commit 82e57d1611877b7d27f7194cb34528b8eca54ea2
author Gilles Peskine <Gilles.Peskine@arm.com> Fri Nov 13 21:31:17 2020 +0100
committer Gilles Peskine <Gilles.Peskine@arm.com> Mon Nov 23 17:42:54 2020 +0100
tree c8a8b79805d85ce265fef1e9196268acd2553d2c
parent 4fc21fdeb6ecff1165b1a7e77cea5676b8058ee0

PSA: support HMAC_DRBG

Support using HMAC_DRBG instead of CTR_DRBG in the PSA subsystem.

Use HMAC_DRBG if CTR_DRBG is available. Choose between SHA-256 and
SHA-512 based on availability.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

library/psa_crypto.c

diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 410d6a1..66c4f7d 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -63,7 +63,6 @@
 #include "mbedtls/cipher.h"
 #include "mbedtls/ccm.h"
 #include "mbedtls/cmac.h"
-#include "mbedtls/ctr_drbg.h"
 #include "mbedtls/des.h"
 #include "mbedtls/ecdh.h"
 #include "mbedtls/ecp.h"
@@ -214,6 +213,8 @@
         case MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED:
             return( PSA_ERROR_HARDWARE_FAILURE );
 
+#if !( defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) ||      \
+       defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE) )
         case MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED:
             return( PSA_ERROR_INSUFFICIENT_ENTROPY );
         case MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG:
@@ -221,6 +222,7 @@
             return( PSA_ERROR_NOT_SUPPORTED );
         case MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR:
             return( PSA_ERROR_INSUFFICIENT_ENTROPY );
+#endif
 
         case MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH:
             return( PSA_ERROR_NOT_SUPPORTED );
@@ -239,6 +241,17 @@
         case MBEDTLS_ERR_GCM_HW_ACCEL_FAILED:
             return( PSA_ERROR_HARDWARE_FAILURE );
 
+#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) &&        \
+    defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE)
+        case MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED:
+            return( PSA_ERROR_INSUFFICIENT_ENTROPY );
+        case MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG:
+        case MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR:
+            return( PSA_ERROR_INSUFFICIENT_ENTROPY );
+#endif
+
         case MBEDTLS_ERR_MD2_HW_ACCEL_FAILED:
         case MBEDTLS_ERR_MD4_HW_ACCEL_FAILED:
         case MBEDTLS_ERR_MD5_HW_ACCEL_FAILED: