType/%s dict in version data\n", __func__, product);
+			return -1;
+		}
+	}
+
+	plist_dict_iter iter = NULL;
+	plist_dict_new_iter(n1, &iter);
+	if (!iter) {
+		error("%s: ERROR: Can't get dict iter\n", __func__);
+		return -1;
+	}
+	n2 = NULL;
+	char* key = NULL;
+	plist_t val = NULL;
+	do {
+		plist_dict_next_item(n1, iter, &key, &val);
+		if (key) {
+			n2 = val;
+			free(key);
+		}
+	} while (val);
+	free(iter);
+
+	if (!n2) {
+		error("%s: ERROR: Can't get last node?!\n", __func__);
+		return -1;
+	}
+
+	uint64_t major = 0;
+	if (plist_get_node_type(n2) == PLIST_ARRAY) {
+		uint32_t sz = plist_array_get_size(n2);
+		plist_t n3 = plist_array_get_item(n2, sz-1);
+		plist_get_uint_val(n3, &major);
+	} else {
+		plist_get_uint_val(n2, &major);
+	}
+
+	if (major == 0) {
+		error("%s: ERROR: Can't find major version?!\n", __func__);
+		return -1;
+	}
+
+	char majstr[32]; // should be enough for a uint64_t value
+	sprintf(majstr, FMT_qu, (long long unsigned int)major);
+	n1 = plist_access_path(version_data, 7, "MobileDeviceSoftwareVersionsByVersion", majstr, "MobileDeviceSoftwareVersions", product, "Unknown", "Universal", "Restore");
+	if (!n1) {
+		error("%s: ERROR: Can't get Unknown/Universal/Restore node?!\n", __func__);
+		return -1;
+	}
+
+	n2 = plist_dict_get_item(n1, "BuildVersion");
+	if (!n2 || (plist_get_node_type(n2) != PLIST_STRING)) {
+		error("%s: ERROR: Can't get build version node?!\n", __func__);
+		return -1;
+	}
+
+	strval = NULL;
+	plist_get_string_val(n2, &strval);
+
+	n1 = plist_access_path(version_data, 5, "MobileDeviceSoftwareVersionsByVersion", majstr, "MobileDeviceSoftwareVersions", product, strval);
+	if (!n1) {
+		error("%s: ERROR: Can't get MobileDeviceSoftwareVersions/%s node?!\n", __func__, strval);
+		free(strval);
+		return -1;
+	}
+	free(strval);
+
+	strval = NULL;
+	n2 = plist_dict_get_item(n1, "SameAs");
+	if (n2) {
+		plist_get_string_val(n2, &strval);
+	}
+	if (strval) {
+		n1 = plist_access_path(version_data, 5, "MobileDeviceSoftwareVersionsByVersion", majstr, "MobileDeviceSoftwareVersions", product, strval);
+		free(strval);
+		strval = NULL;
+		if (!n1 || (plist_dict_get_size(n1) == 0)) {
+			error("%s: ERROR: Can't get MobileDeviceSoftwareVersions/%s dict\n", __func__, product);
+			return -1;
+		}
+	}
+
+	n2 = plist_access_path(n1, 2, "Update", "BuildVersion");
+	if (n2) {
+		strval = NULL;
+		plist_get_string_val(n2, &strval);
+		if (strval) {
+			n1 = plist_access_path(version_data, 5, "MobileDeviceSoftwareVersionsByVersion", majstr, "MobileDeviceSoftwareVersions", product, strval);
+			free(strval);
+			strval = NULL;
+		}
+	}
+
+	n2 = plist_access_path(n1, 2, "Restore", "FirmwareURL");
+	if (!n2 || (plist_get_node_type(n2) != PLIST_STRING)) {
+		error("%s: ERROR: Can't get FirmwareURL node\n", __func__);
+		return -1;
+	}
+
+	plist_get_string_val(n2, fwurl);
+
+	n2 = plist_access_path(n1, 2, "Restore", "FirmwareSHA1");
+	if (n2 && plist_get_node_type(n2) == PLIST_STRING) {
+		strval = NULL;
+		plist_get_string_val(n2, &strval);
+		if (strval) {
+			if (strlen(strval) == 40) {
+				int i;
+				int v;
+				for (i = 0; i < 40; i+=2) {
+					v = 0;
+					sscanf(strval+i, "%02x", &v);
+					sha1buf[i/2] = (unsigned char)v;
+				}
+			}
+			free(strval);
+		}
+	}
+
+	return 0;
+}
+
+static int sha1_verify_fp(FILE* f, unsigned char* expected_sha1)
+{
+	unsigned char tsha1[20];
+	char buf[8192];
+	if (!f) return 0;
+	SHA_CTX sha1ctx;
+	SHA1_Init(&sha1ctx);
+	rewind(f);
+	while (!feof(f)) {
+		size_t sz = fread(buf, 1, 8192, f);
+		SHA1_Update(&sha1ctx, (const void*)buf, sz);
+	}
+	SHA1_Final(tsha1, &sha1ctx);
+	return (memcmp(expected_sha1, tsha1, 20) == 0) ? 1 : 0;
+}
+
+int ipsw_download_latest_fw(plist_t version_data, const char* product, const char* todir, char** ipswfile)
+{
+	char* fwurl = NULL;
+	unsigned char isha1[20];
+
+	*ipswfile = NULL;
+
+	if ((get_latest_fw(version_data, product, &fwurl, isha1) < 0) || !fwurl) {
+		error("ERROR: can't get URL for latest firmware\n");
+		return -1;
+	}
+	char* fwfn = strrchr(fwurl, '/');
+	if (!fwfn) {
+		error("ERROR: can't get local filename for firmware ipsw\n");
+		return -1;
+	}
+	fwfn++;
+
+	info("Latest firmware is %s\n", fwfn);
+
+	char fwlfn[256];
+	sprintf(fwlfn, "%s/%s", todir, fwfn);
+
+	int need_dl = 0;
+	unsigned char zsha1[20] = {0, };
+	FILE* f = fopen(fwlfn, "rb");
+	if (f) {
+		if (memcmp(zsha1, isha1, 20) != 0) {
+			info("Verifying '%s'...\n", fwlfn);
+			if (sha1_verify_fp(f, isha1)) {
+				info("Checksum matches.\n");
+			} else {
+				info("Checksum does not match.\n");
+				need_dl = 1;
+			}
+		}
+		fclose(f);
+	} else {
+		need_dl = 1;
+	}
+
+	int res = 0;
+	if (need_dl) {
+		if (strncmp(fwurl, "protected:", 10) == 0) {
+			error("ERROR: Can't download '%s' because it needs a purchase.\n", fwfn);
+			res = -1;
+		} else {
+			remove(fwlfn);
+			info("Downloading latest firmware (%s)\n", fwurl);
+			download_to_file(fwurl, fwlfn);
+			if (memcmp(isha1, zsha1, 20) != 0) {
+				info("\nVerifying '%s'...\n", fwlfn);
+				FILE* f = fopen(fwlfn, "rb");
+				if (f) {
+					if (sha1_verify_fp(f, isha1)) {
+						info("Checksum matches.\n");
+					} else {
+						error("ERROR: File download failed (checksum mismatch).\n");
+						res = -1;
+					}
+					fclose(f);
+				} else {
+					error("ERROR: Can't open '%s' for checksum verification\n", fwlfn);
+					res = -1;
+				}
+			}
+		}
+	}
+	free(fwurl);
+	if (res == 0) {
+		*ipswfile = strdup(fwlfn);
+	}
+	return res;
+}