cmd: add tlsinfo.

Verify certificates are signed by a CA.

cmd/ca-signed/README.txt

@@ -0,0 +1,40 @@
+ca-signed: verify certificates against a CA
+-------------------------------------------
+
+Description
+  ca-signed verifies whether one or more certificates are signed by a given
+  Certificate Authority (CA). It prints a concise status per input certificate
+  along with the certificate’s expiration date when validation succeeds.
+
+Usage
+  ca-signed CA.pem cert1.pem [cert2.pem ...]
+
+  - CA.pem: A file containing one or more CA certificates in PEM, DER, or PKCS#7/PKCS#12 formats.
+  - certN.pem: A file containing the end-entity (leaf) certificate to verify. If the file contains a chain,
+               the first certificate is treated as the leaf and the remaining ones are used as intermediates.
+
+Output format
+  For each input certificate file, one line is printed:
+    <filename>: OK (expires YYYY-MM-DD)
+    <filename>: INVALID
+
+Special self-test mode
+  ca-signed selftest
+
+  Runs a built-in test suite using embedded certificates. This mode requires no
+  external files or network access. The program exits with code 0 if all tests
+  pass, or a non-zero exit code if any test fails. Example output lines include
+  whether validation succeeds and the leaf’s expiration when applicable.
+
+Examples
+  # Verify a server certificate against a root CA
+  ca-signed isrg-root-x1.pem le-e7.pem
+
+  # Run the embedded self-test suite
+  ca-signed selftest
+
+Notes
+  - The tool attempts to parse certificates in PEM first, then falls back to
+    DER/PKCS#7/PKCS#12 (with an empty password) where applicable.
+  - Expiration is shown for the leaf certificate only.
+  - In selftest mode, test certificates are compiled into the binary using go:embed.

cmd/ca-signed/main.go

@@ -0,0 +1,287 @@
+package main
+
+import (
+	"crypto/x509"
+	"embed"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	"git.wntrmute.dev/kyle/goutils/certlib"
+)
+
+// loadCertsFromFile attempts to parse certificates from a file that may be in
+// PEM or DER/PKCS#7 format. Returns the parsed certificates or an error.
+func loadCertsFromFile(path string) ([]*x509.Certificate, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	// Try PEM first
+	if certs, err := certlib.ParseCertificatesPEM(data); err == nil {
+		return certs, nil
+	}
+
+	// Try DER/PKCS7/PKCS12 (with no password)
+	if certs, _, err := certlib.ParseCertificatesDER(data, ""); err == nil {
+		return certs, nil
+	} else {
+		return nil, err
+	}
+}
+
+func makePoolFromFile(path string) (*x509.CertPool, error) {
+	// Try PEM via helper (it builds a pool)
+	if pool, err := certlib.LoadPEMCertPool(path); err == nil && pool != nil {
+		return pool, nil
+	}
+
+	// Fallback: read as DER(s), add to a new pool
+	certs, err := loadCertsFromFile(path)
+	if err != nil || len(certs) == 0 {
+		return nil, fmt.Errorf("failed to load CA certificates from %s", path)
+	}
+	pool := x509.NewCertPool()
+	for _, c := range certs {
+		pool.AddCert(c)
+	}
+	return pool, nil
+}
+
+//go:embed testdata/*.pem
+var embeddedTestdata embed.FS
+
+// loadCertsFromBytes attempts to parse certificates from bytes that may be in
+// PEM or DER/PKCS#7 format.
+func loadCertsFromBytes(data []byte) ([]*x509.Certificate, error) {
+	// Try PEM first
+	if certs, err := certlib.ParseCertificatesPEM(data); err == nil {
+		return certs, nil
+	}
+	// Try DER/PKCS7/PKCS12 (with no password)
+	if certs, _, err := certlib.ParseCertificatesDER(data, ""); err == nil {
+		return certs, nil
+	} else {
+		return nil, err
+	}
+}
+
+func makePoolFromBytes(data []byte) (*x509.CertPool, error) {
+    certs, err := loadCertsFromBytes(data)
+    if err != nil || len(certs) == 0 {
+        return nil, fmt.Errorf("failed to load CA certificates from embedded bytes")
+    }
+    pool := x509.NewCertPool()
+    for _, c := range certs {
+        pool.AddCert(c)
+    }
+    return pool, nil
+}
+
+// isSelfSigned returns true if the given certificate is self-signed.
+// It checks that the subject and issuer match and that the certificate's
+// signature verifies against its own public key.
+func isSelfSigned(cert *x509.Certificate) bool {
+    if cert == nil {
+        return false
+    }
+    // Quick check: subject and issuer match
+    if cert.Subject.String() != cert.Issuer.String() {
+        return false
+    }
+    // Cryptographic check: the certificate is signed by itself
+    if err := cert.CheckSignatureFrom(cert); err != nil {
+        return false
+    }
+    return true
+}
+
+func verifyAgainstCA(caPool *x509.CertPool, path string) (ok bool, expiry string) {
+	certs, err := loadCertsFromFile(path)
+	if err != nil || len(certs) == 0 {
+		return false, ""
+	}
+
+	leaf := certs[0]
+	ints := x509.NewCertPool()
+	if len(certs) > 1 {
+		for _, ic := range certs[1:] {
+			ints.AddCert(ic)
+		}
+	}
+
+	opts := x509.VerifyOptions{
+		Roots:         caPool,
+		Intermediates: ints,
+		KeyUsages:     []x509.ExtKeyUsage{x509.ExtKeyUsageAny},
+	}
+	if _, err := leaf.Verify(opts); err != nil {
+		return false, ""
+	}
+
+	return true, leaf.NotAfter.Format("2006-01-02")
+}
+
+func verifyAgainstCABytes(caPool *x509.CertPool, certData []byte) (ok bool, expiry string) {
+	certs, err := loadCertsFromBytes(certData)
+	if err != nil || len(certs) == 0 {
+		return false, ""
+	}
+
+	leaf := certs[0]
+	ints := x509.NewCertPool()
+	if len(certs) > 1 {
+		for _, ic := range certs[1:] {
+			ints.AddCert(ic)
+		}
+	}
+
+	opts := x509.VerifyOptions{
+		Roots:         caPool,
+		Intermediates: ints,
+		KeyUsages:     []x509.ExtKeyUsage{x509.ExtKeyUsageAny},
+	}
+	if _, err := leaf.Verify(opts); err != nil {
+		return false, ""
+	}
+
+	return true, leaf.NotAfter.Format("2006-01-02")
+}
+
+// selftest runs built-in validation using embedded certificates.
+func selftest() int {
+	type testCase struct {
+		name     string
+		caFile   string
+		certFile string
+		expectOK bool
+	}
+
+ cases := []testCase{
+        {name: "ISRG Root X1 validates LE E7", caFile: "testdata/isrg-root-x1.pem", certFile: "testdata/le-e7.pem", expectOK: true},
+        {name: "ISRG Root X1 does NOT validate Google WR2", caFile: "testdata/isrg-root-x1.pem", certFile: "testdata/goog-wr2.pem", expectOK: false},
+        {name: "GTS R1 validates Google WR2", caFile: "testdata/gts-r1.pem", certFile: "testdata/goog-wr2.pem", expectOK: true},
+        {name: "GTS R1 does NOT validate LE E7", caFile: "testdata/gts-r1.pem", certFile: "testdata/le-e7.pem", expectOK: false},
+    }
+
+    failures := 0
+    for _, tc := range cases {
+		caBytes, err := embeddedTestdata.ReadFile(tc.caFile)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "selftest: failed to read embedded %s: %v\n", tc.caFile, err)
+			failures++
+			continue
+		}
+		certBytes, err := embeddedTestdata.ReadFile(tc.certFile)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "selftest: failed to read embedded %s: %v\n", tc.certFile, err)
+			failures++
+			continue
+		}
+		pool, err := makePoolFromBytes(caBytes)
+		if err != nil || pool == nil {
+			fmt.Fprintf(os.Stderr, "selftest: failed to build CA pool for %s: %v\n", tc.caFile, err)
+			failures++
+			continue
+		}
+		ok, exp := verifyAgainstCABytes(pool, certBytes)
+		if ok != tc.expectOK {
+			fmt.Printf("%s: unexpected result: got %v, want %v\n", tc.name, ok, tc.expectOK)
+			failures++
+		} else {
+			if ok {
+				fmt.Printf("%s: OK (expires %s)\n", tc.name, exp)
+			} else {
+				fmt.Printf("%s: INVALID (as expected)\n", tc.name)
+			}
+		}
+    }
+
+    // Verify that both embedded root CAs are detected as self-signed
+    roots := []string{"testdata/gts-r1.pem", "testdata/isrg-root-x1.pem"}
+    for _, root := range roots {
+        b, err := embeddedTestdata.ReadFile(root)
+        if err != nil {
+            fmt.Fprintf(os.Stderr, "selftest: failed to read embedded %s: %v\n", root, err)
+            failures++
+            continue
+        }
+        certs, err := loadCertsFromBytes(b)
+        if err != nil || len(certs) == 0 {
+            fmt.Fprintf(os.Stderr, "selftest: failed to parse cert(s) from %s: %v\n", root, err)
+            failures++
+            continue
+        }
+        leaf := certs[0]
+        if isSelfSigned(leaf) {
+            fmt.Printf("%s: SELF-SIGNED (as expected)\n", root)
+        } else {
+            fmt.Printf("%s: expected SELF-SIGNED, but was not detected as such\n", root)
+            failures++
+        }
+    }
+
+    if failures == 0 {
+        fmt.Println("selftest: PASS")
+        return 0
+    }
+    fmt.Fprintf(os.Stderr, "selftest: FAIL (%d failure(s))\n", failures)
+    return 1
+}
+
+func main() {
+	// Special selftest mode: single argument "selftest"
+	if len(os.Args) == 2 && os.Args[1] == "selftest" {
+		os.Exit(selftest())
+	}
+
+	if len(os.Args) < 3 {
+		prog := filepath.Base(os.Args[0])
+		fmt.Fprintf(os.Stderr, "Usage:\n  %s ca.pem cert1.pem cert2.pem ...\n  %s selftest\n", prog, prog)
+		os.Exit(2)
+	}
+
+	caPath := os.Args[1]
+	caPool, err := makePoolFromFile(caPath)
+	if err != nil || caPool == nil {
+		fmt.Fprintf(os.Stderr, "failed to load CA certificate(s): %v\n", err)
+		os.Exit(1)
+	}
+
+    for _, certPath := range os.Args[2:] {
+        ok, exp := verifyAgainstCA(caPool, certPath)
+        name := filepath.Base(certPath)
+        // Load the leaf once for self-signed detection and potential expiry fallback
+        var leaf *x509.Certificate
+        if certs, err := loadCertsFromFile(certPath); err == nil && len(certs) > 0 {
+            leaf = certs[0]
+        }
+
+        // If the certificate is self-signed, prefer the SELF-SIGNED label
+        if isSelfSigned(leaf) {
+            fmt.Printf("%s: SELF-SIGNED\n", name)
+            continue
+        }
+
+        if ok {
+            // Display with the requested format
+            // Example: file: OK (expires 2031-01-01)
+            // Ensure deterministic date formatting
+            // Note: no timezone displayed; date only as per example
+            // If exp ended up empty for some reason, recompute safely
+            if exp == "" {
+                if leaf != nil {
+                    exp = leaf.NotAfter.Format("2006-01-02")
+                } else {
+                    // fallback to the current date to avoid empty; though shouldn't happen
+                    exp = time.Now().Format("2006-01-02")
+                }
+            }
+            fmt.Printf("%s: OK (expires %s)\n", name, exp)
+        } else {
+            fmt.Printf("%s: INVALID\n", name)
+        }
+    }
+}

cmd/ca-signed/testdata/goog-wr2.pem

@@ -0,0 +1,29 @@
+-----BEGIN CERTIFICATE-----
+MIIFCzCCAvOgAwIBAgIQf/AFoHxM3tEArZ1mpRB7mDANBgkqhkiG9w0BAQsFADBH
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+-----END CERTIFICATE-----

cmd/ca-signed/testdata/gts-r1.pem

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----
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+-----END CERTIFICATE-----

cmd/ca-signed/testdata/isrg-root-x1.pem

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----
+MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw
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+3BebYhtF8GaV0nxvwuo77x/Py9auJ/GpsMiu/X1+mvoiBOv/2X/qkSsisRcOj/KK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=
+-----END CERTIFICATE-----

cmd/ca-signed/testdata/le-e7.pem

@@ -0,0 +1,26 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

cmd/certdump/certdump.go

@@ -110,6 +110,14 @@ func showBasicConstraints(cert *x509.Certificate) {
 
 	if cert.IsCA {
 		fmt.Printf(", is a CA certificate")
+		if !cert.BasicConstraintsValid {
+			fmt.Printf(" (basic constraint failure)")
+		}
+	} else {
+		fmt.Printf("is not a CA certificate")
+		if cert.KeyUsage&x509.KeyUsageKeyEncipherment != 0 {
+			fmt.Printf(" (key encipherment usage enabled!)")
+		}
 	}
 
 	if (cert.MaxPathLen == 0 && cert.MaxPathLenZero) || (cert.MaxPathLen > 0) {

cmd/minmax/README

@@ -0,0 +1,3 @@
+minmax
+
+A quick tool to calculate minmax codes if needed for uLisp.

cmd/minmax/minmax.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"strconv"
+)
+
+var kinds = map[string]int{
+	"sym": 0,
+	"tf":  1,
+	"fn":  2,
+	"sp":  3,
+}
+
+func dieIf(err error) {
+	if err == nil {
+		return
+	}
+	fmt.Fprintf(os.Stderr, "[!] %s\n", err)
+	os.Exit(1)
+}
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: minmax type min max\n")
+	fmt.Fprintf(os.Stderr, "    type is one of fn, sp, sym, tf\n")
+	os.Exit(1)
+}
+
+func main() {
+	flag.Parse()
+
+	if flag.NArg() != 3 {
+		usage()
+	}
+
+	kind, ok := kinds[flag.Arg(0)]
+	if !ok {
+		usage()
+	}
+
+	min, err := strconv.Atoi(flag.Arg(1))
+	dieIf(err)
+
+	max, err := strconv.Atoi(flag.Arg(2))
+	dieIf(err)
+
+	code := kind << 6
+	code += (min << 3)
+	code += max
+	fmt.Printf("%0o\n", code)
+}

cmd/tlsinfo/README.txt

@@ -0,0 +1,34 @@
+tlsinfo: show TLS version, cipher, and peer certificates
+---------------------------------------------------------
+
+Description
+  tlsinfo connects to a TLS server and prints the negotiated TLS version and
+  cipher suite, followed by details for each certificate in the server’s
+  presented chain (as provided by the server).
+
+Usage
+  tlsinfo <hostname:port>
+
+Output
+  The program prints the negotiated protocol and cipher, then one section per
+  certificate in the order received from the server. Example fields:
+    TLS Version: TLS 1.3
+    Cipher Suite: TLS_AES_128_GCM_SHA256
+    Certificate 1
+        Subject: CN=example.com, O=Example Corp, C=US
+        Issuer: CN=Example Root CA, O=Example Corp, C=US
+        DNS Names: [example.com www.example.com]
+        Not Before: 2025-01-01 00:00:00 +0000 UTC
+        Not After:  2026-01-01 23:59:59 +0000 UTC
+
+Examples
+  # Inspect a public HTTPS endpoint
+  tlsinfo example.com:443
+
+Notes
+  - Verification is intentionally disabled (InsecureSkipVerify=true). The tool
+    does not validate the server certificate or hostname; it is for inspection
+    only.
+  - The SNI/ServerName is inferred from <hostname> when applicable.
+  - You must specify a port (e.g., 443 for HTTPS).
+  - The entire certificate chain is printed exactly as presented by the server.

cmd/tlsinfo/main.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"os"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Printf("Usage: %s ‹hostname:port>\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	hostPort := os.Args[1]
+	conn, err := tls.Dial("tcp", hostPort, &tls.Config{
+		InsecureSkipVerify: true,
+	})
+
+	if err != nil {
+		fmt.Printf("Failed to connect to the TLS server: %v\n", err)
+		os.Exit(1)
+	}
+	defer conn.Close()
+	state := conn.ConnectionState()
+	printConnectionDetails(state)
+}
+
+func printConnectionDetails(state tls.ConnectionState) {
+	version := tlsVersion(state.Version)
+	cipherSuite := tls.CipherSuiteName(state.CipherSuite)
+	fmt.Printf("TLS Version: %s\n", version)
+	fmt.Printf("Cipher Suite: %s\n", cipherSuite)
+	printPeerCertificates(state.PeerCertificates)
+}
+
+func tlsVersion(version uint16) string {
+	switch version {
+
+	case tls.VersionTLS13:
+		return "TLS 1.3"
+	case tls.VersionTLS12:
+
+		return "TLS 1.2"
+	case tls.VersionTLS11:
+		return "TLS 1.1"
+	case tls.VersionTLS10:
+		return "TLS 1.0"
+	default:
+		return "Unknown"
+	}
+}
+
+func printPeerCertificates(certificates []*x509.Certificate) {
+	for i, cert := range certificates {
+		fmt.Printf("Certificate %d\n", i+1)
+		fmt.Printf("\tSubject: %s\n", cert.Subject)
+		fmt.Printf("\tIssuer: %s\n", cert.Issuer)
+		fmt.Printf("\tDNS Names:	%v\n", cert.DNSNames)
+		fmt.Printf("\tNot Before: %s\n:", cert.NotBefore)
+		fmt.Printf("\tNot After: %s\n", cert.NotAfter)
+	}
+}