1 // Copyright (c) 2012 The Chromium 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 #ifndef CRYPTO_SIGNATURE_VERIFIER_H_ 6 #define CRYPTO_SIGNATURE_VERIFIER_H_ 7 8 #include <vector> 9 10 #include "build/build_config.h" 11 #include "base/basictypes.h" 12 #include "crypto/crypto_export.h" 13 14 #if defined(USE_OPENSSL) 15 typedef struct env_md_st EVP_MD; 16 typedef struct evp_pkey_ctx_st EVP_PKEY_CTX; 17 #else 18 typedef struct HASHContextStr HASHContext; 19 typedef struct SECKEYPublicKeyStr SECKEYPublicKey; 20 typedef struct VFYContextStr VFYContext; 21 #endif 22 23 namespace crypto { 24 25 // The SignatureVerifier class verifies a signature using a bare public key 26 // (as opposed to a certificate). 27 class CRYPTO_EXPORT SignatureVerifier { 28 public: 29 // The set of supported hash functions. Extend as required. 30 enum HashAlgorithm { 31 SHA1, 32 SHA256, 33 }; 34 35 SignatureVerifier(); 36 ~SignatureVerifier(); 37 38 // Streaming interface: 39 40 // Initiates a signature verification operation. This should be followed 41 // by one or more VerifyUpdate calls and a VerifyFinal call. 42 // NOTE: for RSA-PSS signatures, use VerifyInitRSAPSS instead. 43 // 44 // The signature algorithm is specified as a DER encoded ASN.1 45 // AlgorithmIdentifier structure: 46 // AlgorithmIdentifier ::= SEQUENCE { 47 // algorithm OBJECT IDENTIFIER, 48 // parameters ANY DEFINED BY algorithm OPTIONAL } 49 // 50 // The signature is encoded according to the signature algorithm, but it 51 // must not be further encoded in an ASN.1 BIT STRING. 52 // Note: An RSA signature is actually a big integer. It must be in 53 // big-endian byte order. 54 // 55 // The public key is specified as a DER encoded ASN.1 SubjectPublicKeyInfo 56 // structure, which contains not only the public key but also its type 57 // (algorithm): 58 // SubjectPublicKeyInfo ::= SEQUENCE { 59 // algorithm AlgorithmIdentifier, 60 // subjectPublicKey BIT STRING } 61 bool VerifyInit(const uint8* signature_algorithm, 62 int signature_algorithm_len, 63 const uint8* signature, 64 int signature_len, 65 const uint8* public_key_info, 66 int public_key_info_len); 67 68 // Initiates a RSA-PSS signature verification operation. This should be 69 // followed by one or more VerifyUpdate calls and a VerifyFinal call. 70 // 71 // The RSA-PSS signature algorithm parameters are specified with the 72 // |hash_alg|, |mask_hash_alg|, and |salt_len| arguments. 73 // 74 // An RSA-PSS signature is a nonnegative integer encoded as a byte string 75 // (of the same length as the RSA modulus) in big-endian byte order. It 76 // must not be further encoded in an ASN.1 BIT STRING. 77 // 78 // The public key is specified as a DER encoded ASN.1 SubjectPublicKeyInfo 79 // structure, which contains not only the public key but also its type 80 // (algorithm): 81 // SubjectPublicKeyInfo ::= SEQUENCE { 82 // algorithm AlgorithmIdentifier, 83 // subjectPublicKey BIT STRING } 84 bool VerifyInitRSAPSS(HashAlgorithm hash_alg, 85 HashAlgorithm mask_hash_alg, 86 int salt_len, 87 const uint8* signature, 88 int signature_len, 89 const uint8* public_key_info, 90 int public_key_info_len); 91 92 // Feeds a piece of the data to the signature verifier. 93 void VerifyUpdate(const uint8* data_part, int data_part_len); 94 95 // Concludes a signature verification operation. Returns true if the 96 // signature is valid. Returns false if the signature is invalid or an 97 // error occurred. 98 bool VerifyFinal(); 99 100 // Note: we can provide a one-shot interface if there is interest: 101 // bool Verify(const uint8* data, 102 // int data_len, 103 // const uint8* signature_algorithm, 104 // int signature_algorithm_len, 105 // const uint8* signature, 106 // int signature_len, 107 // const uint8* public_key_info, 108 // int public_key_info_len); 109 110 private: 111 #if defined(USE_OPENSSL) 112 bool CommonInit(const EVP_MD* digest, 113 const uint8* signature, 114 int signature_len, 115 const uint8* public_key_info, 116 int public_key_info_len, 117 EVP_PKEY_CTX** pkey_ctx); 118 #else 119 static SECKEYPublicKey* DecodePublicKeyInfo(const uint8* public_key_info, 120 int public_key_info_len); 121 #endif 122 123 void Reset(); 124 125 std::vector<uint8> signature_; 126 127 #if defined(USE_OPENSSL) 128 struct VerifyContext; 129 VerifyContext* verify_context_; 130 #else 131 // Used for all signature types except RSA-PSS. 132 VFYContext* vfy_context_; 133 134 // Used for RSA-PSS signatures. 135 HashAlgorithm hash_alg_; 136 HashAlgorithm mask_hash_alg_; 137 unsigned int salt_len_; 138 SECKEYPublicKey* public_key_; 139 HASHContext* hash_context_; 140 #endif 141 }; 142 143 } // namespace crypto 144 145 #endif // CRYPTO_SIGNATURE_VERIFIER_H_ 146
