Document some preconditions

This commit is contained in:
Pieter Wuille 2014-11-11 15:21:47 -08:00
parent ef6f677679
commit c27fdc0b97

View File

@ -26,6 +26,12 @@ void secp256k1_stop(void);
* 0: incorrect signature
* -1: invalid public key
* -2: invalid signature
* In: msg: the message being verified (cannot be NULL)
* msglen: the length of the message (at most 32)
* 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.
*/
int secp256k1_ecdsa_verify(const unsigned char *msg, int msglen,
@ -35,12 +41,13 @@ int secp256k1_ecdsa_verify(const unsigned char *msg, int msglen,
/** Create an ECDSA signature.
* Returns: 1: signature created
* 0: nonce invalid, try another one
* In: msg: the message being signed
* msglen: the length of the message being signed
* seckey: pointer to a 32-byte secret key (assumed to be valid)
* nonce: pointer to a 32-byte nonce (generated with a cryptographic PRNG)
* Out: sig: pointer to a 72-byte array where the signature will be placed.
* siglen: pointer to an int, which will be updated to the signature length (<=72).
* In: msg: the message being signed (cannot be NULL)
* msglen: the length of the message being signed (at most 32)
* seckey: pointer to a 32-byte secret key (cannot be NULL, assumed to be valid)
* nonce: pointer to a 32-byte nonce (cannot be NULL, generated with a cryptographic PRNG)
* 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).
* Requires starting using SECP256K1_START_SIGN.
*/
int secp256k1_ecdsa_sign(const unsigned char *msg, int msglen,
@ -51,12 +58,12 @@ int secp256k1_ecdsa_sign(const unsigned char *msg, int msglen,
/** Create a compact ECDSA signature (64 byte + recovery id).
* Returns: 1: signature created
* 0: nonce invalid, try another one
* In: msg: the message being signed
* msglen: the length of the message being signed
* seckey: pointer to a 32-byte secret key (assumed to be valid)
* nonce: pointer to a 32-byte nonce (generated with a cryptographic PRNG)
* Out: sig: pointer to a 64-byte array where the signature will be placed.
* recid: pointer to an int, which will be updated to contain the recovery id.
* In: msg: the message being signed (cannot be NULL)
* msglen: the length of the message being signed (at most 32)
* seckey: pointer to a 32-byte secret key (cannot be NULL, assumed to be valid)
* nonce: pointer to a 32-byte nonce (cannot be NULL, generated with a cryptographic PRNG)
* Out: sig: pointer to a 64-byte array where the signature will be placed (cannot be NULL)
* 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 unsigned char *msg, int msglen,
@ -66,15 +73,15 @@ int secp256k1_ecdsa_sign_compact(const unsigned char *msg, int msglen,
int *recid);
/** Recover an ECDSA public key from a compact signature.
* Returns: 1: public key succesfully recovered (which guarantees a correct signature).
* Returns: 1: public key successfully recovered (which guarantees a correct signature).
* 0: otherwise.
* In: msg: the message assumed to be signed
* msglen: the length of the message
* sig64: signature as 64 byte array
* In: msg: the message assumed to be signed (cannot be NULL)
* msglen: the length of the message (at most 32)
* sig64: signature as 64 byte array (cannot be NULL)
* compressed: whether to recover a compressed or uncompressed pubkey
* recid: the recovery id (as returned by ecdsa_sign_compact)
* Out: pubkey: pointer to a 33 or 65 byte array to put the pubkey.
* pubkeylen: pointer to an int that will contain the pubkey length.
* 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.
*/
int secp256k1_ecdsa_recover_compact(const unsigned char *msg, int msglen,
@ -85,23 +92,25 @@ int secp256k1_ecdsa_recover_compact(const unsigned char *msg, int msglen,
/** 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
* In: seckey: pointer to a 32-byte secret key (cannot be NULL)
*/
int secp256k1_ec_seckey_verify(const unsigned char *seckey);
/** 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).
* pubkeylen: length of pubkey
*/
int secp256k1_ec_pubkey_verify(const unsigned char *pubkey, int pubkeylen);
/** Compute the public key for a secret key.
* In: compressed: whether the computed public key should be compressed
* seckey: pointer to a 32-byte private key.
* 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.
* area to store the public key (cannot be NULL)
* pubkeylen: pointer to int that will be updated to contains the pubkey's
* length.
* length (cannot be NULL)
* Returns: 1: secret was valid, public key stores
* 0: secret was invalid, try again.
* Requires starting using SECP256K1_START_SIGN.
@ -110,8 +119,8 @@ int secp256k1_ec_pubkey_create(unsigned char *pubkey, int *pubkeylen, const unsi
/** Decompress a public key.
* 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.
* pubkeylen: pointer to the size of the public key pointed to be pubkey.
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.