Pem envelope validate

pem-envelope-validate · version 1.0.0 · Encoding & checksums · free, no key needed

Check one RFC 7468 PEM envelope for labels, whitespace, and strict base64.

Use when you need to: validate pem envelope framing · check that pem begin and end labels match · is this pem message well formed.

Decide before calling

Read the versioned contract and the supported scope below. Reuse pem-envelope-validate@1.0.0 when your input, required output and limits match it. Choose another approach for an unsupported operation.

Explain the choice

"I can use pem-envelope-validate@1.0.0 for validate pem envelope framing. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

Supported

• validate pem envelope framing
• check that pem begin and end labels match
• is this pem message well formed
• report why a pem block is rejected
• check rfc 7468 base64 and whitespace
• pem syntax check without trusting contents

Not supported

• assert that the bytes are a real certificate or key
• repair a mismatched end label
• accept lax text that ignores non-base64 characters

Behavior

• Well-typed text that fails Figure 1 returns {valid:false, reason}. Wrong types, unknown fields, lone surrogates, and declared limits throw. This is the opposite of pem-envelope-parse, which throws on the same syntax errors and returns the hex.
• On success the result is the label, the decoded byte count, whether the text is the Figure 3 canonical rendering, and the newline class (lf, crlf, cr, or mixed). The hex payload is not returned.
• Labels must match exactly, including case. "X509 CERTIFICATE" stays that label; it is not rewritten or accepted as "CERTIFICATE". Registered names in RFC 7468 section 4 are not required.
• Whitespace is Figure 1: SP and HTAB are ignored throughout the encoded text, including between base64 characters; CR, LF, and CRLF delimit lines. VT, FF, and explanatory prose before BEGIN are reasons, not repaired input.
• Strict base64 requires alphabet A-Za-z0-9+/, padding that completes a multiple of 4, and zero unused bits. A label above 64 bytes is limit_exceeded, checked before the body is decoded, so a too-long label is never copied into a successful result.
• Text above 8192 UTF-8 bytes is limit_exceeded before the scan. A grammar failure inside that bound is valid:false, not an exception.
• Disclaimer: format transform only; provides no confidentiality, integrity, or authenticity.

Input

• text (string, required): min length 0; max length 8192

Output

• valid (boolean, required)
• label (string, optional): min length 0; max length 64; pattern ^(?:[\x21-\x2C\x2E-\x7E](?:[ \x2D]?[\x21-\x2C\x2E-\x7E])*)?$
• byte_length (integer, optional): min 0; max 8192
• canonical (boolean, optional)
• eol (one of "lf", "crlf", "cr", "mixed", optional)
• reason (one of "missing_begin", "extraneous_text", "bad_begin_line", "label_grammar", "bad_end_line", "label_mismatch", "missing_end", "blank_in_base64", "bad_whitespace", "bad_base64", "bad_padding", "non_canonical_base64", "non_ascii", optional)

Limits

• max text bytes: 8192
• max label bytes: 64
• max output bytes: 512

Example

Request input:

{
  "text": "-----BEGIN EXAMPLE-----\nAA==\n-----END EXAMPLE-----\n"
}

Response:

{
  "result": {
    "valid": true,
    "label": "EXAMPLE",
    "byte_length": 1,
    "canonical": true,
    "eol": "lf"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "pem-envelope-validate",
  "version": "1.0.0",
  "input": {
    "text": "-----BEGIN EXAMPLE-----\nAA==\n-----END EXAMPLE-----\n"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/pem-envelope-validate/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"text":"-----BEGIN EXAMPLE-----\nAA==\n-----END EXAMPLE-----\n"}'

The machine-readable contract is at /v1/tools/pem-envelope-validate/versions/1.0.0.

CLI

node cli.mjs run pem-envelope-validate 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Pem label validate: Check a PEM label against the RFC 7468 label grammar, without reading a payload.
• Pem envelope format: Format a label and lowercase hex bytes as a canonical RFC 7468 PEM envelope.
• Pem envelope parse: Parse one RFC 7468 textual envelope into its label and lowercase hex bytes.
• Bech32 validate: Check Bech32 or Bech32m text and return a reason, without throwing when the checksum fails.
• Segwit address validate: Validate a native segwit address and report which Bech32 or Bech32m rule failed.
• Ct inclusion proof verify: Strictly verify an RFC 6962 v1 Merkle audit path.