wip: pack ssh private keys

bin/jwk-to-ssh.js

@@ -5,6 +5,8 @@ var path = require('path');
 var jwktossh = require('../index.js');
 
 var pubfile = process.argv[2];
+var comment = process.argv[3] || 'root@localhost';
+var pub = ('public' === process.argv[4]);
 
 if (!pubfile) {
   console.error("specify a path to JWK");
@@ -12,7 +14,6 @@ if (!pubfile) {
 }
 
 var jwk = require(path.join(process.cwd(), pubfile));
-var comment = process.argv[3] || 'root@localhost';
+var out = jwktossh.pack({ jwk: jwk, comment: comment, public: pub });
-var pub = jwktossh.pack({ jwk: jwk, comment: comment });
 
-console.info(pub);
+console.info(out);

fixtures/privkey-ec-p256.jwk.json

@@ -0,0 +1,7 @@
+{
+  "kty": "EC",
+  "crv": "P-256",
+  "d": "BzKpRmMyXZ4jnSt3ARz0ul6R79AXAr5gQqDAmoFeEKw",
+  "x": "fVmT3gUr4sZIY0Dofcgl15RMeQjfTMofeAiSda4oH_M",
+  "y": "r3eBz3QeZqEhHmgwYfCWoyhLuQqtHD7gqnGqwXssa_E"
+}

fixtures/privkey-ec-p256.jwk.json.2

@@ -0,0 +1,7 @@
+{
+  "kty": "EC",
+  "crv": "P-256",
+  "d": "BzKpRmMyXZ4jnSt3ARz0ul6R79AXAr5gQqDAmoFeEKw",
+  "x": "fVmT3gUr4sZIY0Dofcgl15RMeQjfTMofeAiSda4oH_M",
+  "y": "r3eBz3QeZqEhHmgwYfCWoyhLuQqtHD7gqnGqwXssa_E"
+}

fixtures/privkey-ec-p256.openssh.b64

@@ -0,0 +1,7 @@
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAaAAAABNlY2RzYS
+1zaGEyLW5pc3RwMjU2AAAACG5pc3RwMjU2AAAAQQR9WZPeBSvixkhjQOh9yCXXlEx5CN9M
+yh94CJJ1rigf8693gc90HmahIR5oMGHwlqMoS7kKrRw+4KpxqsF7LGvxAAAAqJZtgRuWbY
+EbAAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBH1Zk94FK+LGSGNA
+6H3IJdeUTHkI30zKH3gIknWuKB/zr3eBz3QeZqEhHmgwYfCWoyhLuQqtHD7gqnGqwXssa/
+EAAAAgBzKpRmMyXZ4jnSt3ARz0ul6R79AXAr5gQqDAmoFeEKwAAAAOYWpAYm93aWUubG9j
+YWwBAg==

fixtures/privkey-ec-p256.openssh.b64.2

@@ -0,0 +1,7 @@
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAaAAAABNlY2RzYS
+1zaGEyLW5pc3RwMjU2AAAACG5pc3RwMjU2AAAAQQR9WZPeBSvixkhjQOh9yCXXlEx5CN9M
+yh94CJJ1rigf8693gc90HmahIR5oMGHwlqMoS7kKrRw+4KpxqsF7LGvxAAAAqGJjanNiY2
+pzAAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBH1Zk94FK+LGSGNA
+6H3IJdeUTHkI30zKH3gIknWuKB/zr3eBz3QeZqEhHmgwYfCWoyhLuQqtHD7gqnGqwXssa/
+EAAAAgBzKpRmMyXZ4jnSt3ARz0ul6R79AXAr5gQqDAmoFeEKwAAAAOYWpAYm93aWUubG9j
+YWwBAg==

fixtures/privkey-ec-p256.openssh.hex

@@ -0,0 +1,20 @@
+00000000: 6f70 656e 7373 682d 6b65 792d 7631 0000  openssh-key-v1..
+00000010: 0000 046e 6f6e 6500 0000 046e 6f6e 6500  ...none....none.
+00000020: 0000 0000 0000 0100 0000 6800 0000 1365  ..........h....e
+00000030: 6364 7361 2d73 6861 322d 6e69 7374 7032  cdsa-sha2-nistp2
+00000040: 3536 0000 0008 6e69 7374 7032 3536 0000  56....nistp256..
+00000050: 0041 047d 5993 de05 2be2 c648 6340 e87d  .A.}Y...+..Hc@.}
+00000060: c825 d794 4c79 08df 4cca 1f78 0892 75ae  .%..Ly..L..x..u.
+00000070: 281f f3af 7781 cf74 1e66 a121 1e68 3061  (...w..t.f.!.h0a
+00000080: f096 a328 4bb9 0aad 1c3e e0aa 71aa c17b  ...(K....>..q..{
+00000090: 2c6b f100 0000 a896 6d81 1b96 6d81 1b00  ,k......m...m...
+000000a0: 0000 1365 6364 7361 2d73 6861 322d 6e69  ...ecdsa-sha2-ni
+000000b0: 7374 7032 3536 0000 0008 6e69 7374 7032  stp256....nistp2
+000000c0: 3536 0000 0041 047d 5993 de05 2be2 c648  56...A.}Y...+..H
+000000d0: 6340 e87d c825 d794 4c79 08df 4cca 1f78  c@.}.%..Ly..L..x
+000000e0: 0892 75ae 281f f3af 7781 cf74 1e66 a121  ..u.(...w..t.f.!
+000000f0: 1e68 3061 f096 a328 4bb9 0aad 1c3e e0aa  .h0a...(K....>..
+00000100: 71aa c17b 2c6b f100 0000 2007 32a9 4663  q..{,k.... .2.Fc
+00000110: 325d 9e23 9d2b 7701 1cf4 ba5e 91ef d017  2].#.+w....^....
+00000120: 02be 6042 a0c0 9a81 5e10 ac00 0000 0e61  ..`B....^......a
+00000130: 6a40 626f 7769 652e 6c6f 6361 6c01 02    j@bowie.local..

fixtures/privkey-ec-p256.openssh.hex.2

@@ -0,0 +1,20 @@
+00000000: 6f70 656e 7373 682d 6b65 792d 7631 0000  openssh-key-v1..
+00000010: 0000 046e 6f6e 6500 0000 046e 6f6e 6500  ...none....none.
+00000020: 0000 0000 0000 0100 0000 6800 0000 1365  ..........h....e
+00000030: 6364 7361 2d73 6861 322d 6e69 7374 7032  cdsa-sha2-nistp2
+00000040: 3536 0000 0008 6e69 7374 7032 3536 0000  56....nistp256..
+00000050: 0041 047d 5993 de05 2be2 c648 6340 e87d  .A.}Y...+..Hc@.}
+00000060: c825 d794 4c79 08df 4cca 1f78 0892 75ae  .%..Ly..L..x..u.
+00000070: 281f f3af 7781 cf74 1e66 a121 1e68 3061  (...w..t.f.!.h0a
+00000080: f096 a328 4bb9 0aad 1c3e e0aa 71aa c17b  ...(K....>..q..{
+00000090: 2c6b f100 0000 a862 636a 7362 636a 7300  ,k.....bcjsbcjs.
+000000a0: 0000 1365 6364 7361 2d73 6861 322d 6e69  ...ecdsa-sha2-ni
+000000b0: 7374 7032 3536 0000 0008 6e69 7374 7032  stp256....nistp2
+000000c0: 3536 0000 0041 047d 5993 de05 2be2 c648  56...A.}Y...+..H
+000000d0: 6340 e87d c825 d794 4c79 08df 4cca 1f78  c@.}.%..Ly..L..x
+000000e0: 0892 75ae 281f f3af 7781 cf74 1e66 a121  ..u.(...w..t.f.!
+000000f0: 1e68 3061 f096 a328 4bb9 0aad 1c3e e0aa  .h0a...(K....>..
+00000100: 71aa c17b 2c6b f100 0000 2007 32a9 4663  q..{,k.... .2.Fc
+00000110: 325d 9e23 9d2b 7701 1cf4 ba5e 91ef d017  2].#.+w....^....
+00000120: 02be 6042 a0c0 9a81 5e10 ac00 0000 0e61  ..`B....^......a
+00000130: 6a40 626f 7769 652e 6c6f 6361 6c01 02    j@bowie.local..

fixtures/privkey-ec-p256.openssh.pem

@@ -0,0 +1,9 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAaAAAABNlY2RzYS
+1zaGEyLW5pc3RwMjU2AAAACG5pc3RwMjU2AAAAQQR9WZPeBSvixkhjQOh9yCXXlEx5CN9M
+yh94CJJ1rigf8693gc90HmahIR5oMGHwlqMoS7kKrRw+4KpxqsF7LGvxAAAAqJZtgRuWbY
+EbAAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBH1Zk94FK+LGSGNA
+6H3IJdeUTHkI30zKH3gIknWuKB/zr3eBz3QeZqEhHmgwYfCWoyhLuQqtHD7gqnGqwXssa/
+EAAAAgBzKpRmMyXZ4jnSt3ARz0ul6R79AXAr5gQqDAmoFeEKwAAAAOYWpAYm93aWUubG9j
+YWwBAg==
+-----END OPENSSH PRIVATE KEY-----

fixtures/privkey-ec-p256.openssh.pem.2

@@ -0,0 +1,9 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAaAAAABNlY2RzYS
+1zaGEyLW5pc3RwMjU2AAAACG5pc3RwMjU2AAAAQQR9WZPeBSvixkhjQOh9yCXXlEx5CN9M
+yh94CJJ1rigf8693gc90HmahIR5oMGHwlqMoS7kKrRw+4KpxqsF7LGvxAAAAqGJjanNiY2
+pzAAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBH1Zk94FK+LGSGNA
+6H3IJdeUTHkI30zKH3gIknWuKB/zr3eBz3QeZqEhHmgwYfCWoyhLuQqtHD7gqnGqwXssa/
+EAAAAgBzKpRmMyXZ4jnSt3ARz0ul6R79AXAr5gQqDAmoFeEKwAAAAOYWpAYm93aWUubG9j
+YWwBAg==
+-----END OPENSSH PRIVATE KEY-----

fixtures/privkey-ec-p256.openssh.pem.2.pub

@@ -0,0 +1 @@
+ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBH1Zk94FK+LGSGNA6H3IJdeUTHkI30zKH3gIknWuKB/zr3eBz3QeZqEhHmgwYfCWoyhLuQqtHD7gqnGqwXssa/E= root@localhost

fixtures/privkey-ec-p256.openssh.pem.pub

@@ -0,0 +1 @@
+ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBH1Zk94FK+LGSGNA6H3IJdeUTHkI30zKH3gIknWuKB/zr3eBz3QeZqEhHmgwYfCWoyhLuQqtHD7gqnGqwXssa/E= root@localhost

lib/encoding.js

@@ -6,6 +6,14 @@ Enc.base64ToHex = function (b64) {
   return Buffer.from(b64, 'base64').toString('hex');
 };
 
+Enc.binToBuf = function (bin) {
+  return Buffer.from(bin, 'binary');
+};
+
+Enc.bufToBase64 = function (u8) {
+  return Buffer.from(u8).toString('base64');
+};
+
 Enc.binToHex = function (bin) {
   return Buffer.from(bin, 'binary').toString('hex');
 };
@@ -13,3 +21,7 @@ Enc.binToHex = function (bin) {
 Enc.hexToBase64 = function (hex) {
   return Buffer.from(hex, 'hex').toString('base64');
 };
+
+Enc.hexToBin = function (hex) {
+  return Buffer.from(hex, 'hex').toString('binary');
+};

lib/pem.js

@@ -0,0 +1,11 @@
+'use strict';
+
+var PEM = module.exports;
+var Enc = require('./encoding.js');
+
+PEM.packBlock = function (opts) {
+  return '-----BEGIN ' + opts.type + '-----\n'
+    + Enc.bufToBase64(opts.bytes).match(/.{1,70}/g).join('\n') + '\n'
+    + '-----END ' + opts.type + '-----'
+  ;
+};

lib/ssh-packer.js

@@ -1,34 +1,87 @@
 'use strict';
 
 var Enc = require('./encoding.js');
+var PEM = require('./pem.js');
 var SSH = module.exports;
 
 SSH.pack = function (opts) {
+  if (opts.jwk.d && !opts.public) {
+    return SSH._packPrivate(opts);
+  } else {
+    delete opts.jwk.d;
+    return SSH._packPublic(opts);
+  }
+};
+
+// https://tools.ietf.org/html/rfc4253#section-6.6
+SSH._packPublic = function (opts) {
+  var els = SSH._packKey(opts);
+  var hex = SSH._packElements(els);
+  var typ = Enc.hexToBin(els[0]);
+  var parts = [ typ, Enc.hexToBase64(hex) ];
+  if (opts.comment) { parts.push(opts.comment); }
+  return parts.join(' ');
+};
+
+SSH._packPrivate = function (opts) {
+  var pubjwk = JSON.parse(JSON.stringify(opts.jwk));
+  delete pubjwk.d;
+  var pubels = SSH._packKey({ jwk: pubjwk });
+  var pubhex = SSH._packElements(pubels);
+  var els = SSH._packKey(opts);
+  var hex = SSH._packElements(els);
+  var privlen = hex.length/2;
+  var padlen = (privlen % 8) && (8 - (privlen % 8)) || 0; // blocksize is 8 (no cipher)
+  var bin = "openssh-key-v1" + String.fromCharCode(0)
+    + Enc.hexToBin(
+        SSH._packElements([
+          Enc.binToHex("none")  // ciphername
+        , Enc.binToHex("none")  // kdfname
+        , ""                    // empty kdf
+        ])
+      + SSH._numToUint32Hex(1)  // number of keys (always 1)
+      + SSH._numToUint32Hex(pubhex.length/2)  // pubkey length
+      + pubhex
+      + SSH._numToUint32Hex(8 + privlen + padlen) // privkey length
+      + '62636a7362636a73'            // 64-bit dummy checksum ("bcjs", "bcjs")
+      + hex                           // (only cihpered keys use real checksums)
+      );
+  var pad = '';
+  var i;
+  for (i = 1; i <= padlen; i += 1) {
+    pad += '0' + i;
+  }
+  return PEM.packBlock({
+    type: "OPENSSH PRIVATE KEY"
+  , bytes: Enc.binToBuf(bin + Enc.hexToBin(pad))
+  });
+};
+
+SSH._packKey = function (opts) {
   var jwk = opts.jwk;
   var els = [];
-  var ssh = {
-    type: ''
-  , _elements: els
-  , comment: opts.comment || ''
-  };
   var len;
 
   if ("RSA" === jwk.kty) {
-    ssh.type = 'ssh-rsa';
+    els.push(Enc.binToHex('ssh-rsa'));
-    els.push(Enc.binToHex(ssh.type));
     els.push(SSH._padRsa(Enc.base64ToHex(jwk.e)));
     els.push(SSH._padRsa(Enc.base64ToHex(jwk.n)));
-    return SSH._packElements(ssh);
+    if (jwk.d) {
+      els.push(SSH._padRsa(Enc.base64ToHex(jwk.d)));
+      els.push(SSH._padRsa(Enc.base64ToHex(jwk.qi)));
+      els.push(SSH._padRsa(Enc.base64ToHex(jwk.p)));
+      els.push(SSH._padRsa(Enc.base64ToHex(jwk.q)));
+      els.push(Enc.binToHex(opts.comment || ''));
+    }
+    return SSH._packElements(els);
   }
 
   if ("P-256" === jwk.crv) {
-    ssh.type = 'ecdsa-sha2-nistp256';
+    els.push(Enc.binToHex('ecdsa-sha2-nistp256'));
-    els.push(Enc.binToHex(ssh.type));
     els.push(Enc.binToHex('nistp256'));
     len = 32;
   } else if ("P-384" === jwk.crv) {
-    ssh.type = 'ecdsa-sha2-nistp384';
+    els.push(Enc.binToHex('ecdsa-sha2-nistp384'));
-    els.push(Enc.binToHex(ssh.type));
     els.push(Enc.binToHex('nistp384'));
     len = 48;
   } else {
@@ -39,14 +92,18 @@ SSH.pack = function (opts) {
     + SSH._padEc(Enc.base64ToHex(jwk.x), len)
     + SSH._padEc(Enc.base64ToHex(jwk.y), len)
   );
-  return SSH._packElements(ssh);
+  if (jwk.d) {
+    els.push(SSH._padEc(Enc.base64ToHex(jwk.d), len));
+    els.push(Enc.binToHex(opts.comment || ''));
+  }
+
+  return els;
 };
 
-SSH._packElements = function (ssh) {
+SSH._packElements = function(els) {
-  var hex = ssh._elements.map(function (hex) {
+  return els.map(function (hex) {
     return SSH._numToUint32Hex(hex.length/2) + hex;
   }).join('');
-  return [ ssh.type, Enc.hexToBase64(hex), ssh.comment ].join(' ');
 };
 
 SSH._numToUint32Hex = function (num) {