diff options
| author | Matt Caswell <matt@openssl.org> | 2021-03-15 16:21:45 +0000 |
|---|---|---|
| committer | Matt Caswell <matt@openssl.org> | 2021-03-17 09:56:33 +0000 |
| commit | 19ad1e9d3737f48c0e1c5cc5397ff1827b6946b8 (patch) | |
| tree | 571d2603c99d18fbecd52ff258fcfad457faca2f /crypto/dh | |
| parent | d11f644ba5f5c7a6e925e625899589d0cdd2c84b (diff) | |
Remove a TODO(3.0) from EVP_PKEY_derive_set_peer()
The TODO described a case where a legacy derive operation is called, but
the peer key is provider based. In practice this will almost never be a
problem. We should never end up in our own legacy EVP_PKEY_METHOD
implementations if no ENGINE has been configured. If an ENGINE has been
configured then we we will be using a third party EVP_PKEY_METHOD
implementation and public APIs will be used to obtain the key data from the
peer key so there will be no "reaching inside" the pkey.
There is a theoretical case where a third party ENGINE wraps our own
internal EVP_PKEY_METHODs using EVP_PKEY_meth_find() or
EVP_PKEY_meth_get0(). For these cases we just ensure all our
EVP_PKEY_METHODs never reach "inside" the implementation of a peer key. We
can never assume that it is a legacy key.
Fixes #14399
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14555)
Diffstat (limited to 'crypto/dh')
| -rw-r--r-- | crypto/dh/dh_pmeth.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/crypto/dh/dh_pmeth.c b/crypto/dh/dh_pmeth.c index fdd9194f1a..584a174ae2 100644 --- a/crypto/dh/dh_pmeth.c +++ b/crypto/dh/dh_pmeth.c @@ -421,23 +421,30 @@ static int pkey_dh_derive(EVP_PKEY_CTX *ctx, unsigned char *key, { int ret; DH *dh; + const DH *dhpub; DH_PKEY_CTX *dctx = ctx->data; - BIGNUM *dhpub; - if (!ctx->pkey || !ctx->peerkey) { + BIGNUM *dhpubbn; + + if (ctx->pkey == NULL || ctx->peerkey == NULL) { ERR_raise(ERR_LIB_DH, DH_R_KEYS_NOT_SET); return 0; } dh = ctx->pkey->pkey.dh; - dhpub = ctx->peerkey->pkey.dh->pub_key; + dhpub = EVP_PKEY_get0_DH(ctx->peerkey); + if (dhpub == NULL) { + ERR_raise(ERR_LIB_DH, DH_R_KEYS_NOT_SET); + return 0; + } + dhpubbn = dhpub->pub_key; if (dctx->kdf_type == EVP_PKEY_DH_KDF_NONE) { if (key == NULL) { *keylen = DH_size(dh); return 1; } if (dctx->pad) - ret = DH_compute_key_padded(key, dhpub, dh); + ret = DH_compute_key_padded(key, dhpubbn, dh); else - ret = DH_compute_key(key, dhpub, dh); + ret = DH_compute_key(key, dhpubbn, dh); if (ret < 0) return ret; *keylen = ret; @@ -461,7 +468,7 @@ static int pkey_dh_derive(EVP_PKEY_CTX *ctx, unsigned char *key, if (Z == NULL) { goto err; } - if (DH_compute_key_padded(Z, dhpub, dh) <= 0) + if (DH_compute_key_padded(Z, dhpubbn, dh) <= 0) goto err; if (!DH_KDF_X9_42(key, *keylen, Z, Zlen, dctx->kdf_oid, dctx->kdf_ukm, dctx->kdf_ukmlen, dctx->kdf_md)) |