New function X509_ALGOR_set_md() to set X509_ALGOR (DigestAlgorithmIdentifier)

from a digest algorithm.

crypto/asn1/x_algor.c

@@ -128,3 +128,17 @@ void X509_ALGOR_get0(ASN1_OBJECT **paobj, int *pptype, void **ppval,
 		}
 	}
 
+/* Set up an X509_ALGOR DigestAlgorithmIdentifier from an EVP_MD */
+
+void X509_ALGOR_set_md(X509_ALGOR *alg, const EVP_MD *md)
+	{
+	int param_type;
+
+	if (md->flags & EVP_MD_FLAG_DIGALGID_ABSENT)
+		param_type = V_ASN1_UNDEF;
+	else
+		param_type = V_ASN1_NULL;
+
+	X509_ALGOR_set0(alg, OBJ_nid2obj(EVP_MD_type(md)), param_type, NULL);
+
+	}

crypto/x509/x509.h

@@ -763,6 +763,7 @@ X509_ALGOR *X509_ALGOR_dup(X509_ALGOR *xn);
 int X509_ALGOR_set0(X509_ALGOR *alg, ASN1_OBJECT *aobj, int ptype, void *pval);
 void X509_ALGOR_get0(ASN1_OBJECT **paobj, int *pptype, void **ppval,
 						X509_ALGOR *algor);
+void X509_ALGOR_set_md(X509_ALGOR *alg, const EVP_MD *md);
 
 X509_NAME *X509_NAME_dup(X509_NAME *xn);
 X509_NAME_ENTRY *X509_NAME_ENTRY_dup(X509_NAME_ENTRY *ne);