Botan 3.7.1
Crypto and TLS for C&
Botan::EMSA Class Referenceabstract

#include <emsa.h>

Inheritance diagram for Botan::EMSA:
Botan::EMSA_PKCS1v15 Botan::EMSA_PKCS1v15_Raw Botan::EMSA_Raw Botan::EMSA_X931 Botan::ISO_9796_DS2 Botan::ISO_9796_DS3 Botan::PSSR Botan::PSSR_Raw

Public Member Functions

virtual std::vector< uint8_t > encoding_of (const std::vector< uint8_t > &msg, size_t output_bits, RandomNumberGenerator &rng)=0
 
virtual std::string hash_function () const =0
 
virtual std::string name () const =0
 
virtual std::vector< uint8_t > raw_data ()=0
 
virtual void update (const uint8_t input[], size_t length)=0
 
virtual bool verify (const std::vector< uint8_t > &coded, const std::vector< uint8_t > &raw, size_t key_bits)=0
 
virtual ~EMSA ()=default
 

Static Public Member Functions

static std::unique_ptr< EMSAcreate (std::string_view algo_spec)
 
static std::unique_ptr< EMSAcreate_or_throw (std::string_view algo_spec)
 

Detailed Description

EMSA, from IEEE 1363s Encoding Method for Signatures, Appendix

Any way of encoding/padding signatures

Definition at line 23 of file emsa.h.

Constructor & Destructor Documentation

◆ ~EMSA()

virtual Botan::EMSA::~EMSA ( )
virtualdefault

Member Function Documentation

◆ create()

std::unique_ptr< EMSA > Botan::EMSA::create ( std::string_view algo_spec)
static

Factory method for EMSA (message-encoding methods for signatures with appendix) objects

Parameters
algo_specthe name of the EMSA to create
Returns
pointer to newly allocated object of that type, or nullptr

Definition at line 35 of file emsa.cpp.

35 {
36 SCAN_Name req(algo_spec);
37
38#if defined(BOTAN_HAS_EMSA_PKCS1)
39 // TODO(Botan4) Remove all but "PKCS1v15"
40 if(req.algo_name() == "EMSA_PKCS1" || req.algo_name() == "PKCS1v15" || req.algo_name() == "EMSA-PKCS1-v1_5" ||
41 req.algo_name() == "EMSA3") {
42 if(req.arg_count() == 2 && req.arg(0) == "Raw") {
43 return std::make_unique<EMSA_PKCS1v15_Raw>(req.arg(1));
44 } else if(req.arg_count() == 1) {
45 if(req.arg(0) == "Raw") {
46 return std::make_unique<EMSA_PKCS1v15_Raw>();
47 } else {
48 if(auto hash = HashFunction::create(req.arg(0))) {
49 return std::make_unique<EMSA_PKCS1v15>(std::move(hash));
50 }
51 }
52 }
53 }
54#endif
55
56#if defined(BOTAN_HAS_EMSA_PSSR)
57 // TODO(Botan4) Remove all but "PSS_Raw"
58 if(req.algo_name() == "PSS_Raw" || req.algo_name() == "PSSR_Raw") {
59 if(req.arg_count_between(1, 3) && req.arg(1, "MGF1") == "MGF1") {
60 if(auto hash = HashFunction::create(req.arg(0))) {
61 if(req.arg_count() == 3) {
62 const size_t salt_size = req.arg_as_integer(2, 0);
63 return std::make_unique<PSSR_Raw>(std::move(hash), salt_size);
64 } else {
65 return std::make_unique<PSSR_Raw>(std::move(hash));
66 }
67 }
68 }
69 }
70
71 // TODO(Botan4) Remove all but "PSS"
72 if(req.algo_name() == "PSS" || req.algo_name() == "PSSR" || req.algo_name() == "EMSA-PSS" ||
73 req.algo_name() == "PSS-MGF1" || req.algo_name() == "EMSA4") {
74 if(req.arg_count_between(1, 3) && req.arg(1, "MGF1") == "MGF1") {
75 if(auto hash = HashFunction::create(req.arg(0))) {
76 if(req.arg_count() == 3) {
77 const size_t salt_size = req.arg_as_integer(2, 0);
78 return std::make_unique<PSSR>(std::move(hash), salt_size);
79 } else {
80 return std::make_unique<PSSR>(std::move(hash));
81 }
82 }
83 }
84 }
85#endif
86
87#if defined(BOTAN_HAS_ISO_9796)
88 if(req.algo_name() == "ISO_9796_DS2") {
89 if(req.arg_count_between(1, 3)) {
90 if(auto hash = HashFunction::create(req.arg(0))) {
91 const size_t salt_size = req.arg_as_integer(2, hash->output_length());
92 const bool implicit = req.arg(1, "exp") == "imp";
93 return std::make_unique<ISO_9796_DS2>(std::move(hash), implicit, salt_size);
94 }
95 }
96 }
97 //ISO-9796-2 DS 3 is deterministic and DS2 without a salt
98 if(req.algo_name() == "ISO_9796_DS3") {
99 if(req.arg_count_between(1, 2)) {
100 if(auto hash = HashFunction::create(req.arg(0))) {
101 const bool implicit = req.arg(1, "exp") == "imp";
102 return std::make_unique<ISO_9796_DS3>(std::move(hash), implicit);
103 }
104 }
105 }
106#endif
107
108#if defined(BOTAN_HAS_EMSA_X931)
109 // TODO(Botan4) Remove all but "X9.31"
110 if(req.algo_name() == "EMSA_X931" || req.algo_name() == "EMSA2" || req.algo_name() == "X9.31") {
111 if(req.arg_count() == 1) {
112 if(auto hash = HashFunction::create(req.arg(0))) {
113 return std::make_unique<EMSA_X931>(std::move(hash));
114 }
115 }
116 }
117#endif
118
119#if defined(BOTAN_HAS_EMSA_RAW)
120 if(req.algo_name() == "Raw") {
121 if(req.arg_count() == 0) {
122 return std::make_unique<EMSA_Raw>();
123 } else {
124 auto hash = HashFunction::create(req.arg(0));
125 if(hash) {
126 return std::make_unique<EMSA_Raw>(hash->output_length());
127 }
128 }
129 }
130#endif
131
132 return nullptr;
133}
static std::unique_ptr< HashFunction > create(std::string_view algo_spec, std::string_view provider="")
Definition hash.cpp:107

References Botan::SCAN_Name::algo_name(), Botan::SCAN_Name::arg(), Botan::SCAN_Name::arg_as_integer(), Botan::SCAN_Name::arg_count(), Botan::SCAN_Name::arg_count_between(), and Botan::HashFunction::create().

Referenced by create_or_throw().

◆ create_or_throw()

std::unique_ptr< EMSA > Botan::EMSA::create_or_throw ( std::string_view algo_spec)
static

Factory method for EMSA (message-encoding methods for signatures with appendix) objects

Parameters
algo_specthe name of the EMSA to create
Returns
pointer to newly allocated object of that type, or throws

Definition at line 135 of file emsa.cpp.

135 {
136 auto emsa = EMSA::create(algo_spec);
137 if(emsa) {
138 return emsa;
139 }
140 throw Algorithm_Not_Found(algo_spec);
141}
static std::unique_ptr< EMSA > create(std::string_view algo_spec)
Definition emsa.cpp:35

References create().

◆ encoding_of()

virtual std::vector< uint8_t > Botan::EMSA::encoding_of ( const std::vector< uint8_t > & msg,
size_t output_bits,
RandomNumberGenerator & rng )
pure virtual

Return the encoding of a message

Parameters
msgthe result of raw_data()
output_bitsthe desired output bit size
rnga random number generator
Returns
encoded signature

Implemented in Botan::EMSA_PKCS1v15, and Botan::EMSA_PKCS1v15_Raw.

◆ hash_function()

virtual std::string Botan::EMSA::hash_function ( ) const
pure virtual

Return the hash function being used by this padding scheme

Implemented in Botan::EMSA_PKCS1v15, Botan::EMSA_PKCS1v15_Raw, Botan::EMSA_Raw, Botan::EMSA_X931, Botan::ISO_9796_DS2, Botan::ISO_9796_DS3, Botan::PSSR, and Botan::PSSR_Raw.

◆ name()

virtual std::string Botan::EMSA::name ( ) const
pure virtual

◆ raw_data()

virtual std::vector< uint8_t > Botan::EMSA::raw_data ( )
pure virtual
Returns
raw hash

Implemented in Botan::EMSA_PKCS1v15, and Botan::EMSA_PKCS1v15_Raw.

◆ update()

virtual void Botan::EMSA::update ( const uint8_t input[],
size_t length )
pure virtual

Add more data to the signature computation

Parameters
inputsome data
lengthlength of input in bytes

Implemented in Botan::EMSA_PKCS1v15, and Botan::EMSA_PKCS1v15_Raw.

◆ verify()

virtual bool Botan::EMSA::verify ( const std::vector< uint8_t > & coded,
const std::vector< uint8_t > & raw,
size_t key_bits )
pure virtual

Verify the encoding

Parameters
codedthe received (coded) message representative
rawthe computed (local, uncoded) message representative
key_bitsthe size of the key in bits
Returns
true if coded is a valid encoding of raw, otherwise false

Implemented in Botan::EMSA_PKCS1v15, and Botan::EMSA_PKCS1v15_Raw.


The documentation for this class was generated from the following files: