# Nid_x9_62_prime256v1

Low-level operations on elliptic curves.

Source code for pycoin.ecdsa.secp256r1. From.Generator import Generator from.native.openssl import createOpenSSLOptimizations, NIDX962prime256v1 p. Enable perfect forward secrecy with NIDX962prime256v1. Patch Instructions: To install this SUSE Recommended Update use the SUSE recommended installation methods like YaST onlineupdate or 'zypper patch'. Alternatively you can run the command listed for your product: SUSE Linux Enterprise Software Development Kit 12-SP3.

NIDX962prime256v1 curve. Writes the public key into a file (let the user choose the name). Then loads the peer public key from a file (let the user choose the name) 3. Derives a shared secret from the generated private key and the peer public key. Write a single source file and then try it by launching two different processes from the. NIDX962prime256v1 (aka NIST P-256) is default curve used in SecureMessage.Themis also can be re-compiled manually with p384 and p521 (need to change default curve in code and re-compile). prev in list next in list prev in thread next in thread List: openssl-dev Subject: Re: EVP and Elliptic curve From: Matt Caswell.

point_conversion_form_t enumerates forms, as defined in X9.62 (ECDSA), for the encoding of a elliptic curve point (x,y)

EC_GROUP_new_by_curve_name returns a fresh EC_GROUP object for the elliptic curve specified by `nid`, or NULL on unsupported NID or allocation failure.

The supported NIDs are:

NID_secp224r1 (P-224),

NID_X9_62_prime256v1 (P-256),

NID_secp384r1 (P-384),

NID_secp521r1 (P-521)

If in doubt, use `NID_X9_62_prime256v1`, or see the curve25519.h header for more modern primitives.

EC_GROUP_dup takes a reference to `a` and returns it.

EC_GROUP_cmp returns zero if `a` and `b` are the same group and non-zero otherwise.

EC_GROUP_get0_generator returns a pointer to the internal `EC_POINT` object in `group` that specifies the generator for the group.

EC_GROUP_get0_order returns a pointer to the internal `BIGNUM` object in `group` that specifies the order of the group.

EC_GROUP_order_bits returns the number of bits of the order of `group`.

EC_GROUP_get_cofactor sets `*cofactor` to the cofactor of `group` using `ctx`, if it's not NULL. It returns one on success and zero otherwise.

EC_GROUP_get_curve_GFp gets various parameters about a group. It sets `*out_p` to the order of the coordinate field and `*out_a` and `*out_b` to the parameters of the curve when expressed as y² = x³ + ax + b. Any of the output parameters can be NULL. It returns one on success and zero on error.

EC_GROUP_get_curve_name returns a NID that identifies `group`.

EC_GROUP_get_degree returns the number of bits needed to represent an element of the field underlying `group`.

EC_curve_nid2nist returns the NIST name of the elliptic curve specified by `nid`, or NULL if `nid` is not a NIST curve. For example, it returns 'P-256' for `NID_X9_62_prime256v1`.

EC_curve_nist2nid returns the NID of the elliptic curve specified by the NIST name `name`, or `NID_undef` if `name` is not a recognized name. For example, it returns `NID_X9_62_prime256v1` for 'P-256'.

EC_POINT_new returns a fresh `EC_POINT` object in the given group, or NULL on error.

EC_POINT_free frees `point` and the data that it points to.

EC_POINT_copy sets `*dest` equal to `*src`. It returns one on success and zero otherwise.

EC_POINT_dup returns a fresh `EC_POINT` that contains the same values as `src`, or NULL on error.

### Nid_x9_62_prime256v1 Openssl

EC_POINT_set_to_infinity sets `point` to be the 'point at infinity' for the given group.

EC_POINT_is_at_infinity returns one iff `point` is the point at infinity and zero otherwise.

EC_POINT_is_on_curve returns one if `point` is an element of `group` and and zero otherwise or when an error occurs. This is different from OpenSSL, which returns -1 on error. If `ctx` is non-NULL, it may be used.

EC_POINT_cmp returns zero if `a` is equal to `b`, greater than zero if not equal and -1 on error. If `ctx` is not NULL, it may be used.

EC_POINT_get_affine_coordinates_GFp sets `x` and `y` to the affine value of `point` using `ctx`, if it's not NULL. It returns one on success and zero otherwise.

Either`x` or `y` may be NULL to skip computing that coordinate. This is slightly faster in the common case where only the x-coordinate is needed.

EC_POINT_get_affine_coordinates is an alias of `EC_POINT_get_affine_coordinates_GFp`.

EC_POINT_set_affine_coordinates_GFp sets the value of `point` to be (`x`, `y`). The `ctx` argument may be used if not NULL. It returns one on success or zero on error. It's considered an error if the point is not on the curve.

Note that the corresponding function in OpenSSL versions prior to 1.0.2s does not check if the point is on the curve. This is a security-critical check, so code additionally supporting OpenSSL should repeat the check with `EC_POINT_is_on_curve` or check for older OpenSSL versions with `OPENSSL_VERSION_NUMBER`.

EC_POINT_set_affine_coordinates is an alias of `EC_POINT_set_affine_coordinates_GFp`.

EC_POINT_point2oct serialises `point` into the X9.62 form given by `form` into, at most, `len` bytes at `buf`. It returns the number of bytes written or zero on error if `buf` is non-NULL, else the number of bytes needed. The `ctx` argument may be used if not NULL.

EC_POINT_point2cbb behaves like `EC_POINT_point2oct` but appends the serialised point to `cbb`. It returns one on success and zero on error.

EC_POINT_oct2point sets `point` from `len` bytes of X9.62 format serialisation in `buf`. It returns one on success and zero on error. The `ctx` argument may be used if not NULL. It's considered an error if `buf` does not represent a point on the curve.

EC_POINT_set_compressed_coordinates_GFp sets `point` to equal the point with the given `x` coordinate and the y coordinate specified by `y_bit` (see X9.62). It returns one on success and zero otherwise.

EC_POINT_add sets `r` equal to `a` plus `b`. It returns one on success and zero otherwise. If `ctx` is not NULL, it may be used.

EC_POINT_dbl sets `r` equal to `a` plus `a`. It returns one on success and zero otherwise. If `ctx` is not NULL, it may be used.

EC_POINT_invert sets `a` equal to minus `a`. It returns one on success and zero otherwise. If `ctx` is not NULL, it may be used.

EC_POINT_mul sets r = generator*n + q*m. It returns one on success and zero otherwise. If `ctx` is not NULL, it may be used.

EC_GROUP_new_curve_GFp creates a new, arbitrary elliptic curve group based on the equation y² = x³ + a·x + b. It returns the new group or NULL on error.

This new group has no generator. It is an error to use a generator-less group with any functions except for `EC_GROUP_free`, `EC_POINT_new`, `EC_POINT_set_affine_coordinates_GFp`, and `EC_GROUP_set_generator`.

`EC_GROUP`s returned by this function will always compare as unequal via `EC_GROUP_cmp` (even to themselves). `EC_GROUP_get_curve_name` will always return `NID_undef`.

Avoid using arbitrary curves and use `EC_GROUP_new_by_curve_name` instead.

EC_GROUP_set_generator sets the generator for `group` to `generator`, which must have the given order and cofactor. It may only be used with `EC_GROUP` objects returned by `EC_GROUP_new_curve_GFp` and may only be used once on each group. `generator` must have been created using `group`.

EC_GROUP_get_order sets `*order` to the order of `group`, if it's not NULL. It returns one on success and zero otherwise. `ctx` is ignored. Use `EC_GROUP_get0_order` instead.

EC_GROUP_get_asn1_flag returns `OPENSSL_EC_NAMED_CURVE`.

EC_GROUP_method_of returns a dummy non-NULL pointer.

EC_METHOD_get_field_type returns NID_X9_62_prime_field.

EC_GROUP_set_point_conversion_form aborts the process if `form` is not `POINT_CONVERSION_UNCOMPRESSED` and otherwise does nothing.

EC_builtin_curve describes a supported elliptic curve.

EC_get_builtin_curves writes at most `max_num_curves` elements to `out_curves` and returns the total number that it would have written, had `max_num_curves` been large enough.

### Nid_x9_62_prime256v1

The `EC_builtin_curve` items describe the supported elliptic curves.