From f1bd13208de9197f3d35d04c8f99a3e3bcb2a91e Mon Sep 17 00:00:00 2001 From: Dmitry Belyavskiy Date: Fri, 26 Jul 2024 16:15:19 +0200 Subject: [PATCH] Use FIPS-compatible API for key derivation RHEL-10 Resolves: RHEL-43592 --- openssh-8.0p1-openssl-kdf.patch | 96 +++++++++++++++++++-------------- openssh.spec | 2 + 2 files changed, 57 insertions(+), 41 deletions(-) diff --git a/openssh-8.0p1-openssl-kdf.patch b/openssh-8.0p1-openssl-kdf.patch index 5d76a4f..c22b210 100644 --- a/openssh-8.0p1-openssl-kdf.patch +++ b/openssh-8.0p1-openssl-kdf.patch @@ -12,7 +12,7 @@ index 2a455e4e..e01c3d43 100644 HMAC_CTX_init \ RSA_generate_key_ex \ RSA_get_default_method \ -+ EVP_KDF_CTX_new_id \ ++ EVP_KDF_CTX_new \ ]) # OpenSSL_add_all_algorithms may be a macro. @@ -20,33 +20,35 @@ diff --git a/kex.c b/kex.c index b6f041f4..1fbce2bb 100644 --- a/kex.c +++ b/kex.c -@@ -38,6 +38,9 @@ +@@ -38,6 +38,11 @@ #ifdef WITH_OPENSSL #include #include -+# ifdef HAVE_EVP_KDF_CTX_NEW_ID ++# ifdef HAVE_EVP_KDF_CTX_NEW +# include ++# include ++# include +# endif #endif #include "ssh.h" -@@ -942,6 +945,95 @@ kex_choose_conf(struct ssh *ssh) +@@ -942,6 +945,107 @@ kex_choose_conf(struct ssh *ssh) return r; } -+#ifdef HAVE_EVP_KDF_CTX_NEW_ID -+static const EVP_MD * ++#ifdef HAVE_EVP_KDF_CTX_NEW ++static const char * +digest_to_md(int digest_type) +{ + switch (digest_type) { + case SSH_DIGEST_SHA1: -+ return EVP_sha1(); ++ return SN_sha1; + case SSH_DIGEST_SHA256: -+ return EVP_sha256(); ++ return SN_sha256; + case SSH_DIGEST_SHA384: -+ return EVP_sha384(); ++ return SN_sha384; + case SSH_DIGEST_SHA512: -+ return EVP_sha512(); ++ return SN_sha512; + } + return NULL; +} @@ -56,52 +58,62 @@ index b6f041f4..1fbce2bb 100644 + const struct sshbuf *shared_secret, u_char **keyp) +{ + struct kex *kex = ssh->kex; -+ EVP_KDF_CTX *ctx = NULL; + u_char *key = NULL; + int r, key_len; + -+ if ((key_len = ssh_digest_bytes(kex->hash_alg)) == 0) -+ return SSH_ERR_INVALID_ARGUMENT; ++ EVP_KDF *kdf = EVP_KDF_fetch(NULL, "SSHKDF", NULL); ++ EVP_KDF_CTX *ctx = EVP_KDF_CTX_new(kdf); ++ OSSL_PARAM_BLD *param_bld = OSSL_PARAM_BLD_new(); ++ OSSL_PARAM *params = NULL; ++ const char *md = digest_to_md(kex->hash_alg); ++ char keytype = (char)id; ++ ++ EVP_KDF_free(kdf); ++ if (!ctx) { ++ r = SSH_ERR_LIBCRYPTO_ERROR; ++ goto out; ++ } ++ if (md == NULL) { ++ r = SSH_ERR_INVALID_ARGUMENT; ++ goto out; ++ } ++ ++ if (param_bld == NULL) { ++ EVP_KDF_CTX_free(ctx); ++ return -1; ++ } ++ if ((key_len = ssh_digest_bytes(kex->hash_alg)) == 0) { ++ r = SSH_ERR_INVALID_ARGUMENT; ++ goto out; ++ } ++ + key_len = ROUNDUP(need, key_len); + if ((key = calloc(1, key_len)) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + -+ ctx = EVP_KDF_CTX_new_id(EVP_KDF_SSHKDF); -+ if (!ctx) { ++ r = OSSL_PARAM_BLD_push_utf8_string(param_bld, OSSL_KDF_PARAM_DIGEST, ++ md, strlen(md)) && /* SN */ ++ OSSL_PARAM_BLD_push_octet_string(param_bld, OSSL_KDF_PARAM_KEY, ++ sshbuf_ptr(shared_secret), sshbuf_len(shared_secret)) && ++ OSSL_PARAM_BLD_push_octet_string(param_bld, OSSL_KDF_PARAM_SSHKDF_XCGHASH, ++ hash, hashlen) && ++ OSSL_PARAM_BLD_push_octet_string(param_bld, OSSL_KDF_PARAM_SSHKDF_SESSION_ID, ++ sshbuf_ptr(kex->session_id), sshbuf_len(kex->session_id)) && ++ OSSL_PARAM_BLD_push_utf8_string(param_bld, OSSL_KDF_PARAM_SSHKDF_TYPE, ++ &keytype, 1); ++ if (r != 1) { + r = SSH_ERR_LIBCRYPTO_ERROR; + goto out; + } + -+ r = EVP_KDF_ctrl(ctx, EVP_KDF_CTRL_SET_MD, digest_to_md(kex->hash_alg)); -+ if (r != 1) { ++ params = OSSL_PARAM_BLD_to_param(param_bld); ++ if (params == NULL) { + r = SSH_ERR_LIBCRYPTO_ERROR; + goto out; + } -+ r = EVP_KDF_ctrl(ctx, EVP_KDF_CTRL_SET_KEY, -+ sshbuf_ptr(shared_secret), sshbuf_len(shared_secret)); -+ if (r != 1) { -+ r = SSH_ERR_LIBCRYPTO_ERROR; -+ goto out; -+ } -+ r = EVP_KDF_ctrl(ctx, EVP_KDF_CTRL_SET_SSHKDF_XCGHASH, hash, hashlen); -+ if (r != 1) { -+ r = SSH_ERR_LIBCRYPTO_ERROR; -+ goto out; -+ } -+ r = EVP_KDF_ctrl(ctx, EVP_KDF_CTRL_SET_SSHKDF_TYPE, id); -+ if (r != 1) { -+ r = SSH_ERR_LIBCRYPTO_ERROR; -+ goto out; -+ } -+ r = EVP_KDF_ctrl(ctx, EVP_KDF_CTRL_SET_SSHKDF_SESSION_ID, -+ sshbuf_ptr(kex->session_id), sshbuf_len(kex->session_id)); -+ if (r != 1) { -+ r = SSH_ERR_LIBCRYPTO_ERROR; -+ goto out; -+ } -+ r = EVP_KDF_derive(ctx, key, key_len); ++ r = EVP_KDF_derive(ctx, key, key_len, params); + if (r != 1) { + r = SSH_ERR_LIBCRYPTO_ERROR; + goto out; @@ -115,6 +127,8 @@ index b6f041f4..1fbce2bb 100644 + r = 0; + +out: ++ OSSL_PARAM_BLD_free(param_bld); ++ OSSL_PARAM_free(params); + free (key); + EVP_KDF_CTX_free(ctx); + if (r < 0) { @@ -130,7 +144,7 @@ index b6f041f4..1fbce2bb 100644 ssh_digest_free(hashctx); return r; } -+#endif /* HAVE_OPENSSL_EVP_KDF_CTX_NEW_ID */ ++#endif /* HAVE_OPENSSL_EVP_KDF_CTX_NEW */ #define NKEYS 6 int diff --git a/openssh.spec b/openssh.spec index ff19cd6..da7a1fa 100644 --- a/openssh.spec +++ b/openssh.spec @@ -658,6 +658,8 @@ test -f %{sysconfig_anaconda} && \ Related: RHEL-42635 - Change ssh-keygen defaults in FIPS mode Resolves: RHEL-37324 +- Use FIPS-compatible API for key derivation RHEL-10 + Resolves: RHEL-43592 * Thu Jul 25 2024 Dmitry Belyavskiy - 9.8p1-1.0 - Rebase OpenSSH to 9.8p1