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Diffstat (limited to 'src/lib/libcrypto/doc/EC_POINT_new.pod')
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diff --git a/src/lib/libcrypto/doc/EC_POINT_new.pod b/src/lib/libcrypto/doc/EC_POINT_new.pod new file mode 100644 index 0000000000..69eb0d1a09 --- /dev/null +++ b/src/lib/libcrypto/doc/EC_POINT_new.pod | |||
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| 1 | =pod | ||
| 2 | |||
| 3 | =head1 NAME | ||
| 4 | |||
| 5 | EC_POINT_new, EC_POINT_free, EC_POINT_clear_free, EC_POINT_copy, EC_POINT_dup, EC_POINT_method_of, EC_POINT_set_to_infinity, EC_POINT_set_Jprojective_coordinates, EC_POINT_get_Jprojective_coordinates_GFp, EC_POINT_set_affine_coordinates_GFp, EC_POINT_get_affine_coordinates_GFp, EC_POINT_set_compressed_coordinates_GFp, EC_POINT_set_affine_coordinates_GF2m, EC_POINT_get_affine_coordinates_GF2m, EC_POINT_set_compressed_coordinates_GF2m, EC_POINT_point2oct, EC_POINT_oct2point, EC_POINT_point2bn, EC_POINT_bn2point, EC_POINT_point2hex, EC_POINT_hex2point - Functions for creating, destroying and manipulating B<EC_POINT> objects. | ||
| 6 | |||
| 7 | =head1 SYNOPSIS | ||
| 8 | |||
| 9 | #include <openssl/ec.h> | ||
| 10 | #include <openssl/bn.h> | ||
| 11 | |||
| 12 | EC_POINT *EC_POINT_new(const EC_GROUP *group); | ||
| 13 | void EC_POINT_free(EC_POINT *point); | ||
| 14 | void EC_POINT_clear_free(EC_POINT *point); | ||
| 15 | int EC_POINT_copy(EC_POINT *dst, const EC_POINT *src); | ||
| 16 | EC_POINT *EC_POINT_dup(const EC_POINT *src, const EC_GROUP *group); | ||
| 17 | const EC_METHOD *EC_POINT_method_of(const EC_POINT *point); | ||
| 18 | int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point); | ||
| 19 | int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group, EC_POINT *p, | ||
| 20 | const BIGNUM *x, const BIGNUM *y, const BIGNUM *z, BN_CTX *ctx); | ||
| 21 | int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group, | ||
| 22 | const EC_POINT *p, BIGNUM *x, BIGNUM *y, BIGNUM *z, BN_CTX *ctx); | ||
| 23 | int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group, EC_POINT *p, | ||
| 24 | const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx); | ||
| 25 | int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group, | ||
| 26 | const EC_POINT *p, BIGNUM *x, BIGNUM *y, BN_CTX *ctx); | ||
| 27 | int EC_POINT_set_compressed_coordinates_GFp(const EC_GROUP *group, EC_POINT *p, | ||
| 28 | const BIGNUM *x, int y_bit, BN_CTX *ctx); | ||
| 29 | int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group, EC_POINT *p, | ||
| 30 | const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx); | ||
| 31 | int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group, | ||
| 32 | const EC_POINT *p, BIGNUM *x, BIGNUM *y, BN_CTX *ctx); | ||
| 33 | int EC_POINT_set_compressed_coordinates_GF2m(const EC_GROUP *group, EC_POINT *p, | ||
| 34 | const BIGNUM *x, int y_bit, BN_CTX *ctx); | ||
| 35 | size_t EC_POINT_point2oct(const EC_GROUP *group, const EC_POINT *p, | ||
| 36 | point_conversion_form_t form, | ||
| 37 | unsigned char *buf, size_t len, BN_CTX *ctx); | ||
| 38 | int EC_POINT_oct2point(const EC_GROUP *group, EC_POINT *p, | ||
| 39 | const unsigned char *buf, size_t len, BN_CTX *ctx); | ||
| 40 | BIGNUM *EC_POINT_point2bn(const EC_GROUP *, const EC_POINT *, | ||
| 41 | point_conversion_form_t form, BIGNUM *, BN_CTX *); | ||
| 42 | EC_POINT *EC_POINT_bn2point(const EC_GROUP *, const BIGNUM *, | ||
| 43 | EC_POINT *, BN_CTX *); | ||
| 44 | char *EC_POINT_point2hex(const EC_GROUP *, const EC_POINT *, | ||
| 45 | point_conversion_form_t form, BN_CTX *); | ||
| 46 | EC_POINT *EC_POINT_hex2point(const EC_GROUP *, const char *, | ||
| 47 | EC_POINT *, BN_CTX *); | ||
| 48 | |||
| 49 | |||
| 50 | =head1 DESCRIPTION | ||
| 51 | |||
| 52 | An EC_POINT represents a point on a curve. A new point is constructed by calling the function EC_POINT_new and providing the B<group> | ||
| 53 | object that the point relates to. | ||
| 54 | |||
| 55 | EC_POINT_free frees the memory associated with the EC_POINT. | ||
| 56 | |||
| 57 | EC_POINT_clear_free destroys any sensitive data held within the EC_POINT and then frees its memory. | ||
| 58 | |||
| 59 | EC_POINT_copy copies the point B<src> into B<dst>. Both B<src> and B<dst> must use the same EC_METHOD. | ||
| 60 | |||
| 61 | EC_POINT_dup creates a new EC_POINT object and copies the content from B<src> to the newly created | ||
| 62 | EC_POINT object. | ||
| 63 | |||
| 64 | EC_POINT_method_of obtains the EC_METHOD associated with B<point>. | ||
| 65 | |||
| 66 | A valid point on a curve is the special point at infinity. A point is set to be at infinity by calling EC_POINT_set_to_infinity. | ||
| 67 | |||
| 68 | The affine co-ordinates for a point describe a point in terms of its x and y position. The functions | ||
| 69 | EC_POINT_set_affine_coordinates_GFp and EC_POINT_set_affine_coordinates_GF2m set the B<x> and B<y> co-ordinates for the point | ||
| 70 | B<p> defined over the curve given in B<group>. | ||
| 71 | |||
| 72 | As well as the affine co-ordinates, a point can alternatively be described in terms of its Jacobian | ||
| 73 | projective co-ordinates (for Fp curves only). Jacobian projective co-ordinates are expressed as three values x, y and z. Working in | ||
| 74 | this co-ordinate system provides more efficient point multiplication operations. | ||
| 75 | A mapping exists between Jacobian projective co-ordinates and affine co-ordinates. A Jacobian projective co-ordinate (x, y, z) can be written as an affine co-ordinate as (x/(z^2), y/(z^3)). Conversion to Jacobian projective to affine co-ordinates is simple. The co-ordinate (x, y) is | ||
| 76 | mapped to (x, y, 1). To set or get the projective co-ordinates use EC_POINT_set_Jprojective_coordinates_GFp and | ||
| 77 | EC_POINT_get_Jprojective_coordinates_GFp respectively. | ||
| 78 | |||
| 79 | Points can also be described in terms of their compressed co-ordinates. For a point (x, y), for any given value for x such that the point is | ||
| 80 | on the curve there will only ever be two possible values for y. Therefore a point can be set using the EC_POINT_set_compressed_coordinates_GFp | ||
| 81 | and EC_POINT_set_compressed_coordinates_GF2m functions where B<x> is the x co-ordinate and B<y_bit> is a value 0 or 1 to identify which of | ||
| 82 | the two possible values for y should be used. | ||
| 83 | |||
| 84 | In addition EC_POINTs can be converted to and from various external representations. Supported representations are octet strings, BIGNUMs and hexadecimal. The format of the external representation is described by the point_conversion_form. See L<EC_GROUP_copy(3)|EC_GROUP_copy(3)> for | ||
| 85 | a description of point_conversion_form. Octet strings are stored in a buffer along with an associated buffer length. A point held in a BIGNUM is calculated by converting the point to an octet string and then converting that octet string into a BIGNUM integer. Points in hexadecimal format are stored in a NULL terminated character string where each character is one of the printable values 0-9 or A-F (or a-f). | ||
| 86 | |||
| 87 | The functions EC_POINT_point2oct, EC_POINT_oct2point, EC_POINT_point2bn, EC_POINT_bn2point, EC_POINT_point2hex and EC_POINT_hex2point convert | ||
| 88 | from and to EC_POINTs for the formats: octet string, BIGNUM and hexadecimal respectively. | ||
| 89 | |||
| 90 | The function EC_POINT_point2oct must be supplied with a buffer long enough to store the octet string. The return value provides the number of | ||
| 91 | octets stored. Calling the function with a NULL buffer will not perform the conversion but will still return the required buffer length. | ||
| 92 | |||
| 93 | The function EC_POINT_point2hex will allocate sufficient memory to store the hexadecimal string. It is the caller's responsibility to free | ||
| 94 | this memory with a subsequent call to OPENSSL_free(). | ||
| 95 | |||
| 96 | =head1 RETURN VALUES | ||
| 97 | |||
| 98 | EC_POINT_new and EC_POINT_dup return the newly allocated EC_POINT or NULL on error. | ||
| 99 | |||
| 100 | The following functions return 1 on success or 0 on error: EC_POINT_copy, EC_POINT_set_to_infinity, EC_POINT_set_Jprojective_coordinates_GFp, | ||
| 101 | EC_POINT_get_Jprojective_coordinates_GFp, EC_POINT_set_affine_coordinates_GFp, EC_POINT_get_affine_coordinates_GFp, | ||
| 102 | EC_POINT_set_compressed_coordinates_GFp, EC_POINT_set_affine_coordinates_GF2m, EC_POINT_get_affine_coordinates_GF2m, | ||
| 103 | EC_POINT_set_compressed_coordinates_GF2m and EC_POINT_oct2point. | ||
| 104 | |||
| 105 | EC_POINT_method_of returns the EC_METHOD associated with the supplied EC_POINT. | ||
| 106 | |||
| 107 | EC_POINT_point2oct returns the length of the required buffer, or 0 on error. | ||
| 108 | |||
| 109 | EC_POINT_point2bn returns the pointer to the BIGNUM supplied, or NULL on error. | ||
| 110 | |||
| 111 | EC_POINT_bn2point returns the pointer to the EC_POINT supplied, or NULL on error. | ||
| 112 | |||
| 113 | EC_POINT_point2hex returns a pointer to the hex string, or NULL on error. | ||
| 114 | |||
| 115 | EC_POINT_hex2point returns the pointer to the EC_POINT supplied, or NULL on error. | ||
| 116 | |||
| 117 | =head1 SEE ALSO | ||
| 118 | |||
| 119 | L<crypto(3)|crypto(3)>, L<ec(3)|ec(3)>, L<EC_GROUP_new(3)|EC_GROUP_new(3)>, L<EC_GROUP_copy(3)|EC_GROUP_copy(3)>, | ||
| 120 | L<EC_POINT_add(3)|EC_POINT_add(3)>, L<EC_KEY_new(3)|EC_KEY_new(3)>, | ||
| 121 | L<EC_GFp_simple_method(3)|EC_GFp_simple_method(3)>, L<d2i_ECPKParameters(3)|d2i_ECPKParameters(3)> | ||
| 122 | |||
| 123 | =cut | ||
