5 EVP_PKEY-RSA, EVP_KEYMGMT-RSA, RSA
6 - EVP_PKEY RSA keytype and algorithm support
10 The B<RSA> keytype is implemented in OpenSSL's default and FIPS providers.
11 That implementation supports the basic RSA keys, containing the modulus I<n>,
12 the public exponent I<e>, the private exponent I<d>, and a collection of prime
13 factors, exponents and coefficient for CRT calculations, of which the first
14 few are known as I<p> and I<q>, I<dP> and I<dQ>, and I<qInv>.
16 =head2 Common RSA parameters
18 In addition to the common parameters that all keytypes should support (see
19 L<provider-keymgmt(7)/Common parameters>), the B<RSA> keytype implementation
20 supports the following.
24 =item "n" (B<OSSL_PKEY_PARAM_RSA_N>) <unsigned integer>
28 =item "e" (B<OSSL_PKEY_PARAM_RSA_E>) <unsigned integer>
32 =item "d" (B<OSSL_PKEY_PARAM_RSA_D>) <unsigned integer>
36 =item "rsa-factor1" (B<OSSL_PKEY_PARAM_RSA_FACTOR1>) <unsigned integer>
38 =item "rsa-factor2" (B<OSSL_PKEY_PARAM_RSA_FACTOR2>) <unsigned integer>
40 =item "rsa-factor3" (B<OSSL_PKEY_PARAM_RSA_FACTOR3>) <unsigned integer>
42 =item "rsa-factor4" (B<OSSL_PKEY_PARAM_RSA_FACTOR4>) <unsigned integer>
44 =item "rsa-factor5" (B<OSSL_PKEY_PARAM_RSA_FACTOR5>) <unsigned integer>
46 =item "rsa-factor6" (B<OSSL_PKEY_PARAM_RSA_FACTOR6>) <unsigned integer>
48 =item "rsa-factor7" (B<OSSL_PKEY_PARAM_RSA_FACTOR7>) <unsigned integer>
50 =item "rsa-factor8" (B<OSSL_PKEY_PARAM_RSA_FACTOR8>) <unsigned integer>
52 =item "rsa-factor9" (B<OSSL_PKEY_PARAM_RSA_FACTOR9>) <unsigned integer>
54 =item "rsa-factor10" (B<OSSL_PKEY_PARAM_RSA_FACTOR10>) <unsigned integer>
56 RSA prime factors. The factors are known as "p", "q" and "r_i" in RFC8017.
57 Up to eight additional "r_i" prime factors are supported.
59 =item "rsa-exponent1" (B<OSSL_PKEY_PARAM_RSA_EXPONENT1>) <unsigned integer>
61 =item "rsa-exponent2" (B<OSSL_PKEY_PARAM_RSA_EXPONENT2>) <unsigned integer>
63 =item "rsa-exponent3" (B<OSSL_PKEY_PARAM_RSA_EXPONENT3>) <unsigned integer>
65 =item "rsa-exponent4" (B<OSSL_PKEY_PARAM_RSA_EXPONENT4>) <unsigned integer>
67 =item "rsa-exponent5" (B<OSSL_PKEY_PARAM_RSA_EXPONENT5>) <unsigned integer>
69 =item "rsa-exponent6" (B<OSSL_PKEY_PARAM_RSA_EXPONENT6>) <unsigned integer>
71 =item "rsa-exponent7" (B<OSSL_PKEY_PARAM_RSA_EXPONENT7>) <unsigned integer>
73 =item "rsa-exponent8" (B<OSSL_PKEY_PARAM_RSA_EXPONENT8>) <unsigned integer>
75 =item "rsa-exponent9" (B<OSSL_PKEY_PARAM_RSA_EXPONENT9>) <unsigned integer>
77 =item "rsa-exponent10" (B<OSSL_PKEY_PARAM_RSA_EXPONENT10>) <unsigned integer>
79 RSA CRT (Chinese Remainder Theorem) exponents. The exponents are known
80 as "dP", "dQ" and "d_i in RFC8017".
81 Up to eight additional "d_i" exponents are supported.
83 =item "rsa-coefficient1" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT1>) <unsigned integer>
85 =item "rsa-coefficient2" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT2>) <unsigned integer>
87 =item "rsa-coefficient3" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT3>) <unsigned integer>
89 =item "rsa-coefficient4" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT4>) <unsigned integer>
91 =item "rsa-coefficient5" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT5>) <unsigned integer>
93 =item "rsa-coefficient6" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT6>) <unsigned integer>
95 =item "rsa-coefficient7" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT7>) <unsigned integer>
97 =item "rsa-coefficient8" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT8>) <unsigned integer>
99 =item "rsa-coefficient9" (B<OSSL_PKEY_PARAM_RSA_COEFFICIENT9>) <unsigned integer>
101 RSA CRT (Chinese Remainder Theorem) coefficients. The coefficients are known as
103 Up to eight additional "t_i" exponents are supported.
107 =head2 RSA key generation parameters
109 When generating RSA keys, the following key generation parameters may be used.
113 =item "bits" (B<OSSL_PKEY_PARAM_RSA_BITS>) <unsigned integer>
115 The value should be the cryptographic length for the B<RSA> cryptosystem, in
118 =item "primes" (B<OSSL_PKEY_PARAM_RSA_PRIMES>) <unsigned integer>
120 The value should be the number of primes for the generated B<RSA> key. The
121 default is 2. It isn't permitted to specify a larger number of primes than
122 10. Additionally, the number of primes is limited by the length of the key
123 being generated so the maximum number could be less.
124 Some providers may only support a value of 2.
132 =item RFC 8017, excluding RSA-PSS and RSA-OAEP
134 =for comment RSA-PSS, and probably also RSA-OAEP, need separate keytypes,
135 and will be described in separate pages for those RSA keytypes.
141 An B<EVP_PKEY> context can be obtained by calling:
144 EVP_PKEY_CTX_new_from_name(NULL, "RSA", NULL);
146 An B<RSA> key can be generated like this:
148 EVP_PKEY *pkey = NULL;
150 EVP_PKEY_CTX_new_from_name(NULL, "RSA", NULL);
152 EVP_PKEY_keygen_init(pctx);
153 EVP_PKEY_gen(pctx, &pkey);
154 EVP_PKEY_CTX_free(pctx);
156 An B<RSA> key can be generated with key generation parameters:
158 unsigned int primes = 3;
159 unsigned int bits = 4096;
160 OSSL_PARAM params[3];
161 EVP_PKEY *pkey = NULL;
162 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_from_name(NULL, "RSA", NULL);
164 EVP_PKEY_keygen_init(pctx);
166 params[0] = OSSL_PARAM_construct_uint("bits", &bits);
167 params[1] = OSSL_PARAM_construct_uint("primes", &primes);
168 params[2] = OSSL_PARAM_construct_end();
169 EVP_PKEY_CTX_set_params(pctx, params);
171 EVP_PKEY_gen(pctx, &pkey);
172 EVP_PKEY_print_private(bio_out, pkey, 0, NULL);
173 EVP_PKEY_CTX_free(pctx);
177 L<EVP_KEYMGMT(3)>, L<EVP_PKEY(3)>, L<provider-keymgmt(7)>
181 Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
183 Licensed under the Apache License 2.0 (the "License"). You may not use
184 this file except in compliance with the License. You can obtain a copy
185 in the file LICENSE in the source distribution or at
186 L<https://www.openssl.org/source/license.html>.