CWE-347
AllowedImproper Verification of Cryptographic Signature
Abstraction: Base · Status: Draft
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
1272 vulnerabilities reference this CWE, most recent first.
GHSA-27FJ-MC8W-J9WG
Vulnerability from github – Published: 2021-04-16 19:52 – Updated: 2023-09-11 18:42Impact
Vulnerable jsrsasign will accept RSA signature with improper PKCS#1.5 padding.
Decoded RSA signature value consists following form:
01(ff...(8 or more ffs)...ff)00[ASN.1 OF DigestInfo]
Its byte length must be the same as RSA key length, however such checking was not sufficient.
To make crafted message for practical attack is very hard.
Patches
Users validating RSA signature should upgrade to 10.2.0 or later.
Workarounds
There is no workaround. Not to use RSA signature validation in jsrsasign.
ACKNOWLEDGEMENT
Thanks to Daniel Yahyazadeh @yahyazadeh for reporting and analyzing this vulnerability.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "jsrsasign"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "10.2.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-30246"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": true,
"github_reviewed_at": "2021-04-13T17:30:34Z",
"nvd_published_at": "2021-04-07T21:15:00Z",
"severity": "CRITICAL"
},
"details": "### Impact\nVulnerable jsrsasign will accept RSA signature with improper PKCS#1.5 padding.\nDecoded RSA signature value consists following form:\n`01(ff...(8 or more ffs)...ff)00[ASN.1 OF DigestInfo]`\nIts byte length must be the same as RSA key length, however such checking was not sufficient.\n\nTo make crafted message for practical attack is very hard.\n\n### Patches\nUsers validating RSA signature should upgrade to 10.2.0 or later.\n\n### Workarounds\nThere is no workaround. Not to use RSA signature validation in jsrsasign.\n\n### ACKNOWLEDGEMENT\nThanks to Daniel Yahyazadeh @yahyazadeh for reporting and analyzing this vulnerability.",
"id": "GHSA-27fj-mc8w-j9wg",
"modified": "2023-09-11T18:42:06Z",
"published": "2021-04-16T19:52:35Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/kjur/jsrsasign/security/advisories/GHSA-27fj-mc8w-j9wg"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-30246"
},
{
"type": "WEB",
"url": "https://github.com/kjur/jsrsasign/issues/478"
},
{
"type": "WEB",
"url": "https://github.com/kjur/jsrsasign/releases/tag/10.1.13"
},
{
"type": "WEB",
"url": "https://kjur.github.io/jsrsasign"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "RSA signature validation vulnerability on maleable encoded message in jsrsasign"
}
GHSA-27H3-67H6-73P2
Vulnerability from github – Published: 2026-03-04 09:31 – Updated: 2026-03-05 15:30SEPPmail Secure Email Gateway before version 15.0.1 does not properly communicate PGP signature verification results, leaving users unable to detect forged emails.
{
"affected": [],
"aliases": [
"CVE-2026-2746"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-03-04T09:15:57Z",
"severity": "MODERATE"
},
"details": "SEPPmail Secure Email Gateway before version 15.0.1 does not properly communicate PGP signature verification results, leaving users unable to detect forged emails.",
"id": "GHSA-27h3-67h6-73p2",
"modified": "2026-03-05T15:30:35Z",
"published": "2026-03-04T09:31:07Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2746"
},
{
"type": "WEB",
"url": "https://downloads.seppmail.com/extrelnotes/150/ERN15.0.html#seppmail-vulnerability-disclosure"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-285F-JC76-FCHH
Vulnerability from github – Published: 2022-05-14 03:24 – Updated: 2022-05-14 03:24In Android before security patch level 2018-04-05 on Qualcomm Snapdragon Automobile, Snapdragon Mobile, and Snapdragon Wear MDM9206, MDM9607, MDM9650, MSM8909W, SD 210/SD 212/SD 205, SD 400, SD 410/12, SD 425, SD 430, SD 450, SD 615/16/SD 415, SD 617, SD 625, SD 650/52, SD 800, SD 808, SD 810, SD 820, SD 820A, SD 835, SD 845, SD 850, in some corner cases, ECDSA signature verification can fail.
{
"affected": [],
"aliases": [
"CVE-2017-18146"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-04-11T15:29:00Z",
"severity": "CRITICAL"
},
"details": "In Android before security patch level 2018-04-05 on Qualcomm Snapdragon Automobile, Snapdragon Mobile, and Snapdragon Wear MDM9206, MDM9607, MDM9650, MSM8909W, SD 210/SD 212/SD 205, SD 400, SD 410/12, SD 425, SD 430, SD 450, SD 615/16/SD 415, SD 617, SD 625, SD 650/52, SD 800, SD 808, SD 810, SD 820, SD 820A, SD 835, SD 845, SD 850, in some corner cases, ECDSA signature verification can fail.",
"id": "GHSA-285f-jc76-fchh",
"modified": "2022-05-14T03:24:10Z",
"published": "2022-05-14T03:24:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-18146"
},
{
"type": "WEB",
"url": "https://source.android.com/security/bulletin/2018-04-01"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/103671"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-29WX-VH33-7X7R
Vulnerability from github – Published: 2024-11-04 23:22 – Updated: 2024-11-12 21:32Summary
Unclear documentation of the error behavior in ParseWithClaims can lead to situation where users are potentially not checking errors in the way they should be. Especially, if a token is both expired and invalid, the errors returned by ParseWithClaims return both error codes. If users only check for the jwt.ErrTokenExpired using error.Is, they will ignore the embedded jwt.ErrTokenSignatureInvalid and thus potentially accept invalid tokens.
Fix
We have back-ported the error handling logic from the v5 branch to the v4 branch. In this logic, the ParseWithClaims function will immediately return in "dangerous" situations (e.g., an invalid signature), limiting the combined errors only to situations where the signature is valid, but further validation failed (e.g., if the signature is valid, but is expired AND has the wrong audience). This fix is part of the 4.5.1 release.
Workaround
We are aware that this changes the behaviour of an established function and is not 100 % backwards compatible, so updating to 4.5.1 might break your code. In case you cannot update to 4.5.0, please make sure that you are properly checking for all errors ("dangerous" ones first), so that you are not running in the case detailed above.
token, err := /* jwt.Parse or similar */
if token.Valid {
fmt.Println("You look nice today")
} else if errors.Is(err, jwt.ErrTokenMalformed) {
fmt.Println("That's not even a token")
} else if errors.Is(err, jwt.ErrTokenUnverifiable) {
fmt.Println("We could not verify this token")
} else if errors.Is(err, jwt.ErrTokenSignatureInvalid) {
fmt.Println("This token has an invalid signature")
} else if errors.Is(err, jwt.ErrTokenExpired) || errors.Is(err, jwt.ErrTokenNotValidYet) {
// Token is either expired or not active yet
fmt.Println("Timing is everything")
} else {
fmt.Println("Couldn't handle this token:", err)
}
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/golang-jwt/jwt/v4"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.5.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-51744"
],
"database_specific": {
"cwe_ids": [
"CWE-347",
"CWE-755"
],
"github_reviewed": true,
"github_reviewed_at": "2024-11-04T23:22:41Z",
"nvd_published_at": "2024-11-04T22:15:03Z",
"severity": "LOW"
},
"details": "### Summary\n\nUnclear documentation of the error behavior in `ParseWithClaims` can lead to situation where users are potentially not checking errors in the way they should be. Especially, if a token is both expired and invalid, the errors returned by `ParseWithClaims` return both error codes. If users only check for the `jwt.ErrTokenExpired ` using `error.Is`, they will ignore the embedded `jwt.ErrTokenSignatureInvalid` and thus potentially accept invalid tokens.\n\n### Fix\n\nWe have back-ported the error handling logic from the `v5` branch to the `v4` branch. In this logic, the `ParseWithClaims` function will immediately return in \"dangerous\" situations (e.g., an invalid signature), limiting the combined errors only to situations where the signature is valid, but further validation failed (e.g., if the signature is valid, but is expired AND has the wrong audience). This fix is part of the 4.5.1 release.\n\n### Workaround \n\nWe are aware that this changes the behaviour of an established function and is not 100 % backwards compatible, so updating to 4.5.1 might break your code. In case you cannot update to 4.5.0, please make sure that you are properly checking for all errors (\"dangerous\" ones first), so that you are not running in the case detailed above.\n\n```Go\ntoken, err := /* jwt.Parse or similar */\nif token.Valid {\n\tfmt.Println(\"You look nice today\")\n} else if errors.Is(err, jwt.ErrTokenMalformed) {\n\tfmt.Println(\"That\u0027s not even a token\")\n} else if errors.Is(err, jwt.ErrTokenUnverifiable) {\n\tfmt.Println(\"We could not verify this token\")\n} else if errors.Is(err, jwt.ErrTokenSignatureInvalid) {\n\tfmt.Println(\"This token has an invalid signature\")\n} else if errors.Is(err, jwt.ErrTokenExpired) || errors.Is(err, jwt.ErrTokenNotValidYet) {\n\t// Token is either expired or not active yet\n\tfmt.Println(\"Timing is everything\")\n} else {\n\tfmt.Println(\"Couldn\u0027t handle this token:\", err)\n}\n```",
"id": "GHSA-29wx-vh33-7x7r",
"modified": "2024-11-12T21:32:34Z",
"published": "2024-11-04T23:22:41Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/golang-jwt/jwt/security/advisories/GHSA-29wx-vh33-7x7r"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-51744"
},
{
"type": "WEB",
"url": "https://github.com/golang-jwt/jwt/commit/7b1c1c00a171c6c79bbdb40e4ce7d197060c1c2c"
},
{
"type": "PACKAGE",
"url": "https://github.com/golang-jwt/jwt"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Bad documentation of error handling in ParseWithClaims can lead to potentially dangerous situations"
}
GHSA-2C5R-8H52-PHWR
Vulnerability from github – Published: 2023-06-13 18:30 – Updated: 2024-04-04 04:47Zoom for Windows clients prior to 5.13.5 contain an improper verification of cryptographic signature vulnerability. A malicious user may potentially downgrade Zoom Client components to previous versions.
{
"affected": [],
"aliases": [
"CVE-2023-28602"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-06-13T18:15:21Z",
"severity": "HIGH"
},
"details": "Zoom for Windows clients prior to 5.13.5 contain an improper verification of cryptographic signature vulnerability. A malicious user may potentially downgrade Zoom Client components to previous versions.",
"id": "GHSA-2c5r-8h52-phwr",
"modified": "2024-04-04T04:47:39Z",
"published": "2023-06-13T18:30:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-28602"
},
{
"type": "WEB",
"url": "https://explore.zoom.us/en/trust/security/security-bulletin"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-2C8P-FCX5-8R73
Vulnerability from github – Published: 2022-08-29 20:06 – Updated: 2022-09-03 00:00Foxit PDF Reader before 11.1 and PDF Editor before 11.1, and PhantomPDF before 10.1.6, mishandle hidden and incremental data in signed documents. An attacker can write to an arbitrary file, and display controlled contents, during signature verification.
{
"affected": [],
"aliases": [
"CVE-2021-40326"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-08-29T05:15:00Z",
"severity": "MODERATE"
},
"details": "Foxit PDF Reader before 11.1 and PDF Editor before 11.1, and PhantomPDF before 10.1.6, mishandle hidden and incremental data in signed documents. An attacker can write to an arbitrary file, and display controlled contents, during signature verification.",
"id": "GHSA-2c8p-fcx5-8r73",
"modified": "2022-09-03T00:00:24Z",
"published": "2022-08-29T20:06:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-40326"
},
{
"type": "WEB",
"url": "https://www.foxit.com/support/security-bulletins.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-2CXW-5886-MFV5
Vulnerability from github – Published: 2026-08-28 09:31 – Updated: 2026-08-28 09:31The WPMU DEV Dashboard plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 5.0.1. This is due to inconsistent and ambiguous HMAC message construction between the unauthenticated wdpsso_step1 and wdpsso_step2 AJAX actions, where step 1 signs and discloses an unseparated concatenation of the token, state, redirect, and domain values, while step 2 verifies an unseparated concatenation that omits the domain field. This makes it possible for unauthenticated attackers, on sites connected to WPMU DEV with Hub SSO enabled and mapped to an administrator, to obtain a valid HMAC from step 1 and replay it to step 2 by moving the domain value into the redirect field, resulting in an authenticated administrator session.
{
"affected": [],
"aliases": [
"CVE-2026-76581"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-28T08:16:41Z",
"severity": "CRITICAL"
},
"details": "The WPMU DEV Dashboard plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 5.0.1. This is due to inconsistent and ambiguous HMAC message construction between the unauthenticated `wdpsso_step1` and `wdpsso_step2` AJAX actions, where step 1 signs and discloses an unseparated concatenation of the token, state, redirect, and domain values, while step 2 verifies an unseparated concatenation that omits the domain field. This makes it possible for unauthenticated attackers, on sites connected to WPMU DEV with Hub SSO enabled and mapped to an administrator, to obtain a valid HMAC from step 1 and replay it to step 2 by moving the domain value into the redirect field, resulting in an authenticated administrator session.",
"id": "GHSA-2cxw-5886-mfv5",
"modified": "2026-08-28T09:31:45Z",
"published": "2026-08-28T09:31:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-76581"
},
{
"type": "WEB",
"url": "https://wpmudev.com/project/wpmu-dev-dashboard"
},
{
"type": "WEB",
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/3d4321c8-15a4-46f5-9b0e-2098a7fcfb5b?source=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-2H8C-CMRC-4Q5C
Vulnerability from github – Published: 2026-06-25 00:33 – Updated: 2026-06-25 00:33ATEN Unizon doCryptoHugeFileToFile Improper Verification of Cryptographic Signature Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of ATEN Unizon. Authentication is required to exploit this vulnerability.
The specific flaw exists within the updateWar method. The issue results from an incorrect implementation of cryptographic signature verification. An attacker can leverage this vulnerability to execute code in the context of SYSTEM. Was ZDI-CAN-28590.
{
"affected": [],
"aliases": [
"CVE-2026-9779"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-24T22:16:50Z",
"severity": "HIGH"
},
"details": "ATEN Unizon doCryptoHugeFileToFile Improper Verification of Cryptographic Signature Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of ATEN Unizon. Authentication is required to exploit this vulnerability.\n\nThe specific flaw exists within the updateWar method. The issue results from an incorrect implementation of cryptographic signature verification. An attacker can leverage this vulnerability to execute code in the context of SYSTEM. Was ZDI-CAN-28590.",
"id": "GHSA-2h8c-cmrc-4q5c",
"modified": "2026-06-25T00:33:23Z",
"published": "2026-06-25T00:33:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9779"
},
{
"type": "WEB",
"url": "https://www.aten.com/global/en/supportcenter/info/security-advisory/32"
},
{
"type": "WEB",
"url": "https://www.zerodayinitiative.com/advisories/ZDI-26-383"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-2HF2-G7JC-242W
Vulnerability from github – Published: 2022-05-24 19:14 – Updated: 2022-05-24 19:14Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for Cisco 8000 Series Routers could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. For more information about these vulnerabilities, see the Details section of this advisory.
{
"affected": [],
"aliases": [
"CVE-2021-34709"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-09-09T05:15:00Z",
"severity": "MODERATE"
},
"details": "Multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for Cisco 8000 Series Routers could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. For more information about these vulnerabilities, see the Details section of this advisory.",
"id": "GHSA-2hf2-g7jc-242w",
"modified": "2022-05-24T19:14:07Z",
"published": "2022-05-24T19:14:07Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-34709"
},
{
"type": "WEB",
"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-lnt-QN9mCzwn"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-2P26-R2GP-7XC2
Vulnerability from github – Published: 2026-03-16 15:30 – Updated: 2026-03-20 15:31Improper verification of cryptographic signature in Font Settings prior to SMR Mar-2026 Release 1 allows physical attackers to use custom font.
{
"affected": [],
"aliases": [
"CVE-2026-20989"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-03-16T14:18:09Z",
"severity": "MODERATE"
},
"details": "Improper verification of cryptographic signature in Font Settings prior to SMR Mar-2026 Release 1 allows physical attackers to use custom font.",
"id": "GHSA-2p26-r2gp-7xc2",
"modified": "2026-03-20T15:31:05Z",
"published": "2026-03-16T15:30:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20989"
},
{
"type": "WEB",
"url": "https://security.samsungmobile.com/securityUpdate.smsb?year=2026\u0026month=03"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
No mitigation information available for this CWE.
CAPEC-463: Padding Oracle Crypto Attack
An adversary is able to efficiently decrypt data without knowing the decryption key if a target system leaks data on whether or not a padding error happened while decrypting the ciphertext. A target system that leaks this type of information becomes the padding oracle and an adversary is able to make use of that oracle to efficiently decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block). In addition to performing decryption, an adversary is also able to produce valid ciphertexts (i.e., perform encryption) by using the padding oracle, all without knowing the encryption key.
CAPEC-475: Signature Spoofing by Improper Validation
An adversary exploits a cryptographic weakness in the signature verification algorithm implementation to generate a valid signature without knowing the key.