From 75bf041a8ad75f8fc9bba69e937e12b129338a4c Mon Sep 17 00:00:00 2001 From: Ethan Yonker Date: Fri, 21 Nov 2014 13:54:27 -0600 Subject: Make the android-5.0 branch compile in 4.4 to 4.1 Migrate previous minzip to minzipold replacing the existing minzipold. This will break compatibility with trees that do not support selinux (ICS and older). Migrate former verifier files to verifierold. Add fuse.h to recovery source because older trees do not have it. Add LOCAL_MODULE_TAGS where needed for 4.1 tree. Change-Id: Iade57cb2b0115af7fce9f56aa98636b1744a1ef4 --- verifierold.cpp | 344 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 344 insertions(+) create mode 100644 verifierold.cpp (limited to 'verifierold.cpp') diff --git a/verifierold.cpp b/verifierold.cpp new file mode 100644 index 000000000..4387ab5a4 --- /dev/null +++ b/verifierold.cpp @@ -0,0 +1,344 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "common.h" +#include "verifierold.h" +#include "ui.h" + +#include "mincrypt/rsa.h" +#include "mincrypt/sha.h" +#include "mincrypt/sha256.h" + +#include +#include +#include + +//extern RecoveryUI* ui; + +#define PUBLIC_KEYS_FILE "/res/keys" + +// Look for an RSA signature embedded in the .ZIP file comment given +// the path to the zip. Verify it matches one of the given public +// keys. +// +// Return VERIFY_SUCCESS, VERIFY_FAILURE (if any error is encountered +// or no key matches the signature). +int verify_file(const char* path) { + //ui->SetProgress(0.0); + + int numKeys; + Certificate* pKeys = load_keys(PUBLIC_KEYS_FILE, &numKeys); + if (pKeys == NULL) { + LOGE("Failed to load keys\n"); + return INSTALL_CORRUPT; + } + LOGI("%d key(s) loaded from %s\n", numKeys, PUBLIC_KEYS_FILE); + + FILE* f = fopen(path, "rb"); + if (f == NULL) { + LOGE("failed to open %s (%s)\n", path, strerror(errno)); + return VERIFY_FAILURE; + } + + // An archive with a whole-file signature will end in six bytes: + // + // (2-byte signature start) $ff $ff (2-byte comment size) + // + // (As far as the ZIP format is concerned, these are part of the + // archive comment.) We start by reading this footer, this tells + // us how far back from the end we have to start reading to find + // the whole comment. + +#define FOOTER_SIZE 6 + + if (fseek(f, -FOOTER_SIZE, SEEK_END) != 0) { + LOGE("failed to seek in %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + + unsigned char footer[FOOTER_SIZE]; + if (fread(footer, 1, FOOTER_SIZE, f) != FOOTER_SIZE) { + LOGE("failed to read footer from %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + + if (footer[2] != 0xff || footer[3] != 0xff) { + LOGE("footer is wrong\n"); + fclose(f); + return VERIFY_FAILURE; + } + + size_t comment_size = footer[4] + (footer[5] << 8); + size_t signature_start = footer[0] + (footer[1] << 8); + LOGI("comment is %d bytes; signature %d bytes from end\n", + comment_size, signature_start); + + if (signature_start - FOOTER_SIZE < RSANUMBYTES) { + // "signature" block isn't big enough to contain an RSA block. + LOGE("signature is too short\n"); + fclose(f); + return VERIFY_FAILURE; + } + +#define EOCD_HEADER_SIZE 22 + + // The end-of-central-directory record is 22 bytes plus any + // comment length. + size_t eocd_size = comment_size + EOCD_HEADER_SIZE; + + if (fseek(f, -eocd_size, SEEK_END) != 0) { + LOGE("failed to seek in %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + + // Determine how much of the file is covered by the signature. + // This is everything except the signature data and length, which + // includes all of the EOCD except for the comment length field (2 + // bytes) and the comment data. + size_t signed_len = ftell(f) + EOCD_HEADER_SIZE - 2; + + unsigned char* eocd = (unsigned char*)malloc(eocd_size); + if (eocd == NULL) { + LOGE("malloc for EOCD record failed\n"); + fclose(f); + return VERIFY_FAILURE; + } + if (fread(eocd, 1, eocd_size, f) != eocd_size) { + LOGE("failed to read eocd from %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + + // If this is really is the EOCD record, it will begin with the + // magic number $50 $4b $05 $06. + if (eocd[0] != 0x50 || eocd[1] != 0x4b || + eocd[2] != 0x05 || eocd[3] != 0x06) { + LOGE("signature length doesn't match EOCD marker\n"); + fclose(f); + return VERIFY_FAILURE; + } + + size_t i; + for (i = 4; i < eocd_size-3; ++i) { + if (eocd[i ] == 0x50 && eocd[i+1] == 0x4b && + eocd[i+2] == 0x05 && eocd[i+3] == 0x06) { + // if the sequence $50 $4b $05 $06 appears anywhere after + // the real one, minzip will find the later (wrong) one, + // which could be exploitable. Fail verification if + // this sequence occurs anywhere after the real one. + LOGE("EOCD marker occurs after start of EOCD\n"); + fclose(f); + return VERIFY_FAILURE; + } + } + +#define BUFFER_SIZE 4096 + + bool need_sha1 = false; + bool need_sha256 = false; + for (i = 0; i < numKeys; ++i) { + switch (pKeys[i].hash_len) { + case SHA_DIGEST_SIZE: need_sha1 = true; break; + case SHA256_DIGEST_SIZE: need_sha256 = true; break; + } + } + + SHA_CTX sha1_ctx; + SHA256_CTX sha256_ctx; + SHA_init(&sha1_ctx); + SHA256_init(&sha256_ctx); + unsigned char* buffer = (unsigned char*)malloc(BUFFER_SIZE); + if (buffer == NULL) { + LOGE("failed to alloc memory for sha1 buffer\n"); + fclose(f); + return VERIFY_FAILURE; + } + + double frac = -1.0; + size_t so_far = 0; + fseek(f, 0, SEEK_SET); + while (so_far < signed_len) { + size_t size = BUFFER_SIZE; + if (signed_len - so_far < size) size = signed_len - so_far; + if (fread(buffer, 1, size, f) != size) { + LOGE("failed to read data from %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + if (need_sha1) SHA_update(&sha1_ctx, buffer, size); + if (need_sha256) SHA256_update(&sha256_ctx, buffer, size); + so_far += size; + double f = so_far / (double)signed_len; + if (f > frac + 0.02 || size == so_far) { + //ui->SetProgress(f); + frac = f; + } + } + fclose(f); + free(buffer); + + const uint8_t* sha1 = SHA_final(&sha1_ctx); + const uint8_t* sha256 = SHA256_final(&sha256_ctx); + + for (i = 0; i < numKeys; ++i) { + const uint8_t* hash; + switch (pKeys[i].hash_len) { + case SHA_DIGEST_SIZE: hash = sha1; break; + case SHA256_DIGEST_SIZE: hash = sha256; break; + default: continue; + } + + // The 6 bytes is the "(signature_start) $ff $ff (comment_size)" that + // the signing tool appends after the signature itself. + if (RSA_verify(pKeys[i].public_key, eocd + eocd_size - 6 - RSANUMBYTES, + RSANUMBYTES, hash, pKeys[i].hash_len)) { + LOGI("whole-file signature verified against key %d\n", i); + free(eocd); + return VERIFY_SUCCESS; + } else { + LOGI("failed to verify against key %d\n", i); + } + LOGI("i: %i, eocd_size: %i, RSANUMBYTES: %i\n", i, eocd_size, RSANUMBYTES); + } + free(eocd); + LOGE("failed to verify whole-file signature\n"); + return VERIFY_FAILURE; +} + +// Reads a file containing one or more public keys as produced by +// DumpPublicKey: this is an RSAPublicKey struct as it would appear +// as a C source literal, eg: +// +// "{64,0xc926ad21,{1795090719,...,-695002876},{-857949815,...,1175080310}}" +// +// For key versions newer than the original 2048-bit e=3 keys +// supported by Android, the string is preceded by a version +// identifier, eg: +// +// "v2 {64,0xc926ad21,{1795090719,...,-695002876},{-857949815,...,1175080310}}" +// +// (Note that the braces and commas in this example are actual +// characters the parser expects to find in the file; the ellipses +// indicate more numbers omitted from this example.) +// +// The file may contain multiple keys in this format, separated by +// commas. The last key must not be followed by a comma. +// +// A Certificate is a pair of an RSAPublicKey and a particular hash +// (we support SHA-1 and SHA-256; we store the hash length to signify +// which is being used). The hash used is implied by the version number. +// +// 1: 2048-bit RSA key with e=3 and SHA-1 hash +// 2: 2048-bit RSA key with e=65537 and SHA-1 hash +// 3: 2048-bit RSA key with e=3 and SHA-256 hash +// 4: 2048-bit RSA key with e=65537 and SHA-256 hash +// +// Returns NULL if the file failed to parse, or if it contain zero keys. +Certificate* +load_keys(const char* filename, int* numKeys) { + Certificate* out = NULL; + *numKeys = 0; + + FILE* f = fopen(filename, "r"); + if (f == NULL) { + LOGE("opening %s: %s\n", filename, strerror(errno)); + goto exit; + } + + { + int i; + bool done = false; + while (!done) { + ++*numKeys; + out = (Certificate*)realloc(out, *numKeys * sizeof(Certificate)); + Certificate* cert = out + (*numKeys - 1); + cert->public_key = (RSAPublicKey*)malloc(sizeof(RSAPublicKey)); + + char start_char; + if (fscanf(f, " %c", &start_char) != 1) goto exit; + if (start_char == '{') { + // a version 1 key has no version specifier. + cert->public_key->exponent = 3; + cert->hash_len = SHA_DIGEST_SIZE; + } else if (start_char == 'v') { + int version; + if (fscanf(f, "%d {", &version) != 1) goto exit; + switch (version) { + case 2: + cert->public_key->exponent = 65537; + cert->hash_len = SHA_DIGEST_SIZE; + break; + case 3: + cert->public_key->exponent = 3; + cert->hash_len = SHA256_DIGEST_SIZE; + break; + case 4: + cert->public_key->exponent = 65537; + cert->hash_len = SHA256_DIGEST_SIZE; + break; + default: + goto exit; + } + } + + RSAPublicKey* key = cert->public_key; + if (fscanf(f, " %i , 0x%x , { %u", + &(key->len), &(key->n0inv), &(key->n[0])) != 3) { + goto exit; + } + if (key->len != RSANUMWORDS) { + LOGE("key length (%d) does not match expected size\n", key->len); + goto exit; + } + for (i = 1; i < key->len; ++i) { + if (fscanf(f, " , %u", &(key->n[i])) != 1) goto exit; + } + if (fscanf(f, " } , { %u", &(key->rr[0])) != 1) goto exit; + for (i = 1; i < key->len; ++i) { + if (fscanf(f, " , %u", &(key->rr[i])) != 1) goto exit; + } + fscanf(f, " } } "); + + // if the line ends in a comma, this file has more keys. + switch (fgetc(f)) { + case ',': + // more keys to come. + break; + + case EOF: + done = true; + break; + + default: + LOGE("unexpected character between keys\n"); + goto exit; + } + LOGI("read key e=%d hash=%d\n", key->exponent, cert->hash_len); + } + } + + fclose(f); + return out; + +exit: + if (f) fclose(f); + free(out); + *numKeys = 0; + return NULL; +} -- cgit v1.2.3