64 Commits
Author SHA1 Message Date
Nicola Murino 10b54ffa51 ssh: raise the RSA modulus limit to 16384 bits
the fix for CVE-2026-39829 capped the accepted RSA modulus at 8192 bits,
matching crypto/tls, to bound the CPU cost of verifying an
attacker-supplied key. That rejected keys OpenSSH generates: ssh-keygen
allows -b up to 16384. Raise the limit to 16384 so those keys interoperate,
both in the public key parser and the OpenSSH private key parser, and
correspondingly raise the prime-factor bound to 8192 bits (each prime is
about half the modulus). The agent's checkRSAKeyParams is updated to match.

Verifying a 16384-bit key costs roughly 3x an 8192-bit one.

Fixes golang/go#80075

Change-Id: Ib08ddd7b48552e692c48dbdf105bbc8579120bbc
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/795421
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Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2026-07-13 20:33:21 -07:00
Nicola Murino 7626c50256 ssh: verify declared key type matches decoded key in authorized_keys
ParseAuthorizedKey and ParseKnownHosts previously ignored the key type
field (e.g. "ssh-rsa") in each entry, relying solely on the type
information embedded within the base64-encoded key blob.

For ParseAuthorizedKey this also caused a single-token option to be
silently dropped: a line such as "restrict <key>" (with the key type
omitted) was parsed as an unrestricted key, because the option token
landed in the key type position and was discarded together with its
meaning. The same happens for no-pty, no-port-forwarding and the other
single-word options. OpenSSH's sshkey_read rejects such lines outright,
as the option token cannot be read as a key type.

OpenSSH's sshkey_read also explicitly verifies that the key type
declared in the text matches the type of the parsed key, returning
SSH_ERR_KEY_TYPE_MISMATCH if they differ.

This change adds, in both functions, a check that the declared key type
matches the decoded key's type, returning an error for malformed lines
where they diverge. This mirrors the fix already applied to the
ssh/knownhosts package in CL 782427.

Change-Id: I9163108d964de4be8a415fe0efd68e6b71f77990
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/792840
Reviewed-by: Filippo Valsorda <filippo@golang.org>
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Reviewed-by: Neal Patel <nealpatel@google.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
2026-06-30 10:24:32 -07:00
Nicola Murino 8f405a4109 ssh: validate ECDSA curve matches expected algorithm
Previously, parseECDSA determined the curve purely based on the key
blob content, ignoring the algorithm identifier passed to parsePubKey.

This allowed a mismatch where a key could be encoded with an algorithm
type of "ecdsa-sha2-nistp256" but contain a NIST P-384 or P-521 curve.
The parser would succeed, returning a key with a type different from
the one indicated by the caller/wire format.

This change updates parseECDSA to accept the expected algorithm type
and verify that it matches the curve specified in the key data. This
matches the behavior of OpenSSH's ssh_ecdsa_deserialize_public in
ssh-ecdsa.c, which rejects a curve identifier that does not correspond
to the key algorithm name.

This issue was found during a security audit by NCC Group Cryptography
Services, sponsored by Teleport, and was assessed and is being fixed as
a non-security bug.

Change-Id: I9c748be948cca65e2f41089bb7510466d3bb316a
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/782425
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Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
2026-06-02 00:24:14 -07:00
Nicola Murino b315afd69a ssh: limit bcrypt KDF rounds in OpenSSH private key decryption
passphraseProtectedOpenSSHKey decodes the bcrypt round count from
the key file and passes it directly to bcrypt_pbkdf.Key, whose
running time is linear in that count. Files specifying very large
round values cause the decryption to consume excessive CPU time:
a uint32 maximum is several months of work on commodity hardware.

Cap the accepted round count at 2048 (128x the default of 16, a
few seconds of CPU on a modern core). OpenSSH itself does not
impose an upper bound, but accepting arbitrary values turns key
loading into a resource-exhaustion footgun for any code that
processes files supplied by end users.

This issue was found during a security audit by NCC Group
Cryptography Services, sponsored by Teleport, and was assessed
and is being fixed as a non-security bug.

Change-Id: I01112bdf1b484ae4fab5dc8841d1a272f112df74
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/782422
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
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2026-06-02 00:22:48 -07:00
Nicola Murino 6f39c5226a ssh: limit RSA key size in OpenSSH private key parsing
parseOpenSSHPrivateKey builds an rsa.PrivateKey directly from the
unmarshalled OpenSSH key blob, bypassing parseRSA and its modulus
limit. Validate() and Precompute() then perform several modular
exponentiations whose cost grows with the size of the prime factors;
in particular Precompute() recomputes the CRT coefficient as
q^(p-2) mod p, which is cubic in |p|. A maliciously crafted key with
oversized N and P can keep the CPU busy for hours or days during a
single load.

Mirror the parseRSA validation here: cap the modulus at 8192 bits
(the same limit enforced by crypto/tls), reject exponents larger than
24 bits, and reject invalid exponent values (< 3 or even). In addition,
bound each prime factor at 4096 bits to prevent the CRT computation
from becoming the dominant cost.

This issue was found during a security audit by NCC Group Cryptography
Services, sponsored by Teleport, and was assessed and is being fixed as
a non-security bug.

Change-Id: Ia5991f25dd41a22eddd7cf63a8fc5106de9e9663
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/782420
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: David Chase <drchase@google.com>
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2026-06-02 00:22:37 -07:00
Nicola Murino b61cf853a8 ssh: enforce user presence verification for security keys
Previously the library did not verify the "User Presence" (UP) bit in
signatures generated by FIDO/U2F security keys
(sk-ecdsa-sha2-nistp256@openssh.com and sk-ssh-ed25519@openssh.com).
This allowed signatures without physical interaction to be accepted
if the underlying hardware produced them, deviating from the default
secure behavior expected by the FIDO standards and OpenSSH.

skECDSAPublicKey.Verify and skEd25519PublicKey.Verify now enforce
the user-presence bit (0x01, constant flagUserPresence) by default.
Signatures whose flags byte has UP clear fail with the sentinel
errSKMissingUserPresence.

The server public-key authentication path honors the OpenSSH
"no-touch-required" extension as an opt-out. noTouchAllowed reports
true when the extension is present either in the Permissions
returned by PublicKeyCallback (authorized_keys-level opt-out) or in
the certificate's own Extensions (CA-level opt-out); in that case
skKeyWithoutUP is used to derive a clone of the SK public key (and,
for certificates, a clone of the wrapping Certificate whose inner
Key is the cloned SK key) whose Verify accepts UP-clear signatures.
The originals are never mutated, so a per-session opt-out cannot
leak across authentication attempts or connections. Matching
OpenSSH, the opt-out is read only from Extensions, never from
CriticalOptions.

skKeyWithoutUP is iterative and unwraps at most one level of
*Certificate: the SSH cert format forbids Certificate.Key from being
another Certificate (parseCert rejects it) but callers can still
construct such a value directly in Go, so a recursive descent would
be driven to unbounded depth by malformed or cyclic input. Any such
pathological *Certificate is returned unchanged.

CertChecker.CheckCert applies skKeyWithoutUP unconditionally to the
certificate's CA key before verifying the CA signature, matching
OpenSSH, which calls sshkey_verify with detailsp==NULL in
sshkey.c:cert_parse and never extracts or enforces UP/UV flags on
CA signatures. The UP bit on a CA signature reflects the CA
operator's presence at cert-issuance time, which has no bearing on
whether the user being authenticated is present now, so enforcing it
here would only break interop with certificates issued by
non-interactive SK CAs without a corresponding security benefit. The
skKeyWithoutUP call is a no-op for non-SK CA keys (the common case).

This change breaks backward compatibility for clients or keys that
generate user-authentication signatures without the User Presence
flag set. Previously those signatures were accepted by the server.
They will now be rejected with "ssh: signature missing required user
presence flag" unless the "no-touch-required" extension is
explicitly granted to the session by the server callbacks, or
carried by the user certificate.

This issue was found during a security audit by NCC Group
Cryptography Services, sponsored by Teleport.

Fixes golang/go#79566
Fixes CVE-2026-39831

Change-Id: I74b6de3bb6a2d7a0f34d7fa36bbbbf06f0b3fc6b
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/781662
Reviewed-by: Neal Patel <nealpatel@google.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
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2026-05-21 17:03:20 -07:00
Nicola Murino 9c2cd33e8d ssh: enforce strict limits on DSA key parameters
The parseDSA function previously accepted DSA keys with arbitrary values
for the sub-prime Q and did not validate that group elements G and Y
were within the modulus P.

Malicious actors could provide a key with a massively large Q (e.g.,
millions of bits), leading to excessive CPU consumption during signature
verification.

This change restricts the sub-prime Q to exactly 160 bits, as required
by FIPS 186-2, and ensures that G and Y are strictly less than P.

This issue was found during a security audit by NCC Group Cryptography
Services, sponsored by Teleport.

Fixes golang/go#79565
Fixes CVE-2026-39829

Change-Id: I526118d94684076088d0625178844f64c1303ec8
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/781661
Reviewed-by: Roland Shoemaker <roland@golang.org>
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Reviewed-by: Neal Patel <nealpatel@google.com>
2026-05-21 17:03:16 -07:00
Nicola Murino 890731877d ssh: reject RSA keys with excessively large moduli
Previously, the RSA key parser accepted keys with arbitrary modulus
sizes. Processing keys with extremely large moduli (e.g., > 8192 bits)
can consume excessive CPU resources during verification, potentially
leading to a Denial of Service (DoS).

This change introduces a limit of 8192 bits for the RSA modulus in
parseRSA, rejecting keys that exceed this size in line with the limit
enforced by crypto/tls.

This issue was found during a security audit by NCC Group Cryptography
Services, sponsored by Teleport.

Fixes golang/go#79565
Fixes CVE-2026-39829

Change-Id: Ibdddad1859a4d9db5c9f052d06c82f29bfc2e5e5
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/781641
Reviewed-by: Neal Patel <nealpatel@google.com>
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2026-05-21 17:03:13 -07:00
Santhanam b4f2b62076 ssh: fix error message on unsupported cipher
Until now, when ssh keys using one of these[1] ciphers were passed, we were
giving a parse error "ssh: parse error in message type 0".

With this fix, we parse it successfully and return the correct error message.

[1] aes{128,256}-gcm@openssh.com and chacha20-poly1305@openssh.com

Fixes golang/go#52135

Change-Id: I3010fff43c48f29f21edb8d63f44e167861a054e
GitHub-Last-Rev: 14ac7e97306d41cba48053b9c60f2ffc7caded45
GitHub-Pull-Request: golang/crypto#324
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/709275
Reviewed-by: Nicola Murino <nicola.murino@gmail.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
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2025-11-12 10:42:48 -08:00
Nicola Murino 66c3d8ce71 ssh: add support for FIPS mode
Unsupported algoritms are silently ignored and not negotiated, or
rejected

Fixes golang/go#75061

Change-Id: I08d50d10a97c08e78aedead89ca61beceff88918
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/698795
Reviewed-by: Mio Mio <miomio0086@gmail.com>
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2025-09-27 12:36:52 -07:00
Nicola Murino ddb4e80c6a ssh: remove custom contains, use slices.Contains
Change-Id: If4784469e7285675bdd51399a76bdc16f0036a2e
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/703635
Reviewed-by: Mark Freeman <markfreeman@google.com>
Reviewed-by: Sean Liao <sean@liao.dev>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
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2025-09-15 23:33:16 -07:00
Nicola Murino f4d47b0db5 ssh: return clearer error when signature algorithm is used as key format
ParsePublicKey now returns a more specific error when a signature
algorithm like rsa-sha2-256 is mistakenly provided as a key format

Change-Id: Ic08286a5b2b326e99dd3e61594919203f0c36791
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/695075
Reviewed-by: Filippo Valsorda <filippo@golang.org>
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2025-09-15 23:32:56 -07:00
Nicola Murino c6fce02826 ssh: refuse to parse certificates that use a certificate as signing key
According to draft-miller-ssh-cert-01, Section 2.1.1, certificates with
certificate keys as signature keys are invalid

Change-Id: I474524ea444deb78f2fa7c2682e47c0fd057f0b8
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/678716
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2025-06-30 09:02:50 -07:00
Nicola Murino ac58737d25 ssh: export supported algorithms
Fixes golang/go#61537

Change-Id: If3478121e3ae445391e3faeceeb889d75e9e3214
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/531935
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2025-05-15 10:43:30 -07:00
Ilia Mirkin 3375612bf4 ssh: add support for unpadded RSA signatures
The original SSH RFC 4253 explicitly disallows padding. This applies to
ssh-rsa signatures.

The updated SSH RFC 8332 which defines the SHA2 RSA signature variants
explicitly calls out the existence of signers who produce short
signatures and specifies that verifiers may allow this behavior.

In practice, PuTTY 0.81 and prior versions, as well as SSH.NET prior to
2024.1.0 always generated short signatures. Furthermore, PuTTY is
embedded in other software like WinSCP and FileZilla, which are updated
on their own schedules as well. This leads to occasional unexplained
login errors, when using RSA keys.

OpenSSH server allows these short signatures for all RSA algorithms.

Fixes golang/go#68286

Change-Id: Ia60ece21bf9c111c490fac0c066443ed5ff7dd29
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/598534
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2024-07-26 16:39:19 +00:00
Mariano Cano 349231f7e4 ssh: implement CryptoPublicKey on sk keys
This commit implements the CryptoPublicKey interface for the
skECDSAPublicKey and skEd25519PublicKey types.

Fixes golang/go#62518

Change-Id: I2b8ac89196fbb3614bf5c675127bed23f1cf6b26
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/526875
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2024-05-29 18:20:30 +00:00
Nicola Murino 42c83fffff ssh: try harder to detect incorrect passwords for legacy PEM encryption
Because of deficiencies in the format, DecryptPEMBlock does not always
detect an incorrect password. In these cases decrypted DER bytes is
random noise. If the parsing of the key returns an asn1.StructuralError
we return x509.IncorrectPasswordError.

Fixes golang/go#62265

Change-Id: Ib8b845f2bd01662c1f1421d35859a32ac5b78da7
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/538835
Reviewed-by: Heschi Kreinick <heschi@google.com>
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2023-11-08 18:01:48 +00:00
Sebastiaan van Stijn b665ba6f6f all: use crypto/ed25519 instead of golang.org/x/crypto/ed25519
This is a follow-up to CL 317169, which dropped go1.12 compatibility,
and made the golang.org/x/crypto/ed25519 package an alias / wrapper for
crypto/ed25519 in stdlib.

This patch updates uses within this repository to use stdlib instead of
depending on the wrapper. With this patch applied, the only remaining
use of the wrapper is in ed25519_test, which appears to be in place to
verify compatibility of the wrapper itself.

Change-Id: I0195396102a75ae20bdd82ca8ab59855c0eb5cea
GitHub-Last-Rev: 24dbec563cbd84bc47bdc7736b0245fc83dd3353
GitHub-Pull-Request: golang/crypto#238
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/448238
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2023-09-27 14:30:17 +00:00
Nicola Murino 28c53ff63c ssh: add MultiAlgorithmSigner
MultiAlgorithmSigner allows to restrict client-side, server-side and
certificate signing algorithms.

Fixes golang/go#52132
Fixes golang/go#36261

Change-Id: I295092f1bba647327aaaf294f110e9157d294159
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/508398
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2023-09-20 18:10:30 +00:00
Mariano Cano d359caa4a3 ssh: support for marshaling keys using the OpenSSH format
This adds methods to marshal private keys, encrypted and unencrypted
to the OpenSSH format.

Fixes golang/go#37132

Change-Id: I1a95301f789ce04858e6b147748c6e8b7700384b
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/218620
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2023-09-05 20:25:46 +00:00
Anmol Sethi c6a20f9984 ssh: document that ParseRawPrivateKey supports Ed25519 keys
From CL 173457 and CL 235358.

Change-Id: Ia46ab9c7e2c57472df3126ddc7050f0068fcaab9
GitHub-Last-Rev: c38e379355602fe4ff11ff65f98c296d5c326281
GitHub-Pull-Request: golang/crypto#146
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/241282
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2023-03-13 12:45:00 +00:00
cui fliter 9be5aaad42 all: fix a few function names on comments
Change-Id: Iac9c8f06b874e62b56f634dede8757b87514f421
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/442135
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2022-10-12 13:45:58 +00:00
Filippo Valsorda 1baeb1ce4c ssh: don't advertise rsa-sha2 algorithms if we can't use them
The server implementation looks at the HostKeys to advertise and
negotiate host key signature algorithms. A fundamental issue of the
Signer and AlgorithmSigner interfaces is that they don't expose the
supported signature algorithms, so really the server has to guess.

Currently, it would guess exclusively based on the PublicKey.Type,
regardless of whether the host key implemented AlgorithmSigner. This
means that a legacy Signer that only supports ssh-rsa still led the
server to negotiate rsa-sha2 algorithms. The server would then fail to
find a suitable host key to make the signature and crash.

This won't happen if only Signers from this package are used, but if a
custom Signer that doesn't support SignWithAlgorithm() but returns
"ssh-rsa" from PublicKey().Type() is used as a HostKey, the server is
vulnerable to DoS.

The only workable rules to determine what to advertise seems to be:

   1. a pure Signer will always Sign with the PublicKey.Type

   2. an AlgorithmSigner supports all algorithms associated with the
      PublicKey.Type

Rule number two means that we can't add new supported algorithms in the
future, which is not great, but it's too late to fix that.

rsaSigner was breaking rule number one, and although it would have been
fine where it's used, I didn't want to break our own interface contract.

It's unclear why we had separate test key entries for rsa-sha2
algorithms, since we can use the ssh-rsa key for those. The only test
that used them, TestCertTypes, seemed broken: the init was actually
failing at making the corresponding signers rsaSigners, and indeed the
test for the SHA-256 signer expected and checked a SHA-512 signature.

Pending CVE
For golang/go#49952

Change-Id: Ie658eefcadd87906e63fc7faae8249376aa96c79
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/392355
Trust: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-14 23:46:59 +00:00
Filippo Valsorda fcc990c556 ssh: deprecate and replace SigAlgo constants
RFC 8332, Section 2 sets up two overlapping namespaces: public key
formats and public key algorithms.

* The formats are what we currently have KeyAlgo constants for, and they
  appear in PublicKey.Type.

* The algorithms are the set of both KeyAlgo and SigAlgo constants, and
  they appear in Signature.Format (amongst other places).

This is incoherent, because that means Signature.Format can be both a
KeyAlgo (like KeyAlgoECDSA256) or a SigAlgo (like SigAlgoRSASHA2256).

One solution would be to duplicate all the KeyAlgo constants into the
SigAlgo namespace, but that would be confusing because applications are
currently using KeyAlgos where they'd be supposed to use the new
SigAlgos (while we can't deprecate the KeyAlgos because they are still
necessary for the PublicKey.Type namespace).

Instead, drop the separate namespaces, and use KeyAlgos throughout.
There are simply some KeyAlgos that can't be a PublicKey.Type.

Take the opportunity to fix the stuttering SHA22565/SHA2512 names. It's
totally ok to call those hashes SHA-256 and SHA-512 without the family
infix.

For golang/go#49952

Change-Id: Ia1fce3912a7e60aa70a88f75ed311be331fd19d5
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/392354
Trust: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-14 23:46:46 +00:00
Hans Nielsen b4de73f9ec ssh: support RSA SHA-2 (RFC8332) signatures
This change adds support for RSA SHA-2 based signatures for host keys and certificates. It also switches the default certificate signature algorithm for RSA to use SHA-512. This is implemented by treating ssh.Signer specially when the key type is `ssh-rsa` by also allowing SHA-256 and SHA-512 signatures.

Fixes golang/go#37278

Change-Id: I2ee1ac4ae4c9c1de441a2d6cf1e806357ef18910
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/220037
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
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Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
2021-11-15 23:45:14 +00:00
Ross Kinsey 0ec3e9974c ssh: support aes256-cbc for passphrase-protected OpenSSH keys
The existing code for decrypting OpenSSH-format keys only allows aes256-ctr, the current ssh-keygen default.
However, the default encryption scheme was aes256-cbc until relatively recently, and some of these keys are still in use.
Support for aes256-cbc has been added.

Fixes golang/go#37939

Change-Id: I3730347109c5dd18e4cbe61b48bbca9566ad61d2
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/224817
Reviewed-by: Filippo Valsorda <filippo@golang.org>
2020-03-23 16:52:09 +00:00
Filippo Valsorda bac4c82f69 ssh: return an error for malformed ed25519 public keys rather than panic
An attacker can craft an ssh-ed25519 or sk-ssh-ed25519@openssh.com
public key, such that the library will panic when trying to verify a
signature with it. Clients can deliver such a public key and signature
to any golang.org/x/crypto/ssh server with a PublicKeyCallback, and
servers can deliver them to any golang.org/x/crypto/ssh client.

This issue was discovered and reported by Alex Gaynor, Fish in a Barrel,
and is tracked as CVE-2020-9283.

Change-Id: Ie25b78a0b0181fbbc8cc7de4f4e27d908777529c
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/220357
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-02-20 18:36:23 +00:00
Mariano Cano a95e85b341 ssh: support ECDSA private keys in OpenSSH format
This adds support for parsing OpenSSH ECDSA private keys. It
implements parsing for P-256, P-384, and P-521 keys.

Fixes golang/go#36722

Change-Id: I77c8e0a23ed6353f6667686cc79ec14661cb10db
GitHub-Last-Rev: 2324b920d080fc7ac35fbcf0a79e25161b6a7f82
GitHub-Pull-Request: golang/crypto#114
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/215540
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-02-07 20:58:29 +00:00
Filippo Valsorda c9f3fb736b ssh: support encrypted OpenSSH private keys
Includes the bcrypt_pbkdf package by Dmitry Chestnykh,
submitted with permission on his behalf under the CLA:
https://go-review.googlesource.com/c/crypto/+/207600/2#message-6a035dd62ff76f6c9367299b911076a1be237fb8

Fixes golang/go#18692

Change-Id: I74e3ab355a8d720948d64d87adc009783a9d9732
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/207600
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
2020-02-04 10:40:54 +00:00
Filippo Valsorda 0a08dada0f ssh: reject unencrypted keys from ParsePrivateKeyWithPassphrase
The behavior of ParsePrivateKeyWithPassphrase when the key is
unencrypted is unspecified. Currently, it just parses them like
ParsePrivateKey, which is unlikely to be what anyone wants: for us to
ignore a passphrase that they explicitly passed. It also makes the
implementation of encrypted OpenSSH keys in the next CL more confused.

Instead, make ParsePrivateKey return a PassphraseNeededError, so the
application logic can be ParsePrivateKey -> detect encrypted key ->
obtain passphrase -> ParsePrivateKeyWithPassphrase. That error will also
let us return the public key for OpenSSH keys.

Change-Id: Ife4fb2499ae538bef36e353adf9bc8e902662386
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/207599
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
2019-12-05 16:18:47 +00:00
Sebastian Kinne 86a70503ff ssh: add sk-ecdsa-sha2-nistp256 and sk-ed25519
This adds server-side support for the newly introduced OpenSSH
keytypes sk-ecdsa-sha2-nistp256@openssh.com and sk-ed25519@openssh.com
(including their corresponding certificates), which are backed
by U2F/FIDO2 tokens.

Change-Id: I53d5ed3d0457ae4758ee986055e187ee5787a2d1
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/208017
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-12-02 14:38:27 +00:00
Ian Haken dab2b1051b ssh: support SSH agent signature flags and custom extensions
This commit implements two new features. To preserve backwards
compatibility the new methods are added to an `ExtendedAgent` interface
which extends `Agent`. The client code implements `ExtendedAgent`
(which extends Agent) so you can call these additional methods against
SSH agents such as the OpenSSH agent. The ServeAgent method still
accepts Agent but will attempt to upcast the agent to `ExtendedAgent`
as needed, so if you supply an ExtendedAgent implementation you can
implement these additional methods (which keyring does).

The first feature is supporting the standard flags that can be passed to
SSH Sign requests, requesting that RSA signatures use SHA-256 or
SHA-512. See section 4.5.1 of the SSH agent protocol draft:
https://tools.ietf.org/html/draft-miller-ssh-agent-02

The second feature is supporting calling custom extensions from clients
and implementing custom extensions from servers. See section 4.7 of the
SSH agent protocol draft:
https://tools.ietf.org/html/draft-miller-ssh-agent-02

Change-Id: I0f74feb893762c27e921ec37604d3a46434ee6ef
GitHub-Last-Rev: 2e23fd01c0e95b664e8507682f0bd5bd61d4c146
GitHub-Pull-Request: golang/crypto#53
Reviewed-on: https://go-review.googlesource.com/c/123955
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-10-29 10:30:14 +00:00
Adam Langley 0709b304e7 ssh: don't panic if a key is too short.
Change-Id: I810eb1c5d4cacc710a427e2ce031db1e9c292454
Reviewed-on: https://go-review.googlesource.com/132656
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-09-04 16:38:35 +00:00
Noel Georgi f027049dab ssh: RFC5208 support PKCS#8 key
Change-Id: I3d0ea816843c88930af3aa1f613978e0e90fa389
Reviewed-on: https://go-review.googlesource.com/127779
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
2018-08-07 10:46:21 +00:00
Han-Wen Nienhuys 8c653846df ssh: document how to unmarshal public keys
Fixes golang/go#21491.

Change-Id: I5c720f1f6c6acfa7f4cd50920f65db7e57ba3792
Reviewed-on: https://go-review.googlesource.com/95115
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-02-27 08:58:43 +00:00
Kevin Burke e8f229864d all: fix errors reported by vet, golint
None are "wrong" per se, but there are a lot of good suggestions and
in one case a docstring that was not present in godoc due to the
presence of an extra newline.

Changed "Id" in struct properties to "ID" in some non-exported
structs. Removed a trailing period from some error messages; I believe
the exact contents of error strings are not covered by the Go
compatibility promise.

Change-Id: I7c620582dc247396f72c52d38c909ccc0ec87b83
Reviewed-on: https://go-review.googlesource.com/80145
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-11-28 17:48:09 +00:00
Han-Wen Nienhuys 88e95fbb56 ssh: reject unsupported DSA key sizes
Fixes golang/go#19424.

Change-Id: I73370603dd612979420d608b73d67e673a52362b
Reviewed-on: https://go-review.googlesource.com/62870
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <hi@filippo.io>
Reviewed-by: Adam Langley <agl@golang.org>
2017-09-12 12:23:26 +00:00
Yasuhiro Matsumoto 84f24dfdf3 ssh: signal incorrect private key passwords with x509.IncorrectPasswordError
Fixes golang/go#20781

Change-Id: Iae42fff3c9b0b9984509e44a92f9bc99a1a12470
Reviewed-on: https://go-review.googlesource.com/46439
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-06-28 15:01:44 +00:00
Yasuhiro Matsumoto fea6c2c835 ssh: add ParsePrivateKeysWithPassphrase
ssh package doesn't provide way to parse private keys with passphrase.

Fixes golang/go#18692

Change-Id: Ic139f11b6dfe7ef61690d6125e0673d50a48db16
Reviewed-on: https://go-review.googlesource.com/36079
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
2017-06-13 13:45:37 +00:00
Paul Querna c2303dcbe8 ssh: Add support for RSA keys stored in OpenSSH's new format
Adds support for parsing RSA keys in the openssh-key-v1 private key format.

Change-Id: Iacdcbaadf72413e4067d146203604fb50b780083
Reviewed-on: https://go-review.googlesource.com/35244
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
Reviewed-by: Paul Querna <paul@querna.org>
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-04-05 15:38:54 +00:00
Paul Querna b82246307b crypto/ssh: fix parsing order for ssh.ParseDSAPrivateKey
The inline struct has the wrong order for the public and private key parts.

Change-Id: Ib3a5d6846296a2300241331a2ad398579e042ca9
Reviewed-on: https://go-review.googlesource.com/35351
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-01-18 01:33:05 +00:00
Ryuzo Yamamoto ede567c8e0 x/crypto/ssh: Add FingerprintLegacyMD5 and FingerprintSHA256 methods
Implement a standards-compliant fingerprint format method (RFC 4716 section 4)
and a newer SHA256 fingerprint format method.

Fixes golang/go#12292

Change-Id: I4f3f8fc1d0a263cb3b0964d0078e69006a39d1a5
Reviewed-on: https://go-review.googlesource.com/32814
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-11-22 14:27:12 +00:00
Dmitry Savintsev 4cd25d65a0 crypto/ssh: fix comment for ssh.NewPublicKey
Change-Id: I88bb7859259c82cd77ab2d26b728143281761def
Reviewed-on: https://go-review.googlesource.com/25232
Reviewed-by: Russ Cox <rsc@golang.org>
2016-10-12 02:54:41 +00:00
Martin Garton 69267d27d2 ssh: add CryptoPublicKey interface, expose underlying crypto.PublicKey
When implemented by ssh.PublicKey types, the new CryptoPublicKey
interface exposes the public key in the the crypto.PublicKey form via a
CryptoPublicKey() method.

This is useful for example in a custom ServerConfig.PublicKeyCallback
function to check or record additional details about the underlying
crypto.PublicKey

Change-Id: I4429df42c6fc5119f7c0023a539aaa9c59648bba
Reviewed-on: https://go-review.googlesource.com/23974
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-10-04 19:14:42 +00:00
Emmanuel Odeke a20de3fa94 x/crypto/ssh: ParsePrivateKey errors out with encrypted private keys
RSA and DSA keys if encrypted have the
phrase ENCRYPTED in their Proc-Type block
header according to RFC 1421 Section 4.6.1.1.

This CL checks for that phrase and errors out
if we encounter it, since we don't yet have
decryption of encrypted private keys.

Fixes golang/go#6650

Change-Id: I5b157716a2f93557d289af5f62994234a2e7a0ed
Reviewed-on: https://go-review.googlesource.com/29676
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-29 09:05:14 +00:00
Martin Hamrle 077efaa604 x/crypto: fix typos
The typos were found by misspell tool.

Change-Id: I120740f12f7ba48330749ebf84050a7b98e01016
Reviewed-on: https://go-review.googlesource.com/24725
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2016-07-06 16:40:51 +00:00
Martin Garton 1e61df8d9e x/crypto/ssh: add support for ed25519 keys
Added support for parsing the "new" openssh private key format.
(ed25519 keys only in this format for now)

Signing and verifying functions now work with ed25519 keys.

ed25519 can now be accepted by the server to authenticate a client.

ed25519 can now be accepted by a client as a server host key.

Related documentation used:
https://www.ietf.org/archive/id/draft-bjh21-ssh-ed25519-02.txt

Change-Id: I84385f24d666fea08de21f980f78623f7bff8007
Reviewed-on: https://go-review.googlesource.com/22512
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
2016-05-12 13:28:31 +00:00
Peter Moody e84a34b1ee x/crypto/ssh: support more keytypes in the agent.
This allows the golang ssh-agent to support the full suite of keys
the library accepts.

Currently constraints are ignored.

Change-Id: I7d48c78e9a355582eb54788571a483a736c3d3ef
Reviewed-on: https://go-review.googlesource.com/21536
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-25 17:01:51 +00:00
Peter Moody 3760e01685 x/crypto/ssh: add function to parse known_hosts files.
Change-Id: I9258ecf2b38258e31bcb6e73ac042ad8125fd2d1
Reviewed-on: https://go-review.googlesource.com/18106
Reviewed-by: Peter Moody <peter.moody@gmail.com>
Reviewed-by: Adam Langley <agl@golang.org>
2016-01-13 19:11:26 +00:00
Evan Broder e74b0352e5 crypto/ssh: Support turning a crypto.Signer into an ssh.Signer
This adds a NewSignerFromSigner to crypto/ssh which takes a
crypto.Signer and turns it into an ssh.Signer, helpful if, e.g., your
crypto.Signer is backed by some sort of hardware device.

The interfaces are very similar - the biggest differences are that a
crypto.Signer accepts hashed data, while an ssh.Signer does not, and
some differences in encoding for DSA and ECDSA signatures.

This also adjusts NewSignerFromKey to use NewSignerFromSigner where
possible, dropping the rsaPrivateKey and ecdsaPrivateKey types in
favor of wrappedSigner. (However, because *dsa.PrivateKey is not a
crypto.Signer, we still have to keep dsaPrivateKey)

Change-Id: Ia2e20ece9c9d3844b4e5a64c1a7d997178ec8781
Reviewed-on: https://go-review.googlesource.com/10953
Reviewed-by: Adam Langley <agl@golang.org>
2015-09-24 18:35:42 +00:00