Add funtions to set item_sign and item_verify

PR#3872
Reviewed-by: NMatt Caswell <matt@openssl.org>
Reviewed-by: NStephen Henson <steve@openssl.org>

crypto/asn1/ameth_lib.c

@@ -464,3 +464,21 @@ void EVP_PKEY_asn1_set_ctrl(EVP_PKEY_ASN1_METHOD *ameth,
 {
     ameth->pkey_ctrl = pkey_ctrl;
 }
+
+void EVP_PKEY_asn1_set_item(EVP_PKEY_ASN1_METHOD *ameth,
+                            int (*item_verify) (EVP_MD_CTX *ctx,
+                                                const ASN1_ITEM *it,
+                                                void *asn,
+                                                X509_ALGOR *a,
+                                                ASN1_BIT_STRING *sig,
+                                                EVP_PKEY *pkey),
+                            int (*item_sign) (EVP_MD_CTX *ctx,
+                                              const ASN1_ITEM *it,
+                                              void *asn,
+                                              X509_ALGOR *alg1,
+                                              X509_ALGOR *alg2,
+                                              ASN1_BIT_STRING *sig))
+{
+    ameth->item_sign = item_sign;
+    ameth->item_verify = item_verify;
+}

crypto/evp/evp.h

@@ -1123,6 +1123,19 @@ void EVP_PKEY_asn1_set_free(EVP_PKEY_ASN1_METHOD *ameth,
 void EVP_PKEY_asn1_set_ctrl(EVP_PKEY_ASN1_METHOD *ameth,
                             int (*pkey_ctrl) (EVP_PKEY *pkey, int op,
                                               long arg1, void *arg2));
+void EVP_PKEY_asn1_set_item(EVP_PKEY_ASN1_METHOD *ameth,
+                            int (*item_verify) (EVP_MD_CTX *ctx,
+                                                const ASN1_ITEM *it,
+                                                void *asn,
+                                                X509_ALGOR *a,
+                                                ASN1_BIT_STRING *sig,
+                                                EVP_PKEY *pkey),
+                            int (*item_sign) (EVP_MD_CTX *ctx,
+                                              const ASN1_ITEM *it,
+                                              void *asn,
+                                              X509_ALGOR *alg1,
+                                              X509_ALGOR *alg2,
+                                              ASN1_BIT_STRING *sig));
 
 # define EVP_PKEY_OP_UNDEFINED           0
 # define EVP_PKEY_OP_PARAMGEN            (1<<1)