- ext
- ssl
- ssl.pl
- crypto.pl -- Cryptography and authentication library
- crypto_n_random_bytes/2
- crypto_data_hash/3
- crypto_file_hash/3
- crypto_context_new/2
- crypto_data_context/3
- crypto_context_hash/2
- crypto_open_hash_stream/3
- crypto_stream_hash/2
- crypto_password_hash/2
- crypto_password_hash/3
- crypto_data_hkdf/4
- ecdsa_sign/4
- ecdsa_verify/4
- hex_bytes/2
- rsa_private_decrypt/4
- rsa_private_encrypt/4
- rsa_public_decrypt/4
- rsa_public_encrypt/4
- rsa_sign/4
- rsa_verify/4
- crypto_data_decrypt/6
- crypto_data_encrypt/6
- crypto_modular_inverse/3
- crypto_generate_prime/3
- crypto_is_prime/2
- crypto_name_curve/2
- crypto_curve_order/2
- crypto_curve_generator/2
- crypto_curve_scalar_mult/4
- xmldsig.pl -- XML Digital signature
- xmlenc.pl -- XML encryption library
- ssl
- crypto_n_random_bytes(+N, -Bytes) is det
- Bytes is unified with a list of N cryptographically secure
pseudo-random bytes. Each byte is an integer between 0 and 255. If
the internal pseudo-random number generator (PRNG) has not been
seeded with enough entropy to ensure an unpredictable byte
sequence, an exception is thrown.
One way to relate such a list of bytes to an integer is to use CLP(FD) constraints as follows:
:- use_module(library(clpfd)). bytes_integer(Bs, N) :- foldl(pow, Bs, 0-0, N-_). pow(B, N0-I0, N-I) :- B in 0..255, N #= N0 + B*256^I0, I #= I0 + 1.With this definition, you can generate a random 256-bit integer from a list of 32 random bytes:
?- crypto_n_random_bytes(32, Bs), bytes_integer(Bs, I). Bs = [98, 9, 35, 100, 126, 174, 48, 176, 246|...], I = 109798276762338328820827...(53 digits omitted).
The above relation also works in the other direction, letting you translate an integer to a list of bytes. In addition, you can use hex_bytes/2 to convert bytes to tokens that can be easily exchanged in your applications. This also works if you have compiled SWI-Prolog without support for large integers.