Removes f_rng from mbedtls_rsa_rsassa_pkcs1_v15_verify

Commit performs removal of f_rng parameter
from mbedtls_rsa_rsassa_pkcs1_v15_verify
function in preparation for removal of mode
parameter.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/include/mbedtls/rsa.h b/include/mbedtls/rsa.h
index 37fdddd..6a0309a 100644
--- a/include/mbedtls/rsa.h
+++ b/include/mbedtls/rsa.h
@@ -1016,9 +1016,6 @@
  *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
  * \param ctx      The initialized RSA public key context to use.
- * \param f_rng    The RNG function to use. If \p mode is #MBEDTLS_RSA_PRIVATE,
- *                 this is used for blinding and should be provided; see
- *                 mbedtls_rsa_private() for more. Otherwise, it is ignored.
  * \param mode     The mode of operation. This must be either
  *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated).
  * \param md_alg   The message-digest algorithm used to hash the original data.
@@ -1038,7 +1035,6 @@
  * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure.
  */
 int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
-                                 int (*f_rng)(void *, unsigned char *, size_t),
                                  int mode,
                                  mbedtls_md_type_t md_alg,
                                  unsigned int hashlen,
diff --git a/library/rsa.c b/library/rsa.c
index 9e2d054..4d56970 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -2331,7 +2331,6 @@
  * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-v1_5-VERIFY function
  */
 int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx,
-                                 int (*f_rng)(void *, unsigned char *, size_t),
                                  int mode,
                                  mbedtls_md_type_t md_alg,
                                  unsigned int hashlen,
@@ -2376,7 +2375,7 @@
 
     ret = ( mode == MBEDTLS_RSA_PUBLIC )
           ? mbedtls_rsa_public(  ctx, sig, encoded )
-          : mbedtls_rsa_private( ctx, f_rng, NULL, sig, encoded );
+          : mbedtls_rsa_private( ctx, NULL, NULL, sig, encoded );
     if( ret != 0 )
         goto cleanup;
 
@@ -2428,7 +2427,7 @@
     {
 #if defined(MBEDTLS_PKCS1_V15)
         case MBEDTLS_RSA_PKCS_V15:
-            return mbedtls_rsa_rsassa_pkcs1_v15_verify( ctx, NULL, MBEDTLS_RSA_PUBLIC, md_alg,
+            return mbedtls_rsa_rsassa_pkcs1_v15_verify( ctx, MBEDTLS_RSA_PUBLIC, md_alg,
                                                 hashlen, hash, sig );
 #endif
 
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index a529c55..8f952b3 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -297,22 +297,22 @@
                                                       buf ) );
 
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
-                            mbedtls_rsa_rsassa_pkcs1_v15_verify( NULL, NULL,
+                            mbedtls_rsa_rsassa_pkcs1_v15_verify( NULL,
                                                           MBEDTLS_RSA_PUBLIC,
                                                           0, sizeof( buf ), buf,
                                                           buf ) );
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
-                            mbedtls_rsa_rsassa_pkcs1_v15_verify( &ctx, NULL,
+                            mbedtls_rsa_rsassa_pkcs1_v15_verify( &ctx,
                                                           MBEDTLS_RSA_PUBLIC,
                                                           0, sizeof( buf ),
                                                           NULL, buf ) );
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
-                            mbedtls_rsa_rsassa_pkcs1_v15_verify( &ctx, NULL,
+                            mbedtls_rsa_rsassa_pkcs1_v15_verify( &ctx,
                                                           MBEDTLS_RSA_PUBLIC,
                                                           0, sizeof( buf ), buf,
                                                           NULL ) );
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
-                            mbedtls_rsa_rsassa_pkcs1_v15_verify( &ctx, NULL,
+                            mbedtls_rsa_rsassa_pkcs1_v15_verify( &ctx,
                                                           MBEDTLS_RSA_PUBLIC,
                                                           MBEDTLS_MD_SHA1,
                                                           0, NULL,