commit 039e02df2716a0ed886b56e1e07b7ac1d8597228
author Jerome Forissier <jerome.forissier@linaro.org> Tue Aug 09 17:10:15 2022 +0200
committer Jérôme Forissier <jerome@forissier.org> Wed Aug 10 20:49:06 2022 +0200
tree 9793d39492b08783ff934ba9065a969bbea85c1b
parent 207505051c368276555a20587449d9fe88e6ac31

Squashed commit upgrading to mbedtls-2.28.1

Squash merging branch import/mbedtls-2.28.1

 ebf1f6a58089 ("libmbedtls: compile new files added with 2.28.1")
 3ffb51b58a54 ("libmbedtls: add SM2 curve")
 c425755720b4 ("libmbedtls: mbedtls_mpi_exp_mod(): optimize mempool usage")
 23493c822a82 ("libmbedtls: mbedtls_mpi_exp_mod(): reduce stack usage")
 dcdca2348dff ("libmbedtls: mbedtls_mpi_exp_mod() initialize W")
 dc2994976958 ("libmbedtls: fix no CRT issue")
 c6628873b281 ("libmbedtls: add interfaces in mbedtls for context memory operation")
 8acd202d3e55 ("libmedtls: mpi_miller_rabin: increase count limit")
 37284e28d5d9 ("libmbedtls: add mbedtls_mpi_init_mempool()")
 b499a75f29f3 ("libmbedtls: make mbedtls_mpi_mont*() available")
 2080a8c96a5d ("mbedtls: configure mbedtls to reach for config")
 e0858334327a ("mbedtls: remove default include/mbedtls/config.h")
 dd9688e6b8ce ("Import mbedtls-2.28.1")

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

lib/libmbedtls/mbedtls/library/asn1write.c

diff --git a/lib/libmbedtls/mbedtls/library/asn1write.c b/lib/libmbedtls/mbedtls/library/asn1write.c
index deb1a2f..afa26a6 100644
--- a/lib/libmbedtls/mbedtls/library/asn1write.c
+++ b/lib/libmbedtls/mbedtls/library/asn1write.c
@@ -60,8 +60,8 @@
         if( *p - start < 3 )
             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 
-        *--(*p) = ( len       ) & 0xFF;
-        *--(*p) = ( len >>  8 ) & 0xFF;
+        *--(*p) = MBEDTLS_BYTE_0( len );
+        *--(*p) = MBEDTLS_BYTE_1( len );
         *--(*p) = 0x82;
         return( 3 );
     }
@@ -71,9 +71,9 @@
         if( *p - start < 4 )
             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 
-        *--(*p) = ( len       ) & 0xFF;
-        *--(*p) = ( len >>  8 ) & 0xFF;
-        *--(*p) = ( len >> 16 ) & 0xFF;
+        *--(*p) = MBEDTLS_BYTE_0( len );
+        *--(*p) = MBEDTLS_BYTE_1( len );
+        *--(*p) = MBEDTLS_BYTE_2( len );
         *--(*p) = 0x83;
         return( 4 );
     }
@@ -85,10 +85,10 @@
         if( *p - start < 5 )
             return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 
-        *--(*p) = ( len       ) & 0xFF;
-        *--(*p) = ( len >>  8 ) & 0xFF;
-        *--(*p) = ( len >> 16 ) & 0xFF;
-        *--(*p) = ( len >> 24 ) & 0xFF;
+        *--(*p) = MBEDTLS_BYTE_0( len );
+        *--(*p) = MBEDTLS_BYTE_1( len );
+        *--(*p) = MBEDTLS_BYTE_2( len );
+        *--(*p) = MBEDTLS_BYTE_3( len );
         *--(*p) = 0x84;
         return( 5 );
     }
@@ -133,6 +133,11 @@
     //
     len = mbedtls_mpi_size( X );
 
+    /* DER represents 0 with a sign bit (0=nonnegative) and 7 value bits, not
+     * as 0 digits. We need to end up with 020100, not with 0200. */
+    if( len == 0 )
+        len = 1;
+
     if( *p < start || (size_t)( *p - start ) < len )
         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
 
@@ -472,7 +477,7 @@
         cur->val.len = val_len;
     }
 
-    if( val != NULL )
+    if( val != NULL && val_len != 0 )
         memcpy( cur->val.p, val, val_len );
 
     return( cur );