fc::em::public_key Class Reference

contains only the public point of an elliptic curve key. More...

#include <elliptic_em.hpp>

Public Member Functions
	public_key ()
	public_key (const public_key &k)
	~public_key ()
public_key_data	serialize () const
public_key_point_data	serialize_ecc_point () const
	operator public_key_data () const
	public_key (const public_key_data &v)
	public_key (const public_key_point_data &v)
	public_key (const compact_signature &c, const fc::sha256 &digest, bool check_canonical=true)
	public_key (const compact_signature &c, const unsigned char *digest, bool check_canonical=true)
public_key	child (const fc::sha256 &offset) const
bool	valid () const
	public_key (public_key &&pk)
public_key &	operator= (public_key &&pk)
public_key &	operator= (const public_key &pk)
std::string	to_base58 () const
	Allows to convert current public key object into base58 number.
unsigned int	fingerprint () const

Static Public Member Functions
static std::string	to_base58 (const public_key_data &key)
static public_key	from_base58 (const std::string &b58)

Friends
class	private_key
bool	operator== (const public_key &a, const public_key &b)
bool	operator!= (const public_key &a, const public_key &b)

Detailed Description

Definition at line 37 of file elliptic_em.hpp.

Constructor & Destructor Documentation

public_key() [1/7]

fc::em::public_key::public_key

(

)

Definition at line 83 of file elliptic_em.cpp.

{}

public_key() [2/7]

fc::em::public_key::public_key

(

const public_key &

k

)

Definition at line 85 of file elliptic_em.cpp.

: my( pk.my ) {}

~public_key()

fc::em::public_key::~public_key

(

)

Definition at line 89 of file elliptic_em.cpp.

{}

public_key() [3/7]

fc::em::public_key::public_key

(

const public_key_data &

v

)

Definition at line 136 of file elliptic_em.cpp.

    {
        my->_key = dat;
    }

public_key() [4/7]

fc::em::public_key::public_key

(

const public_key_point_data &

v

)

Definition at line 120 of file elliptic_em.cpp.

    {
        const char* front = &dat.data[0];
        if( *front == 0 ){}
        else
        {
            EC_KEY *key = EC_KEY_new_by_curve_name( NID_secp256k1 );
            key = o2i_ECPublicKey( &key, (const unsigned char**)&front, sizeof(dat) );
            FC_ASSERT( key );
            EC_KEY_set_conv_form( key, POINT_CONVERSION_COMPRESSED );
            unsigned char* buffer = (unsigned char*) my->_key.begin();
            i2o_ECPublicKey( key, &buffer ); // FIXME: questionable memory handling
            EC_KEY_free( key );
        }
    }

public_key() [5/7]

fc::em::public_key::public_key	(	const compact_signature &	c,
		const fc::sha256 &	digest,
		bool	check_canonical = true )

Definition at line 141 of file elliptic_em.cpp.

    {
        int nV = c.data[0];
        if (nV<27 || nV>=35)
            FC_THROW_EXCEPTION( exception, "unable to reconstruct public key from signature" );
 
        if( check_canonical )
        {
            FC_ASSERT( is_canonical( c ), "signature is not canonical" );
        }
 
        secp256k1_pubkey secp_pub;
        secp256k1_ecdsa_recoverable_signature secp_sig;
 
        FC_ASSERT( secp256k1_ecdsa_recoverable_signature_parse_compact( detail::_get_context(), &secp_sig, (unsigned char*)c.begin() + 1, (*c.begin() - 27) & 3) );
        FC_ASSERT( secp256k1_ecdsa_recover( detail::_get_context(), &secp_pub, &secp_sig, (unsigned char*) digest.data() ) );
 
        size_t serialized_result_sz = my->_key.size();
        secp256k1_ec_pubkey_serialize( detail::_get_context(), (unsigned char*)&my->_key.data, &serialized_result_sz, &secp_pub, SECP256K1_EC_COMPRESSED );
        FC_ASSERT( serialized_result_sz == my->_key.size() );
    }

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public_key() [6/7]

fc::em::public_key::public_key	(	const compact_signature &	c,
		const unsigned char *	digest,
		bool	check_canonical = true )

Definition at line 163 of file elliptic_em.cpp.

                                                                                                        {
        int nV = c.data[0];
        if (nV < 27 || nV >= 35) {
            FC_THROW_EXCEPTION(exception, "unable to reconstruct public key from signature");
        }
 
        if (check_canonical) {
            FC_ASSERT(is_canonical(c), "signature is not canonical");
        }
 
        // Declare the necessary secp256k1 variables for public key and signature
        secp256k1_pubkey secp_pub;
        secp256k1_ecdsa_recoverable_signature secp_sig;
 
        // Parse the compact signature into a recoverable signature
        FC_ASSERT(secp256k1_ecdsa_recoverable_signature_parse_compact(
            detail::_get_context(), 
            &secp_sig, 
            (unsigned char*)c.begin() + 1, 
            (*c.begin() - 27) & 3));
 
        // Recover the public key from the signature and digest
        FC_ASSERT(secp256k1_ecdsa_recover(
            detail::_get_context(), 
            &secp_pub, 
            &secp_sig, 
            digest));
 
        // Prepare to serialize the recovered public key
        size_t serialized_result_sz = my->_key.size();
        secp256k1_ec_pubkey_serialize(
            detail::_get_context(), 
            (unsigned char*)&my->_key.data, 
            &serialized_result_sz, 
            &secp_pub, 
            SECP256K1_EC_COMPRESSED);
        
        // Verify the serialized public key size
        FC_ASSERT(serialized_result_sz == my->_key.size());
    }

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public_key() [7/7]

fc::em::public_key::public_key

(

public_key &&

pk

)

Definition at line 87 of file elliptic_em.cpp.

: my( std::move( pk.my ) ) {}

Member Function Documentation

child()

public_key fc::em::public_key::child

(

const fc::sha256 &

offset

)

const

fingerprint()

unsigned int fc::em::public_key::fingerprint

(

)

const

Definition at line 145 of file elliptic_em_common.cpp.

    {
        public_key_data key = serialize();
        ripemd160 hash = ripemd160::hash( sha256::hash( key.begin(), key.size() ) );
        unsigned char* fp = (unsigned char*) hash._hash;
        return (fp[0] << 24) | (fp[1] << 16) | (fp[2] << 8) | fp[3];
    }

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from_base58()

public_key fc::em::public_key::from_base58 ( const std::string & b58 )

static

Definition at line 132 of file elliptic_em_common.cpp.

    {
        array<char, 37> data;
        size_t s = fc::from_base58(b58, (char*)&data, sizeof(data) );
        FC_ASSERT( s == sizeof(data) );
 
        public_key_data key;
        uint32_t check = (uint32_t)sha256::hash(data.data, sizeof(key))._hash[0];
        FC_ASSERT( memcmp( (char*)&check, data.data + sizeof(key), sizeof(check) ) == 0 );
        memcpy( (char*)key.data, data.data, sizeof(key) );
        return from_key_data(key);
    }

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operator public_key_data()

fc::em::public_key::operator public_key_data ( ) const

inline

Definition at line 47 of file elliptic_em.hpp.

{ return serialize(); }

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operator=() [1/2]

public_key & fc::em::public_key::operator=

(

const public_key &

pk

)

Definition at line 91 of file elliptic_em.cpp.

    {
        my = pk.my;
        return *this;
    }

operator=() [2/2]

public_key & fc::em::public_key::operator=

(

public_key &&

pk

)

Definition at line 97 of file elliptic_em.cpp.

    {
        my = pk.my;
        return *this;
    }

serialize()

public_key_data fc::em::public_key::serialize

(

)

const

Definition at line 114 of file elliptic_em.cpp.

    {
        FC_ASSERT( my->_key != empty_pub );
        return my->_key;
    }

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serialize_ecc_point()

public_key_point_data fc::em::public_key::serialize_ecc_point

(

)

const

Definition at line 282 of file elliptic_em_impl_pub.cpp.

    {
      public_key_point_data dat;
      if( !my->_key ) return dat;
      EC_KEY_set_conv_form( my->_key, POINT_CONVERSION_UNCOMPRESSED );
      char* front = &dat.data[0];
      i2o_ECPublicKey( my->_key, (unsigned char**)&front ); // FIXME: questionable memory handling
      return dat;
    }

to_base58() [1/2]

std::string fc::em::public_key::to_base58

(

)

const

Definition at line 108 of file elliptic_em.cpp.

    {
        FC_ASSERT( my->_key != empty_pub );
        return to_base58( my->_key );
    }

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to_base58() [2/2]

std::string fc::em::public_key::to_base58 ( const public_key_data & key )

static

Definition at line 122 of file elliptic_em_common.cpp.

    {
      uint32_t check = (uint32_t)sha256::hash(key.data, sizeof(key))._hash[0];
      static_assert(sizeof(key) + sizeof(check) == 37, ""); // hack around gcc bug: key.size() should be constexpr, but isn't
      array<char, 37> data;
      memcpy(data.data, key.begin(), key.size());
      memcpy(data.begin() + key.size(), (const char*)&check, sizeof(check));
      return fc::to_base58(data.begin(), data.size(), fc::yield_function_t());
    }

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valid()

bool fc::em::public_key::valid

(

)

const

Definition at line 103 of file elliptic_em.cpp.

    {
      return my->_key != empty_pub;
    }

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Friends And Related Symbol Documentation

operator!=

bool operator!= ( const public_key & a, const public_key & b )

friend

Definition at line 67 of file elliptic_em.hpp.

           {
            return a.serialize() != b.serialize();
           }

operator==

bool operator== ( const public_key & a, const public_key & b )

friend

Definition at line 63 of file elliptic_em.hpp.

           {
            return a.serialize() == b.serialize();
           }

private_key

friend class private_key

friend

Definition at line 80 of file elliptic_em.hpp.

---

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

• libraries/fc/include/fc/crypto/elliptic_em.hpp
• libraries/fc/src/crypto/elliptic_em.cpp
• libraries/fc/src/crypto/elliptic_em_common.cpp
• libraries/fc/src/crypto/elliptic_em_impl_pub.cpp