KolibriOS/kolibrios
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Implemented local storage and checking of remote host keys. (only ssh-rsa for now)

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Known public keys will be stored in /sys/settings/known_hosts.ini

git-svn-id: svn://kolibrios.org@9112 a494cfbc-eb01-0410-851d-a64ba20cac60
This commit is contained in:
hidnplayr 2021-08-04 08:41:16 +00:00
parent 9438fa3384
commit 33d98adcfa
2 changed files with 115 additions and 21 deletions
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19
programs/network/ssh/ssh.asm
View File

@ -142,7 +142,7 @@ start:
DEBUGF 2, "SSH: Init Console\n"
invoke con_start, 1
invoke con_init, 80, 25, 800, 250, title
invoke con_init, 80, 25, 80, 250, title
cmp byte[params], 0
jne main.connect
@ -388,8 +388,9 @@ proc sshlib_callback_hostkey_problem, con_ptr, problem_type, hostkey_sz
invoke con_write_asciiz, str23
; jmp .ask
.ask:
;;; TODO: print hostkey
invoke con_write_asciiz, str24
invoke con_write_asciiz, str24a
invoke con_write_asciiz, [hostkey_sz]
invoke con_write_asciiz, str24b
.getansw:
invoke con_getch2
or al, 0x20 ; convert to lowercase
@ -471,7 +472,8 @@ str22 db "The host key for the server was not found in the cache.", 10
str23 db "The host key provided by the host does not match the cached one.", 10
db "This may indicate that the remote server has been compromised!", 10, 0
str24 db 10, "If you trust this host, press A to accept and store the (new) key.", 10
str24a db 10, "The remote host key is: ", 10, 0
str24b db 10, 10, "If you trust this host, press A to accept and store the (new) key.", 10
db "Press C to connect to the host but don't store the (new) key.", 10
db "Press X to abort.", 10, 0
@ -479,7 +481,7 @@ str24 db 10, "If you trust this host, press A to accept and store the (new) ke
ssh_ident_ha:
dd_n (ssh_msg_ident.length-2)
ssh_msg_ident:
db "SSH-2.0-KolibriOS_SSH_0.05",13,10
db "SSH-2.0-KolibriOS_SSH_0.06",13,10
.length = $ - ssh_msg_ident
@ -592,7 +594,8 @@ align 4
library network, 'network.obj', \
console, 'console.obj', \
libcrash, 'libcrash.obj'
libcrash, 'libcrash.obj', \
libini, 'libini.obj'
import network, \
getaddrinfo, 'getaddrinfo', \
@ -622,6 +625,10 @@ import libcrash, \
md5_update, 'md5_update', \
md5_final, 'md5_final'
import libini, \
ini_get_str, 'ini_get_str', \
ini_set_str, 'ini_set_str'
IncludeIGlobals
i_end:

117
programs/network/ssh/sshlib_host.inc
View File

@ -18,13 +18,21 @@
; https://datatracker.ietf.org/doc/html/rfc4253#section-6.6
; https://datatracker.ietf.org/doc/html/rfc3447
; https://datatracker.ietf.org/doc/html/rfc4716
proc sshlib_host_verify con_ptr, str_host_key, str_signature, message, message_len
locals
known_key_sz rb MAX_PUBLIC_KEY_SIZE
current_hkb64 rb MAX_PUBLIC_KEY_SIZE*4 ; Current Host key in Base64
cached_hkb64 rb MAX_PUBLIC_KEY_SIZE*4 ; Cached Host key in Base64
key_name_sz dd ?
hostname_sz dd ?
current_hk64_end dd ?
endl
mov eax, [con_ptr]
lea ebx, [eax + sshlib_connection.hostname_sz]
mov [hostname_sz], ebx
cmp [eax+sshlib_connection.algo_hostkey], SSHLIB_HOSTKEY_RSA
je .rsa
; ..add more here
@ -35,40 +43,65 @@ endl
stdcall sshlib_host_verify_rsa, [str_host_key], [str_signature], [message], [message_len]
test eax, eax
jnz .err
mov [key_name_sz], ssh_rsa_sz
.lookup:
; lea eax, [known_key_sz]
; mov ebx, [con_ptr]
; lea ebx, [ebx + sshlib_connection.hostname_sz]
; invoke ini_get_str, known_hosts_file, ebx, ssh_rsa_sz, eax, MAX_PUBLIC_KEY_SIZE, null_sz
; test eax, eax
; jnz .unknown
; Convert the current host key to base64
mov esi, [str_host_key]
mov ecx, [esi]
bswap ecx
add esi, 4
lea edi, [current_hkb64]
call base64_encode
mov [current_hk64_end], edi
; TODO: verify cached host key
; jne .mismatch
jmp .unknown ; FIXME
; Try to read the cached key for this host and key type
lea edi, [cached_hkb64]
invoke ini_get_str, known_hostsfile, [hostname_sz], [key_name_sz], edi, MAX_PUBLIC_KEY_SIZE*4, 0
test eax, eax
jnz .unknown
; If the cached key is empty, return SSHLIB_HOSTKEY_PROBLEM_UNKNOWN
lea esi, [cached_hkb64]
cmp byte[esi], 0
je .unknown
; Else, compare it to the current one
lea edi, [current_hkb64]
mov ecx, MAX_PUBLIC_KEY_SIZE*4
.cmploop:
lodsb
scasb
jne .mismatch
test al, al
jz .match
dec ecx
jnz .cmploop
jmp .mismatch
.match:
xor eax, eax
ret
.mismatch:
lea eax, [known_key_sz]
int3
lea eax, [current_hkb64]
stdcall sshlib_callback_hostkey_problem, [con_ptr], SSHLIB_HOSTKEY_PROBLEM_MISMATCH, eax
cmp eax, SSHLIB_HOSTKEY_ACCEPT
je .store
ret
.unknown:
lea eax, [known_key_sz]
lea eax, [current_hkb64]
stdcall sshlib_callback_hostkey_problem, [con_ptr], SSHLIB_HOSTKEY_PROBLEM_UNKNOWN, eax
cmp eax, SSHLIB_HOSTKEY_ACCEPT
je .store
ret
.store:
; TODO: write to know_hosts file and fall-through
lea esi, [current_hkb64]
mov ecx, [current_hk64_end]
sub ecx, esi
invoke ini_set_str, known_hostsfile, [hostname_sz], [key_name_sz], esi, ecx
xor eax, eax
ret
.err:
@ -234,10 +267,64 @@ endl
endp
base64_encode:
xor ebx, ebx
.loop:
lodsb
call .byte
dec ecx
jnz .loop
.final:
mov al, 0
test ebx, ebx
jz .f000
call .byte
test ebx, ebx
jz .f001
call .byte
mov byte[edi-2], '='
.f001:
mov byte[edi-1], '='
.f000:
mov byte[edi], 0
ret
.byte:
inc ebx
shl edx, 8
mov dl, al
cmp ebx, 3
je .b001
ret
.b001:
shl edx, 8
inc ebx
.b002:
rol edx, 6
xor eax, eax
xchg al, dl
mov al, [base64_table+eax]
stosb
dec ebx
jnz .b002
ret
iglobal
known_hostsfile db '/sys/settings/known_hosts.ini', 0
base64_table db 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
rsa_sha1_t db 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2B, 0x0E, 0x03, 0x02, 0x1A, 0x05, 0x00, 0x04, 0x14
.len = $ - rsa_sha1_t
ssh_rsa_sz db 'ssh-rsa', 0
endg