diff options
Diffstat (limited to 'src/secp256k1/include/secp256k1.h')
| -rw-r--r-- | src/secp256k1/include/secp256k1.h | 49 |
1 files changed, 47 insertions, 2 deletions
diff --git a/src/secp256k1/include/secp256k1.h b/src/secp256k1/include/secp256k1.h index 3e9c098d19..43af09c330 100644 --- a/src/secp256k1/include/secp256k1.h +++ b/src/secp256k1/include/secp256k1.h @@ -42,6 +42,19 @@ extern "C" { */ 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 @@ -166,6 +179,13 @@ typedef int (*secp256k1_nonce_function)( #define SECP256K1_TAG_PUBKEY_HYBRID_EVEN 0x06 #define SECP256K1_TAG_PUBKEY_HYBRID_ODD 0x07 +/** A simple secp256k1 context object with no precomputed tables. These are useful for + * type serialization/parsing functions which require a context object to maintain + * API consistency, but currently do not require expensive precomputations or dynamic + * allocations. + */ +SECP256K1_API extern const secp256k1_context *secp256k1_context_no_precomp; + /** Create a secp256k1 context object. * * Returns: a newly created context object. @@ -243,6 +263,26 @@ SECP256K1_API void secp256k1_context_set_error_callback( 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. @@ -498,7 +538,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_create( * * Returns: 1 always * Args: ctx: pointer to a context object - * In/Out: pubkey: pointer to the public key to be negated (cannot be NULL) + * 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, @@ -575,7 +615,7 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_mul( ) 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 + * Returns: 1: randomization successfully updated or nothing to randomize * 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) @@ -590,6 +630,11 @@ SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_mul( * that it does not affect function results, but shields against attacks which * rely on any input-dependent behaviour. * + * This function has currently an effect only on contexts initialized for signing + * because randomization is currently used only for signing. However, this is not + * guaranteed and may change in the future. It is safe to call this function on + * contexts not initialized for signing; then it will have no effect and return 1. + * * You should call this after secp256k1_context_create or * secp256k1_context_clone, and may call this repeatedly afterwards. */ |