diff options
Diffstat (limited to 'doc/crypto/d2i_ECPKParameters.pod')
| -rw-r--r-- | doc/crypto/d2i_ECPKParameters.pod | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/doc/crypto/d2i_ECPKParameters.pod b/doc/crypto/d2i_ECPKParameters.pod new file mode 100644 index 0000000000..3768c410d8 --- /dev/null +++ b/doc/crypto/d2i_ECPKParameters.pod @@ -0,0 +1,84 @@ +=pod + +=head1 NAME + +d2i_ECPKParameters, i2d_ECPKParameters, d2i_ECPKParameters_bio, i2d_ECPKParameters_bio, d2i_ECPKParameters_fp, i2d_ECPKParameters_fp(fp,x), ECPKParameters_print, ECPKParameters_print_fp - Functions for decoding and encoding ASN1 representations of elliptic curve entities + +=head1 SYNOPSIS + + #include <openssl/ec.h> + + EC_GROUP *d2i_ECPKParameters(EC_GROUP **px, const unsigned char **in, long len); + int i2d_ECPKParameters(const EC_GROUP *x, unsigned char **out); + #define d2i_ECPKParameters_bio(bp,x) ASN1_d2i_bio_of(EC_GROUP,NULL,d2i_ECPKParameters,bp,x) + #define i2d_ECPKParameters_bio(bp,x) ASN1_i2d_bio_of_const(EC_GROUP,i2d_ECPKParameters,bp,x) + #define d2i_ECPKParameters_fp(fp,x) (EC_GROUP *)ASN1_d2i_fp(NULL, \ + (char *(*)())d2i_ECPKParameters,(fp),(unsigned char **)(x)) + #define i2d_ECPKParameters_fp(fp,x) ASN1_i2d_fp(i2d_ECPKParameters,(fp), \ + (unsigned char *)(x)) + int ECPKParameters_print(BIO *bp, const EC_GROUP *x, int off); + int ECPKParameters_print_fp(FILE *fp, const EC_GROUP *x, int off); + + +=head1 DESCRIPTION + +The ECPKParameters encode and decode routines encode and parse the public parameters for an +B<EC_GROUP> structure, which represents a curve. + +d2i_ECPKParameters() attempts to decode B<len> bytes at B<*in>. If +successful a pointer to the B<EC_GROUP> structure is returned. If an error +occurred then B<NULL> is returned. If B<px> is not B<NULL> then the +returned structure is written to B<*px>. If B<*px> is not B<NULL> +then it is assumed that B<*px> contains a valid B<EC_GROUP> +structure and an attempt is made to reuse it. If the call is +successful B<*in> is incremented to the byte following the +parsed data. + +i2d_ECPKParameters() encodes the structure pointed to by B<x> into DER format. +If B<out> is not B<NULL> is writes the DER encoded data to the buffer +at B<*out>, and increments it to point after the data just written. +If the return value is negative an error occurred, otherwise it +returns the length of the encoded data. + +If B<*out> is B<NULL> memory will be allocated for a buffer and the encoded +data written to it. In this case B<*out> is not incremented and it points to +the start of the data just written. + +d2i_ECPKParameters_bio() is similar to d2i_ECPKParameters() except it attempts +to parse data from BIO B<bp>. + +d2i_ECPKParameters_fp() is similar to d2i_ECPKParameters() except it attempts +to parse data from FILE pointer B<fp>. + +i2d_ECPKParameters_bio() is similar to i2d_ECPKParameters() except it writes +the encoding of the structure B<x> to BIO B<bp> and it +returns 1 for success and 0 for failure. + +i2d_ECPKParameters_fp() is similar to i2d_ECPKParameters() except it writes +the encoding of the structure B<x> to BIO B<bp> and it +returns 1 for success and 0 for failure. + +These functions are very similar to the X509 functions described in L<d2i_X509(3)|d2i_X509(3)>, +where further notes and examples are available. + +The ECPKParameters_print and ECPKParameters_print_fp functions print a human-readable output +of the public parameters of the EC_GROUP to B<bp> or B<fp>. The output lines are indented by B<off> spaces. + +=head1 RETURN VALUES + +d2i_ECPKParameters(), d2i_ECPKParameters_bio() and d2i_ECPKParameters_fp() return a valid B<EC_GROUP> structure +or B<NULL> if an error occurs. + +i2d_ECPKParameters() returns the number of bytes successfully encoded or a negative +value if an error occurs. + +i2d_ECPKParameters_bio(), i2d_ECPKParameters_fp(), ECPKParameters_print and ECPKParameters_print_fp +return 1 for success and 0 if an error occurs. + +=head1 SEE ALSO + +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)>, +L<EC_POINT_new(3)|EC_POINT_new(3)>, L<EC_POINT_add(3)|EC_POINT_add(3)>, L<EC_KEY_new(3)|EC_KEY_new(3)>, +L<EC_GFp_simple_method(3)|EC_GFp_simple_method(3)>, L<d2i_X509(3)|d2i_X509(3)> + +=cut |