Make PKCS8, PEM and SSH2 keys work (#7600)

* Make PEM and SSH2 keys work

* add ssh2 testcases and PEM cases - and fix PEM

* Add final test to parse the proposed key
This commit is contained in:
zeripath 2019-07-25 20:33:38 +01:00 committed by GitHub
parent 6485962dd5
commit 18c0e9c2a9
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 125 additions and 27 deletions

View File

@ -7,8 +7,12 @@ package models
import (
"bufio"
"crypto/rsa"
"crypto/x509"
"encoding/asn1"
"encoding/base64"
"encoding/binary"
"encoding/pem"
"errors"
"fmt"
"io/ioutil"
@ -94,6 +98,8 @@ func extractTypeFromBase64Key(key string) (string, error) {
return string(b[4 : 4+keyLength]), nil
}
const ssh2keyStart = "---- BEGIN SSH2 PUBLIC KEY ----"
// parseKeyString parses any key string in OpenSSH or SSH2 format to clean OpenSSH string (RFC4253).
func parseKeyString(content string) (string, error) {
// remove whitespace at start and end
@ -101,7 +107,59 @@ func parseKeyString(content string) (string, error) {
var keyType, keyContent, keyComment string
if !strings.Contains(content, "-----BEGIN") {
if content[:len(ssh2keyStart)] == ssh2keyStart {
// Parse SSH2 file format.
// Transform all legal line endings to a single "\n".
content = strings.NewReplacer("\r\n", "\n", "\r", "\n").Replace(content)
lines := strings.Split(content, "\n")
continuationLine := false
for _, line := range lines {
// Skip lines that:
// 1) are a continuation of the previous line,
// 2) contain ":" as that are comment lines
// 3) contain "-" as that are begin and end tags
if continuationLine || strings.ContainsAny(line, ":-") {
continuationLine = strings.HasSuffix(line, "\\")
} else {
keyContent += line
}
}
t, err := extractTypeFromBase64Key(keyContent)
if err != nil {
return "", fmt.Errorf("extractTypeFromBase64Key: %v", err)
}
keyType = t
} else {
if strings.Contains(content, "-----BEGIN") {
// Convert PEM Keys to OpenSSH format
// Transform all legal line endings to a single "\n".
content = strings.NewReplacer("\r\n", "\n", "\r", "\n").Replace(content)
block, _ := pem.Decode([]byte(content))
if block == nil {
return "", fmt.Errorf("failed to parse PEM block containing the public key")
}
pub, err := x509.ParsePKIXPublicKey(block.Bytes)
if err != nil {
var pk rsa.PublicKey
_, err2 := asn1.Unmarshal(block.Bytes, &pk)
if err2 != nil {
return "", fmt.Errorf("failed to parse DER encoded public key as either PKIX or PEM RSA Key: %v %v", err, err2)
}
pub = &pk
}
sshKey, err := ssh.NewPublicKey(pub)
if err != nil {
return "", fmt.Errorf("unable to convert to ssh public key: %v", err)
}
content = string(ssh.MarshalAuthorizedKey(sshKey))
}
// Parse OpenSSH format.
// Remove all newlines
@ -132,32 +190,11 @@ func parseKeyString(content string) (string, error) {
} else if keyType != t {
return "", fmt.Errorf("key type and content does not match: %s - %s", keyType, t)
}
} else {
// Parse SSH2 file format.
// Transform all legal line endings to a single "\n".
content = strings.NewReplacer("\r\n", "\n", "\r", "\n").Replace(content)
lines := strings.Split(content, "\n")
continuationLine := false
for _, line := range lines {
// Skip lines that:
// 1) are a continuation of the previous line,
// 2) contain ":" as that are comment lines
// 3) contain "-" as that are begin and end tags
if continuationLine || strings.ContainsAny(line, ":-") {
continuationLine = strings.HasSuffix(line, "\\")
} else {
keyContent += line
}
}
t, err := extractTypeFromBase64Key(keyContent)
if err != nil {
return "", fmt.Errorf("extractTypeFromBase64Key: %v", err)
}
keyType = t
}
// Finally we need to check whether we can actually read the proposed key:
_, _, _, _, err := ssh.ParseAuthorizedKey([]byte(keyType + " " + keyContent + " " + keyComment))
if err != nil {
return "", fmt.Errorf("invalid ssh public key: %v", err)
}
return keyType + " " + keyContent + " " + keyComment, nil
}

View File

@ -66,6 +66,67 @@ func Test_CheckPublicKeyString(t *testing.T) {
{"ssh-rsa AAAAB3NzaC1yc2EA\r\nAAADAQABAAAAgQDAu7tvI\nvX6ZHrRXuZNfkR3XLHSsuCK9Zn3X58lxBcQzuo5xZgB6vRwwm/QtJuF+zZPtY5hsQILBLmF+\r\nBZ5WpKZp1jBeSjH2G7lxet9kbcH+kIVj0tPFEoyKI9wvW\nqIwC4prx/WVk2wLTJjzBAhyNx\r\nfEq7C9CeiX9pQEbEqJfkKCQ== nocomment\r\n\r\n"},
{"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICV0MGX/W9IvLA4FXpIuUcdDcbj5KX4syHgsTy7soVgf"},
{"\r\nssh-ed25519 \r\nAAAAC3NzaC1lZDI1NTE5AAAAICV0MGX/W9IvLA4FXpIuUcdDcbj5KX4syHgsTy7soVgf\r\n\r\n"},
{`---- BEGIN SSH2 PUBLIC KEY ----
Comment: "1024-bit DSA, converted by andrew@phaedra from OpenSSH"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---- END SSH2 PUBLIC KEY ----
`},
{`---- BEGIN SSH2 PUBLIC KEY ----
Comment: "1024-bit RSA, converted by andrew@phaedra from OpenSSH"
AAAAB3NzaC1yc2EAAAADAQABAAAAgQDAu7tvIvX6ZHrRXuZNfkR3XLHSsuCK9Zn3X58lxB
cQzuo5xZgB6vRwwm/QtJuF+zZPtY5hsQILBLmF+BZ5WpKZp1jBeSjH2G7lxet9kbcH+kIV
j0tPFEoyKI9wvWqIwC4prx/WVk2wLTJjzBAhyNxfEq7C9CeiX9pQEbEqJfkKCQ==
---- END SSH2 PUBLIC KEY ----
`},
{`-----BEGIN RSA PUBLIC KEY-----
MIGJAoGBAMC7u28i9fpketFe5k1+RHdcsdKy4Ir1mfdfnyXEFxDO6jnFmAHq9HDC
b9C0m4X7Nk+1jmGxAgsEuYX4FnlakpmnWMF5KMfYbuXF632Rtwf6QhWPS08USjIo
j3C9aojALimvH9ZWTbAtMmPMECHI3F8SrsL0J6Jf2lARsSol+QoJAgMBAAE=
-----END RSA PUBLIC KEY-----
`},
{`-----BEGIN PUBLIC KEY-----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-----END PUBLIC KEY-----
`},
{`-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDAu7tvIvX6ZHrRXuZNfkR3XLHS
suCK9Zn3X58lxBcQzuo5xZgB6vRwwm/QtJuF+zZPtY5hsQILBLmF+BZ5WpKZp1jB
eSjH2G7lxet9kbcH+kIVj0tPFEoyKI9wvWqIwC4prx/WVk2wLTJjzBAhyNxfEq7C
9CeiX9pQEbEqJfkKCQIDAQAB
-----END PUBLIC KEY-----
`},
{`-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzGV4ftTgVMEh/Q+OcE2s
RK0CDfSKAvcZezCiZKr077+juUUfWFvyCvRW3414F7KaWBobAmaNYRTjrFxzJ3zj
karv8TA8eMj7sryqcOC3jxHIOEw4qWgxbsW1jqnPwVGUWXF7uNUAFnwy6yJ8LJbV
mR0nhu4Y4aWnJeBa1b/VdaUujnOUNTccRM087jS0v/HYma05v2AEEP/gfps1iN8x
LReJomY4wJY1ndS0wT71Nt3dvQ3AZphWoXGeONV2bE3gMBsRv0Oo/DYDV4/VsTHl
sMV1do3gF/xAUqWawlZQkNcibME+sQqfE7gZ04hlmDATU2zmbzwuHtFiNv8mVv7O
RQIDAQAB
-----END PUBLIC KEY-----
`},
{`---- BEGIN SSH2 PUBLIC KEY ----
Comment: "256-bit ED25519, converted by andrew@phaedra from OpenSSH"
AAAAC3NzaC1lZDI1NTE5AAAAICV0MGX/W9IvLA4FXpIuUcdDcbj5KX4syHgsTy7soVgf
---- END SSH2 PUBLIC KEY ----
`},
} {
_, err := CheckPublicKeyString(test.content)
assert.NoError(t, err)