openssl/providers
Nicola Tuveri a16e86683e Honor OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT as set and default to UNCOMPRESSED
Originally the code to im/export the EC pubkey was meant to be consumed
only by the im/export functions when crossing the provider boundary.
Having our providers exporting to a COMPRESSED format octet string made
sense to avoid memory waste, as it wasn't exposed outside the provider
API, and providers had all tools available to convert across the three
formats.

Later on, with #13139 deprecating the `EC_KEY_*` functions, more state
was added among the params imported/exported on an EC provider-native
key (including `OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT`, although it
did not affect the format used to export `OSSL_PKEY_PARAM_PUB_KEY`).

Finally, in #14800, `EVP_PKEY_todata()` was introduced and prominently
exposed directly to users outside the provider API, and the choice of
COMPRESSED over UNCOMPRESSED as the default became less sensible in
light of usability, given the latter is more often needed by
applications and protocols.

This commit fixes it, by using `EC_KEY_get_conv_form()` to get the
point format from the internal state (an `EC_KEY` under the hood) of the
provider-side object, and using it on
`EVP_PKEY_export()`/`EVP_PKEY_todata()` to format
`OSSL_PKEY_PARAM_PUB_KEY`.
The default for an `EC_KEY` was already UNCOMPRESSED, and it is altered
if the user sets `OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT` via
`EVP_PKEY_fromdata()`, `EVP_PKEY_set_params()`, or one of the
more specialized methods.

For symmetry, this commit also alters `ec_pkey_export_to()` in
`crypto/ec/ec_ameth.c`, part of the `EVP_PKEY_ASN1_METHOD` for legacy EC
keys: it exclusively used COMPRESSED format, and now it honors the
conversion format specified in the EC_KEY object being exported to a
provider when this function is called.

Expand documentation about `OSSL_PKEY_PARAM_PUB_KEY` and mention the
3.1 change in behavior for our providers.

Fixes #16595

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19681)

(cherry picked from commit 926db476bc)
2022-11-29 16:03:04 +01:00
..
common Implements Hybrid Public Key Encryption (HPKE) as per RFC9180. 2022-11-25 16:26:55 +00:00
fips Cleanup : directly include of internal/nelem.h when required. 2022-11-23 18:08:25 +01:00
implementations Honor OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT as set and default to UNCOMPRESSED 2022-11-29 16:03:04 +01:00
baseprov.c Cleanup : directly include of internal/nelem.h when required. 2022-11-23 18:08:25 +01:00
build.info Add VERSIONINFO resource to legacy provider if it is not builtin 2022-06-02 11:09:10 -04:00
decoders.inc Support decode SM2 parameters 2022-08-23 11:08:11 +10:00
defltprov.c default provider: include RIPEMD160 2022-10-19 13:21:01 +02:00
encoders.inc ENCODER PROV: Add encoders with EncryptedPrivateKeyInfo output 2021-09-05 21:34:51 +02:00
fips-sources.checksums make update 2021-07-29 15:50:27 +01:00
fips.checksum make update 2021-07-29 15:50:27 +01:00
fips.module.sources make update 2021-07-29 15:50:27 +01:00
legacyprov.c Fix regression in default key length for Blowfish CFB and OFB ciphers 2022-05-23 08:50:42 +02:00
nullprov.c
prov_running.c
stores.inc Add support for loading root CAs from Windows crypto API 2022-09-14 14:10:18 +01:00