Commit graph

276 commits

Author SHA1 Message Date
Gilles Peskine
a05219c70b Add some missing compilation guards
Add missing checks for defined(MBEDTLS_MD_C) around types and
functions that require it (HMAC, HKDF, TLS12_PRF).

Add missing checks for defined(MBEDTLS_ECDSA_DETERMINISTIC) around
code that calls mbedtls_ecdsa_sign_det().

Add missing checks for defined(MBEDTLS_ECDH_C) around ECDH-specific
functions.
2018-11-16 16:09:24 +01:00
Hanno Becker
353e45361d Don't call memcpy() with 0-length arguments
The standard prohibits calling memcpy() with NULL pointer
arguments, even if the size argument is 0.

The TLS-1.2 PRF generator setup function previously called
memcpy() with the label and salt as the source, even if
they were of length 0, as exercised by the derive_key_policy
test case in the PSA crypto test suite.

This commit adds guards around the memcpy() calls so that they
are only executed of salt or label have positive length, respectively.
2018-11-16 11:24:59 +00:00
Hanno Becker
3b339e2342 Simplify psa_generator_tls12_prf_generate_next_block() 2018-11-16 11:24:59 +00:00
Hanno Becker
580fba1431 Dynamically allocate A(i) + seed buffer for TLS-1.2 PRF 2018-11-16 11:24:59 +00:00
Hanno Becker
c8a41d71cb Add implementation of TLS-1.2 PRF 2018-11-16 11:24:55 +00:00
Gilles Peskine
b408661be9 ECDH: check that the keys are on the same curve
In psa_key_agreement_ecdh, check that the public key is on the same
curve as the private key. The underlying mbedtls API doesn't check.

If the curves don't match, psa_key_agreement_ecdh is practically
guaranteed to return INVALID_ARGUMENT anyway, because way the code is
written, the public point is interpreted on the curve of the private
point, and it is rejected because the point is not on the curve. This
is why the test case "PSA key agreement setup: ECDH, raw: public key
on different curve" passed even before adding this check.
2018-11-14 21:17:16 +01:00
Gilles Peskine
88714d78b8 Allow ECDH-only public key in ECDH
In ECDH key agreement, allow a public key with the OID id-ECDH, not
just a public key with the OID id-ecPublicKey.

Public keys with the OID id-ECDH are not permitted by psa_import_key,
at least for now. There would be no way to use the key for a key
agreement operation anyway in the current API.
2018-11-14 21:17:16 +01:00
Gilles Peskine
211a436f2e Document that key agreement produces a maximum-capacity generator 2018-11-14 21:15:37 +01:00
Gilles Peskine
b7ecdf0509 Implement ECDH 2018-11-14 21:15:37 +01:00
Gilles Peskine
01d718cee8 New API function: psa_key_agreement
Set up a generator from a key agreement.
2018-11-14 21:15:37 +01:00
Gilles Peskine
8feb3a886d Support key derivation with non-predefined capacity
psa_key_derivation requires the caller to specify a maximum capacity.
This commit adds a special value that indicates that the maximum
capacity should be the maximum supported by the algorithm. This is
currently meant only for selection algorithms used on the shared
secret produced by a key agreement.
2018-11-14 21:15:37 +01:00
Gilles Peskine
751d965dfc Implement PSA_ALG_SELECT_RAW 2018-11-14 21:15:37 +01:00
Gilles Peskine
cce18aec4c Split off psa_key_derivation_internal
Refactor psa_key_derivation to prepare for key agreement algorithms
which need to plug into key derivation after argument validation.
2018-11-14 21:15:37 +01:00
Gilles Peskine
86a440b638 Reject non-byte-aligned RSA keys
On key import and key generation, for RSA, reject key sizes that are
not a multiple of 8. Such keys are not well-supported in Mbed TLS and
are hardly ever used in practice.

The previous commit removed support for non-byte-aligned keys at the
PSA level. This commit actively rejects such keys and adds
corresponding tests (test keys generated with "openssl genrsa").
2018-11-12 19:14:18 +01:00
Gilles Peskine
aac64a2839 Remove support for non-byte-aligned RSA keys
Remove the need for an extra function mbedtls_rsa_get_bitlen. Use
mbedtls_rsa_get_len, which is only correct for keys whose size is a
multiple of 8. Key sizes that aren't a multiple of 8 are extremely
rarely used, so in practice this is not a problematic limitation.
2018-11-12 18:37:42 +01:00
Gilles Peskine
52b9018cf7 psa_export_key: for raw-byte keys, zero the end of the output buffer
Skip all writing to the target buffer if its size is 0, since in this
case the pointer might be invalid and this would cause the calls to
memcpy and memset to have undefined behavior.
2018-10-31 14:10:06 +01:00
Gilles Peskine
188c71e382 Private EC key format: change to raw secret value (export)
Change the import/export format of private elliptic curve keys from
RFC 5915 to the raw secret value. This commit updates the export code.
2018-10-31 14:10:06 +01:00
Gilles Peskine
f76aa7789b Private EC key format: change to raw secret value (doc, import)
Change the import/export format of private elliptic curve keys from
RFC 5915 to the raw secret value. This commit updates the format
specification and the import code, but not the export code.
2018-10-31 14:10:06 +01:00
Gilles Peskine
e0e9c7c417 New macro PSA_ALG_FULL_LENGTH_MAC
Provide a documented way of constructing the full-length MAC algorithm
from a truncated version.
2018-10-17 18:30:47 +02:00
Gilles Peskine
57fbdb1939 Use a public macro for AEAD tag length variations
Avoid depending on the encoding of algorithms inside psa_crypto.c.
2018-10-17 18:30:47 +02:00
Gilles Peskine
f8a8fe60f8 Fix memory leak with AEAD with non-default tag lengths
When freeing the key context, choose the context format based on the
base algorithm value stored in the operation object.
2018-10-17 13:54:48 +02:00
Gilles Peskine
8cac2e628e Translate GCM_BAD_INPUT to INVALID_ARGUMENT, not NOT_SUPPORTED 2018-10-17 13:54:48 +02:00
Gilles Peskine
99b7d6b700 Wipe sensitive data in psa_mac_verify_finish
Wipe the whole MAC intermediate buffer, not just the requested MAC
size. With truncated MAC algorithms, the requested MAC size may be
smaller than what is written to the intermediate buffer.
2018-10-17 13:54:47 +02:00
Gilles Peskine
87b0ac49f8 Fix possible buffer overread in psa_mac_finish_internal (CMAC) 2018-10-17 13:54:47 +02:00
Gilles Peskine
6d72ff9e79 Document that the minimum truncated MAC length is implementation-defined 2018-10-17 13:54:47 +02:00
Gilles Peskine
23cc2ff9a8 Add support for non-default-tag-size AEAD (CCM and GCM) 2018-10-08 14:42:11 +02:00
Gilles Peskine
edf9a6576d Refactor AEAD setup into a common function
There was a lot of repetition between psa_aead_encrypt and
psa_aead_decrypt. Refactor the code into a new function psa_aead_setup.
The new code should behave identically except that in some cases where
multiple error conditions apply, the code may now return a different
error code.

Internally, I rearranged some of the code:

* I removed a check that the key type was in CATEGORY_SYMMETRIC because
  it's redundant with mbedtls_cipher_info_from_psa which enumerates
  supported key types explicitly.
* The order of some validations is different to allow the split between
  setup and data processing. The code now calls a more robust function
  psa_aead_abort in case of any error after the early stage of the setup.
2018-10-08 14:42:11 +02:00
Gilles Peskine
d911eb7915 Add support for truncated MAC algorithms 2018-10-08 14:42:11 +02:00
Gilles Peskine
159ebf3b8e
Merge pull request #142 from ARMmbed/psa-metadata_validation
Algorithm and key type encoding validation
2018-09-24 10:38:39 +02:00
Jaeden Amero
3bfe5f0388
Merge pull request #150 from ARMmbed/psa-rsa-verify-error
Don't return INVALID_PADDING on an invalid RSA signature
2018-09-21 16:15:10 +01:00
Jaeden Amero
40363fe3f5
Merge pull request #139 from ARMmbed/psa-PSA_ALG-block_cipher_padding
Correct and simplify block-based cipher modes
2018-09-21 09:38:27 +01:00
Gilles Peskine
00709fafb8 Rename PSA_ALG_HMAC_HASH to PSA_ALG_HMAC_GET_HASH
Be consistent with other GET_HASH macros.
2018-09-20 12:00:21 +02:00
Gilles Peskine
daea26f70f Correct and simplify block-based cipher modes
OFB and CFB are streaming modes. XTS is a not a cipher mode but it
doesn't use a separate padding step. This leaves only CBC as a block
cipher mode that needs a padding step.

Since CBC is the only mode that uses a separate padding step, and is
likely to remain the only mode in the future, encode the padding mode
directly in the algorithm constant, rather than building up an
algorithm value from a chaining mode and a padding mode. This greatly
simplifies the interface as well as some parts of the implementation.
2018-09-20 11:58:22 +02:00
Gilles Peskine
ef12c63de0 RSA verification: don't report an invalid padding error
Mbed TLS distinguishes "invalid padding" from "valid padding but the
rest of the signature is invalid". This has little use in practice and
PSA doesn't report this distinction. We just report "invalid
signature".
2018-09-17 14:33:43 +02:00
itayzafrir
90d8c7a728 Ensure the module is initialized in key based functions 2018-09-16 12:15:47 +03:00
itayzafrir
0adf0fc31c Ensure the module is initialized in psa_generate_random 2018-09-16 12:15:46 +03:00
Gilles Peskine
78b3bb670d Change the bitwise encoding of key type categories
There were only 5 categories (now 4). Reduce the category mask from 7
bits to 3.

Combine unformatted, not-necessarily-uniform keys (HMAC, derivation)
with raw data.

Reintroduce a KEY_TYPE_IS_UNSTRUCTURED macro (which used to exist
under the name KEY_TYPE_IS_RAW_DATA macro) for key types that don't
have any structure, including both should-be-uniform keys (such as
block cipher and stream cipher keys) and not-necessarily-uniform
keys (such as HMAC keys and secrets for key derivation).
2018-09-14 10:02:29 +01:00
itayzafrir
534bd7c33b Add missing calls to psa_cipher_abort in cipher functions 2018-09-14 10:02:29 +01:00
itayzafrir
40835d4e56 Add missing calls to psa_hash_abort in hash functions 2018-09-14 10:02:29 +01:00
Jaeden Amero
df3b74f168 Merge pull request #125 from ARMmbed/key_slot_index-fix
Fix off-by-one errors in key slot index limits
2018-09-14 10:02:29 +01:00
Gilles Peskine
9a05634558 psa_crypto_free: destroy the last slot
The last slot in the array was not freed due to an off-by-one error.

Amend the fill_slots test to serve as a non-regression test for this
issue: without this bug fix, it would cause a memory leak.
2018-09-14 10:02:29 +01:00
Gilles Peskine
996deb18cc Fix buffer overflow in the slot array
Slots are numbered from 1, but the slot array is a C array so it's
numbered from 0.

Add a non-regression test.
2018-09-14 10:02:29 +01:00
Darryl Green
9e2d7a09f1 Add ifdefs for psa_internal_export_key function
MBEDTLS_PK_WRITE_C only requires either MBEDTLS_RSA_C or MBEDTLS_ECP_C to be defined.
Added wrappers to handle the cases where only one has been defined.
Moved mbedtls_pk_init to be within the ifdefs, so it's only called if appropriate.
2018-09-14 10:02:28 +01:00
Darryl Green
8800136156 Fix key parameter in psa_key_derivation to use correct type 2018-09-14 10:02:28 +01:00
Darryl Green
8f8aa8f931 Add ifdef for MBEDTLS_ECP_C around ecc_group_to_psa functions
These are unused if MBEDTLS_ECP_C isn't defined.
2018-09-14 10:02:28 +01:00
Darryl Green
5cc689a821 Add handling for (sometimes) unused parameters 2018-09-14 10:02:28 +01:00
Gilles Peskine
9f900a8b25 Merge pull request #105 from ARMmbed/psa-derive_hkdf
PSA key derivation: simple-ish interface, HKDF
2018-09-12 16:50:07 +03:00
Gilles Peskine
08542d8037 Fix psa_generator_import_key for DES
In psa_generator_import_key, if generating a DES or 3DES key, set the
parity bits.

Add tests for deriving a DES key. Also test deriving an AES key while
I'm at it.
2018-09-12 16:50:07 +03:00
Gilles Peskine
d54931c7c4 HKDF: be more robust if we reach the maximum ouptut length
In psa_generator_hkdf_read, return BAD_STATE if we're trying to
construct more output than the algorithm allows. This can't happen
through the API due to the capacity limit, but it could potentially
happen in an internal call.

Also add a test case that verifies that we can set up HKDF with its
maximum capacity and read up to the maximum capacity.
2018-09-12 16:50:05 +03:00
Gilles Peskine
bef7f14f8e Implement HKDF 2018-09-12 16:44:05 +03:00