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author | Ethan Yonker <dees_troy@teamw.in> | 2016-08-29 18:50:34 +0200 |
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committer | Ethan Yonker <dees_troy@teamw.in> | 2016-08-29 18:50:34 +0200 |
commit | 4bf259fab7214331920f3bde864a8e508831f299 (patch) | |
tree | 4c567746de62e80ef874677e4cb56fa406652621 /oldverifier | |
parent | Support update binary log command (diff) | |
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Diffstat (limited to 'oldverifier')
-rw-r--r-- | oldverifier/verifier.cpp | 471 | ||||
-rw-r--r-- | oldverifier/verifier.h | 58 |
2 files changed, 0 insertions, 529 deletions
diff --git a/oldverifier/verifier.cpp b/oldverifier/verifier.cpp deleted file mode 100644 index 98c733732..000000000 --- a/oldverifier/verifier.cpp +++ /dev/null @@ -1,471 +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 "asn1_decoder.h" -#include "common.h" -#include "ui.h" -#include "verifier.h" - -#include "mincrypt/dsa_sig.h" -#include "mincrypt/p256.h" -#include "mincrypt/p256_ecdsa.h" -#include "mincrypt/rsa.h" -#include "mincrypt/sha.h" -#include "mincrypt/sha256.h" - -#include <errno.h> -#include <malloc.h> -#include <stdio.h> -#include <string.h> - -//extern RecoveryUI* ui; - -#define PUBLIC_KEYS_FILE "/res/keys" - -/* - * Simple version of PKCS#7 SignedData extraction. This extracts the - * signature OCTET STRING to be used for signature verification. - * - * For full details, see http://www.ietf.org/rfc/rfc3852.txt - * - * The PKCS#7 structure looks like: - * - * SEQUENCE (ContentInfo) - * OID (ContentType) - * [0] (content) - * SEQUENCE (SignedData) - * INTEGER (version CMSVersion) - * SET (DigestAlgorithmIdentifiers) - * SEQUENCE (EncapsulatedContentInfo) - * [0] (CertificateSet OPTIONAL) - * [1] (RevocationInfoChoices OPTIONAL) - * SET (SignerInfos) - * SEQUENCE (SignerInfo) - * INTEGER (CMSVersion) - * SEQUENCE (SignerIdentifier) - * SEQUENCE (DigestAlgorithmIdentifier) - * SEQUENCE (SignatureAlgorithmIdentifier) - * OCTET STRING (SignatureValue) - */ -static bool read_pkcs7(uint8_t* pkcs7_der, size_t pkcs7_der_len, uint8_t** sig_der, - size_t* sig_der_length) { - asn1_context_t* ctx = asn1_context_new(pkcs7_der, pkcs7_der_len); - if (ctx == NULL) { - return false; - } - - asn1_context_t* pkcs7_seq = asn1_sequence_get(ctx); - if (pkcs7_seq != NULL && asn1_sequence_next(pkcs7_seq)) { - asn1_context_t *signed_data_app = asn1_constructed_get(pkcs7_seq); - if (signed_data_app != NULL) { - asn1_context_t* signed_data_seq = asn1_sequence_get(signed_data_app); - if (signed_data_seq != NULL - && asn1_sequence_next(signed_data_seq) - && asn1_sequence_next(signed_data_seq) - && asn1_sequence_next(signed_data_seq) - && asn1_constructed_skip_all(signed_data_seq)) { - asn1_context_t *sig_set = asn1_set_get(signed_data_seq); - if (sig_set != NULL) { - asn1_context_t* sig_seq = asn1_sequence_get(sig_set); - if (sig_seq != NULL - && asn1_sequence_next(sig_seq) - && asn1_sequence_next(sig_seq) - && asn1_sequence_next(sig_seq) - && asn1_sequence_next(sig_seq)) { - uint8_t* sig_der_ptr; - if (asn1_octet_string_get(sig_seq, &sig_der_ptr, sig_der_length)) { - *sig_der = (uint8_t*) malloc(*sig_der_length); - if (*sig_der != NULL) { - memcpy(*sig_der, sig_der_ptr, *sig_der_length); - } - } - asn1_context_free(sig_seq); - } - asn1_context_free(sig_set); - } - asn1_context_free(signed_data_seq); - } - asn1_context_free(signed_data_app); - } - asn1_context_free(pkcs7_seq); - } - asn1_context_free(ctx); - - return *sig_der != NULL; -} - -// 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(unsigned char* addr, size_t length) { - //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); - - // 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 (length < FOOTER_SIZE) { - LOGE("not big enough to contain footer\n"); - return VERIFY_FAILURE; - } - - unsigned char* footer = addr + length - FOOTER_SIZE; - - if (footer[2] != 0xff || footer[3] != 0xff) { - LOGE("footer is wrong\n"); - return VERIFY_FAILURE; - } - - size_t comment_size = footer[4] + (footer[5] << 8); - size_t signature_start = footer[0] + (footer[1] << 8); - LOGI("comment is %zu bytes; signature %zu bytes from end\n", - comment_size, signature_start); - - if (signature_start <= FOOTER_SIZE) { - LOGE("Signature start is in the footer"); - 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 (length < eocd_size) { - LOGE("not big enough to contain EOCD\n"); - 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 = length - eocd_size + EOCD_HEADER_SIZE - 2; - - unsigned char* eocd = addr + length - eocd_size; - - // 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"); - 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"); - 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); - - double frac = -1.0; - size_t so_far = 0; - while (so_far < signed_len) { - size_t size = signed_len - so_far; - if (size > BUFFER_SIZE) size = BUFFER_SIZE; - - if (need_sha1) SHA_update(&sha1_ctx, addr + so_far, size); - if (need_sha256) SHA256_update(&sha256_ctx, addr + so_far, size); - so_far += size; - - double f = so_far / (double)signed_len; - if (f > frac + 0.02 || size == so_far) { - //ui->SetProgress(f); - frac = f; - } - } - - const uint8_t* sha1 = SHA_final(&sha1_ctx); - const uint8_t* sha256 = SHA256_final(&sha256_ctx); - - uint8_t* sig_der = NULL; - size_t sig_der_length = 0; - - size_t signature_size = signature_start - FOOTER_SIZE; - if (!read_pkcs7(eocd + eocd_size - signature_start, signature_size, &sig_der, - &sig_der_length)) { - LOGE("Could not find signature DER block\n"); - return VERIFY_FAILURE; - } - - /* - * Check to make sure at least one of the keys matches the signature. Since - * any key can match, we need to try each before determining a verification - * failure has happened. - */ - 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 (pKeys[i].key_type == Certificate::RSA) { - if (sig_der_length < RSANUMBYTES) { - // "signature" block isn't big enough to contain an RSA block. - LOGI("signature is too short for RSA key %zu\n", i); - continue; - } - - if (!RSA_verify(pKeys[i].rsa, sig_der, RSANUMBYTES, - hash, pKeys[i].hash_len)) { - LOGI("failed to verify against RSA key %zu\n", i); - continue; - } - - LOGI("whole-file signature verified against RSA key %zu\n", i); - free(sig_der); - return VERIFY_SUCCESS; - } else if (pKeys[i].key_type == Certificate::EC - && pKeys[i].hash_len == SHA256_DIGEST_SIZE) { - p256_int r, s; - if (!dsa_sig_unpack(sig_der, sig_der_length, &r, &s)) { - LOGI("Not a DSA signature block for EC key %zu\n", i); - continue; - } - - p256_int p256_hash; - p256_from_bin(hash, &p256_hash); - if (!p256_ecdsa_verify(&(pKeys[i].ec->x), &(pKeys[i].ec->y), - &p256_hash, &r, &s)) { - LOGI("failed to verify against EC key %zu\n", i); - continue; - } - - LOGI("whole-file signature verified against EC key %zu\n", i); - free(sig_der); - return VERIFY_SUCCESS; - } else { - LOGI("Unknown key type %d\n", pKeys[i].key_type); - } - LOGI("i: %i, eocd_size: %i, RSANUMBYTES: %i\n", i, eocd_size, RSANUMBYTES); - } - free(sig_der); - 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 -// 5: 256-bit EC key using the NIST P-256 curve parameters 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); - memset(cert, '\0', sizeof(Certificate)); - - char start_char; - if (fscanf(f, " %c", &start_char) != 1) goto exit; - if (start_char == '{') { - // a version 1 key has no version specifier. - cert->key_type = Certificate::RSA; - cert->rsa = (RSAPublicKey*)malloc(sizeof(RSAPublicKey)); - cert->rsa->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->key_type = Certificate::RSA; - cert->rsa = (RSAPublicKey*)malloc(sizeof(RSAPublicKey)); - cert->rsa->exponent = 65537; - cert->hash_len = SHA_DIGEST_SIZE; - break; - case 3: - cert->key_type = Certificate::RSA; - cert->rsa = (RSAPublicKey*)malloc(sizeof(RSAPublicKey)); - cert->rsa->exponent = 3; - cert->hash_len = SHA256_DIGEST_SIZE; - break; - case 4: - cert->key_type = Certificate::RSA; - cert->rsa = (RSAPublicKey*)malloc(sizeof(RSAPublicKey)); - cert->rsa->exponent = 65537; - cert->hash_len = SHA256_DIGEST_SIZE; - break; - case 5: - cert->key_type = Certificate::EC; - cert->ec = (ECPublicKey*)calloc(1, sizeof(ECPublicKey)); - cert->hash_len = SHA256_DIGEST_SIZE; - break; - default: - goto exit; - } - } - - if (cert->key_type == Certificate::RSA) { - RSAPublicKey* key = cert->rsa; - 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, " } } "); - - LOGI("read key e=%d hash=%d\n", key->exponent, cert->hash_len); - } else if (cert->key_type == Certificate::EC) { - ECPublicKey* key = cert->ec; - int key_len; - unsigned int byte; - uint8_t x_bytes[P256_NBYTES]; - uint8_t y_bytes[P256_NBYTES]; - if (fscanf(f, " %i , { %u", &key_len, &byte) != 2) goto exit; - if (key_len != P256_NBYTES) { - LOGE("Key length (%d) does not match expected size %d\n", key_len, P256_NBYTES); - goto exit; - } - x_bytes[P256_NBYTES - 1] = byte; - for (i = P256_NBYTES - 2; i >= 0; --i) { - if (fscanf(f, " , %u", &byte) != 1) goto exit; - x_bytes[i] = byte; - } - if (fscanf(f, " } , { %u", &byte) != 1) goto exit; - y_bytes[P256_NBYTES - 1] = byte; - for (i = P256_NBYTES - 2; i >= 0; --i) { - if (fscanf(f, " , %u", &byte) != 1) goto exit; - y_bytes[i] = byte; - } - fscanf(f, " } } "); - p256_from_bin(x_bytes, &key->x); - p256_from_bin(y_bytes, &key->y); - } else { - LOGE("Unknown key type %d\n", cert->key_type); - goto exit; - } - - // 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; - } - } - } - - fclose(f); - return out; - -exit: - if (f) fclose(f); - free(out); - *numKeys = 0; - return NULL; -} diff --git a/oldverifier/verifier.h b/oldverifier/verifier.h deleted file mode 100644 index 17ab257ad..000000000 --- a/oldverifier/verifier.h +++ /dev/null @@ -1,58 +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. - */ - -#ifndef _RECOVERY_VERIFIER_H -#define _RECOVERY_VERIFIER_H - -#include "mincrypt/p256.h" -#include "mincrypt/rsa.h" - -#define ASSUMED_UPDATE_BINARY_NAME "META-INF/com/google/android/update-binary" - -enum { INSTALL_SUCCESS, INSTALL_ERROR, INSTALL_CORRUPT }; - -static const float VERIFICATION_PROGRESS_FRACTION = 0.25; - -typedef struct { - p256_int x; - p256_int y; -} ECPublicKey; - -typedef struct { - typedef enum { - RSA, - EC, - } KeyType; - - int hash_len; // SHA_DIGEST_SIZE (SHA-1) or SHA256_DIGEST_SIZE (SHA-256) - KeyType key_type; - RSAPublicKey* rsa; - ECPublicKey* ec; -} Certificate; - -/* addr and length define a an update package file that has been - * loaded (or mmap'ed, or whatever) into memory. Verify that the file - * is signed and the signature matches one of the given keys. Return - * one of the constants below. - */ -int verify_file(unsigned char* addr, size_t length); - -Certificate* load_keys(const char* filename, int* numKeys); - -#define VERIFY_SUCCESS 0 -#define VERIFY_FAILURE 1 - -#endif /* _RECOVERY_VERIFIER_H */ |