EC_KEY_new.pod 8.1 KB

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  1. =pod
  2. =head1 NAME
  3. EC_KEY_get_method, EC_KEY_set_method,
  4. EC_KEY_new, EC_KEY_get_flags, EC_KEY_set_flags, EC_KEY_clear_flags,
  5. EC_KEY_new_by_curve_name, EC_KEY_free, EC_KEY_copy, EC_KEY_dup, EC_KEY_up_ref,
  6. EC_KEY_get0_engine,
  7. EC_KEY_get0_group, EC_KEY_set_group, EC_KEY_get0_private_key,
  8. EC_KEY_set_private_key, EC_KEY_get0_public_key, EC_KEY_set_public_key,
  9. EC_KEY_get_conv_form,
  10. EC_KEY_set_conv_form, EC_KEY_set_asn1_flag, EC_KEY_precompute_mult,
  11. EC_KEY_generate_key, EC_KEY_check_key, EC_KEY_set_public_key_affine_coordinates,
  12. EC_KEY_oct2key, EC_KEY_key2buf, EC_KEY_oct2priv, EC_KEY_priv2oct,
  13. EC_KEY_priv2buf - Functions for creating, destroying and manipulating
  14. EC_KEY objects
  15. =head1 SYNOPSIS
  16. #include <openssl/ec.h>
  17. EC_KEY *EC_KEY_new(void);
  18. int EC_KEY_get_flags(const EC_KEY *key);
  19. void EC_KEY_set_flags(EC_KEY *key, int flags);
  20. void EC_KEY_clear_flags(EC_KEY *key, int flags);
  21. EC_KEY *EC_KEY_new_by_curve_name(int nid);
  22. void EC_KEY_free(EC_KEY *key);
  23. EC_KEY *EC_KEY_copy(EC_KEY *dst, const EC_KEY *src);
  24. EC_KEY *EC_KEY_dup(const EC_KEY *src);
  25. int EC_KEY_up_ref(EC_KEY *key);
  26. ENGINE *EC_KEY_get0_engine(const EC_KEY *eckey);
  27. const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key);
  28. int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group);
  29. const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key);
  30. int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *prv);
  31. const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key);
  32. int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub);
  33. point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key);
  34. void EC_KEY_set_conv_form(EC_KEY *eckey, point_conversion_form_t cform);
  35. void EC_KEY_set_asn1_flag(EC_KEY *eckey, int asn1_flag);
  36. int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx);
  37. int EC_KEY_generate_key(EC_KEY *key);
  38. int EC_KEY_check_key(const EC_KEY *key);
  39. int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x, BIGNUM *y);
  40. const EC_KEY_METHOD *EC_KEY_get_method(const EC_KEY *key);
  41. int EC_KEY_set_method(EC_KEY *key, const EC_KEY_METHOD *meth);
  42. int EC_KEY_oct2key(EC_KEY *eckey, const unsigned char *buf, size_t len, BN_CTX *ctx);
  43. size_t EC_KEY_key2buf(const EC_KEY *eckey, point_conversion_form_t form,
  44. unsigned char **pbuf, BN_CTX *ctx);
  45. int EC_KEY_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len);
  46. size_t EC_KEY_priv2oct(const EC_KEY *eckey, unsigned char *buf, size_t len);
  47. size_t EC_KEY_priv2buf(const EC_KEY *eckey, unsigned char **pbuf);
  48. =head1 DESCRIPTION
  49. An EC_KEY represents a public key and, optionally, the associated private
  50. key. A new EC_KEY with no associated curve can be constructed by calling
  51. EC_KEY_new(). The reference count for the newly created EC_KEY is initially
  52. set to 1. A curve can be associated with the EC_KEY by calling
  53. EC_KEY_set_group().
  54. Alternatively a new EC_KEY can be constructed by calling
  55. EC_KEY_new_by_curve_name() and supplying the nid of the associated curve. See
  56. L<EC_GROUP_new(3)> for a description of curve names. This function simply
  57. wraps calls to EC_KEY_new() and EC_GROUP_new_by_curve_name().
  58. Calling EC_KEY_free() decrements the reference count for the EC_KEY object,
  59. and if it has dropped to zero then frees the memory associated with it. If
  60. B<key> is NULL nothing is done.
  61. EC_KEY_copy() copies the contents of the EC_KEY in B<src> into B<dest>.
  62. EC_KEY_dup() creates a new EC_KEY object and copies B<ec_key> into it.
  63. EC_KEY_up_ref() increments the reference count associated with the EC_KEY
  64. object.
  65. EC_KEY_get0_engine() returns a handle to the ENGINE that has been set for
  66. this EC_KEY object.
  67. EC_KEY_generate_key() generates a new public and private key for the supplied
  68. B<eckey> object. B<eckey> must have an EC_GROUP object associated with it
  69. before calling this function. The private key is a random integer (0 < priv_key
  70. < order, where I<order> is the order of the EC_GROUP object). The public key is
  71. an EC_POINT on the curve calculated by multiplying the generator for the
  72. curve by the private key.
  73. EC_KEY_check_key() performs various sanity checks on the EC_KEY object to
  74. confirm that it is valid.
  75. EC_KEY_set_public_key_affine_coordinates() sets the public key for B<key> based
  76. on its affine co-ordinates; i.e., it constructs an EC_POINT object based on
  77. the supplied B<x> and B<y> values and sets the public key to be this
  78. EC_POINT. It also performs certain sanity checks on the key to confirm
  79. that it is valid.
  80. The functions EC_KEY_get0_group(), EC_KEY_set_group(),
  81. EC_KEY_get0_private_key(), EC_KEY_set_private_key(), EC_KEY_get0_public_key(),
  82. and EC_KEY_set_public_key() get and set the EC_GROUP object, the private key,
  83. and the EC_POINT public key for the B<key> respectively.
  84. The functions EC_KEY_get_conv_form() and EC_KEY_set_conv_form() get and set the
  85. point_conversion_form for the B<key>. For a description of
  86. point_conversion_forms please see L<EC_POINT_new(3)>.
  87. EC_KEY_set_flags() sets the flags in the B<flags> parameter on the EC_KEY
  88. object. Any flags that are already set are left set. The flags currently
  89. defined are EC_FLAG_NON_FIPS_ALLOW and EC_FLAG_FIPS_CHECKED. In
  90. addition there is the flag EC_FLAG_COFACTOR_ECDH which is specific to ECDH.
  91. EC_KEY_get_flags() returns the current flags that are set for this EC_KEY.
  92. EC_KEY_clear_flags() clears the flags indicated by the B<flags> parameter; all
  93. other flags are left in their existing state.
  94. EC_KEY_set_asn1_flag() sets the asn1_flag on the underlying EC_GROUP object
  95. (if set). Refer to L<EC_GROUP_copy(3)> for further information on the
  96. asn1_flag.
  97. EC_KEY_precompute_mult() stores multiples of the underlying EC_GROUP generator
  98. for faster point multiplication. See also L<EC_POINT_add(3)>.
  99. EC_KEY_oct2key() and EC_KEY_key2buf() are identical to the functions
  100. EC_POINT_oct2point() and EC_KEY_point2buf() except they use the public key
  101. EC_POINT in B<eckey>.
  102. EC_KEY_oct2priv() and EC_KEY_priv2oct() convert between the private key
  103. component of B<eckey> and octet form. The octet form consists of the content
  104. octets of the B<privateKey> OCTET STRING in an B<ECPrivateKey> ASN.1 structure.
  105. The function EC_KEY_priv2oct() must be supplied with a buffer long enough to
  106. store the octet form. The return value provides the number of octets stored.
  107. Calling the function with a NULL buffer will not perform the conversion but
  108. will just return the required buffer length.
  109. The function EC_KEY_priv2buf() allocates a buffer of suitable length and writes
  110. an EC_KEY to it in octet format. The allocated buffer is written to B<*pbuf>
  111. and its length is returned. The caller must free up the allocated buffer with a
  112. call to OPENSSL_free(). Since the allocated buffer value is written to B<*pbuf>
  113. the B<pbuf> parameter B<MUST NOT> be B<NULL>.
  114. EC_KEY_priv2buf() converts an EC_KEY private key into an allocated buffer.
  115. =head1 RETURN VALUES
  116. EC_KEY_new(), EC_KEY_new_by_curve_name() and EC_KEY_dup() return a pointer to
  117. the newly created EC_KEY object, or NULL on error.
  118. EC_KEY_get_flags() returns the flags associated with the EC_KEY object as an
  119. integer.
  120. EC_KEY_copy() returns a pointer to the destination key, or NULL on error.
  121. EC_KEY_get0_engine() returns a pointer to an ENGINE, or NULL if it wasn't set.
  122. EC_KEY_up_ref(), EC_KEY_set_group(), EC_KEY_set_private_key(),
  123. EC_KEY_set_public_key(), EC_KEY_precompute_mult(), EC_KEY_generate_key(),
  124. EC_KEY_check_key(), EC_KEY_set_public_key_affine_coordinates(),
  125. EC_KEY_oct2key() and EC_KEY_oct2priv() return 1 on success or 0 on error.
  126. EC_KEY_get0_group() returns the EC_GROUP associated with the EC_KEY.
  127. EC_KEY_get0_private_key() returns the private key associated with the EC_KEY.
  128. EC_KEY_get_conv_form() return the point_conversion_form for the EC_KEY.
  129. EC_KEY_key2buf(), EC_KEY_priv2oct() and EC_KEY_priv2buf() return the length
  130. of the buffer or 0 on error.
  131. =head1 SEE ALSO
  132. L<crypto(7)>, L<EC_GROUP_new(3)>,
  133. L<EC_GROUP_copy(3)>, L<EC_POINT_new(3)>,
  134. L<EC_POINT_add(3)>,
  135. L<EC_GFp_simple_method(3)>,
  136. L<d2i_ECPKParameters(3)>
  137. =head1 COPYRIGHT
  138. Copyright 2013-2017 The OpenSSL Project Authors. All Rights Reserved.
  139. Licensed under the OpenSSL license (the "License"). You may not use
  140. this file except in compliance with the License. You can obtain a copy
  141. in the file LICENSE in the source distribution or at
  142. L<https://www.openssl.org/source/license.html>.
  143. =cut