SHA-1 produces the 160 bit digest of a message. For example:
>>> from Crypto.Hash import SHA1 >>> >>> h = SHA1.new() >>> h.update(b'Hello') >>> print h.hexdigest()
SHA stands for Secure Hash Algorithm.
This algorithm is not considered secure. Do not use it for new designs.
SHA-1 is vulnerable to length-extension attacks, which are relevant if you are computing the hash of a secret message.
For instance, let’s say you were planning to build a cheap MAC by concatenating a secret key to a public message m (bad idea!):
By only knowing the digest h and the length of m and k, the attacker can easily compute a second digest h’:
where p is a well-known bit string and the attacker can pick a bit string z at will.
Create a new hash object.
Parameters: msg (byte string) – Optional. The very first chunk of the message to hash. It is equivalent to an early call to
A SHA-1 hash object. Do not instantiate directly. Use the
- oid (string) – ASN.1 Object ID
- block_size (integer) – the size in bytes of the internal message block, input to the compression function
- digest_size (integer) – the size in bytes of the resulting hash
Continue hashing of a message by consuming the next chunk of data.
Parameters: msg – The next chunk of the message being hashed.
Return the binary (non-printable) digest of the message that has been hashed so far.
Returns: The hash digest, computed over the data processed so far. Binary form. Return type: byte string
Return the printable digest of the message that has been hashed so far.
Returns: The hash digest, computed over the data processed so far. Hexadecimal encoded. Return type: string