diff options
Diffstat (limited to 'ssh-ecdsa-sk.c')
| -rw-r--r-- | ssh-ecdsa-sk.c | 49 |
1 files changed, 37 insertions, 12 deletions
diff --git a/ssh-ecdsa-sk.c b/ssh-ecdsa-sk.c index 5dcd3c1..27ddf90 100644 --- a/ssh-ecdsa-sk.c +++ b/ssh-ecdsa-sk.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-ecdsa-sk.c,v 1.18 2023/03/08 04:43:12 guenther Exp $ */ +/* $OpenBSD: ssh-ecdsa-sk.c,v 1.19 2024/08/15 00:51:51 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2010 Damien Miller. All rights reserved. @@ -237,11 +237,13 @@ ssh_ecdsa_sk_verify(const struct sshkey *key, struct sshkey_sig_details **detailsp) { ECDSA_SIG *esig = NULL; + EVP_MD_CTX *md_ctx = NULL; BIGNUM *sig_r = NULL, *sig_s = NULL; u_char sig_flags; - u_char msghash[32], apphash[32], sighash[32]; + u_char msghash[32], apphash[32]; u_int sig_counter; - int is_webauthn = 0, ret = SSH_ERR_INTERNAL_ERROR; + u_char *sigb = NULL, *cp; + int is_webauthn = 0, ret = SSH_ERR_INTERNAL_ERROR, len = 0; struct sshbuf *b = NULL, *sigbuf = NULL, *original_signed = NULL; struct sshbuf *webauthn_wrapper = NULL, *webauthn_exts = NULL; char *ktype = NULL, *webauthn_origin = NULL; @@ -252,7 +254,7 @@ ssh_ecdsa_sk_verify(const struct sshkey *key, if (detailsp != NULL) *detailsp = NULL; - if (key == NULL || key->ecdsa == NULL || + if (key == NULL || key->pkey == NULL || sshkey_type_plain(key->type) != KEY_ECDSA_SK || sig == NULL || siglen == 0) return SSH_ERR_INVALID_ARGUMENT; @@ -363,21 +365,43 @@ ssh_ecdsa_sk_verify(const struct sshkey *key, (ret = sshbuf_putb(original_signed, webauthn_exts)) != 0 || (ret = sshbuf_put(original_signed, msghash, sizeof(msghash))) != 0) goto out; - /* Signature is over H(original_signed) */ - if ((ret = ssh_digest_buffer(SSH_DIGEST_SHA256, original_signed, - sighash, sizeof(sighash))) != 0) - goto out; details->sk_counter = sig_counter; details->sk_flags = sig_flags; #ifdef DEBUG_SK fprintf(stderr, "%s: signed buf:\n", __func__); sshbuf_dump(original_signed, stderr); - fprintf(stderr, "%s: signed hash:\n", __func__); - sshbuf_dump_data(sighash, sizeof(sighash), stderr); #endif + if ((md_ctx = EVP_MD_CTX_new()) == NULL) { + ret = SSH_ERR_ALLOC_FAIL; + goto out; + } + if ((len = i2d_ECDSA_SIG(esig, NULL)) <= 0) { + len = 0; + ret = SSH_ERR_LIBCRYPTO_ERROR; + goto out; + } + if ((sigb = calloc(1, len)) == NULL) { + ret = SSH_ERR_ALLOC_FAIL; + goto out; + } + cp = sigb; /* ASN1_item_i2d increments the pointer past the object */ + if (i2d_ECDSA_SIG(esig, &cp) != len) { + ret = SSH_ERR_LIBCRYPTO_ERROR; + goto out; + } +#ifdef DEBUG_SK + fprintf(stderr, "%s: signed hash:\n", __func__); + sshbuf_dump_data(sigb, len, stderr); +#endif /* Verify it */ - switch (ECDSA_do_verify(sighash, sizeof(sighash), esig, key->ecdsa)) { + if (EVP_DigestVerifyInit(md_ctx, NULL, EVP_sha256(), NULL, + key->pkey) != 1) { + ret = SSH_ERR_LIBCRYPTO_ERROR; + goto out; + } + switch (EVP_DigestVerify(md_ctx, sigb, len, + sshbuf_ptr(original_signed), sshbuf_len(original_signed))) { case 1: ret = 0; break; @@ -397,7 +421,6 @@ ssh_ecdsa_sk_verify(const struct sshkey *key, explicit_bzero(&sig_flags, sizeof(sig_flags)); explicit_bzero(&sig_counter, sizeof(sig_counter)); explicit_bzero(msghash, sizeof(msghash)); - explicit_bzero(sighash, sizeof(msghash)); explicit_bzero(apphash, sizeof(apphash)); sshkey_sig_details_free(details); sshbuf_free(webauthn_wrapper); @@ -410,6 +433,8 @@ ssh_ecdsa_sk_verify(const struct sshkey *key, BN_clear_free(sig_r); BN_clear_free(sig_s); free(ktype); + freezero(sigb, len); + EVP_MD_CTX_free(md_ctx); return ret; } |