Modify DSA and DH keys to use a shared FFC_PARAMS struct

This is required in order to share code for FIPS related parameter generation and validation routinues.
Note the 'counter' field is now stored as a integer (as that is the form required for generation/validation functions).

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10860)

2 files changed, 197 insertions, 0 deletions

diff --git a/crypto/ffc/build.info b/crypto/ffc/build.info
new file mode 100644
index 0000000000..154d3c2510
--- /dev/null
+++ b/crypto/ffc/build.info
@@ -0,0 +1,6 @@
+LIBS=../../libcrypto
+
+$COMMON=ffc_params.c
+
+SOURCE[../../libcrypto]=$COMMON
+SOURCE[../../providers/libfips.a]=$COMMON
diff --git a/crypto/ffc/ffc_params.c b/crypto/ffc/ffc_params.c
new file mode 100644
index 0000000000..838ace3827
--- /dev/null
+++ b/crypto/ffc/ffc_params.c
@@ -0,0 +1,191 @@
+/*
+ * Copyright 2019-2020 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 <string.h> /* memset */
+#include "internal/ffc.h"
+#ifndef FIPS_MODE
+# include <openssl/asn1.h> /* ffc_params_print */
+#endif
+
+void ffc_params_init(FFC_PARAMS *params)
+{
+    memset(params, 0, sizeof(FFC_PARAMS));
+    params->pcounter = -1;
+}
+
+void ffc_params_cleanup(FFC_PARAMS *params)
+{
+    BN_free(params->p);
+    BN_free(params->q);
+    BN_free(params->g);
+    BN_free(params->j);
+    OPENSSL_free(params->seed);
+    ffc_params_init(params);
+}
+
+void ffc_params_set0_pqg(FFC_PARAMS *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
+{
+    if (p != NULL && p != d->p) {
+        BN_free(d->p);
+        d->p = p;
+    }
+    if (q != NULL && q != d->q) {
+        BN_free(d->q);
+        d->q = q;
+    }
+    if (g != NULL && g != d->g) {
+        BN_free(d->g);
+        d->g = g;
+    }
+}
+
+void ffc_params_get0_pqg(const FFC_PARAMS *d, const BIGNUM **p,
+                         const BIGNUM **q, const BIGNUM **g)
+{
+    if (p != NULL)
+        *p = d->p;
+    if (q != NULL)
+        *q = d->q;
+    if (g != NULL)
+        *g = d->g;
+}
+
+
+/* j is the 'cofactor' that is optionally output for ASN1. */
+void ffc_params_set0_j(FFC_PARAMS *d, BIGNUM *j)
+{
+    BN_free(d->j);
+    d->j = NULL;
+    if (j != NULL)
+        d->j = j;
+}
+
+int ffc_params_set_validate_params(FFC_PARAMS *params,
+                                   const unsigned char *seed, size_t seedlen,
+                                   int counter)
+{
+    if (params == NULL)
+        return 0;
+
+    if (params->seed != NULL)
+        OPENSSL_free(params->seed);
+
+    if (seed != NULL && seedlen > 0) {
+        params->seed = OPENSSL_memdup(seed, seedlen);
+        if (params->seed == NULL)
+            return 0;
+        params->seedlen = seedlen;
+    } else {
+        params->seed = NULL;
+        params->seedlen = 0;
+    }
+    params->pcounter = counter;
+    return 1;
+}
+
+void ffc_params_get_validate_params(const FFC_PARAMS *params,
+                                    unsigned char **seed, size_t *seedlen,
+                                    int *pcounter)
+{
+    if (seed != NULL)
+        *seed = params->seed;
+    if (seedlen != NULL)
+        *seedlen = params->seedlen;
+    if (pcounter != NULL)
+        *pcounter = params->pcounter;
+}
+
+static int ffc_bn_cpy(BIGNUM **dst, const BIGNUM *src)
+{
+    BIGNUM *a;
+
+    /*
+     * If source is read only just copy the pointer, so
+     * we don't have to reallocate it.
+     */
+    if (src == NULL)
+        a = NULL;
+    else if (BN_get_flags(src, BN_FLG_STATIC_DATA)
+             && !BN_get_flags(src, BN_FLG_MALLOCED))
+        a = (BIGNUM *)src;
+    else if ((a = BN_dup(src)) == NULL)
+        return 0;
+    BN_clear_free(*dst);
+    *dst = a;
+    return 1;
+}
+
+int ffc_params_copy(FFC_PARAMS *dst, const FFC_PARAMS *src)
+{
+    if (!ffc_bn_cpy(&dst->p, src->p)
+        || !ffc_bn_cpy(&dst->g, src->g)
+        || !ffc_bn_cpy(&dst->q, src->q)
+        || !ffc_bn_cpy(&dst->j, src->j))
+        return 0;
+
+    OPENSSL_free(dst->seed);
+    dst->seedlen = src->seedlen;
+    if (src->seed != NULL) {
+        dst->seed = OPENSSL_memdup(src->seed, src->seedlen);
+        if  (dst->seed == NULL)
+            return 0;
+    } else {
+        dst->seed = NULL;
+    }
+    dst->pcounter = src->pcounter;
+    return 1;
+}
+
+int ffc_params_cmp(const FFC_PARAMS *a, const FFC_PARAMS *b, int ignore_q)
+{
+    return BN_cmp(a->p, b->p) == 0
+           && BN_cmp(a->g, b->g) == 0
+           && (ignore_q || BN_cmp(a->q, b->q) == 0); /* Note: q may be NULL */
+}
+
+#ifndef FIPS_MODE
+int ffc_params_print(BIO *bp, const FFC_PARAMS *ffc, int indent)
+{
+    if (!ASN1_bn_print(bp, "prime P:", ffc->p, NULL, indent))
+        goto err;
+    if (!ASN1_bn_print(bp, "generator G:", ffc->g, NULL, indent))
+        goto err;
+    if (ffc->q != NULL
+        && !ASN1_bn_print(bp, "subgroup order Q:", ffc->q, NULL, indent))
+        goto err;
+    if (ffc->j != NULL
+        && !ASN1_bn_print(bp, "subgroup factor:", ffc->j, NULL, indent))
+        goto err;
+    if (ffc->seed != NULL) {
+        size_t i;
+        BIO_indent(bp, indent, 128);
+        BIO_puts(bp, "seed:");
+        for (i = 0; i < ffc->seedlen; i++) {
+            if ((i % 15) == 0) {
+                if (BIO_puts(bp, "\n") <= 0
+                    || !BIO_indent(bp, indent + 4, 128))
+                    goto err;
+            }
+            if (BIO_printf(bp, "%02x%s", ffc->seed[i],
+                           ((i + 1) == ffc->seedlen) ? "" : ":") <= 0)
+                goto err;
+        }
+        if (BIO_write(bp, "\n", 1) <= 0)
+            return 0;
+    }
+    if (ffc->pcounter != -1) {
+        BIO_indent(bp, indent, 128);
+        if (BIO_printf(bp, "counter: %d\n", ffc->pcounter) <= 0)
+            goto err;
+    }
+    return 1;
+err:
+    return 0;
+}
+#endif /* FIPS_MODE */