From 90c573eba184fe31184d14ce10367f810fa1d417 Mon Sep 17 00:00:00 2001 From: schwarze <> Date: Wed, 2 Nov 2016 11:57:56 +0000 Subject: convert DSA and EC manuals from pod to mdoc --- src/lib/libcrypto/man/EC_GROUP_copy.3 | 434 ++++++++++++++++++++++++++++++++++ 1 file changed, 434 insertions(+) create mode 100644 src/lib/libcrypto/man/EC_GROUP_copy.3 (limited to 'src/lib/libcrypto/man/EC_GROUP_copy.3') diff --git a/src/lib/libcrypto/man/EC_GROUP_copy.3 b/src/lib/libcrypto/man/EC_GROUP_copy.3 new file mode 100644 index 0000000000..61c094700a --- /dev/null +++ b/src/lib/libcrypto/man/EC_GROUP_copy.3 @@ -0,0 +1,434 @@ +.Dd $Mdocdate: November 2 2016 $ +.Dt EC_GROUP_COPY 3 +.Os +.Sh NAME +.Nm EC_GROUP_copy , +.Nm EC_GROUP_dup , +.Nm EC_GROUP_method_of , +.Nm EC_GROUP_set_generator , +.Nm EC_GROUP_get0_generator , +.Nm EC_GROUP_get_order , +.Nm EC_GROUP_get_cofactor , +.Nm EC_GROUP_set_curve_name , +.Nm EC_GROUP_get_curve_name , +.Nm EC_GROUP_set_asn1_flag , +.Nm EC_GROUP_get_asn1_flag , +.Nm EC_GROUP_set_point_conversion_form , +.Nm EC_GROUP_get_point_conversion_form , +.Nm EC_GROUP_get0_seed , +.Nm EC_GROUP_get_seed_len , +.Nm EC_GROUP_set_seed , +.Nm EC_GROUP_get_degree , +.Nm EC_GROUP_check , +.Nm EC_GROUP_check_discriminant , +.Nm EC_GROUP_cmp , +.Nm EC_GROUP_get_basis_type , +.Nm EC_GROUP_get_trinomial_basis , +.Nm EC_GROUP_get_pentanomial_basis +.Nd manipulate EC_GROUP objects +.Sh SYNOPSIS +.In openssl/ec.h +.In openssl/bn.h +.Ft int +.Fo EC_GROUP_copy +.Fa "EC_GROUP *dst" +.Fa "const EC_GROUP *src" +.Fc +.Ft EC_GROUP * +.Fo EC_GROUP_dup +.Fa "const EC_GROUP *src" +.Fc +.Ft const EC_METHOD * +.Fo EC_GROUP_method_of +.Fa "const EC_GROUP *group" +.Fc +.Ft int +.Fo EC_GROUP_set_generator +.Fa "EC_GROUP *group" +.Fa "const EC_POINT *generator" +.Fa "const BIGNUM *order" +.Fa "const BIGNUM *cofactor" +.Fc +.Ft const EC_POINT * +.Fo EC_GROUP_get0_generator +.Fa "const EC_GROUP *group" +.Fc +.Ft int +.Fo EC_GROUP_get_order +.Fa "const EC_GROUP *group" +.Fa "BIGNUM *order" +.Fa "BN_CTX *ctx" +.Fc +.Ft int +.Fo EC_GROUP_get_cofactor +.Fa "const EC_GROUP *group" +.Fa "BIGNUM *cofactor" +.Fa "BN_CTX *ctx" +.Fc +.Ft void +.Fo EC_GROUP_set_curve_name +.Fa "EC_GROUP *group" +.Fa "int nid" +.Fc +.Ft int +.Fo EC_GROUP_get_curve_name +.Fa "const EC_GROUP *group" +.Fc +.Ft void +.Fo EC_GROUP_set_asn1_flag +.Fa "EC_GROUP *group" +.Fa "int flag" +.Fc +.Ft int +.Fo EC_GROUP_get_asn1_flag +.Fa "const EC_GROUP *group" +.Fc +.Ft void +.Fo EC_GROUP_set_point_conversion_form +.Fa "EC_GROUP *group" +.Fa "point_conversion_form_t form" +.Fc +.Ft point_conversion_form_t +.Fo EC_GROUP_get_point_conversion_form +.Fa "const EC_GROUP *" +.Fc +.Ft unsigned char * +.Fo EC_GROUP_get0_seed +.Fa "const EC_GROUP *x" +.Fc +.Ft size_t +.Fo EC_GROUP_get_seed_len +.Fa "const EC_GROUP *" +.Fc +.Ft size_t +.Fo EC_GROUP_set_seed +.Fa "EC_GROUP *" +.Fa "const unsigned char *" +.Fa "size_t len" +.Fc +.Ft int +.Fo EC_GROUP_get_degree +.Fa "const EC_GROUP *group" +.Fc +.Ft int +.Fo EC_GROUP_check +.Fa "const EC_GROUP *group" +.Fa "BN_CTX *ctx" +.Fc +.Ft int +.Fo EC_GROUP_check_discriminant +.Fa "const EC_GROUP *group" +.Fa "BN_CTX *ctx" +.Fc +.Ft int +.Fo EC_GROUP_cmp +.Fa "const EC_GROUP *a" +.Fa "const EC_GROUP *b" +.Fa "BN_CTX *ctx" +.Fc +.Ft int +.Fo EC_GROUP_get_basis_type +.Fa "const EC_GROUP *" +.Fc +.Ft int +.Fo EC_GROUP_get_trinomial_basis +.Fa "const EC_GROUP *" +.Fa "unsigned int *k" +.Fc +.Ft int +.Fo EC_GROUP_get_pentanomial_basis +.Fa "const EC_GROUP *" +.Fa "unsigned int *k1" +.Fa "unsigned int *k2" +.Fa "unsigned int *k3" +.Fc +.Sh DESCRIPTION +.Fn EC_GROUP_copy +copies the curve +.Fa src +into +.Fa dst . +Both +.Fa src +and +.Fa dst +must use the same +.Vt EC_METHOD . +.Pp +.Fn EC_GROUP_dup +creates a new +.Vt EC_GROUP +object and copies the content from +.Fa src +to the newly created +.Vt EC_GROUP +object. +.Pp +.Fn EC_GROUP_method_of +obtains the +.Vt EC_METHOD +of +.Fa group . +.Pp +.Fn EC_GROUP_set_generator +sets curve paramaters that must be agreed by all participants using +the curve. +These paramaters include the +.Fa generator , +the +.Fa order +and the +.Fa cofactor . +The +.Fa generator +is a well defined point on the curve chosen for cryptographic +operations. +Integers used for point multiplications will be between 0 and +.Fa order No - 1 . +The +.Fa order +multipied by the +.Fa cofactor +gives the number of points on the curve. +.Pp +.Fn EC_GROUP_get0_generator +returns the generator for the identified +.Fa group . +.Pp +The functions +.Fn EC_GROUP_get_order +and +.Fn EC_GROUP_get_cofactor +populate the provided +.Fa order +and +.Fa cofactor +parameters with the respective order and cofactors for the +.Fa group . +.Pp +The functions +.Fn EC_GROUP_set_curve_name +and +.Fn EC_GROUP_get_curve_name +set and get the NID for the curve, respectively (see +.Xr EC_GROUP_new 3 ) . +If a curve does not have a NID associated with it, then +.Fn EC_GROUP_get_curve_name +will return 0. +.Pp +The asn1_flag value on a curve is used to determine whether there is a +specific ASN1 OID to describe the curve or not. +If the asn1_flag is 1 then this is a named curve with an associated ASN1 OID. +If not then asn1_flag is 0. +The functions +.Fn EC_GROUP_get_asn1_flag +and +.Fn EC_GROUP_set_asn1_flag +get and set the status of the asn1_flag for the curve. +If set, then the curve_name must also be set. +.Pp +The point_conversion_form for a curve controls how +.Vt EC_POINT +data is encoded as ASN1 as defined in X9.62 (ECDSA). +.Vt point_conversion_form_t +is an enum defined as follows: +.Bd -literal +typedef enum { + /** the point is encoded as z||x, where the octet z specifies + * which solution of the quadratic equation y is */ + POINT_CONVERSION_COMPRESSED = 2, + /** the point is encoded as z||x||y, where z is the octet 0x02 */ + POINT_CONVERSION_UNCOMPRESSED = 4, + /** the point is encoded as z||x||y, where the octet z specifies + * which solution of the quadratic equation y is */ + POINT_CONVERSION_HYBRID = 6 +} point_conversion_form_t; +.Ed +.Pp +For +.Dv POINT_CONVERSION_UNCOMPRESSED +the point is encoded as an octet signifying the UNCOMPRESSED form +has been used followed by the octets for x, followed by the octets +for y. +.Pp +For any given x co-ordinate for a point on a curve it is possible to +derive two possible y values. +For +.Dv POINT_CONVERSION_COMPRESSED +the point is encoded as an octet signifying that the COMPRESSED +form has been used AND which of the two possible solutions for y +has been used, followed by the octets for x. +.Pp +For +.Dv POINT_CONVERSION_HYBRID +the point is encoded as an octet signifying the HYBRID form has +been used AND which of the two possible solutions for y has been +used, followed by the octets for x, followed by the octets for y. +.Pp +The functions +.Fn EC_GROUP_set_point_conversion_form +and +.Fn EC_GROUP_get_point_conversion_form +set and get the point_conversion_form for the curve, respectively. +.Pp +ANSI X9.62 (ECDSA standard) defines a method of generating the curve +parameter b from a random number. +This provides advantages in that a parameter obtained in this way is +highly unlikely to be susceptible to special purpose attacks, or have +any trapdoors in it. +If the seed is present for a curve then the b parameter was generated in +a verifiable fashion using that seed. +The OpenSSL EC library does not use this seed value but does enable you +to inspect it using +.Fn EC_GROUP_get0_seed . +This returns a pointer to a memory block containing the seed that was +used. +The length of the memory block can be obtained using +.Fn EC_GROUP_get_seed_len . +A number of the builtin curves within the library provide seed values +that can be obtained. +It is also possible to set a custom seed using +.Fn EC_GROUP_set_seed +and passing a pointer to a memory block, along with the length of +the seed. +Again, the EC library will not use this seed value, although it will be +preserved in any ASN1 based communications. +.Pp +.Fn EC_GROUP_get_degree +gets the degree of the field. +For Fp fields this will be the number of bits in p. +For F2^m fields this will be the value m. +.Pp +The function +.Fn EC_GROUP_check_discriminant +calculates the discriminant for the curve and verifies that it is +valid. +For a curve defined over Fp the discriminant is given by the formula +4*a^3 + 27*b^2 whilst for F2^m curves the discriminant is simply b. +In either case for the curve to be valid the discriminant must be +non-zero. +.Pp +The function +.Fn EC_GROUP_check +performs a number of checks on a curve to verify that it is valid. +Checks performed include verifying that the discriminant is non zero; +that a generator has been defined; that the generator is on the curve +and has the correct order. +.Pp +.Fn EC_GROUP_cmp +compares +.Fa a +and +.Fa b +to determine whether they represent the same curve or not. +.Pp +The functions +.Fn EC_GROUP_get_basis_type , +.Fn EC_GROUP_get_trinomial_basis , +and +.Fn EC_GROUP_get_pentanomial_basis +should only be called for curves defined over an F2^m field. +Addition and multiplication operations within an F2^m field are +performed using an irreducible polynomial function f(x). +This function is either a trinomial of the form: +.Pp +.Dl f(x) = x^m + x^k + 1 with m > k >= 1 +.Pp +or a pentanomial of the form: +.Pp +.Dl f(x) = x^m + x^k3 + x^k2 + x^k1 + 1 with m > k3 > k2 > k1 >= 1 +.Pp +The function +.Fn EC_GROUP_get_basis_type +returns a NID identifying whether a trinomial or pentanomial is in +use for the field. +The function +.Fn EC_GROUP_get_trinomial_basis +must only be called where f(x) is of the trinomial form, and returns +the value of +.Fa k . +Similarly, the function +.Fn EC_GROUP_get_pentanomial_basis +must only be called where f(x) is of the pentanomial form, and +returns the values of +.Fa k1 , +.Fa k2 , +and +.Fa k3 . +.Sh RETURN VALUES +The following functions return 1 on success or 0 on error: +.Fn EC_GROUP_copy , +.Fn EC_GROUP_set_generator , +.Fn EC_GROUP_check , +.Fn EC_GROUP_check_discriminant , +.Fn EC_GROUP_get_trinomial_basis , +and +.Fn EC_GROUP_get_pentanomial_basis . +.Pp +.Fn EC_GROUP_dup +returns a pointer to the duplicated curve or +.Dv NULL +on error. +.Pp +.Fn EC_GROUP_method_of +returns the +.Vt EC_METHOD +implementation in use for the given curve or +.Dv NULL +on error. +.Pp +.Fn EC_GROUP_get0_generator +returns the generator for the given curve or +.Dv NULL +on error. +.Pp +.Fn EC_GROUP_get_order , +.Fn EC_GROUP_get_cofactor , +.Fn EC_GROUP_get_curve_name , +.Fn EC_GROUP_get_asn1_flag , +.Fn EC_GROUP_get_point_conversion_form , +and +.Fn EC_GROUP_get_degree +return the order, cofactor, curve name (NID), ASN1 flag, +point_conversion_form and degree for the specified curve, respectively. +If there is no curve name associated with a curve then +.Fn EC_GROUP_get_curve_name +returns 0. +.Pp +.Fn EC_GROUP_get0_seed +returns a pointer to the seed that was used to generate the parameter +b, or +.Dv NULL +if the seed is not specified. +.Fn EC_GROUP_get_seed_len +returns the length of the seed or 0 if the seed is not specified. +.Pp +.Fn EC_GROUP_set_seed +returns the length of the seed that has been set. +If the supplied seed is +.Dv NULL +or the supplied seed length is 0, the return value will be 1. +On error 0 is returned. +.Pp +.Fn EC_GROUP_cmp +returns 0 if the curves are equal, 1 if they are not equal, +or -1 on error. +.Pp +.Fn EC_GROUP_get_basis_type +returns the values +.Dv NID_X9_62_tpBasis +or +.Dv NID_X9_62_ppBasis +as defined in +.In openssl/obj_mac.h +for a trinomial or pentanomial, respectively. +Alternatively in the event of an error a 0 is returned. +.Sh SEE ALSO +.Xr crypto 3 , +.Xr d2i_ECPKParameters 3 , +.Xr ec 3 , +.Xr EC_GFp_simple_method 3 , +.Xr EC_GROUP_new 3 , +.Xr EC_KEY_new 3 , +.Xr EC_POINT_add 3 , +.Xr EC_POINT_new 3 -- cgit v1.2.3-55-g6feb