When parsing a substructure of an ASN.1 structure, no field within
the substructure must exceed the bounds of the substructure.
Concretely, the `end` pointer passed to the ASN.1 parsing routines
must be updated to point to the end of the substructure while parsing
the latter.
This was previously not the case for the routines
- x509_get_attr_type_and_value(),
- mbedtls_x509_get_crt_ext(),
- mbedtls_x509_get_crl_ext().
These functions kept using the end of the parent structure as the
`end` pointer and would hence allow substructure fields to cross
the substructure boundary. This could lead to successful parsing
of ill-formed X.509 CRTs.
This commit fixes this.
Care has to be taken when adapting `mbedtls_x509_get_crt_ext()`
and `mbedtls_x509_get_crl_ext()`, as the underlying function
`mbedtls_x509_get_ext()` returns `0` if no extensions are present
but doesn't set the variable which holds the bounds of the Extensions
structure in case the latter is present. This commit addresses
this by returning early from `mbedtls_x509_get_crt_ext()` and
`mbedtls_x509_get_crl_ext()` if parsing has reached the end of
the input buffer.
The following X.509 parsing tests need to be adapted:
- "TBSCertificate, issuer two inner set datas"
This test exercises the X.509 CRT parser with a Subject name
which has two empty `AttributeTypeAndValue` structures.
This is supposed to fail with `MBEDTLS_ERR_ASN1_OUT_OF_DATA`
because the parser should attempt to parse the first structure
and fail because of a lack of data. Previously, it failed to
obey the (0-length) bounds of the first AttributeTypeAndValue
structure and would try to interpret the beginning of the second
AttributeTypeAndValue structure as the first field of the first
AttributeTypeAndValue structure, returning an UNEXPECTED_TAG error.
- "TBSCertificate, issuer, no full following string"
This test exercises the parser's behaviour on an AttributeTypeAndValue
structure which contains more data than expected; it should therefore
fail with MBEDTLS_ERR_ASN1_LENGTH_MISMATCH. Because of the missing bounds
check, it previously failed with UNEXPECTED_TAG because it interpreted
the remaining byte in the first AttributeTypeAndValue structure as the
first byte in the second AttributeTypeAndValue structure.
- "SubjectAltName repeated"
This test should exercise two SubjectAltNames extensions in succession,
but a wrong length values makes the second SubjectAltNames extension appear
outside of the Extensions structure. With the new bounds in place, this
therefore fails with a LENGTH_MISMATCH error. This commit adapts the test
data to put the 2nd SubjectAltNames extension inside the Extensions
structure, too.
The X.509 parsing test suite test_suite_x509parse contains a test
exercising X.509 verification for a valid MD4/MD5 certificate in a
profile which doesn't allow MD4/MD5. This commit adds an analogous
test for MD2.
- Replace 'RSA with MD2' OID '2a864886f70d010102' by
'RSA with SHA-256' OID '2a864886f70d01010b':
Only the last byte determines the hash, and
`MBEDTLS_OID_PKCS1_MD2 == MBEDTLS_OID_PKCS1 "\x02"`
`MBEDTLS_OID_PKCS1_SHA256 == MBEDTLS_OID_PKCS1 "\x0b"`
See oid.h.
- Replace MD2 dependency by SHA256 dependency.
- Adapt expected CRT info output.
* restricted/pr/554:
Fix too small buffer in a test
Add changelog entry for mbedtls_ecdh_get_params robustness
Fix ecdh_get_params with mismatching group
Add test case for ecdh_get_params with mismatching group
Add test case for ecdh_calc_secret
It was failing to set the key in the ENCRYPT direction before encrypting.
This just happened to work for GCM and CCM.
After re-encrypting, compare the length to the expected ciphertext
length not the plaintext length. Again this just happens to work for
GCM and CCM since they do not perform any kind of padding.
* public/pr/2148:
Add ChangeLog entry for unused bits in bitstrings
Improve docs for ASN.1 bitstrings and their usage
Add tests for (named) bitstring to suite_asn1write
Fix ASN1 bitstring writing
Add a test case for doing an ECDH calculation by calling
mbedtls_ecdh_get_params on both keys, with keys belonging to
different groups. This should fail, but currently passes.
tests/Makefile had some unused warnings disabled unnecessarily, which
test-ref-configs.pl was turning back on. We don't need to disable these warnings
so I'm turning them back on.
Dependent on configured options, not all of the helper functions were being
used, which was leading to warning of unused functions with Clang.
To avoid any complex compile time options, or adding more logic to
generate_test_code.py to screen out unused functions, those functions which were
provoking the warning were changed to remove static, remove them from file
scope, and expose them to the linker.
Since the AD too long is a limitation on Mbed TLS,
HW accelerators may support this. Run the test for AD too long,
only if `MBEDTLS_CCM_ALT` is not defined.
Addresses comment in #1996.
This commit introduces variants test-ca_utf8.crt,
test-ca_printablestring.crt and test-ca_uppercase.crt
of tests/data_files/test-ca.crt which differ from
test-ca.crt in their choice of string encoding and
upper and lower case letters in the DN field. These
changes should be immaterial to the recovation check,
and three tests are added that crl.pem, which applies
to test-ca.crt, is also considered as applying to
test-ca_*.crt.
The test files were generated using PR #1641 which
- adds a build instruction for test-ca.crt to
tests/data_files/Makefile which allows easy
change of the subject DN.
- changes the default string format from `PrintableString`
to `UTF8String`.
Specifically:
- `test-ca_utf8.crt` was generated by running
`rm test-ca.crt && make test-ca.crt`
on PR #1641.
- `test-ca_uppercase.crt`, too, was generated by running
`rm test-ca.crt && make test-ca.crt`
on PR #1641, after modifying the subject DN line in the build
instruction for `test-ca.crt` in `tests/data_files/Makefile`.
- `test-ca_printable.crt` is a copy of `test-ca.crt`
because at the time of this commit, `PrintableString` is
still the default string format.
Primality tests have to deal with different distribution when generating
primes and when validating primes.
These new tests are testing if mbedtls_mpi_is_prime() is working
properly in the latter setting.
The new tests involve pseudoprimes with maximum number of
non-witnesses. The non-witnesses were generated by printing them
from mpi_miller_rabin(). The pseudoprimes were generated by the
following function:
void gen_monier( mbedtls_mpi* res, int nbits )
{
mbedtls_mpi p_2x_plus_1, p_4x_plus_1, x, tmp;
mbedtls_mpi_init( &p_2x_plus_1 );
mbedtls_mpi_init( &p_4x_plus_1 );
mbedtls_mpi_init( &x ); mbedtls_mpi_init( &tmp );
do
{
mbedtls_mpi_gen_prime( &p_2x_plus_1, nbits >> 1, 0,
rnd_std_rand, NULL );
mbedtls_mpi_sub_int( &x, &p_2x_plus_1, 1 );
mbedtls_mpi_div_int( &x, &tmp, &x, 2 );
if( mbedtls_mpi_get_bit( &x, 0 ) == 0 )
continue;
mbedtls_mpi_mul_int( &p_4x_plus_1, &x, 4 );
mbedtls_mpi_add_int( &p_4x_plus_1, &p_4x_plus_1, 1 );
if( mbedtls_mpi_is_prime( &p_4x_plus_1, rnd_std_rand,
NULL ) == 0 )
break;
} while( 1 );
mbedtls_mpi_mul_mpi( res, &p_2x_plus_1, &p_4x_plus_1 );
}
Functional tests for various payload sizes and output buffer sizes.
When the padding is bad or the plaintext is too large for the output
buffer, verify that function writes some outputs. This doesn't
validate that the implementation is time-constant, but it at least
validates that it doesn't just return early without outputting anything.
Deprecate mbedtls_ctr_drbg_update (which returns void) in favor of a
new function mbedtls_ctr_drbg_update_ret which reports error. The old
function is not officially marked as deprecated in this branch because
this is a stable maintenance branch.
Add pk_write test cases where the ASN.1 INTEGER encoding of the
private value does not have the mandatory size for the OCTET STRING
that contains the value.
ec_256_long_prv.pem is a random secp256r1 private key, selected so
that the private value is >= 2^255, i.e. the top bit of the first byte
is set (which would cause the INTEGER encoding to have an extra
leading 0 byte).
ec_521_short_prv.pem is a random secp521r1 private key, selected so
that the private value is < 2^518, i.e. the first byte is zero and the
top bit of the second byte is 0 (which would cause the INTEGER
encoding to have one less 0 byte at the start).
Address review comments:
1. add `mbedtls_cipher_init()` after freeing context, in test code
2. style comments
3. set `ctx->iv_size = 0` in case `IV == NULL && iv_len == 0`
This PR fixes multiple issues in the source code to address issues raised by
tests/scripts/check-files.py. Specifically:
* incorrect file permissions
* missing newline at the end of files
* trailing whitespace
* Tabs present
* TODOs in the souce code
The relevant ASN.1 definitions for a PKCS#8 encoded Elliptic Curve key are:
PrivateKeyInfo ::= SEQUENCE {
version Version,
privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
privateKey PrivateKey,
attributes [0] IMPLICIT Attributes OPTIONAL
}
AlgorithmIdentifier ::= SEQUENCE {
algorithm OBJECT IDENTIFIER,
parameters ANY DEFINED BY algorithm OPTIONAL
}
ECParameters ::= CHOICE {
namedCurve OBJECT IDENTIFIER
-- implicitCurve NULL
-- specifiedCurve SpecifiedECDomain
}
ECPrivateKey ::= SEQUENCE {
version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
privateKey OCTET STRING,
parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
publicKey [1] BIT STRING OPTIONAL
}
Because of the two optional fields, there are 4 possible variants that need to
be parsed: no optional fields, only parameters, only public key, and both
optional fields. Previously mbedTLS was unable to parse keys with "only
parameters". Also, only "only public key" was tested. There was a test for "no
optional fields", but it was labelled incorrectly as SEC.1 and not run because
of a great renaming mixup.
Conflict resolution:
* ChangeLog
* tests/data_files/Makefile: concurrent additions, order irrelevant
* tests/data_files/test-ca.opensslconf: concurrent additions, order irrelevant
* tests/scripts/all.sh: one comment change conflicted with a code
addition. In addition some of the additions in the
iotssl-1381-x509-verify-refactor-restricted branch need support for
keep-going mode, this will be added in a subsequent commit.
The 'critical' boolean can be set to false in two ways:
- by leaving it implicit (test data generated by openssl)
- by explicitly setting it to false (generated by hand)
This covers all lines added in the previous commit. Coverage was tested using:
make CFLAGS='--coverage -g3 -O0'
(cd tests && ./test_suite_x509parse)
make lcov
firefox Coverage/index.html # then visual check
Test data was generated by taking a copy of tests/data_files/crl-idp.pem,
encoding it as hex, and then manually changing the values of some bytes to
achieve the desired errors, using https://lapo.it/asn1js/ for help in locating
the desired bytes.
Found by running:
CC=clang cmake -D CMAKE_BUILD_TYPE="Check"
tests/scripts/depend-pkalgs.pl
(Also tested with same command but CC=gcc)
Another PR will address improving all.sh and/or the depend-xxx.pl scripts
themselves to catch this kind of thing.
Our current behaviour is a bit inconsistent here:
- when the bad signature is made by a trusted CA, we stop here and don't
include the trusted CA in the chain (don't call vrfy on it)
- otherwise, we just add NOT_TRUSTED to the flags but keep building the chain
and call vrfy on the upper certs
This ensures that the callback can actually clear that flag, and that it is
seen by the callback at the right level. This flag is not set at the same
place than others, and this difference will get bigger in the upcoming
refactor, so let's ensure we don't break anything here.
When a trusted CA is rolling its root keys, it could happen that for some
users the list of trusted roots contains two versions of the same CA with the
same name but different keys. Currently this is supported but wasn't tested.
Note: the intermediate file test-ca-alt.csr is commited on purpose, as not
commiting intermediate files causes make to regenerate files that we don't
want it to touch.
As we accept EE certs that are explicitly trusted (in the list of trusted
roots) and usually look for parent by subject, and in the future we might want
to avoid checking the self-signature on trusted certs, there could a risk that we
incorrectly accept a cert that looks like a trusted root except it doesn't
have the same key. This test ensures this will never happen.
The tests cover chains of length 0, 1 and 2, with one error, located at any of
the available levels in the chain. This exercises all three call sites of
f_vrfy (two in verify_top, one in verify_child). Chains of greater length
would not cover any new code path or behaviour that I can see.
So far there was no test ensuring that the flags passed to the vrfy callback
are correct (ie the flags for the current certificate, not including those of
the parent).
Actual tests case making use of that test function will be added in the next
commit.
