git / moonbite-core / src/secp256k1-zkp/include/secp256k1.h · raw
#ifndef SECP256K1_H#define SECP256K1_H#ifdef __cplusplusextern "C" {#endif#include <stddef.h>/* These rules specify the order of arguments in API calls: * * 1. Context pointers go first, followed by output arguments, combined * output/input arguments, and finally input-only arguments. * 2. Array lengths always immediately the follow the argument whose length * they describe, even if this violates rule 1. * 3. Within the OUT/OUTIN/IN groups, pointers to data that is typically generated * later go first. This means: signatures, public nonces, private nonces, * messages, public keys, secret keys, tweaks. * 4. Arguments that are not data pointers go last, from more complex to less * complex: function pointers, algorithm names, messages, void pointers, * counts, flags, booleans. * 5. Opaque data pointers follow the function pointer they are to be passed to. *//** Opaque data structure that holds context information (precomputed tables etc.). * * The purpose of context structures is to cache large precomputed data tables * that are expensive to construct, and also to maintain the randomization data * for blinding. * * Do not create a new context object for each operation, as construction is * far slower than all other API calls (~100 times slower than an ECDSA * verification). * * A constructed context can safely be used from multiple threads * simultaneously, but API call that take a non-const pointer to a context * need exclusive access to it. In particular this is the case for * secp256k1_context_destroy and secp256k1_context_randomize. * * Regarding randomization, either do it once at creation time (in which case * you do not need any locking for the other calls), or use a read-write lock. */typedef struct secp256k1_context_struct secp256k1_context;/** Opaque data structure that holds rewriteable "scratch space" * * The purpose of this structure is to replace dynamic memory allocations, * because we target architectures where this may not be available. It is * essentially a resizable (within specified parameters) block of bytes, * which is initially created either by memory allocation or TODO as a pointer * into some fixed rewritable space. * * Unlike the context object, this cannot safely be shared between threads * without additional synchronization logic. */typedef struct secp256k1_scratch_space_struct secp256k1_scratch_space;/** Opaque data structure that holds a parsed and valid public key. * * The exact representation of data inside is implementation defined and not * guaranteed to be portable between different platforms or versions. It is * however guaranteed to be 64 bytes in size, and can be safely copied/moved. * If you need to convert to a format suitable for storage, transmission, or * comparison, use secp256k1_ec_pubkey_serialize and secp256k1_ec_pubkey_parse. */typedef struct { unsigned char data[64];} secp256k1_pubkey;/** Opaque data structured that holds a parsed ECDSA signature. * * The exact representation of data inside is implementation defined and not * guaranteed to be portable between different platforms or versions. It is * however guaranteed to be 64 bytes in size, and can be safely copied/moved. * If you need to convert to a format suitable for storage, transmission, or * comparison, use the secp256k1_ecdsa_signature_serialize_* and * secp256k1_ecdsa_signature_parse_* functions. */typedef struct { unsigned char data[64];} secp256k1_ecdsa_signature;/** A pointer to a function to deterministically generate a nonce. * * Returns: 1 if a nonce was successfully generated. 0 will cause signing to fail. * Out: nonce32: pointer to a 32-byte array to be filled by the function. * In: msg32: the 32-byte message hash being verified (will not be NULL) * key32: pointer to a 32-byte secret key (will not be NULL) * algo16: pointer to a 16-byte array describing the signature * algorithm (will be NULL for ECDSA for compatibility). * data: Arbitrary data pointer that is passed through. * attempt: how many iterations we have tried to find a nonce. * This will almost always be 0, but different attempt values * are required to result in a different nonce. * * Except for test cases, this function should compute some cryptographic hash of * the message, the algorithm, the key and the attempt. */typedef int (*secp256k1_nonce_function)( unsigned char *nonce32, const unsigned char *msg32, const unsigned char *key32, const unsigned char *algo16, void *data, unsigned int attempt);# if !defined(SECP256K1_GNUC_PREREQ)# if defined(__GNUC__)&&defined(__GNUC_MINOR__)# define SECP256K1_GNUC_PREREQ(_maj,_min) \ ((__GNUC__<<16)+__GNUC_MINOR__>=((_maj)<<16)+(_min))# else# define SECP256K1_GNUC_PREREQ(_maj,_min) 0# endif# endif# if (!defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L) )# if SECP256K1_GNUC_PREREQ(2,7)# define SECP256K1_INLINE __inline__# elif (defined(_MSC_VER))# define SECP256K1_INLINE __inline# else# define SECP256K1_INLINE# endif# else# define SECP256K1_INLINE inline# endif#ifndef SECP256K1_API# if defined(_WIN32)# ifdef SECP256K1_BUILD# define SECP256K1_API __declspec(dllexport)# else# define SECP256K1_API# endif# elif defined(__GNUC__) && defined(SECP256K1_BUILD)# define SECP256K1_API __attribute__ ((visibility ("default")))# else# define SECP256K1_API# endif#endif/**Warning attributes * NONNULL is not used if SECP256K1_BUILD is set to avoid the compiler optimizing out * some paranoid null checks. */# if defined(__GNUC__) && SECP256K1_GNUC_PREREQ(3, 4)# define SECP256K1_WARN_UNUSED_RESULT __attribute__ ((__warn_unused_result__))# else# define SECP256K1_WARN_UNUSED_RESULT# endif# if !defined(SECP256K1_BUILD) && defined(__GNUC__) && SECP256K1_GNUC_PREREQ(3, 4)# define SECP256K1_ARG_NONNULL(_x) __attribute__ ((__nonnull__(_x)))# else# define SECP256K1_ARG_NONNULL(_x)# endif/** All flags' lower 8 bits indicate what they're for. Do not use directly. */#define SECP256K1_FLAGS_TYPE_MASK ((1 << 8) - 1)#define SECP256K1_FLAGS_TYPE_CONTEXT (1 << 0)#define SECP256K1_FLAGS_TYPE_COMPRESSION (1 << 1)/** The higher bits contain the actual data. Do not use directly. */#define SECP256K1_FLAGS_BIT_CONTEXT_VERIFY (1 << 8)#define SECP256K1_FLAGS_BIT_CONTEXT_SIGN (1 << 9)#define SECP256K1_FLAGS_BIT_COMPRESSION (1 << 8)/** Flags to pass to secp256k1_context_create. */#define SECP256K1_CONTEXT_VERIFY (SECP256K1_FLAGS_TYPE_CONTEXT | SECP256K1_FLAGS_BIT_CONTEXT_VERIFY)#define SECP256K1_CONTEXT_SIGN (SECP256K1_FLAGS_TYPE_CONTEXT | SECP256K1_FLAGS_BIT_CONTEXT_SIGN)#define SECP256K1_CONTEXT_NONE (SECP256K1_FLAGS_TYPE_CONTEXT)/** Flag to pass to secp256k1_ec_pubkey_serialize and secp256k1_ec_privkey_export. */#define SECP256K1_EC_COMPRESSED (SECP256K1_FLAGS_TYPE_COMPRESSION | SECP256K1_FLAGS_BIT_COMPRESSION)#define SECP256K1_EC_UNCOMPRESSED (SECP256K1_FLAGS_TYPE_COMPRESSION)/** Prefix byte used to tag various encoded curvepoints for specific purposes */#define SECP256K1_TAG_PUBKEY_EVEN 0x02#define SECP256K1_TAG_PUBKEY_ODD 0x03#define SECP256K1_TAG_PUBKEY_UNCOMPRESSED 0x04#define SECP256K1_TAG_PUBKEY_HYBRID_EVEN 0x06#define SECP256K1_TAG_PUBKEY_HYBRID_ODD 0x07/** Create a secp256k1 context object. * * Returns: a newly created context object. * In: flags: which parts of the context to initialize. * * See also secp256k1_context_randomize. */SECP256K1_API secp256k1_context* secp256k1_context_create( unsigned int flags) SECP256K1_WARN_UNUSED_RESULT;/** Copies a secp256k1 context object. * * Returns: a newly created context object. * Args: ctx: an existing context to copy (cannot be NULL) */SECP256K1_API secp256k1_context* secp256k1_context_clone( const secp256k1_context* ctx) SECP256K1_ARG_NONNULL(1) SECP256K1_WARN_UNUSED_RESULT;/** Destroy a secp256k1 context object. * * The context pointer may not be used afterwards. * Args: ctx: an existing context to destroy (cannot be NULL) */SECP256K1_API void secp256k1_context_destroy( secp256k1_context* ctx);/** Set a callback function to be called when an illegal argument is passed to * an API call. It will only trigger for violations that are mentioned * explicitly in the header. * * The philosophy is that these shouldn't be dealt with through a * specific return value, as calling code should not have branches to deal with * the case that this code itself is broken. * * On the other hand, during debug stage, one would want to be informed about * such mistakes, and the default (crashing) may be inadvisable. * When this callback is triggered, the API function called is guaranteed not * to cause a crash, though its return value and output arguments are * undefined. * * Args: ctx: an existing context object (cannot be NULL) * In: fun: a pointer to a function to call when an illegal argument is * passed to the API, taking a message and an opaque pointer * (NULL restores a default handler that calls abort). * data: the opaque pointer to pass to fun above. */SECP256K1_API void secp256k1_context_set_illegal_callback( secp256k1_context* ctx, void (*fun)(const char* message, void* data), const void* data) SECP256K1_ARG_NONNULL(1);/** Set a callback function to be called when an internal consistency check * fails. The default is crashing. * * This can only trigger in case of a hardware failure, miscompilation, * memory corruption, serious bug in the library, or other error would can * otherwise result in undefined behaviour. It will not trigger due to mere * incorrect usage of the API (see secp256k1_context_set_illegal_callback * for that). After this callback returns, anything may happen, including * crashing. * * Args: ctx: an existing context object (cannot be NULL) * In: fun: a pointer to a function to call when an internal error occurs, * taking a message and an opaque pointer (NULL restores a default * handler that calls abort). * data: the opaque pointer to pass to fun above. */SECP256K1_API void secp256k1_context_set_error_callback( secp256k1_context* ctx, void (*fun)(const char* message, void* data), const void* data) SECP256K1_ARG_NONNULL(1);/** Create a secp256k1 scratch space object. * * Returns: a newly created scratch space. * Args: ctx: an existing context object (cannot be NULL) * In: max_size: maximum amount of memory to allocate */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT secp256k1_scratch_space* secp256k1_scratch_space_create( const secp256k1_context* ctx, size_t max_size) SECP256K1_ARG_NONNULL(1);/** Destroy a secp256k1 scratch space. * * The pointer may not be used afterwards. * Args: scratch: space to destroy */SECP256K1_API void secp256k1_scratch_space_destroy( secp256k1_scratch_space* scratch);/** Parse a variable-length public key into the 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. * Out: pubkey: pointer to a pubkey object. If 1 is returned, it is set to a * parsed version of input. If not, its value is undefined. * In: input: pointer to a serialized public key * inputlen: length of the array pointed to by input * * This function supports parsing compressed (33 bytes, header byte 0x02 or * 0x03), uncompressed (65 bytes, header byte 0x04), or hybrid (65 bytes, header * byte 0x06 or 0x07) format public keys. */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_parse( const secp256k1_context* ctx, secp256k1_pubkey* pubkey, const unsigned char *input, size_t inputlen) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Serialize a pubkey object into a serialized byte sequence. * * Returns: 1 always. * Args: ctx: a secp256k1 context object. * Out: output: a pointer to a 65-byte (if compressed==0) or 33-byte (if * compressed==1) byte array to place the serialized key * in. * In/Out: outputlen: a pointer to an integer which is initially set to the * size of output, and is overwritten with the written * size. * In: pubkey: a pointer to a secp256k1_pubkey containing an * initialized public key. * flags: SECP256K1_EC_COMPRESSED if serialization should be in * compressed format, otherwise SECP256K1_EC_UNCOMPRESSED. */SECP256K1_API int secp256k1_ec_pubkey_serialize( const secp256k1_context* ctx, unsigned char *output, size_t *outputlen, const secp256k1_pubkey* pubkey, unsigned int flags) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);/** Parse an ECDSA signature in compact (64 bytes) format. * * Returns: 1 when the signature could be parsed, 0 otherwise. * Args: ctx: a secp256k1 context object * Out: sig: a pointer to a signature object * In: input64: a pointer to the 64-byte array to parse * * The signature must consist of a 32-byte big endian R value, followed by a * 32-byte big endian S value. If R or S fall outside of [0..order-1], the * encoding is invalid. R and S with value 0 are allowed in the encoding. * * After the call, sig will always be initialized. If parsing failed or R or * S are zero, the resulting sig value is guaranteed to fail validation for any * message and public key. */SECP256K1_API int secp256k1_ecdsa_signature_parse_compact( const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const unsigned char *input64) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Parse a DER ECDSA signature. * * Returns: 1 when the signature could be parsed, 0 otherwise. * Args: ctx: a secp256k1 context object * Out: sig: a pointer to a signature object * In: input: a pointer to the signature to be parsed * inputlen: the length of the array pointed to be input * * This function will accept any valid DER encoded signature, even if the * encoded numbers are out of range. * * After the call, sig will always be initialized. If parsing failed or the * encoded numbers are out of range, signature validation with it is * guaranteed to fail for every message and public key. */SECP256K1_API int secp256k1_ecdsa_signature_parse_der( const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const unsigned char *input, size_t inputlen) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Serialize an ECDSA signature in DER format. * * Returns: 1 if enough space was available to serialize, 0 otherwise * Args: ctx: a secp256k1 context object * Out: output: a pointer to an array to store the DER serialization * In/Out: outputlen: a pointer to a length integer. Initially, this integer * should be set to the length of output. After the call * it will be set to the length of the serialization (even * if 0 was returned). * In: sig: a pointer to an initialized signature object */SECP256K1_API int secp256k1_ecdsa_signature_serialize_der( const secp256k1_context* ctx, unsigned char *output, size_t *outputlen, const secp256k1_ecdsa_signature* sig) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);/** Serialize an ECDSA signature in compact (64 byte) format. * * Returns: 1 * Args: ctx: a secp256k1 context object * Out: output64: a pointer to a 64-byte array to store the compact serialization * In: sig: a pointer to an initialized signature object * * See secp256k1_ecdsa_signature_parse_compact for details about the encoding. */SECP256K1_API int secp256k1_ecdsa_signature_serialize_compact( const secp256k1_context* ctx, unsigned char *output64, const secp256k1_ecdsa_signature* sig) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Verify an ECDSA signature. * * Returns: 1: correct signature * 0: incorrect or unparseable signature * Args: ctx: a secp256k1 context object, initialized for verification. * In: sig: the signature being verified (cannot be NULL) * msg32: the 32-byte message hash being verified (cannot be NULL) * pubkey: pointer to an initialized public key to verify with (cannot be NULL) * * To avoid accepting malleable signatures, only ECDSA signatures in lower-S * form are accepted. * * If you need to accept ECDSA signatures from sources that do not obey this * rule, apply secp256k1_ecdsa_signature_normalize to the signature prior to * validation, but be aware that doing so results in malleable signatures. * * For details, see the comments for that function. */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_verify( const secp256k1_context* ctx, const secp256k1_ecdsa_signature *sig, const unsigned char *msg32, const secp256k1_pubkey *pubkey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);/** Convert a signature to a normalized lower-S form. * * Returns: 1 if sigin was not normalized, 0 if it already was. * Args: ctx: a secp256k1 context object * Out: sigout: a pointer to a signature to fill with the normalized form, * or copy if the input was already normalized. (can be NULL if * you're only interested in whether the input was already * normalized). * In: sigin: a pointer to a signature to check/normalize (cannot be NULL, * can be identical to sigout) * * With ECDSA a third-party can forge a second distinct signature of the same * message, given a single initial signature, but without knowing the key. This * is done by negating the S value modulo the order of the curve, 'flipping' * the sign of the random point R which is not included in the signature. * * Forgery of the same message isn't universally problematic, but in systems * where message malleability or uniqueness of signatures is important this can * cause issues. This forgery can be blocked by all verifiers forcing signers * to use a normalized form. * * The lower-S form reduces the size of signatures slightly on average when * variable length encodings (such as DER) are used and is cheap to verify, * making it a good choice. Security of always using lower-S is assured because * anyone can trivially modify a signature after the fact to enforce this * property anyway. * * The lower S value is always between 0x1 and * 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, * inclusive. * * No other forms of ECDSA malleability are known and none seem likely, but * there is no formal proof that ECDSA, even with this additional restriction, * is free of other malleability. Commonly used serialization schemes will also * accept various non-unique encodings, so care should be taken when this * property is required for an application. * * The secp256k1_ecdsa_sign function will by default create signatures in the * lower-S form, and secp256k1_ecdsa_verify will not accept others. In case * signatures come from a system that cannot enforce this property, * secp256k1_ecdsa_signature_normalize must be called before verification. */SECP256K1_API int secp256k1_ecdsa_signature_normalize( const secp256k1_context* ctx, secp256k1_ecdsa_signature *sigout, const secp256k1_ecdsa_signature *sigin) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(3);/** An implementation of RFC6979 (using HMAC-SHA256) as nonce generation function. * If a data pointer is passed, it is assumed to be a pointer to 32 bytes of * extra entropy. */SECP256K1_API extern const secp256k1_nonce_function secp256k1_nonce_function_rfc6979;/** A default safe nonce generation function (currently equal to secp256k1_nonce_function_rfc6979). */SECP256K1_API extern const secp256k1_nonce_function secp256k1_nonce_function_default;/** Create an ECDSA signature. * * Returns: 1: signature created * 0: the nonce generation function failed, or the private key was invalid. * Args: ctx: pointer to a context object, initialized for signing (cannot be NULL) * Out: sig: pointer to an array where the signature will be placed (cannot be NULL) * In: msg32: the 32-byte message hash being signed (cannot be NULL) * seckey: pointer to a 32-byte secret key (cannot be NULL) * noncefp:pointer to a nonce generation function. If NULL, secp256k1_nonce_function_default is used * ndata: pointer to arbitrary data used by the nonce generation function (can be NULL) * * The created signature is always in lower-S form. See * secp256k1_ecdsa_signature_normalize for more details. */SECP256K1_API int secp256k1_ecdsa_sign( const secp256k1_context* ctx, secp256k1_ecdsa_signature *sig, const unsigned char *msg32, const unsigned char *seckey, secp256k1_nonce_function noncefp, const void *ndata) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);/** Verify an ECDSA secret key. * * Returns: 1: secret key is valid * 0: secret key is invalid * Args: ctx: pointer to a context object (cannot be NULL) * In: seckey: pointer to a 32-byte secret key (cannot be NULL) */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_verify( const secp256k1_context* ctx, const unsigned char *seckey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);/** Compute the public key for a secret key. * * Returns: 1: secret was valid, public key stores * 0: secret was invalid, try again * Args: ctx: pointer to a context object, initialized for signing (cannot be NULL) * Out: pubkey: pointer to the created public key (cannot be NULL) * In: seckey: pointer to a 32-byte private key (cannot be NULL) */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_create( const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *seckey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Negates a secret key in place. * * Returns: 0 if the given secret key is invalid according to * secp256k1_ec_seckey_verify. 1 otherwise * Args: ctx: pointer to a context object * In/Out: seckey: pointer to the 32-byte secret key to be negated. If the * secret key is invalid according to * secp256k1_ec_seckey_verify, this function returns 0 and * seckey will be set to some unspecified value. (cannot be * NULL) */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_negate( const secp256k1_context* ctx, unsigned char *seckey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);/** Negates a private key in place. * * Returns: 1 always * Args: ctx: pointer to a context object * In/Out: seckey: pointer to the 32-byte private key to be negated (cannot be NULL) */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_negate( const secp256k1_context* ctx, unsigned char *seckey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);/** Negates a public key in place. * * Returns: 1 always * Args: ctx: pointer to a context object * In/Out: pubkey: pointer to the public key to be negated (cannot be NULL) */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_negate( const secp256k1_context* ctx, secp256k1_pubkey *pubkey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);/** Tweak a secret key by adding tweak to it. * * Returns: 0 if the arguments are invalid or the resulting secret key would be * invalid (only when the tweak is the negation of the secret key). 1 * otherwise. * Args: ctx: pointer to a context object (cannot be NULL). * In/Out: seckey: pointer to a 32-byte secret key. If the secret key is * invalid according to secp256k1_ec_seckey_verify, this * function returns 0. seckey will be set to some unspecified * value if this function returns 0. (cannot be NULL) * In: tweak: 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). */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_tweak_add( const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Tweak a private key by adding tweak to it. * Returns: 0 if the tweak was out of range (chance of around 1 in 2^128 for * uniformly random 32-byte arrays, or if the resulting private key * would be invalid (only when the tweak is the complement of the * private key). 1 otherwise. * Args: ctx: pointer to a context object (cannot be NULL). * In/Out: seckey: pointer to a 32-byte private key. * In: tweak: pointer to a 32-byte tweak. */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_add( const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Tweak a public key by adding tweak times the generator to it. * Returns: 0 if the tweak was out of range (chance of around 1 in 2^128 for * uniformly random 32-byte arrays, or if the resulting public key * would be invalid (only when the tweak is the complement of the * corresponding private key). 1 otherwise. * Args: ctx: pointer to a context object initialized for validation * (cannot be NULL). * In/Out: pubkey: pointer to a public key object. * In: tweak: pointer to a 32-byte tweak. */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_add( const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *tweak) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Tweak a private key by multiplying it by a tweak. * Returns: 0 if the tweak was out of range (chance of around 1 in 2^128 for * uniformly random 32-byte arrays, or equal to zero. 1 otherwise. * Args: ctx: pointer to a context object (cannot be NULL). * In/Out: seckey: pointer to a 32-byte private key. * In: tweak: pointer to a 32-byte tweak. */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_mul( const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Tweak a public key by multiplying it by a tweak value. * Returns: 0 if the tweak was out of range (chance of around 1 in 2^128 for * uniformly random 32-byte arrays, or equal to zero. 1 otherwise. * Args: ctx: pointer to a context object initialized for validation * (cannot be NULL). * In/Out: pubkey: pointer to a public key obkect. * In: tweak: pointer to a 32-byte tweak. */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_mul( const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *tweak) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Updates the context randomization to protect against side-channel leakage. * Returns: 1: randomization successfully updated * 0: error * Args: ctx: pointer to a context object (cannot be NULL) * In: seed32: pointer to a 32-byte random seed (NULL resets to initial state) * * While secp256k1 code is written to be constant-time no matter what secret * values are, it's possible that a future compiler may output code which isn't, * and also that the CPU may not emit the same radio frequencies or draw the same * amount power for all values. * * This function provides a seed which is combined into the blinding value: that * blinding value is added before each multiplication (and removed afterwards) so * that it does not affect function results, but shields against attacks which * rely on any input-dependent behaviour. * * You should call this after secp256k1_context_create or * secp256k1_context_clone, and may call this repeatedly afterwards. */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_context_randomize( secp256k1_context* ctx, const unsigned char *seed32) SECP256K1_ARG_NONNULL(1);/** Add a number of public keys together. * Returns: 1: the sum of the public keys is valid. * 0: the sum of the public keys is not valid. * Args: ctx: pointer to a context object * Out: out: pointer to a public key object for placing the resulting public key * (cannot be NULL) * In: ins: pointer to array of pointers to public keys (cannot be NULL) * n: the number of public keys to add together (must be at least 1) */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_combine( const secp256k1_context* ctx, secp256k1_pubkey *out, const secp256k1_pubkey * const * ins, size_t n) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);/** Tweak a private key by inverting it. * Returns: 0 if the input was out of range. 1 otherwise. * Args: ctx: pointer to a context object (cannot be NULL). * In/Out: seckey: pointer to a 32-byte private key. */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_inv( const secp256k1_context* ctx, unsigned char *seckey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);/** Tweak a private key by negating it. * Returns: 0 if the input was out of range. 1 otherwise. * Args: ctx: pointer to a context object (cannot be NULL). * In/Out: seckey: pointer to a 32-byte private key. */SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_neg( const secp256k1_context* ctx, unsigned char *seckey) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);#ifdef __cplusplus}#endif#endif /* SECP256K1_H */