commit 61b05e572bd4b5cf398f8a2724ede7314e78afce
author Hanno Becker <hanno.becker@arm.com> Fri Aug 23 15:24:34 2019 +0100
committer Hanno Becker <hanno.becker@arm.com> Wed Sep 04 16:19:49 2019 +0100
tree 4fa0fa5fcc9516d2de74dd0990ee4df00caa356e
parent d82f60da364149a067e29b1d50339ef94fd226a9

Remove dependency of MBEDTLS_X509_USE_C on MBEDTLS_BIGNUM_C

There is no apparent direct dependency, and the indirect dependency
through the RSA and legacy ECP modules is already encoded in the
chain

   MBEDTLS_X509_USE_C
-> MBEDTLS_PK_PARSE_C
-> MBEDTLS_PK_C
-> MBEDTLS_RSA_C || MBEDTLS_ECP_C
-> MBEDTLS_BIGNUM_C

which will be modified to

   MBEDTLS_X509_USE_C
-> MBEDTLS_PK_PARSE_C
-> MBEDTLS_PK_C
-> MBEDTLS_RSA_C || MBEDTLS_ECP_C || MBEDTLS_USE_TINYCRYPT

in which case MBEDTLS_BIGNUM_C is not needed for MBEDTLS_X509_USE_C
if only MBEDTLS_USE_TINYCRYPT is set, but not MBEDTLS_RSA_C or
MBEDTLS_ECP_C.

include/mbedtls/check_config.h

diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index 3ed61ed..b202ddd 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -785,9 +785,10 @@
 #error "MBEDTLS_VERSION_FEATURES defined, but not all prerequisites"
 #endif
 
-#if defined(MBEDTLS_X509_USE_C) && ( !defined(MBEDTLS_BIGNUM_C) ||  \
-    !defined(MBEDTLS_OID_C) || !defined(MBEDTLS_ASN1_PARSE_C) ||      \
-    !defined(MBEDTLS_PK_PARSE_C) )
+#if defined(MBEDTLS_X509_USE_C) &&              \
+    ( !defined(MBEDTLS_OID_C)        ||         \
+      !defined(MBEDTLS_ASN1_PARSE_C) ||         \
+      !defined(MBEDTLS_PK_PARSE_C) )
 #error "MBEDTLS_X509_USE_C defined, but not all prerequisites"
 #endif