Bitcoin Core  0.20.99
P2P Digital Currency
Classes | Functions
secp256k1_extrakeys.h File Reference
#include "secp256k1.h"
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Classes

struct  secp256k1_xonly_pubkey
 Opaque data structure that holds a parsed and valid "x-only" public key. More...
 
struct  secp256k1_keypair
 Opaque data structure that holds a keypair consisting of a secret and a public key. More...
 

Functions

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_xonly_pubkey_parse (const secp256k1_context *ctx, secp256k1_xonly_pubkey *pubkey, const unsigned char *input32) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3)
 Parse a 32-byte sequence into a xonly_pubkey object. More...
 
SECP256K1_API int secp256k1_xonly_pubkey_serialize (const secp256k1_context *ctx, unsigned char *output32, const secp256k1_xonly_pubkey *pubkey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3)
 Serialize an xonly_pubkey object into a 32-byte sequence. More...
 
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_xonly_pubkey_from_pubkey (const secp256k1_context *ctx, secp256k1_xonly_pubkey *xonly_pubkey, int *pk_parity, const secp256k1_pubkey *pubkey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(4)
 Converts a secp256k1_pubkey into a secp256k1_xonly_pubkey. More...
 
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_xonly_pubkey_tweak_add (const secp256k1_context *ctx, secp256k1_pubkey *output_pubkey, const secp256k1_xonly_pubkey *internal_pubkey, const unsigned char *tweak32) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4)
 Tweak an x-only public key by adding the generator multiplied with tweak32 to it. More...
 
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_xonly_pubkey_tweak_add_check (const secp256k1_context *ctx, const unsigned char *tweaked_pubkey32, int tweaked_pk_parity, const secp256k1_xonly_pubkey *internal_pubkey, const unsigned char *tweak32) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(4) SECP256K1_ARG_NONNULL(5)
 Checks that a tweaked pubkey is the result of calling secp256k1_xonly_pubkey_tweak_add with internal_pubkey and tweak32. More...
 
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_create (const secp256k1_context *ctx, secp256k1_keypair *keypair, const unsigned char *seckey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3)
 Compute the keypair for a secret key. More...
 
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_pub (const secp256k1_context *ctx, secp256k1_pubkey *pubkey, const secp256k1_keypair *keypair) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3)
 Get the public key from a keypair. More...
 
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_xonly_pub (const secp256k1_context *ctx, secp256k1_xonly_pubkey *pubkey, int *pk_parity, const secp256k1_keypair *keypair) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(4)
 Get the x-only public key from a keypair. More...
 
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_xonly_tweak_add (const secp256k1_context *ctx, secp256k1_keypair *keypair, const unsigned char *tweak32) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3)
 Tweak a keypair by adding tweak32 to the secret key and updating the public key accordingly. More...
 

Function Documentation

◆ secp256k1_keypair_create()

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_create ( const secp256k1_context ctx,
secp256k1_keypair keypair,
const unsigned char *  seckey 
)

Compute the keypair for a secret key.

Returns: 1: secret was valid, keypair is ready to use 0: secret was invalid, try again with a different secret Args: ctx: pointer to a context object, initialized for signing (cannot be NULL) Out: keypair: pointer to the created keypair (cannot be NULL) In: seckey: pointer to a 32-byte secret key (cannot be NULL)

Definition at line 171 of file main_impl.h.

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◆ secp256k1_keypair_pub()

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_pub ( const secp256k1_context ctx,
secp256k1_pubkey pubkey,
const secp256k1_keypair keypair 
)

Get the public key from a keypair.

Returns: 0 if the arguments are invalid. 1 otherwise. Args: ctx: pointer to a context object (cannot be NULL) Out: pubkey: pointer to a pubkey object. If 1 is returned, it is set to the keypair public key. If not, it's set to an invalid value. (cannot be NULL) In: keypair: pointer to a keypair (cannot be NULL)

Definition at line 189 of file main_impl.h.

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◆ secp256k1_keypair_xonly_pub()

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_xonly_pub ( const secp256k1_context ctx,
secp256k1_xonly_pubkey pubkey,
int *  pk_parity,
const secp256k1_keypair keypair 
)

Get the x-only public key from a keypair.

This is the same as calling secp256k1_keypair_pub and then secp256k1_xonly_pubkey_from_pubkey.

Returns: 0 if the arguments are invalid. 1 otherwise. Args: ctx: pointer to a context object (cannot be NULL) Out: pubkey: pointer to an xonly_pubkey object. If 1 is returned, it is set to the keypair public key after converting it to an xonly_pubkey. If not, it's set to an invalid value (cannot be NULL). pk_parity: pointer to an integer that will be set to the pk_parity argument of secp256k1_xonly_pubkey_from_pubkey (can be NULL). In: keypair: pointer to a keypair (cannot be NULL)

Definition at line 199 of file main_impl.h.

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◆ secp256k1_keypair_xonly_tweak_add()

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_keypair_xonly_tweak_add ( const secp256k1_context ctx,
secp256k1_keypair keypair,
const unsigned char *  tweak32 
)

Tweak a keypair by adding tweak32 to the secret key and updating the public key accordingly.

Calling this function and then secp256k1_keypair_pub results in the same public key as calling secp256k1_keypair_xonly_pub and then secp256k1_xonly_pubkey_tweak_add.

Returns: 0 if the arguments are invalid or the resulting keypair would be invalid (only when the tweak is the negation of the keypair's secret key). 1 otherwise.

Args: ctx: pointer to a context object initialized for verification (cannot be NULL) In/Out: keypair: pointer to a keypair to apply the tweak to. Will be set to an invalid value if this function returns 0 (cannot be NULL). In: tweak32: pointer to a 32-byte tweak. If the tweak is invalid according to secp256k1_ec_seckey_verify, this function returns 0. For uniformly random 32-byte arrays the chance of being invalid is negligible (around 1 in 2^128) (cannot be NULL).

Definition at line 220 of file main_impl.h.

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◆ secp256k1_xonly_pubkey_from_pubkey()

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_xonly_pubkey_from_pubkey ( const secp256k1_context ctx,
secp256k1_xonly_pubkey xonly_pubkey,
int *  pk_parity,
const secp256k1_pubkey pubkey 
)

Converts a secp256k1_pubkey into a secp256k1_xonly_pubkey.

Returns: 1 if the public key was successfully converted 0 otherwise

Args: ctx: pointer to a context object (cannot be NULL) Out: xonly_pubkey: pointer to an x-only public key object for placing the converted public key (cannot be NULL) pk_parity: pointer to an integer that will be set to 1 if the point encoded by xonly_pubkey is the negation of the pubkey and set to 0 otherwise. (can be NULL) In: pubkey: pointer to a public key that is converted (cannot be NULL)

Definition at line 72 of file main_impl.h.

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◆ secp256k1_xonly_pubkey_parse()

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_xonly_pubkey_parse ( const secp256k1_context ctx,
secp256k1_xonly_pubkey pubkey,
const unsigned char *  input32 
)

Parse a 32-byte sequence into a xonly_pubkey object.

Returns: 1 if the public key was fully valid. 0 if the public key could not be parsed or is invalid.

Args: ctx: a secp256k1 context object (cannot be NULL). Out: pubkey: pointer to a pubkey object. If 1 is returned, it is set to a parsed version of input. If not, it's set to an invalid value. (cannot be NULL). In: input32: pointer to a serialized xonly_pubkey (cannot be NULL)

Definition at line 21 of file main_impl.h.

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◆ secp256k1_xonly_pubkey_serialize()

SECP256K1_API int secp256k1_xonly_pubkey_serialize ( const secp256k1_context ctx,
unsigned char *  output32,
const secp256k1_xonly_pubkey pubkey 
)

Serialize an xonly_pubkey object into a 32-byte sequence.

Returns: 1 always.

Args: ctx: a secp256k1 context object (cannot be NULL). Out: output32: a pointer to a 32-byte array to place the serialized key in (cannot be NULL). In: pubkey: a pointer to a secp256k1_xonly_pubkey containing an initialized public key (cannot be NULL).

Definition at line 43 of file main_impl.h.

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◆ secp256k1_xonly_pubkey_tweak_add()

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_xonly_pubkey_tweak_add ( const secp256k1_context ctx,
secp256k1_pubkey output_pubkey,
const secp256k1_xonly_pubkey internal_pubkey,
const unsigned char *  tweak32 
)

Tweak an x-only public key by adding the generator multiplied with tweak32 to it.

Note that the resulting point can not in general be represented by an x-only pubkey because it may have an odd Y coordinate. Instead, the output_pubkey is a normal secp256k1_pubkey.

Returns: 0 if the arguments are invalid or the resulting public key would be invalid (only when the tweak is the negation of the corresponding secret key). 1 otherwise.

Args: ctx: pointer to a context object initialized for verification (cannot be NULL) Out: output_pubkey: pointer to a public key to store the result. Will be set to an invalid value if this function returns 0 (cannot be NULL) In: internal_pubkey: pointer to an x-only pubkey to apply the tweak to. (cannot be NULL). tweak32: pointer to a 32-byte tweak. If the tweak is invalid according to secp256k1_ec_seckey_verify, this function returns 0. For uniformly random 32-byte arrays the chance of being invalid is negligible (around 1 in 2^128) (cannot be NULL).

Definition at line 91 of file main_impl.h.

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◆ secp256k1_xonly_pubkey_tweak_add_check()

SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_xonly_pubkey_tweak_add_check ( const secp256k1_context ctx,
const unsigned char *  tweaked_pubkey32,
int  tweaked_pk_parity,
const secp256k1_xonly_pubkey internal_pubkey,
const unsigned char *  tweak32 
)

Checks that a tweaked pubkey is the result of calling secp256k1_xonly_pubkey_tweak_add with internal_pubkey and tweak32.

The tweaked pubkey is represented by its 32-byte x-only serialization and its pk_parity, which can both be obtained by converting the result of tweak_add to a secp256k1_xonly_pubkey.

Note that this alone does not verify that the tweaked pubkey is a commitment. If the tweak is not chosen in a specific way, the tweaked pubkey can easily be the result of a different internal_pubkey and tweak.

Returns: 0 if the arguments are invalid or the tweaked pubkey is not the result of tweaking the internal_pubkey with tweak32. 1 otherwise. Args: ctx: pointer to a context object initialized for verification (cannot be NULL) In: tweaked_pubkey32: pointer to a serialized xonly_pubkey (cannot be NULL) tweaked_pk_parity: the parity of the tweaked pubkey (whose serialization is passed in as tweaked_pubkey32). This must match the pk_parity value that is returned when calling secp256k1_xonly_pubkey with the tweaked pubkey, or this function will fail. internal_pubkey: pointer to an x-only public key object to apply the tweak to (cannot be NULL) tweak32: pointer to a 32-byte tweak (cannot be NULL)

Definition at line 109 of file main_impl.h.

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