New SP 800-56A compliant version of DH_compute_key().
authorDr. Stephen Henson <steve@openssl.org>
Tue, 8 Mar 2011 19:07:26 +0000 (19:07 +0000)
committerDr. Stephen Henson <steve@openssl.org>
Tue, 8 Mar 2011 19:07:26 +0000 (19:07 +0000)
crypto/dh/dh.h
crypto/dh/dh_key.c

index 084dc08..63db8c9 100644 (file)
@@ -202,6 +202,7 @@ int DH_check(const DH *dh,int *codes);
 int    DH_check_pub_key(const DH *dh,const BIGNUM *pub_key, int *codes);
 int    DH_generate_key(DH *dh);
 int    DH_compute_key(unsigned char *key,const BIGNUM *pub_key,DH *dh);
+int    DH_compute_key_padded(unsigned char *key,const BIGNUM *pub_key,DH *dh);
 DH *   d2i_DHparams(DH **a,const unsigned char **pp, long length);
 int    i2d_DHparams(const DH *a,unsigned char **pp);
 #ifndef OPENSSL_NO_FP_API
index bba83be..6c7a457 100644 (file)
@@ -86,6 +86,21 @@ int DH_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
        return dh->meth->compute_key(key, pub_key, dh);
        }
 
+int DH_compute_key_padded(unsigned char *key, const BIGNUM *pub_key, DH *dh)
+       {
+       int rv, pad;
+       rv = dh->meth->compute_key(key, pub_key, dh);
+       if (rv <= 0)
+               return rv;
+       pad = BN_num_bytes(dh->p) - rv;
+       if (pad > 0)
+               {
+               memmove(key + pad, key, rv);
+               memset(key, 0, pad);
+               }
+       return rv + pad;
+       }
+
 static DH_METHOD dh_ossl = {
 "OpenSSL DH Method",
 generate_key,