docs: Add comments when handling parsing errors

ProtonMail · Nov 14, 2024 · 6e34c69 · 6e34c69
1 parent 6525f78
commit 6e34c69
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Showing 2 changed files with 16 additions and 0 deletions.
diff --git a/openpgp/read.go b/openpgp/read.go
@@ -234,8 +234,12 @@ FindKey:
 	mdFinal, sensitiveParsingErr := readSignedMessage(packets, md, keyring, config)
 	if sensitiveParsingErr != nil {
 		if md.decrypted != nil {
+			// The data is read from a stream that decrypts using a session key;
+			// therefore, we need to handle parsing errors appropriately.
+			// It's essential to mitigate the risk of oracle attacks.
 			return nil, errors.HandleDecryptionSensitiveParsingError(sensitiveParsingErr)
 		}
+		// Data was not encrypted and is directly read in plaintext.
 		return nil, errors.StructuralError(errors.GenericParsingErrorMessage)
 	}
 	return mdFinal, nil
@@ -447,8 +451,12 @@ func (scr *signatureCheckReader) Read(buf []byte) (int, error) {
 
 	if sensitiveParsingError != nil {
 		if scr.md.decrypted != nil {
+			// The data is read from a stream that decrypts using a session key;
+			// therefore, we need to handle parsing errors appropriately.
+			// This is essential to mitigate the risk of oracle attacks.
 			return n, errors.HandleDecryptionSensitiveParsingError(sensitiveParsingError)
 		}
+		// Data was not encrypted and is directly read in plaintext.
 		return n, errors.StructuralError(errors.GenericParsingErrorMessage)
 	}
 

diff --git a/openpgp/v2/read.go b/openpgp/v2/read.go
@@ -269,8 +269,12 @@ FindKey:
 	mdFinal, sensitiveParsingErr := readSignedMessage(packets, md, keyring, config)
 	if sensitiveParsingErr != nil {
 		if md.decrypted != nil {
+			// The data is read from a stream that decrypts using a session key;
+			// therefore, we need to handle parsing errors appropriately.
+			// This is essential to mitigate the risk of oracle attacks.
 			return nil, errors.HandleDecryptionSensitiveParsingError(sensitiveParsingErr)
 		}
+		// Data was not encrypted and is directly read in plaintext.
 		return nil, errors.StructuralError(errors.GenericParsingErrorMessage)
 	}
 	return mdFinal, nil
@@ -654,8 +658,12 @@ func (scr *signatureCheckReader) Read(buf []byte) (int, error) {
 
 	if sensitiveParsingError != nil {
 		if scr.md.decrypted != nil {
+			// The data is read from a stream that decrypts using a session key;
+			// therefore, we need to handle parsing errors appropriately.
+			// This is essential to mitigate the risk of oracle attacks.
 			return n, errors.HandleDecryptionSensitiveParsingError(sensitiveParsingError)
 		}
+		// Data was not encrypted and is directly read in plaintext.
 		return n, errors.StructuralError(errors.GenericParsingErrorMessage)
 	}