Mercurial > dropbear
diff signkey.c @ 1855:35d504d59c05
Implement server-side support for sk-ecdsa U2F-backed keys (#142)
* Implement server-side support for sk-ecdsa U2F-backed keys
* Fix out-of-bounds read on normal ecdsa-sha2-[identifier] keys
* Fix one more potential out-of-bounds read
* Check if nistp256 curve is used in sk-ecdsa-sha2- key
It's the only allowed curve per PROTOCOL.u2f specification
* Implement server-side support for sk-ed25519 FIDO2-backed keys
* Keys with type sk-* make no sense as host keys, so they should be
disabled
* fix typo
* Make sk-ecdsa call buf_ecdsa_verify
This reduces code duplication, the SK code just handles the
different message format.
* Reduce sk specific code
The application id can be stored in signkey, then we don't need
to call sk-specific functions from svr-authpubkey
* Remove debugging output, which causes compilation errors with DEBUG_TRACE disabled
* Proper cleanup of sk_app
Co-authored-by: Matt Johnston <[email protected]>
| author | egor-duda <egor-duda@users.noreply.github.com> |
|---|---|
| date | Sat, 22 Jan 2022 16:53:04 +0300 |
| parents | fa6ff07dcc77 |
| children | 3f4cdf839a1a |
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--- a/signkey.c Sat Jan 22 12:46:08 2022 +0800 +++ b/signkey.c Sat Jan 22 16:53:04 2022 +0300 @@ -28,6 +28,8 @@ #include "buffer.h" #include "ssh.h" #include "ecdsa.h" +#include "sk-ecdsa.h" +#include "sk-ed25519.h" #include "rsa.h" #include "dss.h" #include "ed25519.h" @@ -43,9 +45,15 @@ "ecdsa-sha2-nistp256", "ecdsa-sha2-nistp384", "ecdsa-sha2-nistp521", +#if DROPBEAR_SK_ECDSA + "[email protected]", +#endif /* DROPBEAR_SK_ECDSA */ #endif /* DROPBEAR_ECDSA */ #if DROPBEAR_ED25519 "ssh-ed25519", +#if DROPBEAR_SK_ED25519 + "[email protected]", +#endif /* DROPBEAR_SK_ED25519 */ #endif /* DROPBEAR_ED25519 */ /* "rsa-sha2-256" is special-cased below since it is only a signature name, not key type */ }; @@ -180,11 +188,17 @@ switch (type) { #if DROPBEAR_ED25519 case DROPBEAR_SIGNKEY_ED25519: +#if DROPBEAR_SK_ED25519 + case DROPBEAR_SIGNKEY_SK_ED25519: +#endif return (void**)&key->ed25519key; #endif #if DROPBEAR_ECDSA #if DROPBEAR_ECC_256 case DROPBEAR_SIGNKEY_ECDSA_NISTP256: +#if DROPBEAR_SK_ECDSA + case DROPBEAR_SIGNKEY_SK_ECDSA_NISTP256: +#endif return (void**)&key->ecckey256; #endif #if DROPBEAR_ECC_384 @@ -260,7 +274,11 @@ } #endif #if DROPBEAR_ECDSA - if (signkey_is_ecdsa(keytype)) { + if (signkey_is_ecdsa(keytype) +#if DROPBEAR_SK_ECDSA + || keytype == DROPBEAR_SIGNKEY_SK_ECDSA_NISTP256 +#endif + ) { ecc_key **eck = (ecc_key**)signkey_key_ptr(key, keytype); if (eck) { if (*eck) { @@ -276,10 +294,14 @@ } #endif #if DROPBEAR_ED25519 - if (keytype == DROPBEAR_SIGNKEY_ED25519) { + if (keytype == DROPBEAR_SIGNKEY_ED25519 +#if DROPBEAR_SK_ED25519 + || keytype == DROPBEAR_SIGNKEY_SK_ED25519 +#endif + ) { ed25519_key_free(key->ed25519key); key->ed25519key = m_malloc(sizeof(*key->ed25519key)); - ret = buf_get_ed25519_pub_key(buf, key->ed25519key); + ret = buf_get_ed25519_pub_key(buf, key->ed25519key, keytype); if (ret == DROPBEAR_FAILURE) { m_free(key->ed25519key); key->ed25519key = NULL; @@ -287,6 +309,19 @@ } #endif +#if DROPBEAR_SK_ECDSA || DROPBEAR_SK_ED25519 + if (0 +#if DROPBEAR_SK_ED25519 + || keytype == DROPBEAR_SIGNKEY_SK_ED25519 +#endif +#if DROPBEAR_SK_ECDSA + || keytype == DROPBEAR_SIGNKEY_SK_ECDSA_NISTP256 +#endif + ) { + key->sk_app = buf_getstring(buf, &key->sk_applen); + } +#endif + TRACE2(("leave buf_get_pub_key")) return ret; @@ -401,7 +436,11 @@ } #endif #if DROPBEAR_ED25519 - if (type == DROPBEAR_SIGNKEY_ED25519) { + if (type == DROPBEAR_SIGNKEY_ED25519 +#if DROPBEAR_SK_ED25519 + || type == DROPBEAR_SIGNKEY_SK_ED25519 +#endif + ) { buf_put_ed25519_pub_key(pubkeys, key->ed25519key); } #endif @@ -495,6 +534,11 @@ #endif m_free(key->filename); +#if DROPBEAR_SK_ECDSA || DROPBEAR_SK_ED25519 + if (key->sk_app) { + m_free(key->sk_app); + } +#endif m_free(key); TRACE2(("leave sign_key_free")) @@ -639,6 +683,7 @@ } #if DROPBEAR_SIGNKEY_VERIFY + /* Return DROPBEAR_SUCCESS or DROPBEAR_FAILURE. * If FAILURE is returned, the position of * buf is undefined. If SUCCESS is returned, buf will be positioned after the @@ -695,6 +740,22 @@ return buf_ed25519_verify(buf, key->ed25519key, data_buf); } #endif +#if DROPBEAR_SK_ECDSA + if (keytype == DROPBEAR_SIGNKEY_SK_ECDSA_NISTP256) { + ecc_key **eck = (ecc_key**)signkey_key_ptr(key, keytype); + if (eck && *eck) { + return buf_sk_ecdsa_verify(buf, *eck, data_buf, key->sk_app, key->sk_applen); + } + } +#endif +#if DROPBEAR_SK_ED25519 + if (keytype == DROPBEAR_SIGNKEY_SK_ED25519) { + dropbear_ed25519_key **eck = (dropbear_ed25519_key**)signkey_key_ptr(key, keytype); + if (eck && *eck) { + return buf_sk_ed25519_verify(buf, *eck, data_buf, key->sk_app, key->sk_applen); + } + } +#endif dropbear_exit("Non-matching signing type"); return DROPBEAR_FAILURE;