crypto.pem: add a static method Block.new, to replace new (#18846)

vlib/crypto/pem/decode.v

@@ -2,14 +2,12 @@ module pem
 
 import encoding.base64
 
-// `decode` reads `data` and returns the first parsed PEM Block along with the rest of
+// decode reads `data` and returns the first parsed PEM Block along with the rest of
 // the string. `none` is returned when a header is expected, but not present
 // or when a start of '-----BEGIN' or end of '-----END' can't be found in `data`
 pub fn decode(data string) ?(Block, string) {
 	mut rest := data[data.index(pem_begin)?..]
-	mut block := Block{
-		block_type: rest[pem_begin.len..].all_before(pem_eol)
-	}
+	mut block := Block.new(rest[pem_begin.len..].all_before(pem_eol))
 	block.headers, rest = parse_headers(rest[pem_begin.len..].all_after(pem_eol).trim_left(' \n\t\v\f\r'))?
 
 	block_end_index := rest.index(pem_end)?

vlib/crypto/pem/encode.v

@@ -3,7 +3,7 @@ module pem
 import encoding.base64
 import arrays
 
-// `encode_config` encodes the given block into a
+// encode encodes the given block into a
 // string using the EncodeConfig. It returns an error if `block_type` is undefined
 // or if a value in `headers` contains an invalid character ':'
 //

vlib/crypto/pem/pem.v

@@ -9,6 +9,13 @@ const (
 	colon     = ':'
 )
 
+// new returns a new `Block` with the specified block_type
+[deprecated: 'use Block.new instead']
+[inline]
+pub fn new(block_type string) Block {
+	return Block.new(block_type)
+}
+
 [params]
 pub struct EncodeConfig {
 pub mut:
@@ -34,7 +41,7 @@ pub enum Header {
 	crl
 }
 
-// `str` returns the string representation of the header
+// str returns the string representation of the header
 pub fn (header Header) str() string {
 	return match header {
 		.proctype { 'Proc-Type' }
@@ -62,6 +69,14 @@ pub mut:
 	data []u8
 }
 
+// Block.new returns a new `Block` with the specified block_type
+[inline]
+pub fn Block.new(block_type string) Block {
+	return Block{
+		block_type: block_type
+	}
+}
+
 // free the resources taken by the Block `block`
 [unsafe]
 pub fn (mut block Block) free() {
@@ -75,15 +90,7 @@ pub fn (mut block Block) free() {
 	}
 }
 
-// returns a new `Block` with the specified block_type
-[inline]
-pub fn new(block_type string) Block {
-	return Block{
-		block_type: block_type
-	}
-}
-
-// returns the selected key using the Header enum
+// header_by_key returns the selected key using the Header enum
 //
 // same as `block.headers[key.str()]`
 [inline]

vlib/crypto/pem/pem_test.v

@@ -44,6 +44,23 @@ fn test_encode_config() {
 	}
 }
 
+fn test_decode_no_pem() {
+	for test in pem.test_data_no_pem {
+		if _, _ := decode(test) {
+			assert false, 'Block.decode_partial should return `none` on input without PEM data'
+		} else {
+			assert true
+		}
+	}
+}
+
+const test_data_no_pem = [
+	'',
+	'-----BEGIN',
+	'-----BEGIN -----',
+	'-----END',
+]
+
 // https://datatracker.ietf.org/doc/html/rfc7468#section-4
 const test_data_rfc1421 = [
 	'-----BEGIN PRIVACY-ENHANCED MESSAGE-----