Test that overly large Diffie-Hellman keys are rejected

Adds test cases to ensure that `mbedtls_mpi_exp_mod` will return an error with
an exponent or modulus that is greater than `MBEDTLS_MPI_MAX_SIZE` in size.

Adds test cases to ensure that Diffie-Hellman will fail to make a key pair
(using `mbedtls_dhm_make_public`) when the prime modulus is greater than
`MBEDTLS_MPI_MAX_SIZE` in size.

Signed-off-by: Chris Jones <christopher.jones@arm.com>

tests/suites/test_suite_dhm.data

@@ -22,8 +22,11 @@ dhm_do_dhm:10:"3":10:"5":MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED
 Diffie-Hellman zero modulus
 dhm_do_dhm:10:"0":10:"5":MBEDTLS_ERR_DHM_BAD_INPUT_DATA
 
-Diffie-Hellman huge modulus
+Diffie-Hellman MPI_MAX_SIZE modulus
-dhm_do_dhm:16:"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":10:"5":MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED+MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+dhm_make_public:MBEDTLS_MPI_MAX_SIZE:10:"5":0
+
+Diffie-Hellman MPI_MAX_SIZE + 1 modulus
+dhm_make_public:MBEDTLS_MPI_MAX_SIZE + 1:10:"5":MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED+MBEDTLS_ERR_MPI_BAD_INPUT_DATA
 
 Diffie-Hellman load parameters from file [#1]
 dhm_file:"data_files/dhparams.pem":"9e35f430443a09904f3a39a979797d070df53378e79c2438bef4e761f3c714553328589b041c809be1d6c6b5f1fc9f47d3a25443188253a992a56818b37ba9de5a40d362e56eff0be5417474c125c199272c8fe41dea733df6f662c92ae76556e755d10c64e6a50968f67fc6ea73d0dca8569be2ba204e23580d8bca2f4975b3":"02":128

tests/suites/test_suite_dhm.function

@@ -206,6 +206,36 @@ exit:
 }
 /* END_CASE */
 
+/* BEGIN_CASE */
+void dhm_make_public( int P_bytes, int radix_G, char *input_G, int result )
+{
+    mbedtls_mpi P, G;
+    mbedtls_dhm_context ctx;
+    unsigned char output[MBEDTLS_MPI_MAX_SIZE];
+
+    mbedtls_mpi_init( &P );
+    mbedtls_mpi_init( &G );
+    mbedtls_dhm_init( &ctx );
+
+    TEST_ASSERT( mbedtls_mpi_lset( &P, 1 ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_shift_l( &P, ( P_bytes * 8 ) - 1 ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_set_bit( &P, 0, 1 ) == 0 );
+
+    TEST_ASSERT( mbedtls_mpi_read_string( &G, radix_G, input_G ) == 0 );
+
+    TEST_ASSERT( mbedtls_dhm_set_group( &ctx, &P, &G ) == 0 );
+    TEST_ASSERT( mbedtls_dhm_make_public( &ctx, (int) mbedtls_mpi_size( &P ),
+                                          output, sizeof(output),
+                                          &mbedtls_test_rnd_pseudo_rand,
+                                          NULL ) == result );
+
+exit:
+    mbedtls_mpi_free( &P );
+    mbedtls_mpi_free( &G );
+    mbedtls_dhm_free( &ctx );
+}
+/* END_CASE */
+
 /* BEGIN_CASE depends_on:MBEDTLS_FS_IO */
 void dhm_file( char * filename, char * p, char * g, int len )
 {

tests/suites/test_suite_mpi.data

@@ -682,8 +682,17 @@ mbedtls_mpi_exp_mod:10:"23":10:"-13":10:"29":10:"":10:"0":MBEDTLS_ERR_MPI_BAD_IN
 Base test mbedtls_mpi_exp_mod #6 (Negative base + exponent)
 mbedtls_mpi_exp_mod:10:"-23":10:"-13":10:"29":10:"":10:"0":MBEDTLS_ERR_MPI_BAD_INPUT_DATA
 
-Base test mbedtls_mpi_exp_mod #7 (Huge exponent)
+Base test mbedtls_mpi_exp_mod #7 (MAX_SIZE exponent)
-mbedtls_mpi_exp_mod:10:"23":16:"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":10:"29":10:"":10:"0":MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+mbedtls_mpi_exp_mod_size:2:MBEDTLS_MPI_MAX_SIZE:2:10:"":0
+
+Base test mbedtls_mpi_exp_mod #8 (MAX_SIZE + 1 exponent)
+mbedtls_mpi_exp_mod_size:2:MBEDTLS_MPI_MAX_SIZE + 1:2:10:"":MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+
+Base test mbedtls_mpi_exp_mod #9 (MAX_SIZE modulus)
+mbedtls_mpi_exp_mod_size:2:2:MBEDTLS_MPI_MAX_SIZE:10:"":0
+
+Base test mbedtls_mpi_exp_mod #10 (MAX_SIZE + 1 modulus)
+mbedtls_mpi_exp_mod_size:2:2:MBEDTLS_MPI_MAX_SIZE + 1:10:"":MBEDTLS_ERR_MPI_BAD_INPUT_DATA
 
 Test mbedtls_mpi_exp_mod #1
 mbedtls_mpi_exp_mod:10:"433019240910377478217373572959560109819648647016096560523769010881172869083338285573756574557395862965095016483867813043663981946477698466501451832407592327356331263124555137732393938242285782144928753919588632679050799198937132922145084847":10:"5781538327977828897150909166778407659250458379645823062042492461576758526757490910073628008613977550546382774775570888130029763571528699574717583228939535960234464230882573615930384979100379102915657483866755371559811718767760594919456971354184113721":10:"583137007797276923956891216216022144052044091311388601652961409557516421612874571554415606746479105795833145583959622117418531166391184939066520869800857530421873250114773204354963864729386957427276448683092491947566992077136553066273207777134303397724679138833126700957":10:"":10:"114597449276684355144920670007147953232659436380163461553186940113929777196018164149703566472936578890991049344459204199888254907113495794730452699842273939581048142004834330369483813876618772578869083248061616444392091693787039636316845512292127097865026290173004860736":0

tests/suites/test_suite_mpi.function

@@ -1110,6 +1110,37 @@ exit:
 }
 /* END_CASE */
 
+/* BEGIN_CASE */
+void mbedtls_mpi_exp_mod_size( int A_bytes, int E_bytes, int N_bytes,
+                               int radix_RR, char * input_RR, int div_result )
+{
+    mbedtls_mpi A, E, N, RR, Z;
+    mbedtls_mpi_init( &A  ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &N );
+    mbedtls_mpi_init( &RR ); mbedtls_mpi_init( &Z );
+
+    TEST_ASSERT( mbedtls_mpi_lset( &A, 1 ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_lset( &E, 1 ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_lset( &N, 1 ) == 0 );
+
+    TEST_ASSERT( mbedtls_mpi_shift_l( &A, ( A_bytes * 8 ) - 1 ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_shift_l( &E, ( E_bytes * 8 ) - 1 ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_shift_l( &N, ( N_bytes * 8 ) - 1 ) == 0 );
+
+    TEST_ASSERT( mbedtls_mpi_set_bit( &A, 0, 1 ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_set_bit( &E, 0, 1 ) == 0 );
+    TEST_ASSERT( mbedtls_mpi_set_bit( &N, 0, 1 ) == 0 );
+
+    if( strlen( input_RR ) )
+        TEST_ASSERT( mbedtls_mpi_read_string( &RR, radix_RR, input_RR ) == 0 );
+
+    TEST_ASSERT( mbedtls_mpi_exp_mod( &Z, &A, &E, &N, &RR ) == div_result );
+
+exit:
+    mbedtls_mpi_free( &A  ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &N );
+    mbedtls_mpi_free( &RR ); mbedtls_mpi_free( &Z );
+}
+/* END_CASE */
+
 /* BEGIN_CASE */
 void mbedtls_mpi_inv_mod( int radix_X, char * input_X, int radix_Y,
                           char * input_Y, int radix_A, char * input_A,