CSR Parser Skill

Overview

Send the `csr` as PEM text in the POST body. If the BEGIN and END lines are missing they are added, so a bare base64 block also works. The content is base64-decoded into DER and walked as ASN.1 following the PKCS#10 structure. Input that does not decode to a DER sequence, or lacks the parts every CSR must have, returns a 400 rather than a partly empty result. The signature on the request is not verified.

`version` is the PKCS#10 version as `v1`. `subject` reads common name, organisation, organisational unit, locality, state, country and email address from the distinguished name; any that are absent are null. Other subject attributes are not returned.

`public_key.algorithm` is `RSA` or `EC`, or the dotted OID for anything else. For RSA, `size_bits` is the modulus length and `exponent` the public exponent, usually 65537. For EC, a `curve` field names the curve (prime256v1, secp384r1 or secp521r1) and `size_bits` is its size. `signature_algorithm` is a name such as `SHA256withRSA` or `ecdsa-with-SHA256`, or the OID when unrecognised.

`fingerprints` are SHA-1, SHA-256 and MD5 digests of the DER bytes, in colon-separated uppercase hex. `size_bytes` is the DER length and `pem` the normalised text. `security_assessment` sets `is_weak_key` for RSA under 2048 bits or EC under 256, `is_deprecated_signature` for SHA-1 or MD5 signatures, and `key_strength` as weak, acceptable, strong (RSA 3072 and above, EC 384 and above) or unknown. The exponent, signature algorithm, fingerprints and assessment are null on the Free plan.

Live Test CSR Parser Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as CSRParserSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

{
  "name": "CSRParserSkill",
  "arguments": {
    "csr": "-----BEGIN CERTIFICATE REQUEST-----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\r\nrJCMi+GypGf9xQUfCJBhTDQVQ3fmCKTfddDeeVbJBrA=\r\n-----END CERTIFICATE REQUEST-----"
  }
}

You do not name the tool yourself; the model picks it. Asking about -----BEGIN CERTIFICATE REQUEST----- MIICvDCCAaQCAQAwdzELMAkGA1UEBhMCVVMxEzARBgNVBAgMCkNhbGlmb3JuaWEx FjAUBgNVBAcMDVNhbiBGcmFuY2lzY28xEzARBgNVBAoMCkV4YW1wbGUgQ28xEDAO BgNVBAsMB0RldlRlYW0xFDASBgNVBAMMC2V4YW1wbGUuY29tMIIBIjANBgkqhkiG 9w0BAQEFAAOCAQ8AMIIBCgKCAQEAjd/RepiCLQ5/HfKynijcPdiwygrSgxQeTKPo T/WiEaRTaUToW9uDUeiIHK83Tgn2+TIONpMoLJRNG+zslpHybWhVVWNlamkrlRwP XFQJzsxDN5+TQugILatLsp680SgMNyyPtDIpT3niiNuQ4NFepQLvQTbjXgj1celb U86CCeJzYengTF0ZE9Ra+/SsRTA+oy0fNLChNMc2DBaybccxwV2rNWvlvPdhfB7M sel3sw/x2hsbWoYC/kudzYmoDPZKX+XOhCkFwUgwib8V4hbjVLcOYsPBJcROYpRh 9d5g7xdRlbF1I7dHsCRKnsvkIONtwKQmJ2v/UPqYahjtm2TPUQIDAQABoAAwDQYJ KoZIhvcNAQELBQADggEBAFEHOsN2SkB3qFBMk9JR5IDoh8rSUKj/310DOwilOQm+ 5lAwRfcFMYCl9yf4IV+XPPfvT3ahzUFfi8Fc98CDeIxAhEwtuZFlE7LA5+/F4HXM H3gzqTFwOZq+Wa2m029/BvcyII830h4Z+gU68R52px7O7wYSbAR/n7t1fh2bxzmW KqqjrvCpHoMVpgcm9y2bYTj+HLxgX4/uADFvotQppOWZi0ctam+if3Kqb3Kd2MFD vVHZp9NwEoqNPxmFEzcyOk2y1PYhhRja7rjdC6bdAqj6JRt+WSzStvgx7aEsxBQj rJCMi+GypGf9xQUfCJBhTDQVQ3fmCKTfddDeeVbJBrA= -----END CERTIFICATE REQUEST----- in the terms this skill covers is enough for it to reach for CSRParserSkill on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

https://api.vervekit.com/v1/mcp

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

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{
  "status": "ok",
  "error": null,
  "data": {
    "version": "v1",
    "subject": {
      "common_name": "example.com",
      "organization": "Example Co",
      "organizational_unit": "DevTeam",
      "locality": "San Francisco",
      "state": "California",
      "country": "US",
      "email": null
    },
    "public_key": {
      "algorithm": "RSA",
      "size_bits": 2048,
      "exponent": 65537
    },
    "signature_algorithm": "SHA256withRSA",
    "extensions": [],
    "fingerprints": {
      "sha1": "05:E5:65:28:8A:47:01:D3:05:EA:3B:3F:F5:DC:C7:42:BF:06:E2:5F",
      "sha256": "E0:0B:C1:59:A3:9E:F9:96:13:7B:CE:98:BC:8F:A1:49:62:4D:2E:CF:85:D5:36:2C:DD:46:9E:96:CF:92:A3:AF",
      "md5": "27:C7:EC:94:73:34:E3:B7:3F:F6:FD:3E:0A:81:EA:3D"
    },
    "pem": "-----BEGIN CERTIFICATE REQUEST-----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\nrJCMi+GypGf9xQUfCJBhTDQVQ3fmCKTfddDeeVbJBrA=\n-----END CERTIFICATE REQUEST-----",
    "size_bytes": 704,
    "format": "PEM",
    "is_valid": true,
    "security_assessment": {
      "is_weak_key": false,
      "is_deprecated_signature": false,
      "key_strength": "acceptable"
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

A call costs 2 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

CSR Validation

Validate Certificate Signing Requests before certificate issuance to ensure proper formatting and required fields

Information Extraction

Extract subject information, public key details, and signature algorithms from certificate requests for processing

Certificate Management

Build certificate management systems with automated CSR parsing and validation capabilities

SSL/TLS Automation

Automate SSL/TLS certificate workflows including CSR generation validation, certificate issuance, and renewal processes

Other ways to use CSR Parser Skill

Set up CSR Parser Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

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