1RSA_PADDING_ADD_PKCS1_TYPE_1(3) OpenSSL RSA_PADDING_ADD_PKCS1_TYPE_1(3)
2
6 RSA_padding_add_PKCS1_type_1, RSA_padding_check_PKCS1_type_1,
7 RSA_padding_add_PKCS1_type_2, RSA_padding_check_PKCS1_type_2,
8 RSA_padding_add_PKCS1_OAEP, RSA_padding_check_PKCS1_OAEP,
9 RSA_padding_add_PKCS1_OAEP_mgf1, RSA_padding_check_PKCS1_OAEP_mgf1,
10 RSA_padding_add_SSLv23, RSA_padding_check_SSLv23, RSA_padding_add_none,
11 RSA_padding_check_none - asymmetric encryption padding
12
14 #include <openssl/rsa.h>
15 int RSA_padding_add_PKCS1_type_1(unsigned char *to, int tlen,
17 const unsigned char *f, int fl);
18 int RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen,
20 const unsigned char *f, int fl, int rsa_len);
21 int RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen,
23 const unsigned char *f, int fl);
24 int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen,
26 const unsigned char *f, int fl, int rsa_len);
27 int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen,
29 const unsigned char *f, int fl,
30 const unsigned char *p, int pl);
31 int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen,
33 const unsigned char *f, int fl, int rsa_len,
34 const unsigned char *p, int pl);
35 int RSA_padding_add_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
37 const unsigned char *f, int fl,
38 const unsigned char *p, int pl,
39 const EVP_MD *md, const EVP_MD *mgf1md);
40 int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
42 const unsigned char *f, int fl, int rsa_len,
43 const unsigned char *p, int pl,
44 const EVP_MD *md, const EVP_MD *mgf1md);
45 int RSA_padding_add_SSLv23(unsigned char *to, int tlen,
47 const unsigned char *f, int fl);
48 int RSA_padding_check_SSLv23(unsigned char *to, int tlen,
50 const unsigned char *f, int fl, int rsa_len);
51 int RSA_padding_add_none(unsigned char *to, int tlen,
53 const unsigned char *f, int fl);
54 int RSA_padding_check_none(unsigned char *to, int tlen,
56 const unsigned char *f, int fl, int rsa_len);
57
59 The RSA_padding_xxx_xxx() functions are called from the RSA encrypt,
60 decrypt, sign and verify functions. Normally they should not be called
61 from application programs.
62 However, they can also be called directly to implement padding for
64 other asymmetric ciphers. RSA_padding_add_PKCS1_OAEP() and
65 RSA_padding_check_PKCS1_OAEP() may be used in an application combined
66 with RSA_NO_PADDING in order to implement OAEP with an encoding
67 parameter.
68 RSA_padding_add_xxx() encodes fl bytes from f so as to fit into tlen
70 bytes and stores the result at to. An error occurs if fl does not meet
71 the size requirements of the encoding method.
72 The following encoding methods are implemented:
74 PKCS1_type_1
76 PKCS #1 v2.0 EMSA-PKCS1-v1_5 (PKCS #1 v1.5 block type 1); used for
77 signatures
78 PKCS1_type_2
80 PKCS #1 v2.0 EME-PKCS1-v1_5 (PKCS #1 v1.5 block type 2)
81 PKCS1_OAEP
83 PKCS #1 v2.0 EME-OAEP
84 SSLv23
86 PKCS #1 EME-PKCS1-v1_5 with SSL-specific modification
87 none
89 simply copy the data
90 The random number generator must be seeded prior to calling
92 RSA_padding_add_xxx().
93 RSA_padding_check_xxx() verifies that the fl bytes at f contain a valid
95 encoding for a rsa_len byte RSA key in the respective encoding method
96 and stores the recovered data of at most tlen bytes (for
97 RSA_NO_PADDING: of size tlen) at to.
98 For RSA_padding_xxx_OAEP(), p points to the encoding parameter of
100 length pl. p may be NULL if pl is 0.
101 For RSA_padding_xxx_OAEP_mgf1(), md points to the md hash, if md is
103 NULL that means md=sha1, and mgf1md points to the mgf1 hash, if mgf1md
104 is NULL that means mgf1md=md.
105
107 The RSA_padding_add_xxx() functions return 1 on success, 0 on error.
108 The RSA_padding_check_xxx() functions return the length of the
109 recovered data, -1 on error. Error codes can be obtained by calling
110 ERR_get_error(3).
111
113 The result of RSA_padding_check_PKCS1_type_2() is a very sensitive
114 information which can potentially be used to mount a Bleichenbacher
115 padding oracle attack. This is an inherent weakness in the PKCS #1 v1.5
116 padding design. Prefer PKCS1_OAEP padding. If that is not possible, the
117 result of RSA_padding_check_PKCS1_type_2() should be checked in
118 constant time if it matches the expected length of the plaintext and
119 additionally some application specific consistency checks on the
120 plaintext need to be performed in constant time. If the plaintext is
121 rejected it must be kept secret which of the checks caused the
122 application to reject the message. Do not remove the zero-padding from
123 the decrypted raw RSA data which was computed by RSA_private_decrypt()
124 with RSA_NO_PADDING, as this would create a small timing side channel
125 which could be used to mount a Bleichenbacher attack against any
126 padding mode including PKCS1_OAEP.
127
129 RSA_public_encrypt(3), RSA_private_decrypt(3), RSA_sign(3),
130 RSA_verify(3)
131
133 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
134 Licensed under the OpenSSL license (the "License"). You may not use
136 this file except in compliance with the License. You can obtain a copy
137 in the file LICENSE in the source distribution or at
138 <https://www.openssl.org/source/license.html>.
1391.1.1c 2019-05-28 RSA_PADDING_ADD_PKCS1_TYPE_1(3)