1 /* Copyright (c) 2014 The Chromium OS Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 */ 5 6 #ifndef VBOOT_REFERENCE_2RSA_H_ 7 #define VBOOT_REFERENCE_2RSA_H_ 8 9 #include "2crypto.h" 10 #include "2struct.h" 11 12 struct vb2_workbuf; 13 14 /* Public key structure in RAM */ 15 struct vb2_public_key { 16 uint32_t arrsize; /* Length of n[] and rr[] in number of uint32_t */ 17 uint32_t n0inv; /* -1 / n[0] mod 2^32 */ 18 const uint32_t *n; /* Modulus as little endian array */ 19 const uint32_t *rr; /* R^2 as little endian array */ 20 enum vb2_signature_algorithm sig_alg; /* Signature algorithm */ 21 enum vb2_hash_algorithm hash_alg; /* Hash algorithm */ 22 const char *desc; /* Description */ 23 uint32_t version; /* Key version */ 24 const struct vb2_guid *guid; /* Key GUID */ 25 }; 26 27 /** 28 * Convert vb2_crypto_algorithm to vb2_signature_algorithm. 29 * 30 * @param algorithm Crypto algorithm (vb2_crypto_algorithm) 31 * 32 * @return The signature algorithm for that crypto algorithm, or 33 * VB2_SIG_INVALID if the crypto algorithm or its corresponding signature 34 * algorithm is invalid or not supported. 35 */ 36 enum vb2_signature_algorithm vb2_crypto_to_signature(uint32_t algorithm); 37 38 /** 39 * Return the size of a RSA signature 40 * 41 * @param sig_alg Signature algorithm 42 * @return The size of the signature in bytes, or 0 if error. 43 */ 44 uint32_t vb2_rsa_sig_size(enum vb2_signature_algorithm sig_alg); 45 46 /** 47 * Return the size of a pre-processed RSA public key. 48 * 49 * @param sig_alg Signature algorithm 50 * @return The size of the preprocessed key in bytes, or 0 if error. 51 */ 52 uint32_t vb2_packed_key_size(enum vb2_signature_algorithm sig_alg); 53 54 /** 55 * Check pkcs 1.5 padding bytes 56 * 57 * @param sig Signature to verify 58 * @param key Key to take signature and hash algorithms from 59 * @return VB2_SUCCESS, or non-zero if error. 60 */ 61 int vb2_check_padding(const uint8_t *sig, const struct vb2_public_key *key); 62 63 /* Size of work buffer sufficient for vb2_rsa_verify_digest() worst case */ 64 #define VB2_VERIFY_RSA_DIGEST_WORKBUF_BYTES (3 * 1024) 65 66 /** 67 * Verify a RSA PKCS1.5 signature against an expected hash digest. 68 * 69 * @param key Key to use in signature verification 70 * @param sig Signature to verify (destroyed in process) 71 * @param digest Digest of signed data 72 * @param wb Work buffer 73 * @return VB2_SUCCESS, or non-zero if error. 74 */ 75 int vb2_rsa_verify_digest(const struct vb2_public_key *key, 76 uint8_t *sig, 77 const uint8_t *digest, 78 const struct vb2_workbuf *wb); 79 80 #endif /* VBOOT_REFERENCE_2RSA_H_ */ 81