Module validation 

Centralized validation and helper functions.

Enums

ValidationError

Security validation error types

Constants

MAX_CONTIGS

Maximum number of contigs allowed in a single file (DOS protection)

MAX_FILENAME_LENGTH

Security-related constants for input validation

MIN_FILE_CONTENT_SIZE

Functions

check_contig_limit

Check if adding another contig would exceed the maximum allowed.

compute_signature

Compute a signature hash from a set of MD5 checksums.

is_valid_md5

Validate that a string is a valid MD5 checksum (32 hex characters).

normalize_md5

Normalize an MD5 string to lowercase. Returns None if the input is not a valid MD5.

validate_file_content

Validate that file content is not malicious or malformed

validate_file_format

Validate file content using magic numbers for known binary formats

validate_filename

Secure filename validation to prevent directory traversal and other attacks

validate_upload

Comprehensive input validation combining filename and content checks