mbedtls/library
Hanno Becker ad4a137965 Add CID configuration API
Context:
The CID draft does not require that the length of CIDs used for incoming
records must not change in the course of a connection. Since the record
header does not contain a length field for the CID, this means that if
CIDs of varying lengths are used, the CID length must be inferred from
other aspects of the record header (such as the epoch) and/or by means
outside of the protocol, e.g. by coding its length in the CID itself.

Inferring the CID length from the record's epoch is theoretically possible
in DTLS 1.2, but it requires the information about the epoch to be present
even if the epoch is no longer used: That's because one should silently drop
records from old epochs, but not the entire datagrams to which they belong
(there might be entire flights in a single datagram, including a change of
epoch); however, in order to do so, one needs to parse the record's content
length, the position of which is only known once the CID length for the epoch
is known. In conclusion, it puts a significant burden on the implementation
to infer the CID length from the record epoch, which moreover mangles record
processing with the high-level logic of the protocol (determining which epochs
are in use in which flights, when they are changed, etc. -- this would normally
determine when we drop epochs).

Moreover, with DTLS 1.3, CIDs are no longer uniquely associated to epochs,
but every epoch may use a set of CIDs of varying lengths -- in that case,
it's even theoretically impossible to do record header parsing based on
the epoch configuration only.

We must therefore seek a way for standalone record header parsing, which
means that we must either (a) fix the CID lengths for incoming records,
or (b) allow the application-code to configure a callback to implement
an application-specific CID parsing which would somehow infer the length
of the CID from the CID itself.

Supporting multiple lengths for incoming CIDs significantly increases
complexity while, on the other hand, the restriction to a fixed CID length
for incoming CIDs (which the application controls - in contrast to the
lengths of the CIDs used when writing messages to the peer) doesn't
appear to severely limit the usefulness of the CID extension.

Therefore, the initial implementation of the CID feature will require
a fixed length for incoming CIDs, which is what this commit enforces,
in the following way:

In order to avoid a change of API in case support for variable lengths
CIDs shall be added at some point, we keep mbedtls_ssl_set_cid(), which
includes a CID length parameter, but add a new API mbedtls_ssl_conf_cid_len()
which applies to an SSL configuration, and which fixes the CID length that
any call to mbetls_ssl_set_cid() which applies to an SSL context that is bound
to the given SSL configuration must use.

While this creates a slight redundancy of parameters, it allows to
potentially add an API like mbedtls_ssl_conf_cid_len_cb() later which
could allow users to register a callback which dynamically infers the
length of a CID at record header parsing time, without changing the
rest of the API.
2019-06-03 16:07:50 +01:00
..
.gitignore
aes.c Add further missing brackets around macro parameters 2019-02-19 17:59:57 +00:00
aesni.c Warn if using a memory sanitizer on AESNI 2018-04-05 15:37:38 +02:00
arc4.c Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00
aria.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
asn1parse.c Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00
asn1write.c Add new function mbedtls_asn1_write_named_bitstring() 2019-02-28 09:36:30 +00:00
base64.c Add comment to integer overflow fix in base64.c 2017-02-15 23:31:07 +02:00
bignum.c Merge remote-tracking branch 'origin/pr/2405' into development 2019-04-05 14:08:49 +01:00
blowfish.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
camellia.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
ccm.c Merge remote-tracking branch 'origin/pr/2092' into development 2019-04-24 11:17:21 +01:00
certs.c Use certificates from data_files and refer them 2019-02-12 15:30:26 +02:00
chacha20.c Improve macro hygiene 2019-02-19 17:59:00 +00:00
chachapoly.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
cipher.c Wrap lines at 80 columns 2019-04-02 10:07:28 -07:00
cipher_wrap.c Wrap lines at 80 columns 2019-04-02 10:07:28 -07:00
cmac.c Merge remote-tracking branch 'public/pr/1390' into development 2018-06-27 10:51:47 +01:00
CMakeLists.txt Force the usage of crypto submodule 2019-05-23 03:01:35 -04:00
ctr_drbg.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
debug.c Merge remote-tracking branch 'origin/pr/1818' into development 2019-03-05 16:27:38 +00:00
des.c Improve macro hygiene 2019-02-19 17:59:00 +00:00
dhm.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
ecdh.c Fix ECDH secret export for Mongomery curves 2019-02-26 16:49:52 +00:00
ecdsa.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
ecjpake.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
ecp.c Merge remote-tracking branch 'origin/pr/2092' into development 2019-04-24 11:17:21 +01:00
ecp_curves.c Improve macro hygiene 2019-02-19 17:59:00 +00:00
entropy.c Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00
entropy_poll.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
error.c Regenerate errors.c 2019-04-30 16:47:36 +01:00
gcm.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
havege.c Improve macro hygiene 2019-02-19 17:59:00 +00:00
hkdf.c Fix issue if salt = NULL and salt_len !=0 in mbedtls_hkdf_extract() 2018-07-23 10:34:47 -07:00
hmac_drbg.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
Makefile Force the usage of crypto submodule 2019-05-23 03:01:35 -04:00
md.c Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00
md2.c Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00
md4.c Add more missing parentheses around macro parameters 2019-02-19 17:59:57 +00:00
md5.c Add further missing brackets around macro parameters 2019-02-19 17:59:57 +00:00
md_wrap.c New MD API: rename functions from _ext to _ret 2018-01-22 11:54:42 +01:00
memory_buffer_alloc.c Fix braces in mbedtls_memory_buffer_alloc_status() 2018-06-12 16:56:04 +01:00
net_sockets.c Merge remote-tracking branch 'public/pr/1198' into development 2018-07-24 17:20:17 +01:00
nist_kw.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
oid.c Add support for RSA PKCSv1.5 signatures using RIPEMD-160 2019-05-06 12:15:17 -04:00
padlock.c
pem.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
pk.c pk: restructure precondition check 2019-02-05 05:09:05 -05:00
pk_wrap.c Fix outdated comment in ecdsa_verify_wrap() 2019-01-29 08:26:15 +00:00
pkcs5.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
pkcs11.c
pkcs12.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
pkparse.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
pkwrite.c Merge development-psa commit 80b5662 into development-psa-merged branch 2019-02-05 06:02:51 -05:00
platform.c Merge remote-tracking branch 'origin/pr/1551' into development 2019-01-30 13:24:55 +00:00
platform_util.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
poly1305.c Improve macro hygiene 2019-02-19 17:59:00 +00:00
ripemd160.c Improve macro hygiene 2019-02-19 17:59:00 +00:00
rsa.c rsa: Enable use of zero-length null output 2019-02-11 03:39:51 -05:00
rsa_internal.c Bignum: Deprecate mbedtls_mpi_is_prime() 2018-10-09 16:36:53 +01:00
sha1.c Add further missing brackets around macro parameters 2019-02-19 17:59:57 +00:00
sha256.c Add further missing brackets around macro parameters 2019-02-19 17:59:57 +00:00
sha512.c Add more missing parentheses around macro parameters 2019-02-19 17:59:57 +00:00
ssl_cache.c Remove peer CRT from cache if !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE 2019-02-26 14:38:09 +00:00
ssl_ciphersuites.c Reduce priority of 3DES ciphersuites 2019-03-01 10:19:27 +01:00
ssl_cli.c Set pointer to start of plaintext at record decryption time 2019-06-03 16:07:50 +01:00
ssl_cookie.c Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00
ssl_srv.c Split mbedtls_ssl_hdr_len() in separate functions for in/out records 2019-06-03 16:07:50 +01:00
ssl_ticket.c Fix typo in SSL ticket documentation 2019-02-26 14:38:09 +00:00
ssl_tls.c Add CID configuration API 2019-06-03 16:07:50 +01:00
threading.c Don't declare and define gmtime()-mutex on Windows platforms 2018-09-06 12:09:56 +01:00
timing.c Merge remote-tracking branch 'public/pr/1777' into development-proposed 2018-11-04 18:51:36 +00:00
version.c Fix missing void argument declarations #678 2016-11-04 23:05:56 +01:00
version_features.c Update version_features.c 2019-06-03 14:42:08 +01:00
x509.c Merge remote-tracking branch 'origin/pr/2092' into development 2019-04-24 11:17:21 +01:00
x509_create.c Break overly long line in library/x509_create.c 2018-11-02 10:52:38 +00:00
x509_crl.c Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00
x509_crt.c Set next sequence of subject_alt_names to NULL 2019-05-22 16:50:24 +03:00
x509_csr.c Merge development commit 8e76332 into development-psa 2019-01-31 08:20:20 -05:00
x509write_crt.c Add new function mbedtls_asn1_write_named_bitstring() 2019-02-28 09:36:30 +00:00
x509write_csr.c Add new function mbedtls_asn1_write_named_bitstring() 2019-02-28 09:36:30 +00:00
xtea.c Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00