| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Permission is hereby granted, free of charge, to any person |
| * obtaining a copy of this software and associated documentation |
| * files (the "Software"), to deal in the Software without |
| * restriction, including without limitation the rights to use, copy, |
| * modify, merge, publish, distribute, sublicense, and/or sell copies |
| * of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be |
| * included in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
| * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
| * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
| * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| * SOFTWARE. |
| */ |
| |
| #if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) |
| #error "Never include this file directly, include libavb.h instead." |
| #endif |
| |
| #ifndef AVB_CRYPTO_H_ |
| #define AVB_CRYPTO_H_ |
| |
| #include "avb_sysdeps.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /* Size of a RSA-2048 signature. */ |
| #define AVB_RSA2048_NUM_BYTES 256 |
| |
| /* Size of a RSA-4096 signature. */ |
| #define AVB_RSA4096_NUM_BYTES 512 |
| |
| /* Size of a RSA-8192 signature. */ |
| #define AVB_RSA8192_NUM_BYTES 1024 |
| |
| /* Size in bytes of a SHA-256 digest. */ |
| #define AVB_SHA256_DIGEST_SIZE 32 |
| |
| /* Size in bytes of a SHA-512 digest. */ |
| #define AVB_SHA512_DIGEST_SIZE 64 |
| |
| /* Algorithms that can be used in the vbmeta image for |
| * verification. An algorithm consists of a hash type and a signature |
| * type. |
| * |
| * The data used to calculate the hash is the three blocks mentioned |
| * in the documentation for |AvbVBMetaImageHeader| except for the data |
| * in the "Authentication data" block. |
| * |
| * For signatures with RSA keys, PKCS v1.5 padding is used. The public |
| * key data is stored in the auxiliary data block, see |
| * |AvbRSAPublicKeyHeader| for the serialization format. |
| * |
| * Each algorithm type is described below: |
| * |
| * AVB_ALGORITHM_TYPE_NONE: There is no hash, no signature of the |
| * data, and no public key. The data cannot be verified. The fields |
| * |hash_size|, |signature_size|, and |public_key_size| must be zero. |
| * |
| * AVB_ALGORITHM_TYPE_SHA256_RSA2048: The hash function used is |
| * SHA-256, resulting in 32 bytes of hash digest data. This hash is |
| * signed with a 2048-bit RSA key. The field |hash_size| must be 32, |
| * |signature_size| must be 256, and the public key data must have |
| * |key_num_bits| set to 2048. |
| * |
| * AVB_ALGORITHM_TYPE_SHA256_RSA4096: Like above, but only with |
| * a 4096-bit RSA key and |signature_size| set to 512. |
| * |
| * AVB_ALGORITHM_TYPE_SHA256_RSA8192: Like above, but only with |
| * a 8192-bit RSA key and |signature_size| set to 1024. |
| * |
| * AVB_ALGORITHM_TYPE_SHA512_RSA2048: The hash function used is |
| * SHA-512, resulting in 64 bytes of hash digest data. This hash is |
| * signed with a 2048-bit RSA key. The field |hash_size| must be 64, |
| * |signature_size| must be 256, and the public key data must have |
| * |key_num_bits| set to 2048. |
| * |
| * AVB_ALGORITHM_TYPE_SHA512_RSA4096: Like above, but only with |
| * a 4096-bit RSA key and |signature_size| set to 512. |
| * |
| * AVB_ALGORITHM_TYPE_SHA512_RSA8192: Like above, but only with |
| * a 8192-bit RSA key and |signature_size| set to 1024. |
| */ |
| typedef enum { |
| AVB_ALGORITHM_TYPE_NONE, |
| AVB_ALGORITHM_TYPE_SHA256_RSA2048, |
| AVB_ALGORITHM_TYPE_SHA256_RSA4096, |
| AVB_ALGORITHM_TYPE_SHA256_RSA8192, |
| AVB_ALGORITHM_TYPE_SHA512_RSA2048, |
| AVB_ALGORITHM_TYPE_SHA512_RSA4096, |
| AVB_ALGORITHM_TYPE_SHA512_RSA8192, |
| _AVB_ALGORITHM_NUM_TYPES |
| } AvbAlgorithmType; |
| |
| /* Holds algorithm-specific data. The |padding| is needed by avb_rsa_verify. */ |
| typedef struct { |
| const uint8_t* padding; |
| size_t padding_len; |
| size_t hash_len; |
| } AvbAlgorithmData; |
| |
| /* Provides algorithm-specific data for a given |algorithm|. Returns NULL if |
| * |algorithm| is invalid. |
| */ |
| const AvbAlgorithmData* avb_get_algorithm_data(AvbAlgorithmType algorithm) |
| AVB_ATTR_WARN_UNUSED_RESULT; |
| |
| /* The header for a serialized RSA public key. |
| * |
| * The size of the key is given by |key_num_bits|, for example 2048 |
| * for a RSA-2048 key. By definition, a RSA public key is the pair (n, |
| * e) where |n| is the modulus (which can be represented in |
| * |key_num_bits| bits) and |e| is the public exponent. The exponent |
| * is not stored since it's assumed to always be 65537. |
| * |
| * To optimize verification, the key block includes two precomputed |
| * values, |n0inv| (fits in 32 bits) and |rr| and can always be |
| * represented in |key_num_bits|. |
| |
| * The value |n0inv| is the value -1/n[0] (mod 2^32). The value |rr| |
| * is (2^key_num_bits)^2 (mod n). |
| * |
| * Following this header is |key_num_bits| bits of |n|, then |
| * |key_num_bits| bits of |rr|. Both values are stored with most |
| * significant bit first. Each serialized number takes up |
| * |key_num_bits|/8 bytes. |
| * |
| * All fields in this struct are stored in network byte order when |
| * serialized. To generate a copy with fields swapped to native byte |
| * order, use the function avb_rsa_public_key_header_validate_and_byteswap(). |
| * |
| * The avb_rsa_verify() function expects a key in this serialized |
| * format. |
| * |
| * The 'avbtool extract_public_key' command can be used to generate a |
| * serialized RSA public key. |
| */ |
| typedef struct AvbRSAPublicKeyHeader { |
| uint32_t key_num_bits; |
| uint32_t n0inv; |
| } AVB_ATTR_PACKED AvbRSAPublicKeyHeader; |
| |
| /* Copies |src| to |dest| and validates, byte-swapping fields in the |
| * process if needed. Returns true if valid, false if invalid. |
| */ |
| bool avb_rsa_public_key_header_validate_and_byteswap( |
| const AvbRSAPublicKeyHeader* src, |
| AvbRSAPublicKeyHeader* dest) AVB_ATTR_WARN_UNUSED_RESULT; |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* AVB_CRYPTO_H_ */ |