From 7b420a896f8e90151a465420f5ed0621ce6de84c Mon Sep 17 00:00:00 2001
From: Tom Cosgrove <tom.cosgrove@arm.com>
Date: Mon, 15 Nov 2021 09:59:53 +0000
Subject: [PATCH 1/2] Fix builds when config.h only defines MBEDTLS_BIGNUM_C

Fixes #4929

Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
---
 include/mbedtls/entropy.h | 2 +-
 library/bignum.c          | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/mbedtls/entropy.h b/include/mbedtls/entropy.h
index ac977cf817..eea786e352 100644
--- a/include/mbedtls/entropy.h
+++ b/include/mbedtls/entropy.h
@@ -157,7 +157,7 @@ typedef struct mbedtls_entropy_context
                               * -1 after free. */
 #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
     mbedtls_sha512_context  accumulator;
-#else
+#elif defined(MBEDTLS_ENTROPY_SHA256_ACCUMULATOR)
     mbedtls_sha256_context  accumulator;
 #endif
     int             source_count; /* Number of entries used in source. */
diff --git a/library/bignum.c b/library/bignum.c
index 3df905203f..c553d0c5af 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -72,6 +72,7 @@
 #include "mbedtls/bn_mul.h"
 #include "mbedtls/platform_util.h"
 
+#include <limits.h>
 #include <string.h>
 
 #if defined(MBEDTLS_PLATFORM_C)

From 942f8b6854af04fae9994dc72367f4e029ee293b Mon Sep 17 00:00:00 2001
From: Gilles Peskine <Gilles.Peskine@arm.com>
Date: Mon, 6 Dec 2021 20:56:55 +0100
Subject: [PATCH 2/2] Add changelog entry for build error fixes

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
---
 ChangeLog.d/build-without-sha.txt | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 ChangeLog.d/build-without-sha.txt

diff --git a/ChangeLog.d/build-without-sha.txt b/ChangeLog.d/build-without-sha.txt
new file mode 100644
index 0000000000..78ba27694a
--- /dev/null
+++ b/ChangeLog.d/build-without-sha.txt
@@ -0,0 +1,3 @@
+Bugfix
+   * Fix the build when no SHA2 module is included. Fixes #4930.
+   * Fix the build when only the bignum module is included. Fixes #4929.