rsa: fix version of rsa implicit rejection introduction

[openssl.git] / doc / man3 / EVP_PKEY_decrypt.pod

diff --git a/doc/man3/EVP_PKEY_decrypt.pod b/doc/man3/EVP_PKEY_decrypt.pod
index a78c1ee8e4ceba095dc5d0c7618e3779ab377c1f..67e3f2da1ec80f00b65eaefb2de1efb1c1eb2600 100644 (file)
--- a/doc/man3/EVP_PKEY_decrypt.pod
+++ b/doc/man3/EVP_PKEY_decrypt.pod
@@ -2,13 +2,15 @@
 
 =head1 NAME
 
-EVP_PKEY_decrypt_init, EVP_PKEY_decrypt - decrypt using a public key algorithm
+EVP_PKEY_decrypt_init, EVP_PKEY_decrypt_init_ex,
+EVP_PKEY_decrypt - decrypt using a public key algorithm
 
 =head1 SYNOPSIS
 
  #include <openssl/evp.h>
 
  int EVP_PKEY_decrypt_init(EVP_PKEY_CTX *ctx);
+ int EVP_PKEY_decrypt_init_ex(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[]);
  int EVP_PKEY_decrypt(EVP_PKEY_CTX *ctx,
                       unsigned char *out, size_t *outlen,
                       const unsigned char *in, size_t inlen);
@@ -16,30 +18,50 @@ EVP_PKEY_decrypt_init, EVP_PKEY_decrypt - decrypt using a public key algorithm
 =head1 DESCRIPTION
 
 The EVP_PKEY_decrypt_init() function initializes a public key algorithm
-context using key B<pkey> for a decryption operation.
+context using key I<pkey> for a decryption operation.
+
+The EVP_PKEY_decrypt_init_ex() function initializes a public key algorithm
+context using key I<pkey> for a decryption operation and sets the
+algorithm specific I<params>.
 
 The EVP_PKEY_decrypt() function performs a public key decryption operation
-using B<ctx>. The data to be decrypted is specified using the B<in> and
-B<inlen> parameters. If B<out> is B<NULL> then the maximum size of the output
-buffer is written to the B<outlen> parameter. If B<out> is not B<NULL> then
-before the call the B<outlen> parameter should contain the length of the
-B<out> buffer, if the call is successful the decrypted data is written to
-B<out> and the amount of data written to B<outlen>.
+using I<ctx>. The data to be decrypted is specified using the I<in> and
+I<inlen> parameters. If I<out> is NULL then the minimum required size of
+the output buffer is written to the I<*outlen> parameter.
+
+If I<out> is not NULL then before the call the I<*outlen> parameter must
+contain the length of the I<out> buffer. If the call is successful the
+decrypted data is written to I<out> and the amount of the decrypted data
+written to I<*outlen>, otherwise an error is returned.
 
 =head1 NOTES
 
 After the call to EVP_PKEY_decrypt_init() algorithm specific control
 operations can be performed to set any appropriate parameters for the
-operation.
+operation.  These operations can be included in the EVP_PKEY_decrypt_init_ex()
+call.
 
 The function EVP_PKEY_decrypt() can be called more than once on the same
 context if several operations are performed using the same parameters.
 
 =head1 RETURN VALUES
 
-EVP_PKEY_decrypt_init() and EVP_PKEY_decrypt() return 1 for success and 0
-or a negative value for failure. In particular a return value of -2
-indicates the operation is not supported by the public key algorithm.
+EVP_PKEY_decrypt_init(), EVP_PKEY_decrypt_init_ex() and EVP_PKEY_decrypt()
+return 1 for success and 0 or a negative value for failure. In particular a
+return value of -2 indicates the operation is not supported by the public key
+algorithm.
+
+=head1 WARNINGS
+
+In OpenSSL versions before 3.2.0, when used in PKCS#1 v1.5 padding,
+both the return value from the EVP_PKEY_decrypt() and the B<outlen> provided
+information useful in mounting a Bleichenbacher attack against the
+used private key. They had to processed in a side-channel free way.
+
+Since version 3.2.0, the EVP_PKEY_decrypt() method when used with PKCS#1
+v1.5 padding doesn't return an error in case it detects an error in padding,
+instead it returns a pseudo-randomly generated message, removing the need
+of side-channel secure code from applications using OpenSSL.
 
 =head1 EXAMPLES
 
@@ -63,7 +85,7 @@ Decrypt data using OAEP (for RSA keys):
      /* Error occurred */
  if (EVP_PKEY_decrypt_init(ctx) <= 0)
      /* Error */
- if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_OAEP_PADDING) <= 0)
+ if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_OAEP_PADDING) <= 0)
      /* Error */
 
  /* Determine buffer length */
@@ -95,7 +117,7 @@ These functions were added in OpenSSL 1.0.0.
 
 =head1 COPYRIGHT
 
-Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved.
 
 Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy