Commit Graph

365 Commits

Author SHA1 Message Date
Hanno Becker
15b73b4066 Correct placement of comment on X.509 SAN parsing 2019-06-25 09:10:57 +01:00
Hanno Becker
f6bc8886c7 Move declarations of internal X.509 functions to separate header
This makes it easier to distinguish public from internal functions;
for us, for users, and for automated API compatibility checkers.
2019-06-25 09:10:57 +01:00
Hanno Becker
76428359b3 Move existence check for pk/frame to mbedtls_x509_crt_provide_xxx() 2019-06-25 09:07:16 +01:00
Hanno Becker
bc685199d9 Implement MBEDTLS_X509_ALWAYS_FLUSH 2019-06-25 09:07:16 +01:00
Hanno Becker
c6d1c3ed1c Remove frame/pk parameter from mbedtls_x509_crt_xxx_release() 2019-06-25 09:07:16 +01:00
Hanno Becker
38f0cb487c Introduce helpers for conversion between X.509 buffer structs
This commit introduces two static helpers
- `x509_buf_to_buf_raw()`
- `x509_buf_raw_to_buf()`
which convert to/from the old `mbedtls_x509_buf` and
the new `mbedtls_x509_buf_raw` (the latter omitting the
ASN.1 tag field).
2019-06-25 09:07:16 +01:00
Hanno Becker
1e11f217d4 Solely use raw X.509 name data references including SEQUENCE header
So far, the CRT frame structure `mbedtls_x509_crt_frame` used
as `issuer_raw` and `subject_raw` the _content_ of the ASN.1
name structure for issuer resp. subject. This was in contrast
to the fields `issuer_raw` and `subject_raw` from the legacy
`mbedtls_x509_crt` structure, and caused some information
duplication by having both variants `xxx_no_hdr` and `xxx_with_hdr`
in `mbedtls_x509_crt` and `mbedtls_x509_crt_frame`.

This commit removes this mismatch by solely using the legacy
form of `issuer_raw` and `subject_raw`, i.e. those _including_
the ASN.1 name header.
2019-06-25 09:07:16 +01:00
Hanno Becker
4e021c8f50 Remove raw SubjectAltNames and ExtKeyUsage from legacy CRT struct 2019-06-25 09:07:16 +01:00
Hanno Becker
ea32d8ba2a Provide direct way of setting up a CRT frame from legacy CRT struct
Previously, `mbedtls_x509_crt_cache_provide_frame()` provided the requested
CRT frame by always parsing the raw data underlying the CRT. That's inefficient
in legacy mode, where the CRTs fields are permanently accessible through the
legacy `mbedtls_x509_crt` structure.

This commit modifies `mbedtls_x509_crt_cache_provide_frame()` in legacy mode
(that is, !MBEDTLS_X509_ON_DEMAND_PARSING) to setup the CRT frame by copying
fields from the legacy CRT structure.
2019-06-25 09:07:16 +01:00
Hanno Becker
5226c53e13 Modify mbedtls_x509_crt_info() to use getter API 2019-06-25 09:06:26 +01:00
Hanno Becker
7a4de9cdab Flush CRT cache after parsing
This commit modifies the CRT parsing routine to flush
the CRT cache after parsing. More specifically, the
frame cache is flushed before the PK is parsed, to
avoid storing the PK and frame in RAM at the same time.
2019-06-25 09:06:26 +01:00
Hanno Becker
2bcc7640f8 Give x509_{sequence|name}_free() external linkage
With the introduction of `mbedtls_x509_crt_get_{issuer|name}()`,
users need an easy way of freeing the dynamic name structures these
functions return.

To that end, this commit renames `x509_{sequence|name}_free()`
to `mbedtls_x509_{sequence|name}_free()` and gives them external linkage.
2019-06-25 09:06:26 +01:00
Hanno Becker
ab6c8ea8bc Add public API to query SubjectAltNames and ExtKeyUsage extensions 2019-06-25 09:06:26 +01:00
Hanno Becker
63e6998dd7 Add public API to query subject and issuer from CRT
The legacy `mbedtls_x509_crt` contains fields `issuer/subject`
which are dynamically allocated linked list presentations of the
CRTs issuer and subject names, respectively.

The new CRT frame structure `mbedtls_x509_crt_frame`, however,
only provides pointers to the raw ASN.1 buffers for the issuer
and subject, for reasons of memory usage.

For convenience to users that previously used the `issuer`/`subject`
fields of `mbedtls_x509_crt`, this commit adds two public API functions
`mbedtls_x509_crt_get_subject()` and `mbedtls_x509_crt_get_issuer()`
which allow to request the legacy linked list presentation of the
CRTs subject / issuer names.

Similar to `mbedtls_x509_crt_get_pk()`, the returned names are owned
by the user, and must be freed through a call to `mbedtls_x509_name_free()`.
2019-06-25 09:06:26 +01:00
Hanno Becker
823efad6e8 Add public API to query for CRT frame and PK
This commit unconditionally adds two convenience API functions:
- mbedtls_x509_crt_get_frame()
- mbedtls_x509_crt_get_pk()
which allow users to extract a CRT frame or PK context
from a certificate.

The difference with the existing acquire/release API for frame and PK
contexts is that in contrast to the latter, the structures returned by
the new API are owned by the user (and, in case of the PK context, need
to be freed by him). This makes the API easier to use, but comes at the
cost of additional memory overhead.
2019-06-25 09:06:26 +01:00
Hanno Becker
180f7bf60b Add compile-time option to remove legacy CRT fields 2019-06-25 09:06:26 +01:00
Hanno Becker
b6c39fca5c Add parsing cache to mbedtls_x509_crt
This commit replaces the dummy implementation of the CRT acquire/release
framework by a cache-based implementation which remembers frame and PK
associated to a CRT across multiple `acquire/release` pairs.
2019-06-25 09:06:26 +01:00
Hanno Becker
8723336831 Make use of CRT acquire/release in x509_crt_verify_restartable 2019-06-25 09:06:26 +01:00
Hanno Becker
082435c011 Make use of CRT acquire/release in x509_crt_verify_name()
This commit modifies the static function `x509_crt_verify_name()` to
use the acquire/release API to access the given CRTs `subject` field.

This function is solely called from the beginning of the CRT chain
verification routine, which also needs to access the child's CRT frame.
It should therefore be considered - for a later commit - to collapse
the two acquire/release pairs to one, thereby saving some code.
2019-06-25 09:06:26 +01:00
Hanno Becker
58c35646df Make use of CRT acquire/release in CRT chain verification #2 2019-06-25 09:06:26 +01:00
Hanno Becker
bb26613d32 Make use of CRT acquire/release in x509_crt_verifycrl() 2019-06-25 09:06:26 +01:00
Hanno Becker
79ae5b68e7 Make use of CRT acquire/release in x509_serial_is_revoked() 2019-06-25 09:06:26 +01:00
Hanno Becker
e9718b451a Make use of CRT acquire/release in ExtKeyUsage checking 2019-06-25 09:06:26 +01:00
Hanno Becker
371e0e4573 Determine whether CRT is initialized or not through raw data pointer
Previously, `mbedtls_x509_crt_der_internal()` used the `version` field
(which is `0` after initialization but strictly greater than 0 once a
CRT has successfully been parsed) to determine whether an
`mbedtls_x509_crt` instance had already been setup.

Preparating for the removal of `version` from the structure, this
commit modifies the code to instead peek at the raw data pointer,
which is NULL as long as the CRT structure hasn't been setup with a CRT,
and will be kept in the new CRT structure.
2019-06-25 09:06:26 +01:00
Hanno Becker
4f869eda64 Make use of CRT acquire/release in mbedtls_x509_crt_info()
This commit adapts `mbedtls_x509_crt_info()` to no longer access
structure fields from `mbedtls_x509_crt` directly, but to instead
query for a `mbedtls_x509_crt_frame` and `mbedtls_pk_context` and
use these to extract the required CRT information.
2019-06-25 09:06:26 +01:00
Hanno Becker
45eedf1ace Make use of CRT acquire/release in mbedtls_x509_crt_check_key_usage 2019-06-25 09:06:26 +01:00
Hanno Becker
43bf900018 Make use of CRT acquire/release searching for issuer in CRT verif.
This commit continues rewriting the CRT chain verification to use
the new acquire/release framework for CRTs. Specifically, it replaces
all member accesses of the current _parent_ CRT by accesses to the
respective frame.
2019-06-25 09:06:26 +01:00
Hanno Becker
e449e2d846 Make use of CRT acquire/release for X.509 CRT signature checking 2019-06-25 09:06:26 +01:00
Hanno Becker
5299cf87d4 Add structure holding X.509 CRT signature information
This commit introduces an internal structure `mbedtls_x509_crt_sig_info`
containing all information that has to be kept from a child CRT when searching
for a potential parent:
- The issuer name
- The signature type
- The signature
- The hash of the CRT

The structure can be obtained from a CRT frame via `x509_crt_get_sig_info()`
and freed via `x509_crt_free_sig_info()`.

The purpose of this is to reduce the amount of RAM used during CRT
chain verification; once we've extracted the signature info structure
from the current child CRT, we can free all cached data for that CRT
(frame and PK) before searching for a suitable parent. This way, there
will ultimately not be more than one frame needed at a single point
during the verification.
2019-06-25 09:06:26 +01:00
Hanno Becker
a788cab46d Check validity of potential parent before checking signature
The function `x509_crt_find_parent_in()` traverses a list of CRTs
to find a potential parent to a given CRT. So far, the logic was
the following: For each candidate,
- check basic parenting skills (mostly name match)
- verify signature
- verify validity
This order is insuitable for the new acquire/release layer of
indirection when dealing with CRTs, because we either have to
query the candidate's CRT frame twice, or query frame and PK
simultaneously.

This commit moves the validity check to the beginning of the
routine to allow querying for the frame and then for the PK.

The entry point for restartable ECC needs to be moved for that
to not forget the validity-flag while pausing ECC computations.
2019-06-25 09:06:26 +01:00
Hanno Becker
1e0677acc1 Make use of CRT acquire/release for child in CRT chain verification
During CRT verification, `x509_crt_check_signature()` checks whether a
candidate parent CRT correctly signs the current child CRT.

This commit rewrites this function to use the new acquire/release
framework for using CRTs.
2019-06-25 09:06:26 +01:00
Hanno Becker
337088aa2d Add internal API for acquire/release of CRT frames and PKs
The goal of the subsequent commits is to remove all direct uses
of the existing `mbedtls_x509_crt` apart from the `raw` buffer
and the linked list `next` pointer.

The approach is the following: Whenever a code-path needs to inspect
a CRT, it can request a frame for the CRT through the API
`x509_crt_frame_acquire()`. On success, this function returns a pointer
to a frame structure for the CRT (the origin of which is flexible and
need not concern the caller) that can be used to inspect the desired
fields. Once done, the caller hands back the frame through an explicit
call to `x509_crt_frame_release()`.

This commit also adds an inefficient dummy implementation for
`x509_crt_frame_acquire()` which always allocates a new
`mbedtls_x509_crt_frame` structure on the heap and parses it
from the raw data underlying the CRT. This will change in subsequent
commits, but it constitutes a valid implementation to test against.

Ultimately, `x509_crt_frame_acquire()` is to compute a frame for the
given CRT only once, and cache it for subsequent calls.

The need for `x509_crt_frame_release()` is the following: When
implementing `x509_crt_frame_acquire()` through a flushable cache
as indicated above, it must be ensured that no thread destroys
a cached frame structure for the time it is needed by another
thread. The `acquire/release` pair allows to explicitly delimit
the lifetime requirements for the returned frame structure.
The frame pointer must not be used after the `release` call anymore;
and in fact, the dummy implementation shows that it would
immediately lead to a memory failure.

Analogously to `x509_crt_frame_{acquire|release}()`, there's also
`x509_crt_pk_{acquire|release}()` which allows to acquire/release
a PK context setup from the public key contained within the CRT.
2019-06-25 09:06:26 +01:00
Hanno Becker
21f5567571 Introduce X.509 CRT frame structure
This commit restructures the parsing of X.509 CRTs in the following way:

First, it introduces a 'frame' structure `mbedtls_x509_crt_frame`, which
contains pointers to some structured fields of a CRT as well as copies of
primitive fields. For example, there's a pointer-length pair delimiting the raw
public key data in the CRT, but there's a C-uint8 to store the CRT version
(not a pointer-length pair delimiting the ASN.1 structure holding the version).

Setting up a frame from a raw CRT buffer does not require any memory outside
of the frame structure itself; it's just attaches a 'template' to the buffer
that allows to inspect the structured parts of the CRT afterwards.

Note that the frame structure does not correspond to a particular ASN.1
structure; for example, it contains pointers to delimit the three parts
of a CRT (TBS, SignatureAlgorithm, Signature), but also pointers to the
fields of the TBS, and pointers into the Extensions substructure of the TBS.

Further, the commit introduces an internal function `x509_crt_parse_frame()`
which sets up a frame from a raw CRT buffer, as well as several small helper
functions which help setting up the more complex structures (Subject, Issuer, PK)
from the frame.

These functions are then put to use to rewrite the existing parsing function
`mbedtls_x509_crt_parse_der_core()` by setting up a CRT frame from the input
buffer, residing on the stack, and afterwards copying the respective fields
to the actual `mbedtls_x509_crt` structure and performing the deeper parsing
through the various helper functions.
2019-06-25 09:06:26 +01:00
Hanno Becker
6b37812a45 Add next_merged field to X.509 name comparison abort callback 2019-06-25 09:06:26 +01:00
Hanno Becker
10e6b9b2b5 Move point of re-entry for restartable X.509 verification 2019-06-25 09:06:26 +01:00
Hanno Becker
c84fd1cd95 Check whether CRT is revoked by passing its serial number only
CRLs reference revoked CRTs through their serial number only.
2019-06-25 09:06:26 +01:00
Hanno Becker
b3def1d341 Move length check into mbedtls_x509_memcasecmp()
At every occasion where we're using `mbedtls_x509_memcasecmp()` we're
checking that the two buffer lengths coincide before making the call.

This commit saves a few bytes of code by moving this length check
to `mbedtls_x509_memcasecmp()`.
2019-06-25 09:06:26 +01:00
Hanno Becker
f1b39bf18c Implement v3 Extension parsing through ASN.1 SEQUENCE OF traversal
This commit rewrites the v3 ext parsing routine `x509_crt_get_ext_cb()`
in terms of the generic ASN.1 SEQUENCE traversal routine.
2019-06-25 09:06:26 +01:00
Hanno Becker
c7c638eddd Implement ExtKeyUsage traversal via ASN.1 SEQUENCE OF traversal
This commit re-implements the `ExtendedKeyUsage` traversal
routine in terms of the generic ASN.1 SEQUENCE traversal routine.
2019-06-25 09:06:26 +01:00
Hanno Becker
90b9408dd0 Implement SubjectAltName traversal via ASN.1 SEQUENCE OF traversal
This commit re-implements the `SubjectAlternativeName` traversal
routine in terms of the generic ASN.1 SEQUENCE traversal routine.
2019-06-25 09:06:26 +01:00
Hanno Becker
5984d30f4b Make use of cb to build linked list presentation of SubjectAltName 2019-06-25 09:06:26 +01:00
Hanno Becker
ad46219a88 Add cb to build dynamic linked list representation of SubjectAltName
This commit adds a callback for use with `x509_subject_alt_name_traverse()`
which builds the legacy dynamically allocated linked list presentation
of the `SubjectAlternativeNames` extension while traversing the raw data.
2019-06-25 09:06:26 +01:00
Hanno Becker
da410828f4 Add callback to search through SubjectAltNames extension
The current CN name verification x509_crt_verify_name() traverses
the dynamically allocated linked list presentation of the subject
alternative name extension, searching for an alternative name that
matches the desired hostname configured by the application.

Eventually, we want to remove this dynamically allocated linked list
for the benefit of reduced code size and RAM usage, and hence need to
rewrite x509_crt_verify_name() in a way that builds on the raw ASN.1
buffer holding the SubjectAlternativeNames extension.

This commit does this by using the existing SubjectAlternativeNames
traversal routine x509_subject_alt_name_traverse(), passing to it a
callback which compares the current alternative name component to the
desired hostname configured by the application.
2019-06-25 09:06:26 +01:00
Hanno Becker
2c6cc045c2 Add function to traverse raw SubjectAltName extension
This commit adds a new function `x509_subject_alt_name_traverse()`
which allows to traverse the raw ASN.1 data of a `SubjectAlternativeNames`
extension.

The `SubjectAlternativeNames` extension needs to be traversed
in the following situations:
1 Initial traversal to check well-formedness of ASN.1 data
2 Traversal to check for a particular name component
3 Building the legacy linked list presentation

Analogously to how multiple tasks related to X.509 name comparison
are implemented through the workhorse `mbedtlS_x509_name_cmp_raw()`,
the new function `x509_subject_alt_name_traverse()` allows to pass
an arbitrary callback which is called on any component of the
`SubjectAlternativeNames` extension found. This way, the above
three tasks can be implemented by passing
1 a NULL callback,
2 a name comparison callback
3 a linked list building callback.
2019-06-25 09:06:26 +01:00
Hanno Becker
2492622289 Pass raw data to x509_check_wildcard() and x509_crt_check_cn()
In preparation for rewriting the `SubjectAlternativeName` search routine
to use raw ASN.1 data, this commit changes `x509_check_wildcard()` and
`x509_check_cn()`, responsible for checking whether a name matches a
wildcard pattern, to take a raw buffer pointer and length as parameters
instead of an `mbedtls_x509_buf` instance.
2019-06-25 09:06:26 +01:00
Hanno Becker
ded167e18c Add raw buffer holding SubjectAlternativeName ext to CRT structure
This is analogous to a previous commit for the `ExtendedKeyUsage`
extension: We aim at not using dynamically allocated linked lists
to represent the components of the `SubjectAlternativeName` extension,
but to traverse the raw ASN.1 data when needed.

This commit adds a field to `mbedtls_x509_crt` containing the raw
ASN.1 buffer bounds of the `SubjectAlternativeNames` extension.
2019-06-25 09:06:26 +01:00
Hanno Becker
e1956af057 Check for extended key usage by traversing raw extension data
This commit re-implements `mbedtls_x509_crt_check_extended_key_usage()`
to not use the dynamically allocated linked list presentation of the
`ExtendedKeyUsage` but to search for the required usage by traversing
the raw ASN.1 data.
2019-06-25 09:06:26 +01:00
Hanno Becker
7ec9c368f1 Add buffer holding raw ExtKeyUsage extension data to CRT struct
The previous commits replace the use of dynamically allocated linked lists
for X.509 name inspection. This commit is the first in a series which attempts
the same for the `ExtendedKeyUsage` extension. So far, when a CRT is parsed,
the extension is traversed and converted into a dynamically allocated linked
list, which is then search through whenever the usage of a CRT needs to be
checked through `mbedtls_x509_check_extended_key_usage()`.

As a first step, this commit introduces a raw buffer holding the bounds
of the `ExtendedKeyUsage` extension to the `mbedtls_x509_crt` structure.
2019-06-25 09:06:26 +01:00
Hanno Becker
8b543b3ca8 Make use of abort condition callback in CN comparison
The previous CN name comparison function x509_crt_verify_name()
traversed the dynamically allocated linked list presentation of
the CRT's subject, comparing each entry to the desired hostname
configured by the application code.

Eventually, we want to get rid of the linked list presentation of
the CRT's subject to save both code and RAM usage, and hence need
to rewrite the CN verification routine in a way that builds on the
raw ASN.1 subject data only.

In order to avoid duplicating the code for the parsing of the nested
ASN.1 name structure, this commit performs the name search by using
the existing name traversal function mbedtls_x509_name_cmp_raw(),
passing to it a callback which checks whether the current name
component matches the desired hostname.
2019-06-25 09:06:26 +01:00
Hanno Becker
67284cce00 Add abort condition callback to mbedtls_x509_name_cmp_raw()
There are three operations that need to be performed on an X.509 name:
1 Initial traversal to check well-formedness of the ASN.1 structure.
2 Comparison between two X.509 name sequences.
3 Checking whether an X.509 name matches a client's ServerName request.

Each of these tasks involves traversing the nested ASN.1 structure,
In the interest of saving code, we aim to provide a single function
which can perform all of the above tasks.

The existing comparison function is already suitable not only for task 2,
but also for 1: One can simply pass two equal ASN.1 name buffers, in which
case the function will succeed if and only if that buffer is a well-formed
ASN.1 name.

This commit further adds a callback to `mbedtls_x509_name_cmp_raw()` which
is called after each successful step in the simultaneous name traversal and
comparison; it may perform any operation on the current name and potentially
signal that the comparison should be aborted.

With that, task 3 can be implemented by passing equal names and a callback
which aborts as soon as it finds the desired name component.
2019-06-25 09:06:26 +01:00
Hanno Becker
7dee12a38c Make use of raw comparison function in CRT verification
This commit replaces the previous calls to `mbedtls_x509_name_cmp()`
during CRT verification (to match child and parent, to check whether
a CRT is self-issued, and to match CRLs and CAs) by calls to the new
`mbedtls_x509_name_cmp_raw()` using the raw ASN.1 data; it passes the
raw buffers introduced in the last commits.

The previous name comparison function mbedtls_x509_name_cmp() is now
both unused and unneeded, and is removed.
2019-06-25 09:06:26 +01:00
Hanno Becker
f8a42862b7 Add buffers with raw issuer/subject data to CRT structure 2019-06-25 09:06:26 +01:00
Hanno Becker
88de342c95 Move x509_name_cmp() from x509_crt.c to x509.c
This is to prepare a subsequent rewrite of `x509_name_cmp()` in terms
of the X.509 name traversal helper `x509_set_sequence_iterate()`
from `x509.c`.
2019-06-25 09:06:26 +01:00
Hanno Becker
83cd8676fa Remove sig_oid parameter from mbedtls_x509_sig_alg_gets()
The function `mbedtls_x509_sig_alg_gets()` previously needed the
raw ASN.1 OID string even though it is implicit in the PK and MD
parameters.

This commit modifies `mbedtls_x509_sig_alg_gets()` to infer the OID
and remove it from the parameters.

This will be needed for the new X.509 CRT structure which will
likely not store the signature OID.

Care has to be taken to handle the case of RSASSA-PSS correctly,
where the hash algorithm in the OID list is set to MBEDTLS_MD_NONE
because it's only determined by the algorithm parameters.
2019-06-25 09:06:26 +01:00
Hanno Becker
cd03bb2048 Introduce helper functions to free X.509 names and sequences
`mbedtls_x509_name` and `mbedtls_x509_sequence` are dynamically allocated
linked lists that need a loop to free properly. Introduce a static helper
function to do that and use it in `mbedtls_x509_crt_free()`, where the
CRT's issuer and subject names (of type `mbedtls_x509_name`) and the
SubjectAlternativeName and ExtendedKeyUsage extensions (of type
`mbedtls_x509_sequence`) need freeing. Increases code-clarity and saves
a few bytes of flash.
2019-06-25 09:00:25 +01:00
Jaeden Amero
096bccf204 Merge remote-tracking branch 'origin/pr/2450' into mbedtls-2.16
* origin/pr/2450:
  Fix #2370, minor typos and spelling mistakes
2019-06-21 15:59:29 +01:00
Hanno Becker
32c530ece2 Add raw public key buffer bounds to mbedtls_x509_crt struct
This commit adds an ASN.1 buffer field `pk_raw` to `mbedtls_x509_crt`
which stores the bounds of the raw public key data within an X.509 CRT.

This will be useful in subsequent commits to extract the peer's public
key from its certificate chain.
2019-06-19 10:25:01 +01:00
Hanno Becker
02a2193f60 Rename MBEDTLS_X509_INFO to !MBEDTLS_X509_REMOVE_INFO 2019-06-18 11:05:44 +01:00
Peter Kolbus
dc470ae8af Reduce code size when mbedtls_x509_*_info() unused
Introduce MBEDTLS_X509_INFO to indicate the availability of the
mbedtls_x509_*_info() function and closely related APIs. When this is
not defined, also omit name and description from
mbedtls_oid_descriptor_t, and omit OID arrays, macros, and types that
are entirely unused. This saves several KB of code space.

Change-Id: I056312613379890e0d70e1d08c34171287c0aa17
2019-06-18 11:05:37 +01:00
Hanno Becker
1abb159e90 Merge branch 'mbedtls-2.16' into baremetal 2019-06-18 09:00:37 +01:00
Hanno Becker
aa8665ac26 Add a new X.509 API call for copy-less parsing of CRTs
Context:
The existing API `mbedtls_x509_parse_crt_der()` for parsing DER
encoded X.509 CRTs unconditionally makes creates a copy of the
input buffer in RAM. While this comes at the benefit of easy use,
-- specifically: allowing the user to free or re-use the input
buffer right after the call -- it creates a significant memory
overhead, as the CRT is duplicated in memory (at least temporarily).
This might not be tolerable a resource constrained device.

As a remedy, this commit adds a new X.509 API call

   `mbedtls_x509_parse_crt_der_nocopy()`

which has the same signature as `mbedtls_x509_parse_crt_der()`
and almost the same semantics, with one difference: The input
buffer must persist and be unmodified for the lifetime of the
established instance of `mbedtls_x509_crt`, that is, until
`mbedtls_x509_crt_free()` is called.
2019-06-05 13:16:55 +01:00
Hanno Becker
2f472140f9 Always return a high-level error code from X.509 module
Some functions within the X.509 module return an ASN.1 low level
error code where instead this error code should be wrapped by a
high-level X.509 error code as in the bulk of the module.

Specifically, the following functions are affected:
- mbedtls_x509_get_ext()
- x509_get_version()
- x509_get_uid()

This commit modifies these functions to always return an
X.509 high level error code.

Care has to be taken when adapting `mbetls_x509_get_ext()`:
Currently, the callers `mbedtls_x509_crt_ext()` treat the
return code `MBEDTLS_ERR_ASN1_UNEXPECTED_TAG` specially to
gracefully detect and continue if the extension structure is not
present. Wrapping the ASN.1 error with
`MBEDTLS_ERR_X509_INVALID_EXTENSIONS` and adapting the check
accordingly would mean that an unexpected tag somewhere
down the extension parsing would be ignored by the caller.

The way out of this is the following: Luckily, the extension
structure is always the last field in the surrounding structure,
so if there is some data remaining, it must be an Extension
structure, so we don't need to deal with a tag mismatch gracefully
in the first place.

We may therefore wrap the return code from the initial call to
`mbedtls_asn1_get_tag()` in `mbedtls_x509_get_ext()` by
`MBEDTLS_ERR_X509_INVALID_EXTENSIONS` and simply remove
the special treatment of `MBEDTLS_ERR_ASN1_UNEXPECTED_TAG`
in the callers `x509_crl_get_ext()` and `x509_crt_get_ext()`.

This renders `mbedtls_x509_get_ext()` unsuitable if it ever
happened that an Extension structure is optional and does not
occur at the end of its surrounding structure, but for CRTs
and CRLs, it's fine.

The following tests need to be adapted:
- "TBSCertificate v3, issuerID wrong tag"
  The issuerID is optional, so if we look for its presence
  but find a different tag, we silently continue and try
  parsing the subjectID, and then the extensions. The tag '00'
  used in this test doesn't match either of these, and the
  previous code would hence return LENGTH_MISMATCH after
  unsucessfully trying issuerID, subjectID and Extensions.
  With the new code, any data remaining after issuerID and
  subjectID _must_ be Extension data, so we fail with
  UNEXPECTED_TAG when trying to parse the Extension data.
- "TBSCertificate v3, UIDs, invalid length"
  The test hardcodes the expectation of
  MBEDTLS_ERR_ASN1_INVALID_LENGTH, which needs to be
  wrapped in MBEDTLS_ERR_X509_INVALID_FORMAT now.

Fixes #2431.
2019-06-04 14:01:10 +01:00
Hanno Becker
4e1bfc19cc Obey bounds of ASN.1 substructures
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.
2019-06-04 14:01:10 +01:00
Hanno Becker
d6028a1894 Improve macro hygiene
This commit improves hygiene and formatting of macro definitions
throughout the library. Specifically:
- It adds brackets around parameters to avoid unintended
  interpretation of arguments, e.g. due to operator precedence.
- It adds uses of the `do { ... } while( 0 )` idiom for macros that
  can be used as commands.
2019-04-24 10:51:54 +02:00
Antonin Décimo
d5f4759594 Fix #2370, minor typos and spelling mistakes 2019-02-18 14:50:57 +00:00
Hanno Becker
d6ddcd660f Avoid MSVC compiler warning
MSVC warns about use of unary `-` operator on unsigned integers.
2019-01-10 09:23:48 +00:00
Jaeden Amero
5b46fe774b Merge remote-tracking branch 'upstream-public/pr/2157' into development 2018-12-06 16:06:57 +00:00
Simon Butcher
d83448b736 Merge remote-tracking branch 'public/pr/2052' into development-restricted-proposed 2018-11-07 12:59:14 +00:00
Hanno Becker
b75ffb5061 Don't perform binary comparison of CRL issuer and CA subject
Previously, when checking whether a CRT was revoked through
one of the configured CRLs, the library would only consider
those CRLs whose `issuer` field binary-matches the `subject`
field of the CA that has issued the CRT in question. If those
fields were not binary equivalent, the corresponding CRL was
discarded.

This is not in line with RFC 5280, which demands that the
comparison should be format- and case-insensitive. For example:

- If the same string is once encoded as a `PrintableString` and
  another time as a `UTF8String`, they should compare equal.
- If two strings differ only in their choice of upper and lower case
  letters, they should compare equal.

This commit fixes this by using the dedicated x509_name_cmp()
function to compare the CRL issuer with the CA subject.

Fixes #1784.
2018-11-05 11:54:06 +00:00
Hanno Becker
1f8527f1cf Move static x509_name_cmp() in library/x509_crt.c
A subsequent change will need this function earlier
within the file.
2018-11-05 11:54:06 +00:00
Krzysztof Stachowiak
c388a8c394 Fix typo in a test condition code 2018-10-31 16:49:20 +01:00
Manuel Pégourié-Gonnard
a5a3e40c4e Fix missing dereference.
Went unnoticed because it was only on a defensive code path, in an internal
function, so not exercised.
2018-10-16 11:27:23 +02:00
Manuel Pégourié-Gonnard
ee68cff813 Fix or improve some comments (and whitespace) 2018-10-15 15:27:49 +02:00
Simon Butcher
d2642584cb Make inclusion of stdio.h conditional in x509_crt.c
stdio.h was being included both conditionally if MBEDTLS_FS_IO was
defined, and also unconditionally, which made at least one of them
redundant.

This change removes the unconditional inclusion of stdio.h and makes it
conditional on MBEDTLS_PLATFORM_C.
2018-10-03 15:11:19 +01:00
Manuel Pégourié-Gonnard
125af948c3 Merge branch 'development-restricted' into iotssl-1260-non-blocking-ecc-restricted
* development-restricted: (578 commits)
  Update library version number to 2.13.1
  Don't define _POSIX_C_SOURCE in header file
  Don't declare and define gmtime()-mutex on Windows platforms
  Correct preprocessor guards determining use of gmtime()
  Correct documentation of mbedtls_platform_gmtime_r()
  Correct typo in documentation of mbedtls_platform_gmtime_r()
  Correct POSIX version check to determine presence of gmtime_r()
  Improve documentation of mbedtls_platform_gmtime_r()
  platform_utils.{c/h} -> platform_util.{c/h}
  Don't include platform_time.h if !MBEDTLS_HAVE_TIME
  Improve wording of documentation of MBEDTLS_PLATFORM_GMTIME_R_ALT
  Fix typo in documentation of MBEDTLS_PLATFORM_GMTIME_R_ALT
  Replace 'thread safe' by 'thread-safe' in the documentation
  Improve documentation of MBEDTLS_HAVE_TIME_DATE
  ChangeLog: Add missing renamings gmtime -> gmtime_r
  Improve documentation of MBEDTLS_HAVE_TIME_DATE
  Minor documentation improvements
  Style: Add missing period in documentation in threading.h
  Rename mbedtls_platform_gmtime() to mbedtls_platform_gmtime_r()
  Guard decl and use of gmtime mutex by HAVE_TIME_DATE and !GMTIME_ALT
  ...
2018-09-11 12:39:14 +02:00
Simon Butcher
129fa82908 Merge remote-tracking branch 'restricted/pr/470' into development-restricted 2018-08-28 15:26:11 +01:00
k-stachowiak
463928a74b Fix code formatting 2018-07-24 12:50:59 +02:00
Manuel Pégourié-Gonnard
78d7e8cbc7 Rename internal variable for consistency 2018-07-02 12:33:14 +02:00
k-stachowiak
dcae78a7a9 Make a buffer limit more specific 2018-06-28 16:32:54 +02:00
k-stachowiak
470dfbabb9 Simplify OID tag parsing in x509_get_cert_ext( ) 2018-06-28 16:23:39 +02:00
Manuel Pégourié-Gonnard
da19f4c79f Merge branch 'development' into iotssl-1260-non-blocking-ecc-restricted
Summary of merge conflicts:

include/mbedtls/ecdh.h -> documentation style
include/mbedtls/ecdsa.h -> documentation style
include/mbedtls/ecp.h -> alt style, new error codes, documentation style
include/mbedtls/error.h -> new error codes
library/error.c -> new error codes (generated anyway)
library/ecp.c:
    - code of an extracted function was changed
library/ssl_cli.c:
    - code addition on one side near code change on the other side
      (ciphersuite validation)
library/x509_crt.c -> various things
    - top fo file: helper structure added near old zeroize removed
    - documentation of find_parent_in()'s signature: improved on one side,
      added arguments on the other side
    - documentation of find_parent()'s signature: same as above
    - verify_chain(): variables initialised later to give compiler an
      opportunity to warn us if not initialised on a code path
    - find_parent(): funcion structure completely changed, for some reason git
      tried to insert a paragraph of the old structure...
    - merge_flags_with_cb(): data structure changed, one line was fixed with a
      cast to keep MSVC happy, this cast is already in the new version
    - in verify_restratable(): adjacent independent changes (function
      signature on one line, variable type on the next)
programs/ssl/ssl_client2.c:
    - testing for IN_PROGRESS return code near idle() (event-driven):
      don't wait for data in the the socket if ECP_IN_PROGRESS
tests/data_files/Makefile: adjacent independent additions
tests/suites/test_suite_ecdsa.data: adjacent independent additions
tests/suites/test_suite_x509parse.data: adjacent independent additions

* development: (1059 commits)
  Change symlink to hardlink to avoid permission issues
  Fix out-of-tree testing symlinks on Windows
  Updated version number to 2.10.0 for release
  Add a disabled CMAC define in the no-entropy configuration
  Adapt the ARIA test cases for new ECB function
  Fix file permissions for ssl.h
  Add ChangeLog entry for PR#1651
  Fix MicroBlaze register typo.
  Fix typo in doc and copy missing warning
  Fix edit mistake in cipher_wrap.c
  Update CTR doc for the 64-bit block cipher
  Update CTR doc for other 128-bit block ciphers
  Slightly tune ARIA CTR documentation
  Remove double declaration of mbedtls_ssl_list_ciphersuites
  Update CTR documentation
  Use zeroize function from new platform_util
  Move to new header style for ALT implementations
  Add ifdef for selftest in header file
  Fix typo in comments
  Use more appropriate type for local variable
  ...
2018-06-13 09:52:54 +02:00
Philippe Antoine
b5b254300e Fix undefined shifts
- in x509_profile_check_pk_alg
- in x509_profile_check_md_alg
- in x509_profile_check_key

and in ssl_cli.c : unsigned char gets promoted to signed integer
2018-06-06 14:27:12 +02:00
Darryl Green
11999bb72e Fix minor code style issues 2018-05-15 09:21:57 +01:00
Andres Amaya Garcia
1f6301b3c8 Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00
Andres Amaya Garcia
e32df087fb Remove individual copies of mbedtls_zeroize()
This commit removes all the static occurrencies of the function
mbedtls_zeroize() in each of the individual .c modules. Instead the
function has been moved to utils.h that is included in each of the
modules.
2018-04-17 09:19:05 -05:00
Krzysztof Stachowiak
fe60132305 Move a buffer size test before the first relevant read 2018-04-05 16:53:35 +02:00
Gilles Peskine
15ad579895 Merge tag 'mbedtls-2.8.0' into iotssl-1381-x509-verify-refactor-restricted
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.
2018-03-23 02:16:22 +01:00
Gilles Peskine
5f1932817c Merge remote-tracking branch 'upstream-restricted/pr/398' into development-restricted-proposed 2018-03-13 17:18:06 +01:00
Manuel Pégourié-Gonnard
e57d7438b0 Improve documentation of some internal functions 2018-03-07 10:00:57 +01:00
Manuel Pégourié-Gonnard
05c00ed8b2 Fix some more MSVC size_t -> int warnings 2018-03-06 11:48:50 +01:00
Manuel Pégourié-Gonnard
f5bb78183a Fix MSVC warnings
library\x509_crt.c(2137): warning C4267: 'function' : conversion from 'size_t' to 'int', possible loss of data
library\x509_crt.c(2265): warning C4267: 'function' : conversion from 'size_t' to 'int', possible loss of data
2018-03-05 12:48:53 +01:00
Manuel Pégourié-Gonnard
05e464dff7 Merge branch 'development' into iotssl-1381-x509-verify-refactor-restricted
* development: (557 commits)
  Add attribution for #1351 report
  Adapt version_features.c
  Note incompatibility of truncated HMAC extension in ChangeLog
  Add LinkLibraryDependencies to VS2010 app template
  Add ChangeLog entry for PR #1382
  MD: Make deprecated functions not inline
  Add ChangeLog entry for PR #1384
  Have Visual Studio handle linking to mbedTLS.lib internally
  Mention in ChangeLog that this fixes #1351
  Add issue number to ChangeLog
  Note in the changelog that this fixes an interoperability issue.
  Style fix in ChangeLog
  Add ChangeLog entries for PR #1168 and #1362
  Add ChangeLog entry for PR #1165
  ctr_drbg: Typo fix in the file description comment.
  dhm: Fix typo in RFC 5114 constants
  tests_suite_pkparse: new PKCS8-v2 keys with PRF != SHA1
  data_files/pkcs8-v2: add keys generated with PRF != SHA1
  tests/pkcs5/pbkdf2_hmac: extend array to accommodate longer results
  tests/pkcs5/pbkdf2_hmac: add unit tests for additional SHA algorithms
  ...
2018-03-05 11:55:38 +01:00
Ron Eldor
85e1dcff6a Fix handshake failure in suite B
Fix handshake failure where PK key is translated as `MBEDTLS_ECKEY`
instead of `MBEDTLS_ECDSA`
2018-02-06 15:59:38 +02:00
Andres Amaya Garcia
849bc65bbf Fix x509_get_subject_alt_name to drop invalid tag
Fix the x509_get_subject_alt_name() function to not accept invalid
tags. The problem was that the ASN.1 class for tags consists of two
bits. Simply doing bit-wise and of the CONTEXT_SPECIFIC macro with the
input tag has the potential of accepting tag values 0x10 (private)
which would indicate that the certificate has an incorrect format.
2017-11-07 19:34:35 +00:00
Manuel Pégourié-Gonnard
3f81691d29 Revert to old behaviour of profile_check_key()
Was never documented to check for key alg compatibility, so should not start
doing so. Just stop relying on the pk_alg argument instead.
2017-10-26 10:24:16 +02:00
Manuel Pégourié-Gonnard
19773ff835 Avoid comparing size between RSA and EC keys 2017-10-24 10:51:26 +02:00
Manuel Pégourié-Gonnard
08c36635cb Avoid possible miscast of PK key
I don't think this can cause a crash as the member accessed is in the
beginning of the context, so wouldn't be outside of valid memory if the actual
context was RSA.

Also, the mismatch will be caught later when checking signature, so the cert
chain will be rejected anyway.
2017-10-18 14:57:11 +02:00
Manuel Pégourié-Gonnard
900fba616f Fix check_wildcard() calling convention
We shouldn't return a surprising value in case there is no wildcard and then
rely on the caller to ensure that this doesn't happen
2017-10-18 14:40:13 +02:00
Manuel Pégourié-Gonnard
08eacecc62 Fix some style issues and comment typos 2017-10-18 14:40:11 +02:00
Manuel Pégourié-Gonnard
bb216bd940 Fix MSVC 64-bit warnings
"conversion from size_t to int, possible loss of data"
2017-08-28 13:25:55 +02:00