Merge pull request #3937 from geecrypt/mbedtls-2.7
Backport to Mbedtls 2.7: Support set *_drbg reseed interval before seed
diff --git a/ChangeLog.d/ecp-bignum-error-checks.txt b/ChangeLog.d/ecp-bignum-error-checks.txt
new file mode 100644
index 0000000..8cad08e
--- /dev/null
+++ b/ChangeLog.d/ecp-bignum-error-checks.txt
@@ -0,0 +1,5 @@
+Bugfix
+ * Fix a memory leak in mbedtls_mpi_sub_abs() when the result was negative
+ (an error condition) and the second operand was aliased to the result.
+ * Fix a case in elliptic curve arithmetic where an out-of-memory condition
+ could go undetected, resulting in an incorrect result.
diff --git a/library/bignum.c b/library/bignum.c
index 0e39e3a..c4eb7b0 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -1201,7 +1201,10 @@
/* If we ran out of space for the carry, it means that the result
* is negative. */
if( n == X->n )
- return( MBEDTLS_ERR_MPI_NEGATIVE_VALUE );
+ {
+ ret = MBEDTLS_ERR_MPI_NEGATIVE_VALUE;
+ goto cleanup;
+ }
--X->p[n];
}
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 26f6258..9331587 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -974,7 +974,7 @@
STORE32; i++; \
cur = c > 0 ? c : 0; STORE32; \
cur = 0; while( ++i < MAX32 ) { STORE32; } \
- if( c < 0 ) fix_negative( N, c, &C, bits );
+ if( c < 0 ) MBEDTLS_MPI_CHK( fix_negative( N, c, &C, bits ) );
/*
* If the result is negative, we get it in the form
diff --git a/tests/suites/test_suite_mpi.data b/tests/suites/test_suite_mpi.data
index a6a6423..a07e9af 100644
--- a/tests/suites/test_suite_mpi.data
+++ b/tests/suites/test_suite_mpi.data
@@ -427,12 +427,6 @@
Test mbedtls_mpi_add_abs #1
mbedtls_mpi_add_abs:10:"-643808006803554439230129854961492699151386107534013432918073439524138264842370630061369715394739134090922937332590384720397133335969549256322620979036686633213903952966175107096769180017646161851573147596390153":10:"56125680981752282333498088313568935051383833838594899821664631784577337171193624243181360054669678410455329112434552942717084003541384594864129940145043086760031292483340068923506115878221189886491132772739661669044958531131327771":10:"56125680981752282334141896320372489490613963693556392520816017892111350604111697682705498319512049040516698827829292076808006940873974979584527073481012636016353913462376755556720019831187364993587901952757307830896531678727717924"
-Test mbedtls_mpi_add_abs #2 (add to first value)
-mpi_add_abs_add_first:10:"123123":10:"123123":10:"246246"
-
-Test mbedtls_mpi_add_abs #3 (add to second value)
-mpi_add_abs_add_second:10:"123123":10:"123123":10:"246246"
-
Regression mbedtls_mpi_add_abs (add small to very large MPI with carry rollover)
mbedtls_mpi_add_abs:16:"FFFFFFFFFFFFFFFFFFFFFFFFFFFFF8":16:"08":16:"1000000000000000000000000000000"
diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index d023466..0d311e3 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -570,6 +570,15 @@
TEST_ASSERT( mbedtls_mpi_add_mpi( &Z, &X, &Y ) == 0 );
TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
+ /* result == first operand */
+ TEST_ASSERT( mbedtls_mpi_add_mpi( &X, &X, &Y ) == 0 );
+ TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
+ TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+
+ /* result == second operand */
+ TEST_ASSERT( mbedtls_mpi_add_mpi( &Y, &X, &Y ) == 0 );
+ TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
+
exit:
mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
}
@@ -614,44 +623,17 @@
TEST_ASSERT( mbedtls_mpi_add_abs( &Z, &X, &Y ) == 0 );
TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
-exit:
- mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
-}
-/* END_CASE */
-
-/* BEGIN_CASE */
-void mpi_add_abs_add_first( int radix_X, char *input_X, int radix_Y,
- char *input_Y, int radix_A, char *input_A )
-{
- mbedtls_mpi X, Y, A;
- mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &A );
-
- TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
- TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
- TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+ /* result == first operand */
TEST_ASSERT( mbedtls_mpi_add_abs( &X, &X, &Y ) == 0 );
TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
-
-exit:
- mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &A );
-}
-/* END_CASE */
-
-/* BEGIN_CASE */
-void mpi_add_abs_add_second( int radix_X, char *input_X, int radix_Y,
- char *input_Y, int radix_A, char *input_A )
-{
- mbedtls_mpi X, Y, A;
- mbedtls_mpi_init( &X ); mbedtls_mpi_init( &Y ); mbedtls_mpi_init( &A );
-
TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
- TEST_ASSERT( mbedtls_mpi_read_string( &Y, radix_Y, input_Y ) == 0 );
- TEST_ASSERT( mbedtls_mpi_read_string( &A, radix_A, input_A ) == 0 );
+
+ /* result == second operand */
TEST_ASSERT( mbedtls_mpi_add_abs( &Y, &X, &Y ) == 0 );
TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
exit:
- mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &A );
+ mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
}
/* END_CASE */
@@ -685,6 +667,15 @@
TEST_ASSERT( mbedtls_mpi_sub_mpi( &Z, &X, &Y ) == 0 );
TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
+ /* result == first operand */
+ TEST_ASSERT( mbedtls_mpi_sub_mpi( &X, &X, &Y ) == 0 );
+ TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
+ TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+
+ /* result == second operand */
+ TEST_ASSERT( mbedtls_mpi_sub_mpi( &Y, &X, &Y ) == 0 );
+ TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
+
exit:
mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
}
@@ -707,6 +698,17 @@
if( res == 0 )
TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Z, &A ) == 0 );
+ /* result == first operand */
+ TEST_ASSERT( mbedtls_mpi_sub_abs( &X, &X, &Y ) == sub_result );
+ if( sub_result == 0 )
+ TEST_ASSERT( mbedtls_mpi_cmp_mpi( &X, &A ) == 0 );
+ TEST_ASSERT( mbedtls_mpi_read_string( &X, radix_X, input_X ) == 0 );
+
+ /* result == second operand */
+ TEST_ASSERT( mbedtls_mpi_sub_abs( &Y, &X, &Y ) == sub_result );
+ if( sub_result == 0 )
+ TEST_ASSERT( mbedtls_mpi_cmp_mpi( &Y, &A ) == 0 );
+
exit:
mbedtls_mpi_free( &X ); mbedtls_mpi_free( &Y ); mbedtls_mpi_free( &Z ); mbedtls_mpi_free( &A );
}