Add certificate properties table.

Add certificate table giving properties of each certificate index:
specifically the NID associated with the index and the the auth mask
value for any cipher the certificate can be used with.

This will be used to generalise certificate handling instead of hard coding
algorithm specific cases.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3858)

ssl/ssl_cert.c

@@ -976,3 +976,41 @@ int ssl_ctx_security(const SSL_CTX *ctx, int op, int bits, int nid, void *other)
     return ctx->cert->sec_cb(NULL, ctx, op, bits, nid, other,
                              ctx->cert->sec_ex);
 }
+
+/*
+ * Certificate table information. NB: table entries must match SSL_PKEY indices
+ */
+static const SSL_CERT_LOOKUP ssl_cert_info [] = {
+    {EVP_PKEY_RSA, SSL_aRSA}, /* SSL_PKEY_RSA */
+    {EVP_PKEY_DSA, SSL_aDSS}, /* SSL_PKEY_DSA_SIGN */
+    {EVP_PKEY_EC, SSL_aECDSA}, /* SSL_PKEY_ECC */
+    {NID_id_GostR3410_2001, SSL_aGOST01}, /* SSL_PKEY_GOST01 */
+    {NID_id_GostR3410_2012_256, SSL_aGOST12}, /* SSL_PKEY_GOST12_256 */
+    {NID_id_GostR3410_2012_512, SSL_aGOST12}, /* SSL_PKEY_GOST12_512 */
+    {EVP_PKEY_ED25519, SSL_aECDSA} /* SSL_PKEY_ED25519 */
+};
+
+const SSL_CERT_LOOKUP *ssl_cert_lookup_by_pkey(const EVP_PKEY *pk, size_t *pidx)
+{
+    int nid = EVP_PKEY_id(pk);
+    size_t i;
+
+    if (nid == NID_undef)
+        return NULL;
+
+    for (i = 0; i < OSSL_NELEM(ssl_cert_info); i++) {
+        if (ssl_cert_info[i].nid == nid) {
+            if (pidx != NULL)
+                *pidx = i;
+            return &ssl_cert_info[i];
+        }
+    }
+    return NULL;
+}
+
+const SSL_CERT_LOOKUP *ssl_cert_lookup_by_idx(size_t idx)
+{
+    if (idx >= OSSL_NELEM(ssl_cert_info))
+        return 0;
+    return &ssl_cert_info[idx];
+}

ssl/ssl_ciph.c

@@ -1996,3 +1996,12 @@ int ssl_cipher_get_overhead(const SSL_CIPHER *c, size_t *mac_overhead,
 
     return 1;
 }
+
+int ssl_cert_is_disabled(size_t idx)
+{
+    const SSL_CERT_LOOKUP *cl = ssl_cert_lookup_by_idx(idx);
+
+    if (cl == NULL || (cl->amask & disabled_auth_mask) != 0)
+        return 1;
+    return 0;
+}

ssl/ssl_locl.h

@@ -1345,6 +1345,15 @@ typedef struct sigalg_lookup_st {
 
 typedef struct cert_pkey_st CERT_PKEY;
 
+/*
+ * Structure containing table entry of certificate info corresponding to
+ * CERT_PKEY entries
+ */
+typedef struct {
+    int nid; /* NID of pubic key algorithm */
+    uint32_t amask; /* authmask corresponding to key type */
+} SSL_CERT_LOOKUP;
+
 typedef struct ssl3_state_st {
     long flags;
     size_t read_mac_secret_size;
@@ -2092,6 +2101,7 @@ __owur int ssl_cipher_get_evp(const SSL_SESSION *s, const EVP_CIPHER **enc,
 __owur int ssl_cipher_get_overhead(const SSL_CIPHER *c, size_t *mac_overhead,
                                    size_t *int_overhead, size_t *blocksize,
                                    size_t *ext_overhead);
+__owur int ssl_cert_is_disabled(size_t idx);
 __owur int ssl_cipher_get_cert_index(const SSL_CIPHER *c);
 __owur const SSL_CIPHER *ssl_get_cipher_by_char(SSL *ssl,
                                                 const unsigned char *ptr,
@@ -2114,6 +2124,10 @@ __owur int ssl_security(const SSL *s, int op, int bits, int nid, void *other);
 __owur int ssl_ctx_security(const SSL_CTX *ctx, int op, int bits, int nid,
                             void *other);
 
+__owur const SSL_CERT_LOOKUP *ssl_cert_lookup_by_pkey(const EVP_PKEY *pk,
+                                                      size_t *pidx);
+__owur const SSL_CERT_LOOKUP *ssl_cert_lookup_by_idx(size_t idx);
+
 int ssl_undefined_function(SSL *s);
 __owur int ssl_undefined_void_function(void);
 __owur int ssl_undefined_const_function(const SSL *s);