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| author | Michael Brown <mcb30@ipxe.org> | 2024-01-30 13:14:21 +0000 |
|---|---|---|
| committer | Michael Brown <mcb30@ipxe.org> | 2024-01-30 13:21:01 +0000 |
| commit | 27398f136030efb8845c45fbe154e544feefd7e5 (patch) | |
| tree | 11a7010a065c90bb0e0cd8040a158cf9cb41e09c /src/include/ipxe | |
| parent | de8a0821c7bc737e724fa3dfb6d89dc36f591d7a (diff) | |
| download | ipxe-27398f136030efb8845c45fbe154e544feefd7e5.zip ipxe-27398f136030efb8845c45fbe154e544feefd7e5.tar.gz ipxe-27398f136030efb8845c45fbe154e544feefd7e5.tar.bz2 | |
[crypto] Check for all-zeros result from X25519 key exchange
RFC7748 states that it is entirely optional for X25519 Diffie-Hellman
implementations to check whether or not the result is the all-zero
value (indicating that an attacker sent a malicious public key with a
small order). RFC8422 states that implementations in TLS must abort
the handshake if the all-zero value is obtained.
Return an error if the all-zero value is obtained, so that the TLS
code will not require knowledge specific to the X25519 curve.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/include/ipxe')
| -rw-r--r-- | src/include/ipxe/errfile.h | 1 | ||||
| -rw-r--r-- | src/include/ipxe/x25519.h | 6 |
2 files changed, 4 insertions, 3 deletions
diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h index 320835a..060a42a 100644 --- a/src/include/ipxe/errfile.h +++ b/src/include/ipxe/errfile.h @@ -407,6 +407,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #define ERRFILE_efi_rng ( ERRFILE_OTHER | 0x005c0000 ) #define ERRFILE_efi_shim ( ERRFILE_OTHER | 0x005d0000 ) #define ERRFILE_efi_settings ( ERRFILE_OTHER | 0x005e0000 ) +#define ERRFILE_x25519 ( ERRFILE_OTHER | 0x005f0000 ) /** @} */ diff --git a/src/include/ipxe/x25519.h b/src/include/ipxe/x25519.h index 7a86c11..6524abb 100644 --- a/src/include/ipxe/x25519.h +++ b/src/include/ipxe/x25519.h @@ -84,8 +84,8 @@ extern void x25519_multiply ( const union x25519_oct258 *multiplicand, extern void x25519_invert ( const union x25519_oct258 *invertend, union x25519_quad257 *result ); extern void x25519_reduce ( union x25519_quad257 *value ); -extern void x25519_key ( const struct x25519_value *base, - const struct x25519_value *scalar, - struct x25519_value *result ); +extern int x25519_key ( const struct x25519_value *base, + const struct x25519_value *scalar, + struct x25519_value *result ); #endif /* _IPXE_X25519_H */ |