Update libsecp256k1.

This commit is contained in:
Pieter Wuille
2015-03-27 14:03:36 -07:00
38 changed files with 2529 additions and 1469 deletions

View File

@@ -78,7 +78,7 @@ SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_verify(
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(4);
/** A pointer to a function to deterministically generate a nonce.
* Returns: 1 if a nonce was succesfully generated. 0 will cause signing to fail.
* Returns: 1 if a nonce was successfully generated. 0 will cause signing to fail.
* 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)
* attempt: how many iterations we have tried to find a nonce.
@@ -97,7 +97,10 @@ typedef int (*secp256k1_nonce_function_t)(
const void *data
);
/** An implementation of RFC6979 (using HMAC-SHA256) as nonce generation function. */
/** 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.
*/
extern const secp256k1_nonce_function_t secp256k1_nonce_function_rfc6979;
/** A default safe nonce generation function (currently equal to secp256k1_nonce_function_rfc6979). */
@@ -106,15 +109,43 @@ extern const secp256k1_nonce_function_t secp256k1_nonce_function_default;
/** Create an ECDSA signature.
* Returns: 1: signature created
* 0: the nonce generation function failed
* 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)
* seckey: pointer to a 32-byte secret key (cannot be NULL, assumed to be valid)
* 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).
* to contain the actual signature length (<=72). If 0 is returned, this will be
* set to zero.
* Requires starting using SECP256K1_START_SIGN.
*
* The sig always has an s value in the lower half of the range (From 0x1
* to 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0,
* inclusive), unlike many other implementations.
* With ECDSA a third-party can can forge a second distinct signature
* of the same message given a single initial signature without knowing
* the key by setting s to its additive inverse mod-order, 'flipping' the
* sign of the random point R which is not included in the signature.
* Since the forgery is of the same message this 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 canonical 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. Adjusting it inside the signing
* function avoids the need to re-serialize or have curve specific
* constants outside of the library. By always using a canonical form
* even in applications where it isn't needed it becomes possible to
* impose a requirement later if a need is discovered.
* 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.
*/
int secp256k1_ecdsa_sign(
const unsigned char *msg32,
@@ -127,12 +158,13 @@ int secp256k1_ecdsa_sign(
/** Create a compact ECDSA signature (64 byte + recovery id).
* Returns: 1: signature created
* 0: the nonce generation function failed
* 0: the nonce generation function failed, or the secret key was invalid.
* In: msg32: the 32-byte message hash being signed (cannot be NULL)
* seckey: pointer to a 32-byte secret key (cannot be NULL, assumed to be valid)
* 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.
*/