commit fec4117e5cd5558c3b1a1804abd1cc45adbb8cc4 · veryroundbird.house/core

+103

cmd/verifysig/main.go

···

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       package main

     

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       import (

     

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       	"flag"

     

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       	"fmt"

     

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       	"io"

     

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       	"os"

     

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       	"strings"

     

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       	"tangled.sh/tangled.sh/core/crypto"

     

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       )

     

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       func parseCommitObject(commitData string) (string, string, error) {

     

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       	lines := strings.Split(commitData, "\n")

     

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       	var payloadLines []string

     

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       	var signatureLines []string

     

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       	var inSignature bool

     

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       	var foundSignature bool

     

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       	for _, line := range lines {

     

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       		if strings.HasPrefix(line, "gpgsig ") {

     

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       			foundSignature = true

     

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       			inSignature = true

     

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       			// remove 'gpgsig' prefix

     

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       			sigLine := strings.TrimPrefix(line, "gpgsig ")

     

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       			signatureLines = append(signatureLines, sigLine)

     

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       			continue

     

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       		}

     

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       		if inSignature {

     

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       			// check if this line is part of the signature (starts with space)

     

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       			if strings.HasPrefix(line, " ") {

     

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       				// remove the leading space and add to signature

     

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       				sigLine := strings.TrimPrefix(line, " ")

     

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       				signatureLines = append(signatureLines, sigLine)

     

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       				continue

     

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       			} else {

     

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       				// end of signature block

     

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       				inSignature = false

     

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       				// this line is part of payload, so add it

     

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       				payloadLines = append(payloadLines, line)

     

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       			}

     

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       		} else {

     

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       			// regular payload line

     

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       			payloadLines = append(payloadLines, line)

     

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       		}

     

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       	}

     

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       	if !foundSignature {

     

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       		return "", commitData, nil // no signature found, return empty signature and full data as payload

     

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       	}

     

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       	signature := strings.Join(signatureLines, "\n")

     

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       	payload := strings.Join(payloadLines, "\n")

     

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       	return signature, payload, nil

     

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       }

     

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       func main() {

     

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       	var pubkeyPath string

     

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       	flag.StringVar(&pubkeyPath, "pubkey", "", "Path to the public key file")

     

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       	flag.Parse()

     

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       	var pubKey []byte

     

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       	var err error

     

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       	if pubkeyPath != "" {

     

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       		pubKey, err = os.ReadFile(pubkeyPath)

     

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       		if err != nil {

     

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       			fmt.Fprintf(os.Stderr, "error reading public key file: %v\n", err)

     

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       			os.Exit(1)

     

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       		}

     

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       	}

     

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       	input, err := io.ReadAll(os.Stdin)

     

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       	if err != nil {

     

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       		fmt.Fprintf(os.Stderr, "error reading from stdin: %v\n", err)

     

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       		os.Exit(1)

     

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       	}

     

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       	commitData := string(input)

     

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       	signature, payload, err := parseCommitObject(commitData)

     

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       	if err != nil {

     

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       		fmt.Fprintf(os.Stderr, "error parsing commit: %v\n", err)

     

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       		os.Exit(1)

     

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       	}

     

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       	fmt.Println("signature")

     

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       	fmt.Println(signature)

     

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       	fmt.Println()

     

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       	fmt.Println("payload:")

     

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       	fmt.Println(payload)

     

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       	err, ok := crypto.VerifySignature(pubKey, []byte(signature), []byte(payload))

     

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       	if err != nil {

     

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       		fmt.Fprintf(os.Stderr, "%v\n", err)

     

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       		os.Exit(1)

     

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       	}

     

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       	if ok {

     

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       		fmt.Println("ok")

     

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       	}

     

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       }

+4 -1

crypto/verify.go

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       	}

     

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       	buf := bytes.NewBuffer(payload)

     

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       	sshsig.Verify(buf, sig, pub, sshsig.HashSHA256, "git")

     

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       	// we use sha-512 because ed25519 keys require it internally; rsa keys support

     

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       	// multiple algorithms but sha-512 is most secure, and git's ssh signing defaults

     

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       	// to sha-512 for all key types anyway.

     

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       	err = sshsig.Verify(buf, sig, pub, sshsig.HashSHA512, "git")

     

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       	return err, err == nil

     

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       }

     

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