1EVP_PKEY-RSA(7ossl) OpenSSL EVP_PKEY-RSA(7ossl)
2
6 EVP_PKEY-RSA, EVP_KEYMGMT-RSA, RSA - EVP_PKEY RSA keytype and algorithm
7 support
8
10 The RSA keytype is implemented in OpenSSL's default and FIPS providers.
11 That implementation supports the basic RSA keys, containing the modulus
12 n, the public exponent e, the private exponent d, and a collection of
13 prime factors, exponents and coefficient for CRT calculations, of which
14 the first few are known as p and q, dP and dQ, and qInv.
15 Common RSA parameters
17 In addition to the common parameters that all keytypes should support
18 (see "Common parameters" in provider-keymgmt(7)), the RSA keytype
19 implementation supports the following.
20 "n" (OSSL_PKEY_PARAM_RSA_N) <unsigned integer>
22 The RSA "n" value.
23 "e" (OSSL_PKEY_PARAM_RSA_E) <unsigned integer>
25 The RSA "e" value.
26 "d" (OSSL_PKEY_PARAM_RSA_D) <unsigned integer>
28 The RSA "d" value.
29 "rsa-factor1" (OSSL_PKEY_PARAM_RSA_FACTOR1) <unsigned integer>
31 "rsa-factor2" (OSSL_PKEY_PARAM_RSA_FACTOR2) <unsigned integer>
32 "rsa-factor3" (OSSL_PKEY_PARAM_RSA_FACTOR3) <unsigned integer>
33 "rsa-factor4" (OSSL_PKEY_PARAM_RSA_FACTOR4) <unsigned integer>
34 "rsa-factor5" (OSSL_PKEY_PARAM_RSA_FACTOR5) <unsigned integer>
35 "rsa-factor6" (OSSL_PKEY_PARAM_RSA_FACTOR6) <unsigned integer>
36 "rsa-factor7" (OSSL_PKEY_PARAM_RSA_FACTOR7) <unsigned integer>
37 "rsa-factor8" (OSSL_PKEY_PARAM_RSA_FACTOR8) <unsigned integer>
38 "rsa-factor9" (OSSL_PKEY_PARAM_RSA_FACTOR9) <unsigned integer>
39 "rsa-factor10" (OSSL_PKEY_PARAM_RSA_FACTOR10) <unsigned integer>
40 RSA prime factors. The factors are known as "p", "q" and "r_i" in
41 RFC8017. Up to eight additional "r_i" prime factors are supported.
42 "rsa-exponent1" (OSSL_PKEY_PARAM_RSA_EXPONENT1) <unsigned integer>
44 "rsa-exponent2" (OSSL_PKEY_PARAM_RSA_EXPONENT2) <unsigned integer>
45 "rsa-exponent3" (OSSL_PKEY_PARAM_RSA_EXPONENT3) <unsigned integer>
46 "rsa-exponent4" (OSSL_PKEY_PARAM_RSA_EXPONENT4) <unsigned integer>
47 "rsa-exponent5" (OSSL_PKEY_PARAM_RSA_EXPONENT5) <unsigned integer>
48 "rsa-exponent6" (OSSL_PKEY_PARAM_RSA_EXPONENT6) <unsigned integer>
49 "rsa-exponent7" (OSSL_PKEY_PARAM_RSA_EXPONENT7) <unsigned integer>
50 "rsa-exponent8" (OSSL_PKEY_PARAM_RSA_EXPONENT8) <unsigned integer>
51 "rsa-exponent9" (OSSL_PKEY_PARAM_RSA_EXPONENT9) <unsigned integer>
52 "rsa-exponent10" (OSSL_PKEY_PARAM_RSA_EXPONENT10) <unsigned integer>
53 RSA CRT (Chinese Remainder Theorem) exponents. The exponents are
54 known as "dP", "dQ" and "d_i in RFC8017". Up to eight additional
55 "d_i" exponents are supported.
56 "rsa-coefficient1" (OSSL_PKEY_PARAM_RSA_COEFFICIENT1) <unsigned
58 integer>
59 "rsa-coefficient2" (OSSL_PKEY_PARAM_RSA_COEFFICIENT2) <unsigned
60 integer>
61 "rsa-coefficient3" (OSSL_PKEY_PARAM_RSA_COEFFICIENT3) <unsigned
62 integer>
63 "rsa-coefficient4" (OSSL_PKEY_PARAM_RSA_COEFFICIENT4) <unsigned
64 integer>
65 "rsa-coefficient5" (OSSL_PKEY_PARAM_RSA_COEFFICIENT5) <unsigned
66 integer>
67 "rsa-coefficient6" (OSSL_PKEY_PARAM_RSA_COEFFICIENT6) <unsigned
68 integer>
69 "rsa-coefficient7" (OSSL_PKEY_PARAM_RSA_COEFFICIENT7) <unsigned
70 integer>
71 "rsa-coefficient8" (OSSL_PKEY_PARAM_RSA_COEFFICIENT8) <unsigned
72 integer>
73 "rsa-coefficient9" (OSSL_PKEY_PARAM_RSA_COEFFICIENT9) <unsigned
74 integer>
75 RSA CRT (Chinese Remainder Theorem) coefficients. The coefficients
76 are known as "qInv" and "t_i". Up to eight additional "t_i"
77 exponents are supported.
78 RSA key generation parameters
80 When generating RSA keys, the following key generation parameters may
81 be used.
82 "bits" (OSSL_PKEY_PARAM_RSA_BITS) <unsigned integer>
84 The value should be the cryptographic length for the RSA
85 cryptosystem, in bits.
86 "primes" (OSSL_PKEY_PARAM_RSA_PRIMES) <unsigned integer>
88 The value should be the number of primes for the generated RSA key.
89 The default is 2. It isn't permitted to specify a larger number of
90 primes than 10. Additionally, the number of primes is limited by
91 the length of the key being generated so the maximum number could
92 be less. Some providers may only support a value of 2.
93 "e" (OSSL_PKEY_PARAM_RSA_E) <unsigned integer>
95 The RSA "e" value. The value may be any odd number greater than or
96 equal to 65537. The default value is 65537. For legacy reasons a
97 value of 3 is currently accepted but is deprecated.
98 RSA key generation parameters for FIPS module testing
100 When generating RSA keys, the following additional key generation
101 parameters may be used for algorithm testing purposes only. Do not use
102 these to generate RSA keys for a production environment.
103 "xp" (OSSL_PKEY_PARAM_RSA_TEST_XP) <unsigned integer>
105 "xq" (OSSL_PKEY_PARAM_RSA_TEST_XQ) <unsigned integer>
106 These 2 fields are normally randomly generated and are used to
107 generate "p" and "q".
108 "xp1" (OSSL_PKEY_PARAM_RSA_TEST_XP1) <unsigned integer>
110 "xp2" (OSSL_PKEY_PARAM_RSA_TEST_XP2) <unsigned integer>
111 "xq1" (OSSL_PKEY_PARAM_RSA_TEST_XQ1) <unsigned integer>
112 "xq2" (OSSL_PKEY_PARAM_RSA_TEST_XQ2) <unsigned integer>
113 These 4 fields are normally randomly generated. The prime factors
114 "p1", "p2", "q1" and "q2" are determined from these values.
115 RSA key parameters for FIPS module testing
117 The following intermediate values can be retrieved only if the values
118 specified in "RSA key generation parameters for FIPS module testing"
119 are set. These should not be accessed in a production environment.
120 "p1" (OSSL_PKEY_PARAM_RSA_TEST_P1) <unsigned integer>
122 "p2" (OSSL_PKEY_PARAM_RSA_TEST_P2) <unsigned integer>
123 "q1" (OSSL_PKEY_PARAM_RSA_TEST_Q1) <unsigned integer>
124 "q2" (OSSL_PKEY_PARAM_RSA_TEST_Q2) <unsigned integer>
125 The auxiliary probable primes.
126 RSA key validation
128 For RSA keys, EVP_PKEY_param_check(3) and EVP_PKEY_param_check_quick(3)
129 both return 1 unconditionally.
130 For RSA keys, EVP_PKEY_public_check(3) conforms to the SP800-56Br1
132 public key check when the OpenSSL FIPS provider is used. The OpenSSL
133 default provider performs similiar tests but relaxes the keysize
134 restrictions for backwards compatibility.
135 For RSA keys, EVP_PKEY_public_check_quick(3) is the same as
137 EVP_PKEY_public_check(3).
138 For RSA keys, EVP_PKEY_private_check(3) conforms to the SP800-56Br1
140 private key test.
141 For RSA keys, EVP_PKEY_pairwise_check(3) conforms to the SP800-56Br1
143 KeyPair Validation check for the OpenSSL FIPS provider. The OpenSSL
144 default provider allows testing of the validity of multi-primes.
145
147 FIPS186-4
148 Section B.3.6 Generation of Probable Primes with Conditions Based
149 on Auxiliary Probable Primes
150 RFC 8017, excluding RSA-PSS and RSA-OAEP
152
154 An EVP_PKEY context can be obtained by calling:
155 EVP_PKEY_CTX *pctx =
157 EVP_PKEY_CTX_new_from_name(NULL, "RSA", NULL);
158 An RSA key can be generated simply like this:
160 pkey = EVP_RSA_gen(4096);
162 or like this:
164 EVP_PKEY *pkey = NULL;
166 EVP_PKEY_CTX *pctx =
167 EVP_PKEY_CTX_new_from_name(NULL, "RSA", NULL);
168 EVP_PKEY_keygen_init(pctx);
170 EVP_PKEY_generate(pctx, &pkey);
171 EVP_PKEY_CTX_free(pctx);
172 An RSA key can be generated with key generation parameters:
174 unsigned int primes = 3;
176 unsigned int bits = 4096;
177 OSSL_PARAM params[3];
178 EVP_PKEY *pkey = NULL;
179 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_from_name(NULL, "RSA", NULL);
180 EVP_PKEY_keygen_init(pctx);
182 params[0] = OSSL_PARAM_construct_uint("bits", &bits);
184 params[1] = OSSL_PARAM_construct_uint("primes", &primes);
185 params[2] = OSSL_PARAM_construct_end();
186 EVP_PKEY_CTX_set_params(pctx, params);
187 EVP_PKEY_generate(pctx, &pkey);
189 EVP_PKEY_print_private(bio_out, pkey, 0, NULL);
190 EVP_PKEY_CTX_free(pctx);
191
193 EVP_RSA_gen(3), EVP_KEYMGMT(3), EVP_PKEY(3), provider-keymgmt(7)
194
196 Copyright 2020-2022 The OpenSSL Project Authors. All Rights Reserved.
197 Licensed under the Apache License 2.0 (the "License"). You may not use
199 this file except in compliance with the License. You can obtain a copy
200 in the file LICENSE in the source distribution or at
201 <https://www.openssl.org/source/license.html>.
2023.0.5 2022-11-01 EVP_PKEY-RSA(7ossl)