Merge pull request #5917 from gilles-peskine-arm/asn1write-0-fix
Improve ASN.1 write tests
diff --git a/ChangeLog.d/asn1write-0-fix b/ChangeLog.d/asn1write-0-fix
new file mode 100644
index 0000000..2e01244
--- /dev/null
+++ b/ChangeLog.d/asn1write-0-fix
@@ -0,0 +1,2 @@
+Bugfix
+ * Fix mbedtls_asn1_write_mpi() writing an incorrect encoding of 0.
diff --git a/library/asn1write.c b/library/asn1write.c
index 2110052..053dbb6 100644
--- a/library/asn1write.c
+++ b/library/asn1write.c
@@ -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 );
diff --git a/tests/suites/test_suite_asn1write.data b/tests/suites/test_suite_asn1write.data
index f844d48..725cbc2 100644
--- a/tests/suites/test_suite_asn1write.data
+++ b/tests/suites/test_suite_asn1write.data
@@ -91,8 +91,11 @@
ASN.1 Write enum 2147483647
mbedtls_asn1_write_enum:0x7fffffff:"0A047fffffff"
-#ASN.1 Write mpi 0
-#mbedtls_asn1_write_mpi:"00":"020100"
+ASN.1 Write mpi 0 (null)
+mbedtls_asn1_write_mpi:"":"020100"
+
+ASN.1 Write mpi 0 (1 limb)
+mbedtls_asn1_write_mpi:"00":"020100"
ASN.1 Write mpi 1
mbedtls_asn1_write_mpi:"01":"020101"
@@ -100,11 +103,17 @@
ASN.1 Write mpi 0x7f
mbedtls_asn1_write_mpi:"7f":"02017f"
-#ASN.1 Write mpi 0x80
-#mbedtls_asn1_write_mpi:"7f":"02020080"
+ASN.1 Write mpi 0x7f with leading 0 limb
+mbedtls_asn1_write_mpi:"00000000000000007f":"02017f"
-#ASN.1 Write mpi 0xff
-#mbedtls_asn1_write_mpi:"7f":"020200ff"
+ASN.1 Write mpi 0x80
+mbedtls_asn1_write_mpi:"80":"02020080"
+
+ASN.1 Write mpi 0x80 with leading 0 limb
+mbedtls_asn1_write_mpi:"000000000000000080":"02020080"
+
+ASN.1 Write mpi 0xff
+mbedtls_asn1_write_mpi:"ff":"020200ff"
ASN.1 Write mpi 0x100
mbedtls_asn1_write_mpi:"0100":"02020100"
@@ -112,17 +121,17 @@
ASN.1 Write mpi, 127*8-1 bits
mbedtls_asn1_write_mpi:"7f7b16e05c1537de7c41cef1a0985d6a3ced98aec28e091874cbad6b5e40a5c956258f18861c28bed8ba808259339ee34b2e509c4080149474d5d5b86093f90c475a6443fc87e1a293d4151be625d652f1c32a00a018bba10c8a2ae5b2b0ee4be64e053dce9d07ec7919526c9dfcf2ec9fc3db485caa8e5a68a2cd0a427de8":"027f7f7b16e05c1537de7c41cef1a0985d6a3ced98aec28e091874cbad6b5e40a5c956258f18861c28bed8ba808259339ee34b2e509c4080149474d5d5b86093f90c475a6443fc87e1a293d4151be625d652f1c32a00a018bba10c8a2ae5b2b0ee4be64e053dce9d07ec7919526c9dfcf2ec9fc3db485caa8e5a68a2cd0a427de8"
-#ASN.1 Write mpi, 127*8 bits
-#mbedtls_asn1_write_mpi:"e77b16e05c1537de7c41cef1a0985d6a3ced98aec28e091874cbad6b5e40a5c956258f18861c28bed8ba808259339ee34b2e509c4080149474d5d5b86093f90c475a6443fc87e1a293d4151be625d652f1c32a00a018bba10c8a2ae5b2b0ee4be64e053dce9d07ec7919526c9dfcf2ec9fc3db485caa8e5a68a2cd0a427de8":"028180e77b16e05c1537de7c41cef1a0985d6a3ced98aec28e091874cbad6b5e40a5c956258f18861c28bed8ba808259339ee34b2e509c4080149474d5d5b86093f90c475a6443fc87e1a293d4151be625d652f1c32a00a018bba10c8a2ae5b2b0ee4be64e053dce9d07ec7919526c9dfcf2ec9fc3db485caa8e5a68a2cd0a427de8"
+ASN.1 Write mpi, 127*8 bits
+mbedtls_asn1_write_mpi:"e77b16e05c1537de7c41cef1a0985d6a3ced98aec28e091874cbad6b5e40a5c956258f18861c28bed8ba808259339ee34b2e509c4080149474d5d5b86093f90c475a6443fc87e1a293d4151be625d652f1c32a00a018bba10c8a2ae5b2b0ee4be64e053dce9d07ec7919526c9dfcf2ec9fc3db485caa8e5a68a2cd0a427de8":"02818000e77b16e05c1537de7c41cef1a0985d6a3ced98aec28e091874cbad6b5e40a5c956258f18861c28bed8ba808259339ee34b2e509c4080149474d5d5b86093f90c475a6443fc87e1a293d4151be625d652f1c32a00a018bba10c8a2ae5b2b0ee4be64e053dce9d07ec7919526c9dfcf2ec9fc3db485caa8e5a68a2cd0a427de8"
ASN.1 Write mpi, 127*8+1 bits
-mbedtls_asn1_write_mpi:"108446d68934cc1af23c4cd909884d4bd737a1890e12f5ef8bf3d807d72feffa63c0bf2633345f8b8418d144617c871a7a0277ac0150eed4b3db7f9dff21114cd0d7f282400f03c931cb00c367550e374a1ed3762a1801ca714cfc8d5aac69707ca81e0661400ed0014d97cba48f94d835dd681fc3053c51958afbf7583cf49c":"028180108446d68934cc1af23c4cd909884d4bd737a1890e12f5ef8bf3d807d72feffa63c0bf2633345f8b8418d144617c871a7a0277ac0150eed4b3db7f9dff21114cd0d7f282400f03c931cb00c367550e374a1ed3762a1801ca714cfc8d5aac69707ca81e0661400ed0014d97cba48f94d835dd681fc3053c51958afbf7583cf49c"
+mbedtls_asn1_write_mpi:"018446d68934cc1af23c4cd909884d4bd737a1890e12f5ef8bf3d807d72feffa63c0bf2633345f8b8418d144617c871a7a0277ac0150eed4b3db7f9dff21114cd0d7f282400f03c931cb00c367550e374a1ed3762a1801ca714cfc8d5aac69707ca81e0661400ed0014d97cba48f94d835dd681fc3053c51958afbf7583cf49c":"028180018446d68934cc1af23c4cd909884d4bd737a1890e12f5ef8bf3d807d72feffa63c0bf2633345f8b8418d144617c871a7a0277ac0150eed4b3db7f9dff21114cd0d7f282400f03c931cb00c367550e374a1ed3762a1801ca714cfc8d5aac69707ca81e0661400ed0014d97cba48f94d835dd681fc3053c51958afbf7583cf49c"
ASN.1 Write mpi, 255*8-1 bits
mbedtls_asn1_write_mpi:"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":"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"
-#ASN.1 Write mpi, 255*8 bits
-#mbedtls_asn1_write_mpi:"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":"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"
+ASN.1 Write mpi, 255*8 bits
+mbedtls_asn1_write_mpi:"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":"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"
ASN.1 Write mpi, 256*8-1 bits
mbedtls_asn1_write_mpi:"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":"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"
@@ -191,7 +200,7 @@
mbedtls_asn1_write_string:MBEDTLS_ASN1_OID:"41":"060141"
ASN.1 Write AlgorithmIdentifier, null parameters
-mbedtls_asn1_write_algorithm_identifier:"4f4944":8:"300d06034f4944"
+mbedtls_asn1_write_algorithm_identifier:"4f4944":0:"300706034f49440500"
ASN.1 Write AlgorithmIdentifier, parameters (8 bytes)
mbedtls_asn1_write_algorithm_identifier:"4f4944":8:"300d06034f4944"
diff --git a/tests/suites/test_suite_asn1write.function b/tests/suites/test_suite_asn1write.function
index 8d5579d..4ed8644 100644
--- a/tests/suites/test_suite_asn1write.function
+++ b/tests/suites/test_suite_asn1write.function
@@ -16,6 +16,8 @@
int generic_write_start_step( generic_write_data_t *data )
{
mbedtls_test_set_step( data->size );
+ mbedtls_free( data->output );
+ data->output = NULL;
ASSERT_ALLOC( data->output, data->size == 0 ? 1 : data->size );
data->end = data->output + data->size;
data->p = data->end;
@@ -45,8 +47,6 @@
ok = 1;
exit:
- mbedtls_free( data->output );
- data->output = NULL;
return( ok );
}
@@ -63,13 +63,14 @@
generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
int ret;
- for( data.size = 0; data.size < expected->len + 1; data.size++ )
+ for( data.size = 0; data.size <= expected->len + 1; data.size++ )
{
if( ! generic_write_start_step( &data ) )
goto exit;
ret = mbedtls_asn1_write_null( &data.p, data.start );
if( ! generic_write_finish_step( &data, expected, ret ) )
goto exit;
+ /* There's no parsing function for NULL. */
}
exit:
@@ -83,13 +84,21 @@
generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
int ret;
- for( data.size = 0; data.size < expected->len + 1; data.size++ )
+ for( data.size = 0; data.size <= expected->len + 1; data.size++ )
{
if( ! generic_write_start_step( &data ) )
goto exit;
ret = mbedtls_asn1_write_bool( &data.p, data.start, val );
if( ! generic_write_finish_step( &data, expected, ret ) )
goto exit;
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ if( ret >= 0 )
+ {
+ int read = 0xdeadbeef;
+ TEST_EQUAL( mbedtls_asn1_get_bool( &data.p, data.end, &read ), 0 );
+ TEST_EQUAL( val, read );
+ }
+#endif /* MBEDTLS_ASN1_PARSE_C */
}
exit:
@@ -103,13 +112,21 @@
generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
int ret;
- for( data.size = 0; data.size < expected->len + 1; data.size++ )
+ for( data.size = 0; data.size <= expected->len + 1; data.size++ )
{
if( ! generic_write_start_step( &data ) )
goto exit;
ret = mbedtls_asn1_write_int( &data.p, data.start, val );
if( ! generic_write_finish_step( &data, expected, ret ) )
goto exit;
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ if( ret >= 0 )
+ {
+ int read = 0xdeadbeef;
+ TEST_EQUAL( mbedtls_asn1_get_int( &data.p, data.end, &read ), 0 );
+ TEST_EQUAL( val, read );
+ }
+#endif /* MBEDTLS_ASN1_PARSE_C */
}
exit:
@@ -124,13 +141,21 @@
generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
int ret;
- for( data.size = 0; data.size < expected->len + 1; data.size++ )
+ for( data.size = 0; data.size <= expected->len + 1; data.size++ )
{
if( ! generic_write_start_step( &data ) )
goto exit;
ret = mbedtls_asn1_write_enum( &data.p, data.start, val );
if( ! generic_write_finish_step( &data, expected, ret ) )
goto exit;
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ if( ret >= 0 )
+ {
+ int read = 0xdeadbeef;
+ TEST_EQUAL( mbedtls_asn1_get_enum( &data.p, data.end, &read ), 0 );
+ TEST_EQUAL( val, read );
+ }
+#endif /* MBEDTLS_ASN1_PARSE_C */
}
exit:
@@ -142,25 +167,35 @@
void mbedtls_asn1_write_mpi( data_t *val, data_t *expected )
{
generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
- mbedtls_mpi mpi;
+ mbedtls_mpi mpi, read;
int ret;
mbedtls_mpi_init( &mpi );
+ mbedtls_mpi_init( &read );
TEST_ASSERT( mbedtls_mpi_read_binary( &mpi, val->x, val->len ) == 0 );
- for( data.size = 0; data.size < expected->len + 1; data.size++ )
+ for( data.size = 0; data.size <= expected->len + 1; data.size++ )
{
if( ! generic_write_start_step( &data ) )
goto exit;
ret = mbedtls_asn1_write_mpi( &data.p, data.start, &mpi );
if( ! generic_write_finish_step( &data, expected, ret ) )
goto exit;
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ if( ret >= 0 )
+ {
+ TEST_EQUAL( mbedtls_asn1_get_mpi( &data.p, data.end, &read ), 0 );
+ TEST_EQUAL( 0, mbedtls_mpi_cmp_mpi( &mpi, &read ) );
+ }
+#endif /* MBEDTLS_ASN1_PARSE_C */
+ /* Skip some intermediate lengths, they're boring. */
if( expected->len > 10 && data.size == 8 )
data.size = expected->len - 2;
}
exit:
mbedtls_mpi_free( &mpi );
+ mbedtls_mpi_free( &read );
mbedtls_free( data.output );
}
/* END_CASE */
@@ -171,7 +206,7 @@
generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
int ret;
- for( data.size = 0; data.size < expected->len + 1; data.size++ )
+ for( data.size = 0; data.size <= expected->len + 1; data.size++ )
{
if( ! generic_write_start_step( &data ) )
goto exit;
@@ -208,6 +243,8 @@
}
if( ! generic_write_finish_step( &data, expected, ret ) )
goto exit;
+ /* There's no parsing function for octet or character strings. */
+ /* Skip some intermediate lengths, they're boring. */
if( expected->len > 10 && data.size == 8 )
data.size = expected->len - 2;
}
@@ -224,8 +261,11 @@
{
generic_write_data_t data = { NULL, NULL, NULL, NULL, 0 };
int ret;
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ unsigned char *buf_complete = NULL;
+#endif /* MBEDTLS_ASN1_PARSE_C */
- for( data.size = 0; data.size < expected->len + 1; data.size++ )
+ for( data.size = 0; data.size <= expected->len + 1; data.size++ )
{
if( ! generic_write_start_step( &data ) )
goto exit;
@@ -240,10 +280,69 @@
ret -= par_len;
if( ! generic_write_finish_step( &data, expected, ret ) )
goto exit;
+
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ /* Only do a parse-back test if the parameters aren't too large for
+ * a small-heap environment. The boundary is somewhat arbitrary. */
+ if( ret >= 0 && par_len <= 1234 )
+ {
+ mbedtls_asn1_buf alg = {0, 0, NULL};
+ mbedtls_asn1_buf params = {0, 0, NULL};
+ /* The writing function doesn't write the parameters unless
+ * they're null: it only takes their length as input. But the
+ * parsing function requires the parameters to be present.
+ * Thus make up parameters. */
+ size_t data_len = data.end - data.p;
+ size_t len_complete = data_len + par_len;
+ unsigned char expected_params_tag;
+ size_t expected_params_len;
+ ASSERT_ALLOC( buf_complete, len_complete );
+ unsigned char *end_complete = buf_complete + len_complete;
+ memcpy( buf_complete, data.p, data_len );
+ if( par_len == 0 )
+ {
+ /* mbedtls_asn1_write_algorithm_identifier() wrote a NULL */
+ expected_params_tag = 0x05;
+ expected_params_len = 0;
+ }
+ else if( par_len >= 2 && par_len < 2 + 128 )
+ {
+ /* Write an OCTET STRING with a short length encoding */
+ expected_params_tag = buf_complete[data_len] = 0x04;
+ expected_params_len = par_len - 2;
+ buf_complete[data_len + 1] = (unsigned char) expected_params_len;
+ }
+ else if( par_len >= 4 + 128 && par_len < 3 + 256 * 256 )
+ {
+ /* Write an OCTET STRING with a two-byte length encoding */
+ expected_params_tag = buf_complete[data_len] = 0x04;
+ expected_params_len = par_len - 4;
+ buf_complete[data_len + 1] = 0x82;
+ buf_complete[data_len + 2] = (unsigned char) ( expected_params_len >> 8 );
+ buf_complete[data_len + 3] = (unsigned char) ( expected_params_len );
+ }
+ else
+ {
+ TEST_ASSERT( ! "Bad test data: invalid length of ASN.1 element" );
+ }
+ unsigned char *p = buf_complete;
+ TEST_EQUAL( mbedtls_asn1_get_alg( &p, end_complete,
+ &alg, ¶ms ), 0 );
+ TEST_EQUAL( alg.tag, MBEDTLS_ASN1_OID );
+ ASSERT_COMPARE( alg.p, alg.len, oid->x, oid->len );
+ TEST_EQUAL( params.tag, expected_params_tag );
+ TEST_EQUAL( params.len, expected_params_len );
+ mbedtls_free( buf_complete );
+ buf_complete = NULL;
+ }
+#endif /* MBEDTLS_ASN1_PARSE_C */
}
exit:
mbedtls_free( data.output );
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ mbedtls_free( buf_complete );
+#endif /* MBEDTLS_ASN1_PARSE_C */
}
/* END_CASE */
@@ -308,18 +407,63 @@
const unsigned char *buf, size_t bits ) =
( is_named ? mbedtls_asn1_write_named_bitstring :
mbedtls_asn1_write_bitstring );
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ unsigned char *masked_bitstring = NULL;
+#endif /* MBEDTLS_ASN1_PARSE_C */
- for( data.size = 0; data.size < expected->len + 1; data.size++ )
+ /* The API expects `bitstring->x` to contain `bits` bits. */
+ size_t byte_length = ( bits + 7 ) / 8;
+ TEST_ASSERT( bitstring->len >= byte_length );
+
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ ASSERT_ALLOC( masked_bitstring, byte_length );
+ if( byte_length != 0 )
+ {
+ memcpy( masked_bitstring, bitstring->x, byte_length );
+ if( bits % 8 != 0 )
+ masked_bitstring[byte_length - 1] &= ~( 0xff >> ( bits % 8 ) );
+ }
+ size_t value_bits = bits;
+ if( is_named )
+ {
+ /* In a named bit string, all trailing 0 bits are removed. */
+ while( byte_length > 0 && masked_bitstring[byte_length - 1] == 0 )
+ --byte_length;
+ value_bits = 8 * byte_length;
+ if( byte_length > 0 )
+ {
+ unsigned char last_byte = masked_bitstring[byte_length - 1];
+ for( unsigned b = 1; b < 0xff && ( last_byte & b ) == 0; b <<= 1 )
+ --value_bits;
+ }
+ }
+#endif /* MBEDTLS_ASN1_PARSE_C */
+
+ for( data.size = 0; data.size <= expected->len + 1; data.size++ )
{
if( ! generic_write_start_step( &data ) )
goto exit;
ret = ( *func )( &data.p, data.start, bitstring->x, bits );
if( ! generic_write_finish_step( &data, expected, ret ) )
goto exit;
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ if( ret >= 0 )
+ {
+ mbedtls_asn1_bitstring read = {0, 0, NULL};
+ TEST_EQUAL( mbedtls_asn1_get_bitstring( &data.p, data.end,
+ &read ), 0 );
+ ASSERT_COMPARE( read.p, read.len,
+ masked_bitstring, byte_length );
+ TEST_EQUAL( read.unused_bits, 8 * byte_length - value_bits );
+ }
+#endif /* MBEDTLS_ASN1_PARSE_C */
}
exit:
mbedtls_free( data.output );
+#if defined(MBEDTLS_ASN1_PARSE_C)
+ mbedtls_free( masked_bitstring );
+#endif /* MBEDTLS_ASN1_PARSE_C */
}
/* END_CASE */
