diff options
Diffstat (limited to 'verifierold.cpp')
-rw-r--r-- | verifierold.cpp | 344 |
1 files changed, 0 insertions, 344 deletions
diff --git a/verifierold.cpp b/verifierold.cpp deleted file mode 100644 index 4387ab5a4..000000000 --- a/verifierold.cpp +++ /dev/null @@ -1,344 +0,0 @@ -/* - * 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 <string.h> -#include <stdio.h> -#include <errno.h> - -//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; -} |