New RSA keymgmt implementation to handle import / export of RSA keys

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10190)

4 files changed, 253 insertions, 0 deletions

diff --git a/providers/defltprov.c b/providers/defltprov.c
index 2d457ae53f..8104227fff 100644
--- a/providers/defltprov.c
+++ b/providers/defltprov.c
@@ -364,6 +364,7 @@ static const OSSL_ALGORITHM deflt_keymgmt[] = {
 #ifndef OPENSSL_NO_DSA
     { "DSA", "default=yes", dsa_keymgmt_functions },
 #endif
+    { "RSA", "default=yes", rsa_keymgmt_functions },
     { NULL, NULL, NULL }
 };
 
diff --git a/providers/implementations/include/prov/implementations.h b/providers/implementations/include/prov/implementations.h
index 44b0a6fbc2..16f2129115 100644
--- a/providers/implementations/include/prov/implementations.h
+++ b/providers/implementations/include/prov/implementations.h
@@ -241,6 +241,7 @@ extern const OSSL_DISPATCH kdf_x942_kdf_functions[];
 /* Key management */
 extern const OSSL_DISPATCH dh_keymgmt_functions[];
 extern const OSSL_DISPATCH dsa_keymgmt_functions[];
+extern const OSSL_DISPATCH rsa_keymgmt_functions[];
 
 /* Key Exchange */
 extern const OSSL_DISPATCH dh_keyexch_functions[];
diff --git a/providers/implementations/keymgmt/build.info b/providers/implementations/keymgmt/build.info
index dc6039b02d..f4a9d1a5de 100644
--- a/providers/implementations/keymgmt/build.info
+++ b/providers/implementations/keymgmt/build.info
@@ -3,6 +3,7 @@
 
 $DH_GOAL=../../libimplementations.a
 $DSA_GOAL=../../libimplementations.a
+$RSA_GOAL=../../libimplementations.a
 
 IF[{- !$disabled{dh} -}]
   SOURCE[$DH_GOAL]=dh_kmgmt.c
@@ -10,3 +11,4 @@ ENDIF
 IF[{- !$disabled{dsa} -}]
   SOURCE[$DSA_GOAL]=dsa_kmgmt.c
 ENDIF
+SOURCE[$RSA_GOAL]=rsa_kmgmt.c
diff --git a/providers/implementations/keymgmt/rsa_kmgmt.c b/providers/implementations/keymgmt/rsa_kmgmt.c
new file mode 100644
index 0000000000..aaa9815aa9
--- /dev/null
+++ b/providers/implementations/keymgmt/rsa_kmgmt.c
@@ -0,0 +1,249 @@
+/*
+ * Copyright 2019 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
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <openssl/core_numbers.h>
+#include <openssl/core_names.h>
+#include <openssl/bn.h>
+#include <openssl/rsa.h>
+#include <openssl/params.h>
+#include <openssl/types.h>
+#include "prov/implementations.h"
+#include "crypto/rsa.h"
+
+static OSSL_OP_keymgmt_importkey_fn rsa_importkey;
+static OSSL_OP_keymgmt_exportkey_fn rsa_exportkey;
+
+DEFINE_STACK_OF(BIGNUM)
+DEFINE_SPECIAL_STACK_OF_CONST(BIGNUM_const, BIGNUM)
+
+static int collect_numbers(STACK_OF(BIGNUM) *numbers,
+                           const OSSL_PARAM params[], const char *key)
+{
+    const OSSL_PARAM *p = NULL;
+
+    if (numbers == NULL)
+        return 0;
+
+    for (p = params; (p = OSSL_PARAM_locate_const(p, key)) != NULL; p++) {
+        BIGNUM *tmp = NULL;
+
+        if (!OSSL_PARAM_get_BN(p, &tmp))
+            return 0;
+        sk_BIGNUM_push(numbers, tmp);
+    }
+
+    return 1;
+}
+
+static int params_to_key(RSA *rsa, const OSSL_PARAM params[])
+{
+    const OSSL_PARAM *param_n, *param_e,  *param_d;
+    BIGNUM *n = NULL, *e = NULL, *d = NULL;
+    STACK_OF(BIGNUM) *factors = NULL, *exps = NULL, *coeffs = NULL;
+    int is_private = 0;
+
+    if (rsa == NULL)
+        return 0;
+
+    param_n = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_N);
+    param_e = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_E);
+    param_d = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_D);
+
+    if ((param_n != NULL && !OSSL_PARAM_get_BN(param_n, &n))
+        || (param_e != NULL && !OSSL_PARAM_get_BN(param_e, &e))
+        || (param_d != NULL && !OSSL_PARAM_get_BN(param_d, &d)))
+        goto err;
+
+    is_private = (d != NULL);
+
+    if (!RSA_set0_key(rsa, n, e, d))
+        goto err;
+    n = e = d = NULL;
+
+    if (is_private) {
+        if (!collect_numbers(factors = sk_BIGNUM_new_null(), params,
+                             OSSL_PKEY_PARAM_RSA_FACTOR)
+            || !collect_numbers(exps = sk_BIGNUM_new_null(), params,
+                                OSSL_PKEY_PARAM_RSA_EXPONENT)
+            || !collect_numbers(coeffs = sk_BIGNUM_new_null(), params,
+                                OSSL_PKEY_PARAM_RSA_COEFFICIENT))
+            goto err;
+
+        /* It's ok if this private key just has n, e and d */
+        if (sk_BIGNUM_num(factors) != 0
+            && !rsa_set0_all_params(rsa, factors, exps, coeffs))
+            goto err;
+    }
+
+    sk_BIGNUM_free(factors);
+    sk_BIGNUM_free(exps);
+    sk_BIGNUM_free(coeffs);
+    return 1;
+
+ err:
+    BN_free(n);
+    BN_free(e);
+    BN_free(d);
+    sk_BIGNUM_pop_free(factors, BN_free);
+    sk_BIGNUM_pop_free(exps, BN_free);
+    sk_BIGNUM_pop_free(coeffs, BN_free);
+    return 0;
+}
+
+static int export_numbers(OSSL_PARAM params[], const char *key,
+                          STACK_OF(BIGNUM_const) *numbers)
+{
+    OSSL_PARAM *p = NULL;
+    int i, nnum;
+
+    if (numbers == NULL)
+        return 0;
+
+    nnum = sk_BIGNUM_const_num(numbers);
+
+    for (p = params, i = 0;
+         i < nnum && (p = OSSL_PARAM_locate(p, key)) != NULL;
+         p++, i++) {
+        if (!OSSL_PARAM_set_BN(p, sk_BIGNUM_const_value(numbers, i)))
+            return 0;
+    }
+
+    /*
+     * If we didn't export the amount of numbers we have, the caller didn't
+     * specify enough OSSL_PARAM entries named |key|.
+     */
+    return i == nnum;
+}
+
+static int key_to_params(RSA *rsa, OSSL_PARAM params[])
+{
+    int ret = 0;
+    OSSL_PARAM *p;
+    const BIGNUM *rsa_d = NULL, *rsa_n = NULL, *rsa_e = NULL;
+    STACK_OF(BIGNUM_const) *factors = sk_BIGNUM_const_new_null();
+    STACK_OF(BIGNUM_const) *exps = sk_BIGNUM_const_new_null();
+    STACK_OF(BIGNUM_const) *coeffs = sk_BIGNUM_const_new_null();
+
+    if (rsa == NULL || factors == NULL || exps == NULL || coeffs == NULL)
+        goto err;
+
+    RSA_get0_key(rsa, &rsa_n, &rsa_e, &rsa_d);
+    rsa_get0_all_params(rsa, factors, exps, coeffs);
+
+    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_RSA_N)) != NULL
+        && !OSSL_PARAM_set_BN(p, rsa_n))
+        goto err;
+    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_RSA_E)) != NULL
+        && !OSSL_PARAM_set_BN(p, rsa_e))
+        goto err;
+    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_RSA_D)) != NULL
+        && !OSSL_PARAM_set_BN(p, rsa_d))
+        goto err;
+
+    if (!export_numbers(params, OSSL_PKEY_PARAM_RSA_FACTOR, factors)
+        || !export_numbers(params, OSSL_PKEY_PARAM_RSA_EXPONENT, exps)
+        || !export_numbers(params, OSSL_PKEY_PARAM_RSA_COEFFICIENT, coeffs))
+        goto err;
+
+    ret = 1;
+ err:
+    sk_BIGNUM_const_free(factors);
+    sk_BIGNUM_const_free(exps);
+    sk_BIGNUM_const_free(coeffs);
+    return ret;
+}
+
+static void *rsa_importkey(void *provctx, const OSSL_PARAM params[])
+{
+    RSA *rsa;
+
+    if ((rsa = RSA_new()) == NULL
+        || !params_to_key(rsa, params)) {
+        RSA_free(rsa);
+        rsa = NULL;
+    }
+    return rsa;
+}
+
+static int rsa_exportkey(void *key, OSSL_PARAM params[])
+{
+    RSA *rsa = key;
+
+    return rsa != NULL && key_to_params(rsa, params);
+}
+
+/*
+ * This provider can export everything in an RSA key, so we use the exact
+ * same type description for export as for import.  Other providers might
+ * choose to import full keys, but only export the public parts, and will
+ * therefore have the importkey_types and importkey_types functions return
+ * different arrays.
+ */
+static const OSSL_PARAM rsa_key_types[] = {
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_N, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_E, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_D, NULL, 0),
+    /* We tolerate up to 10 factors... */
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_FACTOR, NULL, 0),
+    /* ..., up to 10 CRT exponents... */
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_EXPONENT, NULL, 0),
+    /* ..., and up to 9 CRT coefficients */
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
+    OSSL_PARAM_BN(OSSL_PKEY_PARAM_RSA_COEFFICIENT, NULL, 0),
+};
+/*
+ * We lied about the amount of factors, exponents and coefficients, the
+ * export and import functions can really deal with an infinite amount
+ * of these numbers.  However, RSA keys with too many primes are futile,
+ * so we at least pretend to have some limits.
+ */
+
+static const OSSL_PARAM *rsa_exportkey_types(void)
+{
+    return rsa_key_types;
+}
+
+static const OSSL_PARAM *rsa_importkey_types(void)
+{
+    return rsa_key_types;
+}
+
+const OSSL_DISPATCH rsa_keymgmt_functions[] = {
+    { OSSL_FUNC_KEYMGMT_IMPORTKEY, (void (*)(void))rsa_importkey },
+    { OSSL_FUNC_KEYMGMT_IMPORTKEY_TYPES, (void (*)(void))rsa_importkey_types },
+    { OSSL_FUNC_KEYMGMT_EXPORTKEY, (void (*)(void))rsa_exportkey },
+    { OSSL_FUNC_KEYMGMT_EXPORTKEY_TYPES, (void (*)(void))rsa_exportkey_types },
+    { OSSL_FUNC_KEYMGMT_FREEKEY, (void (*)(void))RSA_free },
+    { 0, NULL }
+};