diff options
Diffstat (limited to 'src/secp256k1/include/secp256k1.h')
-rw-r--r-- | src/secp256k1/include/secp256k1.h | 150 |
1 files changed, 101 insertions, 49 deletions
diff --git a/src/secp256k1/include/secp256k1.h b/src/secp256k1/include/secp256k1.h index a6e39d13db..06afd4c65b 100644 --- a/src/secp256k1/include/secp256k1.h +++ b/src/secp256k1/include/secp256k1.h @@ -40,42 +40,60 @@ extern "C" { # define SECP256K1_ARG_NONNULL(_x) # endif +/** Opaque data structure that holds context information (precomputed tables etc.). + * Only functions that take a pointer to a non-const context require exclusive + * access to it. Multiple functions that take a pointer to a const context may + * run simultaneously. + */ +typedef struct secp256k1_context_struct secp256k1_context_t; + +/** Flags to pass to secp256k1_context_create. */ +# define SECP256K1_CONTEXT_VERIFY (1 << 0) +# define SECP256K1_CONTEXT_SIGN (1 << 1) -/** Flags to pass to secp256k1_start. */ -# define SECP256K1_START_VERIFY (1 << 0) -# define SECP256K1_START_SIGN (1 << 1) +/** Create a secp256k1 context object. + * Returns: a newly created context object. + * In: flags: which parts of the context to initialize. + */ +secp256k1_context_t* secp256k1_context_create( + int flags +) SECP256K1_WARN_UNUSED_RESULT; -/** Initialize the library. This may take some time (10-100 ms). - * You need to call this before calling any other function. - * It cannot run in parallel with any other functions, but once - * secp256k1_start() returns, all other functions are thread-safe. +/** Copies a secp256k1 context object. + * Returns: a newly created context object. + * In: ctx: an existing context to copy */ -void secp256k1_start(unsigned int flags); +secp256k1_context_t* secp256k1_context_clone( + const secp256k1_context_t* ctx +) SECP256K1_WARN_UNUSED_RESULT; -/** Free all memory associated with this library. After this, no - * functions can be called anymore, except secp256k1_start() +/** Destroy a secp256k1 context object. + * The context pointer may not be used afterwards. */ -void secp256k1_stop(void); +void secp256k1_context_destroy( + secp256k1_context_t* ctx +) SECP256K1_ARG_NONNULL(1); /** Verify an ECDSA signature. * Returns: 1: correct signature * 0: incorrect signature * -1: invalid public key * -2: invalid signature - * In: msg32: the 32-byte message hash being verified (cannot be NULL) + * In: ctx: a secp256k1 context object, initialized for verification. + * msg32: the 32-byte message hash being verified (cannot be NULL) * sig: the signature being verified (cannot be NULL) * siglen: the length of the signature * pubkey: the public key to verify with (cannot be NULL) * pubkeylen: the length of pubkey - * Requires starting using SECP256K1_START_VERIFY. */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_verify( + const secp256k1_context_t* ctx, const unsigned char *msg32, const unsigned char *sig, int siglen, const unsigned char *pubkey, int pubkeylen -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(4); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(5); /** A pointer to a function to deterministically generate a nonce. * Returns: 1 if a nonce was successfully generated. 0 will cause signing to fail. @@ -111,15 +129,14 @@ extern const secp256k1_nonce_function_t secp256k1_nonce_function_default; * Returns: 1: signature created * 0: the nonce generation function failed, the private key was invalid, or there is not * enough space in the signature (as indicated by siglen). - * In: msg32: the 32-byte message hash being signed (cannot be NULL) + * In: ctx: pointer to a context object, initialized for signing (cannot be NULL) + * 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) * Out: sig: pointer to an array where the signature will be placed (cannot be NULL) * In/Out: siglen: pointer to an int with the length of sig, which will be updated - * to contain the actual signature length (<=72). If 0 is returned, this will be - * set to zero. - * Requires starting using SECP256K1_START_SIGN. + * to contain the actual signature length (<=72). * * The sig always has an s value in the lower half of the range (From 0x1 * to 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, @@ -148,145 +165,180 @@ extern const secp256k1_nonce_function_t secp256k1_nonce_function_default; * be taken when this property is required for an application. */ int secp256k1_ecdsa_sign( + const secp256k1_context_t* ctx, const unsigned char *msg32, unsigned char *sig, int *siglen, const unsigned char *seckey, secp256k1_nonce_function_t noncefp, const void *ndata -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4) SECP256K1_ARG_NONNULL(5); /** Create a compact ECDSA signature (64 byte + recovery id). * Returns: 1: signature created * 0: the nonce generation function failed, or the secret key was invalid. - * In: msg32: the 32-byte message hash being signed (cannot be NULL) + * In: ctx: pointer to a context object, initialized for signing (cannot be NULL) + * 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) * Out: sig: pointer to a 64-byte array where the signature will be placed (cannot be NULL) * In case 0 is returned, the returned signature length will be zero. * recid: pointer to an int, which will be updated to contain the recovery id (can be NULL) - * Requires starting using SECP256K1_START_SIGN. */ int secp256k1_ecdsa_sign_compact( + const secp256k1_context_t* ctx, const unsigned char *msg32, unsigned char *sig64, const unsigned char *seckey, secp256k1_nonce_function_t noncefp, const void *ndata, int *recid -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4); /** Recover an ECDSA public key from a compact signature. * Returns: 1: public key successfully recovered (which guarantees a correct signature). * 0: otherwise. - * In: msg32: the 32-byte message hash assumed to be signed (cannot be NULL) + * In: ctx: pointer to a context object, initialized for verification (cannot be NULL) + * msg32: the 32-byte message hash assumed to be signed (cannot be NULL) * sig64: signature as 64 byte array (cannot be NULL) * compressed: whether to recover a compressed or uncompressed pubkey * recid: the recovery id (0-3, as returned by ecdsa_sign_compact) * Out: pubkey: pointer to a 33 or 65 byte array to put the pubkey (cannot be NULL) * pubkeylen: pointer to an int that will contain the pubkey length (cannot be NULL) - * Requires starting using SECP256K1_START_VERIFY. */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_recover_compact( + const secp256k1_context_t* ctx, const unsigned char *msg32, const unsigned char *sig64, unsigned char *pubkey, int *pubkeylen, int compressed, int recid -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4) SECP256K1_ARG_NONNULL(5); /** Verify an ECDSA secret key. * Returns: 1: secret key is valid * 0: secret key is invalid - * In: seckey: pointer to a 32-byte secret key (cannot be NULL) + * In: ctx: pointer to a context object (cannot be NULL) + * seckey: pointer to a 32-byte secret key (cannot be NULL) */ -SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_verify(const unsigned char *seckey) SECP256K1_ARG_NONNULL(1); +SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_verify( + const secp256k1_context_t* ctx, + const unsigned char *seckey +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2); /** Just validate a public key. - * Returns: 1: valid public key - * 0: invalid public key - * In: pubkey: pointer to a 33-byte or 65-byte public key (cannot be NULL). + * Returns: 1: public key is valid + * 0: public key is invalid + * In: ctx: pointer to a context object (cannot be NULL) + * pubkey: pointer to a 33-byte or 65-byte public key (cannot be NULL). * pubkeylen: length of pubkey */ -SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_verify(const unsigned char *pubkey, int pubkeylen) SECP256K1_ARG_NONNULL(1); +SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_verify( + const secp256k1_context_t* ctx, + const unsigned char *pubkey, + int pubkeylen +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2); /** Compute the public key for a secret key. - * In: compressed: whether the computed public key should be compressed + * In: ctx: pointer to a context object, initialized for signing (cannot be NULL) + * compressed: whether the computed public key should be compressed * seckey: pointer to a 32-byte private key (cannot be NULL) * Out: pubkey: pointer to a 33-byte (if compressed) or 65-byte (if uncompressed) * area to store the public key (cannot be NULL) * pubkeylen: pointer to int that will be updated to contains the pubkey's * length (cannot be NULL) * Returns: 1: secret was valid, public key stores - * 0: secret was invalid, try again. - * Requires starting using SECP256K1_START_SIGN. + * 0: secret was invalid, try again */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_create( + const secp256k1_context_t* ctx, unsigned char *pubkey, int *pubkeylen, const unsigned char *seckey, int compressed -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4); /** Decompress a public key. + * In: ctx: pointer to a context object (cannot be NULL) * In/Out: pubkey: pointer to a 65-byte array to put the decompressed public key. - It must contain a 33-byte or 65-byte public key already (cannot be NULL) + * It must contain a 33-byte or 65-byte public key already (cannot be NULL) * pubkeylen: pointer to the size of the public key pointed to by pubkey (cannot be NULL) - It will be updated to reflect the new size. - * Returns: 0 if the passed public key was invalid, 1 otherwise. If 1 is returned, the - pubkey is replaced with its decompressed version. + * It will be updated to reflect the new size. + * Returns: 0: pubkey was invalid + * 1: pubkey was valid, and was replaced with its decompressed version */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_decompress( + const secp256k1_context_t* ctx, unsigned char *pubkey, int *pubkeylen -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3); -/** Export a private key in DER format. */ +/** Export a private key in DER format. + * In: ctx: pointer to a context object, initialized for signing (cannot be NULL) + */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_export( + const secp256k1_context_t* ctx, const unsigned char *seckey, unsigned char *privkey, int *privkeylen, int compressed -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4); /** Import a private key in DER format. */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_import( + const secp256k1_context_t* ctx, unsigned char *seckey, const unsigned char *privkey, int privkeylen -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3); /** Tweak a private key by adding tweak to it. */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_add( + const secp256k1_context_t* ctx, unsigned char *seckey, const unsigned char *tweak -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3); /** Tweak a public key by adding tweak times the generator to it. - * Requires starting with SECP256K1_START_VERIFY. + * In: ctx: pointer to a context object, initialized for verification (cannot be NULL) */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_add( + const secp256k1_context_t* ctx, unsigned char *pubkey, int pubkeylen, const unsigned char *tweak -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(3); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(4); /** Tweak a private key by multiplying it with tweak. */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_mul( + const secp256k1_context_t* ctx, unsigned char *seckey, const unsigned char *tweak -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3); /** Tweak a public key by multiplying it with tweak. - * Requires starting with SECP256K1_START_VERIFY. + * In: ctx: pointer to a context object, initialized for verification (cannot be NULL) */ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_mul( + const secp256k1_context_t* ctx, unsigned char *pubkey, int pubkeylen, const unsigned char *tweak -) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(3); +) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(4); + +/** Updates the context randomization. + * Returns: 1: randomization successfully updated + * 0: error + * In: ctx: pointer to a context object (cannot be NULL) + * seed32: pointer to a 32-byte random seed (NULL resets to initial state) + */ +SECP256K1_WARN_UNUSED_RESULT int secp256k1_context_randomize( + secp256k1_context_t* ctx, + const unsigned char *seed32 +) SECP256K1_ARG_NONNULL(1); + # ifdef __cplusplus } |