diff --git a/include/polarssl/pk.h b/include/polarssl/pk.h
index f06ec68..a2d166f 100644
--- a/include/polarssl/pk.h
+++ b/include/polarssl/pk.h
@@ -89,6 +89,9 @@
     /** Public key type */
     pk_type_t type;
 
+    /** Tell if the context implements this type (eg ECKEY can do ECDSA) */
+    int (*can_do)( pk_type_t type );
+
     /** Verify signature */
     int (*verify_func)( void *ctx,
                         const unsigned char *hash, const md_info_t *md_info,
@@ -131,33 +134,6 @@
  */
 int pk_set_type( pk_context *ctx, pk_type_t type );
 
-#if defined(POLARSSL_ECDSA_C)
-/**
- * \brief           Convert a generic EC key into an ECDSA context
- *
- * \param ctx       Context to convert
- *
- * \return          0 on success, or
- *                  POLARSSL_ERR_PK_MALLOC_FAILED or
- *                  POLARSSL_ERR_PK_TYPE_MISMATCH.
- */
-int pk_ec_to_ecdsa( pk_context *ctx );
-
-/**
- * \brief           Tell if a PK context can be used for ECDSA
- *
- * \param ctx       Context to check
- *
- * \return          0 if context cannot be used for ECDSA,
- *                  1 otherwise
- */
-static inline int pk_can_ecdsa( pk_context ctx )
-{
-    return( ctx.type == POLARSSL_PK_ECKEY ||
-            ctx.type == POLARSSL_PK_ECDSA );
-}
-#endif /* POLARSSL_ECDSA_C */
-
 #if defined(POLARSSL_RSA_C)
 /**
  * \brief           Wrap a RSA context in a PK context
diff --git a/library/pk.c b/library/pk.c
index 1210490..6cfc16b 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -146,42 +146,6 @@
     return( 0 );
 }
 
-#if defined(POLARSSL_ECDSA_C)
-/*
- * Convert generic EC context to ECDSA
- */
-int pk_ec_to_ecdsa( pk_context *ctx )
-{
-    ecp_keypair *eckey;
-    ecdsa_context *ecdsa;
-
-    if( ctx->type == POLARSSL_PK_ECDSA )
-        return( 0 );
-
-    if( ctx->type != POLARSSL_PK_ECKEY )
-        return( POLARSSL_ERR_PK_TYPE_MISMATCH );
-
-    eckey = (ecp_keypair *) ctx->data;
-
-    if( ( ecdsa = polarssl_malloc( sizeof( ecdsa_context ) ) ) == NULL )
-        return( POLARSSL_ERR_PK_MALLOC_FAILED );
-
-    ecdsa_init( ecdsa );
-
-    /* struct ecdsa_context begins the same as struct ecp_keypair */
-    memcpy( ecdsa, eckey, sizeof( ecp_keypair ) );
-
-    if( ! ctx->dont_free )
-        polarssl_free( eckey );
-
-    ctx->dont_free = 0;
-    ctx->type = POLARSSL_PK_ECDSA;
-    ctx->data = ecdsa;
-
-    return( 0 );
-}
-#endif /* POLARSSL_ECDSA_C */
-
 #if defined(POLARSSL_RSA_C)
 /*
  * Wrap an RSA context in a PK context
diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index fe47b38..f7b0833 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -40,6 +40,11 @@
 #endif
 
 #if defined(POLARSSL_RSA_C)
+static int rsa_can_do( pk_type_t type )
+{
+    return( type == POLARSSL_PK_RSA );
+}
+
 static int rsa_verify_wrap( void *ctx,
                    const unsigned char *hash, const md_info_t *md_info,
                    const unsigned char *sig, size_t sig_len )
@@ -52,11 +57,17 @@
 
 const pk_info_t rsa_info = {
     POLARSSL_PK_RSA,
+    rsa_can_do,
     rsa_verify_wrap,
 };
 #endif /* POLARSSL_RSA_C */
 
 #if defined(POLARSSL_ECDSA_C)
+int ecdsa_can_do( pk_type_t type )
+{
+    return( type == POLARSSL_PK_ECDSA );
+}
+
 int ecdsa_verify_wrap( void *ctx,
                        const unsigned char *hash, const md_info_t *md_info,
                        const unsigned char *sig, size_t sig_len )
@@ -67,11 +78,19 @@
 
 const pk_info_t ecdsa_info = {
     POLARSSL_PK_ECDSA,
+    ecdsa_can_do,
     ecdsa_verify_wrap,
 };
 #endif /* POLARSSL_ECDSA_C */
 
 #if defined(POLARSSL_ECP_C)
+static int eckey_can_do( pk_type_t type )
+{
+    return( type == POLARSSL_PK_ECKEY ||
+            type == POLARSSL_PK_ECKEY_DH ||
+            type == POLARSSL_PK_ECDSA );
+}
+
 static int eckey_verify_wrap( void *ctx,
                        const unsigned char *hash, const md_info_t *md_info,
                        const unsigned char *sig, size_t sig_len )
@@ -101,6 +120,7 @@
 
 const pk_info_t eckey_info = {
     POLARSSL_PK_ECKEY,
+    eckey_can_do,
     eckey_verify_wrap,
 };
 #endif /* POLARSSL_ECP_C */
diff --git a/library/x509parse.c b/library/x509parse.c
index 15823bd..31b1fa0 100644
--- a/library/x509parse.c
+++ b/library/x509parse.c
@@ -3344,33 +3344,13 @@
 
         md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash );
 
-#if defined(POLARSSL_RSA_C)
-        if( crl_list->sig_pk == POLARSSL_PK_RSA )
+        if( ca->pk.info->can_do( crl_list->sig_pk ) == 0 ||
+                ca->pk.info->verify_func( ca->pk.data, hash, md_info,
+                                    crl_list->sig.p, crl_list->sig.len ) != 0 )
         {
-            if( ca->pk.type != POLARSSL_PK_RSA ||
-                ca->pk.info->verify_func( ca->pk.data,
-                    hash, md_info, crl_list->sig.p, crl_list->sig.len ) != 0 )
-            {
-                flags |= BADCRL_NOT_TRUSTED;
-                break;
-            }
+            flags |= BADCRL_NOT_TRUSTED;
+            break;
         }
-        else
-#endif /* POLARSSL_RSA_C */
-#if defined(POLARSSL_ECDSA_C)
-        if( crl_list->sig_pk == POLARSSL_PK_ECDSA )
-        {
-            if( ! pk_can_ecdsa( ca->pk ) ||
-                ca->pk.info->verify_func( ca->pk.data,
-                    hash, md_info, crl_list->sig.p, crl_list->sig.len ) != 0 )
-            {
-                flags |= BADCRL_NOT_TRUSTED;
-                break;
-            }
-        }
-        else
-#endif /* POLARSSL_ECDSA_C */
-            return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE );
 
         /*
          * Check for validity of CRL (Do not drop out)
@@ -3457,7 +3437,7 @@
          */
         if( child->subject_raw.len == trust_ca->subject_raw.len &&
             memcmp( child->subject_raw.p, trust_ca->subject_raw.p,
-                            child->issuer_raw.len ) == 0 ) 
+                            child->issuer_raw.len ) == 0 )
         {
             check_path_cnt--;
         }
@@ -3481,33 +3461,13 @@
 
         md( md_info, child->tbs.p, child->tbs.len, hash );
 
-#if defined(POLARSSL_RSA_C)
-        if( child->sig_pk == POLARSSL_PK_RSA )
+        if( trust_ca->pk.info->can_do( child->sig_pk ) == 0 ||
+            trust_ca->pk.info->verify_func( trust_ca->pk.data, hash, md_info,
+                                        child->sig.p, child->sig.len ) != 0 )
         {
-            if( trust_ca->pk.type != POLARSSL_PK_RSA ||
-                trust_ca->pk.info->verify_func( trust_ca->pk.data,
-                        hash, md_info, child->sig.p, child->sig.len ) != 0 )
-            {
-                trust_ca = trust_ca->next;
-                continue;
-            }
+            trust_ca = trust_ca->next;
+            continue;
         }
-        else
-#endif /* POLARSSL_RSA_C */
-#if defined(POLARSSL_ECDSA_C)
-        if( child->sig_pk == POLARSSL_PK_ECDSA )
-        {
-            if( ! pk_can_ecdsa( trust_ca->pk ) ||
-                trust_ca->pk.info->verify_func( trust_ca->pk.data,
-                        hash, md_info, child->sig.p, child->sig.len ) != 0 )
-            {
-                trust_ca = trust_ca->next;
-                continue;
-            }
-        }
-        else
-#endif /* POLARSSL_ECDSA_C */
-            return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE );
 
         /*
          * Top of chain is signed by a trusted CA
@@ -3578,31 +3538,12 @@
     {
         md( md_info, child->tbs.p, child->tbs.len, hash );
 
-#if defined(POLARSSL_RSA_C)
-        if( child->sig_pk == POLARSSL_PK_RSA )
+        if( parent->pk.info->can_do( child->sig_pk ) == 0 ||
+                parent->pk.info->verify_func( parent->pk.data, hash, md_info,
+                                        child->sig.p, child->sig.len ) != 0 )
         {
-            if( parent->pk.type != POLARSSL_PK_RSA ||
-                parent->pk.info->verify_func( parent->pk.data,
-                        hash, md_info, child->sig.p, child->sig.len ) != 0 )
-            {
-                *flags |= BADCERT_NOT_TRUSTED;
-            }
+            *flags |= BADCERT_NOT_TRUSTED;
         }
-        else
-#endif /* POLARSSL_RSA_C */
-#if defined(POLARSSL_ECDSA_C)
-        if( child->sig_pk == POLARSSL_PK_ECDSA )
-        {
-            if( ! pk_can_ecdsa( parent->pk ) ||
-                parent->pk.info->verify_func( parent->pk.data,
-                        hash, md_info, child->sig.p, child->sig.len ) != 0 )
-            {
-                *flags |= BADCERT_NOT_TRUSTED;
-            }
-        }
-        else
-#endif /* POLARSSL_ECDSA_C */
-            return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE );
     }
 
     /* Check trusted CA's CRL for the given crt */