EVP_MD_meth_new.pod 8.0 KB

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  1. =pod
  2. =head1 NAME
  3. EVP_MD_meth_new, EVP_MD_meth_dup, EVP_MD_meth_free,
  4. EVP_MD_meth_set_input_blocksize,
  5. EVP_MD_meth_set_result_size, EVP_MD_meth_set_app_datasize,
  6. EVP_MD_meth_set_flags, EVP_MD_meth_set_init, EVP_MD_meth_set_update,
  7. EVP_MD_meth_set_final, EVP_MD_meth_set_copy, EVP_MD_meth_set_cleanup,
  8. EVP_MD_meth_set_ctrl, EVP_MD_meth_get_input_blocksize,
  9. EVP_MD_meth_get_result_size, EVP_MD_meth_get_app_datasize,
  10. EVP_MD_meth_get_flags, EVP_MD_meth_get_init, EVP_MD_meth_get_update,
  11. EVP_MD_meth_get_final, EVP_MD_meth_get_copy, EVP_MD_meth_get_cleanup,
  12. EVP_MD_meth_get_ctrl
  13. - Routines to build up legacy EVP_MD methods
  14. =head1 SYNOPSIS
  15. #include <openssl/evp.h>
  16. Deprecated since OpenSSL 3.0, can be hidden entirely by defining
  17. B<OPENSSL_API_COMPAT> with a suitable version value, see
  18. L<openssl_user_macros(7)>:
  19. EVP_MD *EVP_MD_meth_new(int md_type, int pkey_type);
  20. void EVP_MD_meth_free(EVP_MD *md);
  21. EVP_MD *EVP_MD_meth_dup(const EVP_MD *md);
  22. int EVP_MD_meth_set_input_blocksize(EVP_MD *md, int blocksize);
  23. int EVP_MD_meth_set_result_size(EVP_MD *md, int resultsize);
  24. int EVP_MD_meth_set_app_datasize(EVP_MD *md, int datasize);
  25. int EVP_MD_meth_set_flags(EVP_MD *md, unsigned long flags);
  26. int EVP_MD_meth_set_init(EVP_MD *md, int (*init)(EVP_MD_CTX *ctx));
  27. int EVP_MD_meth_set_update(EVP_MD *md, int (*update)(EVP_MD_CTX *ctx,
  28. const void *data,
  29. size_t count));
  30. int EVP_MD_meth_set_final(EVP_MD *md, int (*final)(EVP_MD_CTX *ctx,
  31. unsigned char *md));
  32. int EVP_MD_meth_set_copy(EVP_MD *md, int (*copy)(EVP_MD_CTX *to,
  33. const EVP_MD_CTX *from));
  34. int EVP_MD_meth_set_cleanup(EVP_MD *md, int (*cleanup)(EVP_MD_CTX *ctx));
  35. int EVP_MD_meth_set_ctrl(EVP_MD *md, int (*ctrl)(EVP_MD_CTX *ctx, int cmd,
  36. int p1, void *p2));
  37. int EVP_MD_meth_get_input_blocksize(const EVP_MD *md);
  38. int EVP_MD_meth_get_result_size(const EVP_MD *md);
  39. int EVP_MD_meth_get_app_datasize(const EVP_MD *md);
  40. unsigned long EVP_MD_meth_get_flags(const EVP_MD *md);
  41. int (*EVP_MD_meth_get_init(const EVP_MD *md))(EVP_MD_CTX *ctx);
  42. int (*EVP_MD_meth_get_update(const EVP_MD *md))(EVP_MD_CTX *ctx,
  43. const void *data,
  44. size_t count);
  45. int (*EVP_MD_meth_get_final(const EVP_MD *md))(EVP_MD_CTX *ctx,
  46. unsigned char *md);
  47. int (*EVP_MD_meth_get_copy(const EVP_MD *md))(EVP_MD_CTX *to,
  48. const EVP_MD_CTX *from);
  49. int (*EVP_MD_meth_get_cleanup(const EVP_MD *md))(EVP_MD_CTX *ctx);
  50. int (*EVP_MD_meth_get_ctrl(const EVP_MD *md))(EVP_MD_CTX *ctx, int cmd,
  51. int p1, void *p2);
  52. =head1 DESCRIPTION
  53. All of the functions described on this page are deprecated.
  54. Applications should instead use the OSSL_PROVIDER APIs.
  55. The B<EVP_MD> type is a structure for digest method implementation.
  56. It can also have associated public/private key signing and verifying
  57. routines.
  58. EVP_MD_meth_new() creates a new B<EVP_MD> structure.
  59. These B<EVP_MD> structures are reference counted.
  60. EVP_MD_meth_dup() creates a copy of B<md>.
  61. EVP_MD_meth_free() decrements the reference count for the B<EVP_MD> structure.
  62. If the reference count drops to 0 then the structure is freed.
  63. EVP_MD_meth_set_input_blocksize() sets the internal input block size
  64. for the method B<md> to B<blocksize> bytes.
  65. EVP_MD_meth_set_result_size() sets the size of the result that the
  66. digest method in B<md> is expected to produce to B<resultsize> bytes.
  67. The digest method may have its own private data, which OpenSSL will
  68. allocate for it. EVP_MD_meth_set_app_datasize() should be used to
  69. set the size for it to B<datasize>.
  70. EVP_MD_meth_set_flags() sets the flags to describe optional
  71. behaviours in the particular B<md>. Several flags can be or'd
  72. together. The available flags are:
  73. =over 4
  74. =item EVP_MD_FLAG_ONESHOT
  75. This digest method can only handle one block of input.
  76. =item EVP_MD_FLAG_XOF
  77. This digest method is an extensible-output function (XOF) and supports
  78. the B<EVP_MD_CTRL_XOF_LEN> control.
  79. =item EVP_MD_FLAG_DIGALGID_NULL
  80. When setting up a DigestAlgorithmIdentifier, this flag will have the
  81. parameter set to NULL by default. Use this for PKCS#1. I<Note: if
  82. combined with EVP_MD_FLAG_DIGALGID_ABSENT, the latter will override.>
  83. =item EVP_MD_FLAG_DIGALGID_ABSENT
  84. When setting up a DigestAlgorithmIdentifier, this flag will have the
  85. parameter be left absent by default. I<Note: if combined with
  86. EVP_MD_FLAG_DIGALGID_NULL, the latter will be overridden.>
  87. =item EVP_MD_FLAG_DIGALGID_CUSTOM
  88. Custom DigestAlgorithmIdentifier handling via ctrl, with
  89. B<EVP_MD_FLAG_DIGALGID_ABSENT> as default. I<Note: if combined with
  90. EVP_MD_FLAG_DIGALGID_NULL, the latter will be overridden.>
  91. Currently unused.
  92. =item EVP_MD_FLAG_FIPS
  93. This digest method is suitable for use in FIPS mode.
  94. Currently unused.
  95. =back
  96. EVP_MD_meth_set_init() sets the digest init function for B<md>.
  97. The digest init function is called by EVP_Digest(), EVP_DigestInit(),
  98. EVP_DigestInit_ex(), EVP_SignInit, EVP_SignInit_ex(), EVP_VerifyInit()
  99. and EVP_VerifyInit_ex().
  100. EVP_MD_meth_set_update() sets the digest update function for B<md>.
  101. The digest update function is called by EVP_Digest(), EVP_DigestUpdate() and
  102. EVP_SignUpdate().
  103. EVP_MD_meth_set_final() sets the digest final function for B<md>.
  104. The digest final function is called by EVP_Digest(), EVP_DigestFinal(),
  105. EVP_DigestFinal_ex(), EVP_SignFinal() and EVP_VerifyFinal().
  106. EVP_MD_meth_set_copy() sets the function for B<md> to do extra
  107. computations after the method's private data structure has been copied
  108. from one B<EVP_MD_CTX> to another. If all that's needed is to copy
  109. the data, there is no need for this copy function.
  110. Note that the copy function is passed two B<EVP_MD_CTX *>, the private
  111. data structure is then available with EVP_MD_CTX_md_data().
  112. This copy function is called by EVP_MD_CTX_copy() and
  113. EVP_MD_CTX_copy_ex().
  114. EVP_MD_meth_set_cleanup() sets the function for B<md> to do extra
  115. cleanup before the method's private data structure is cleaned out and
  116. freed.
  117. Note that the cleanup function is passed a B<EVP_MD_CTX *>, the
  118. private data structure is then available with EVP_MD_CTX_md_data().
  119. This cleanup function is called by EVP_MD_CTX_reset() and
  120. EVP_MD_CTX_free().
  121. EVP_MD_meth_set_ctrl() sets the control function for B<md>.
  122. See L<EVP_MD_CTX_ctrl(3)> for the available controls.
  123. EVP_MD_meth_get_input_blocksize(), EVP_MD_meth_get_result_size(),
  124. EVP_MD_meth_get_app_datasize(), EVP_MD_meth_get_flags(),
  125. EVP_MD_meth_get_init(), EVP_MD_meth_get_update(),
  126. EVP_MD_meth_get_final(), EVP_MD_meth_get_copy(),
  127. EVP_MD_meth_get_cleanup() and EVP_MD_meth_get_ctrl() are all used
  128. to retrieve the method data given with the EVP_MD_meth_set_*()
  129. functions above.
  130. =head1 RETURN VALUES
  131. EVP_MD_meth_new() and EVP_MD_meth_dup() return a pointer to a newly
  132. created B<EVP_MD>, or NULL on failure.
  133. All EVP_MD_meth_set_*() functions return 1.
  134. EVP_MD_get_input_blocksize(), EVP_MD_meth_get_result_size(),
  135. EVP_MD_meth_get_app_datasize() and EVP_MD_meth_get_flags() return the
  136. indicated sizes or flags.
  137. All other EVP_CIPHER_meth_get_*() functions return pointers to their
  138. respective B<md> function.
  139. =head1 SEE ALSO
  140. L<EVP_DigestInit(3)>, L<EVP_SignInit(3)>, L<EVP_VerifyInit(3)>
  141. =head1 HISTORY
  142. All of these functions were deprecated in OpenSSL 3.0.
  143. The B<EVP_MD> structure was openly available in OpenSSL before version
  144. 1.1.
  145. The functions described here were added in OpenSSL 1.1.
  146. The B<EVP_MD> structure created with these functions became reference
  147. counted in OpenSSL 3.0.
  148. =head1 COPYRIGHT
  149. Copyright 2015-2020 The OpenSSL Project Authors. All Rights Reserved.
  150. Licensed under the Apache License 2.0 (the "License"). You may not use
  151. this file except in compliance with the License. You can obtain a copy
  152. in the file LICENSE in the source distribution or at
  153. L<https://www.openssl.org/source/license.html>.
  154. =cut