crypto - Crypto Functions
Please see following description for synopsis
crypto(3) Erlang Module Definition crypto(3)
NAME
crypto - Crypto Functions
DESCRIPTION
This module provides a set of cryptographic functions.
Hash functions:
SHA1, SHA2:
Secure Hash Standard [FIPS PUB 180-4]
SHA3:
SHA-3 Standard: Permutation-Based Hash and Extendable-Output
Functions [FIPS PUB 202]
BLAKE2:
BLAKE2 -- fast secure hashing
MD5:
The MD5 Message Digest Algorithm [RFC 1321]
MD4:
The MD4 Message Digest Algorithm [RFC 1320]
MACs - Message Authentication Codes:
Hmac functions:
Keyed-Hashing for Message Authentication [RFC 2104]
Cmac functions:
The AES-CMAC Algorithm [RFC 4493]
POLY1305:
ChaCha20 and Poly1305 for IETF Protocols [RFC 7539]
Symmetric Ciphers:
DES, 3DES and AES:
Block Cipher Techniques [NIST]
Blowfish:
Fast Software Encryption, Cambridge Security Workshop Proceed-
ings (December 1993), Springer-Verlag, 1994, pp. 191-204.
Chacha20:
ChaCha20 and Poly1305 for IETF Protocols [RFC 7539]
Chacha20_poly1305:
ChaCha20 and Poly1305 for IETF Protocols [RFC 7539]
Modes:
ECB, CBC, CFB, OFB and CTR:
Recommendation for Block Cipher Modes of Operation: Methods and
Techniques [NIST SP 800-38A]
GCM:
Recommendation for Block Cipher Modes of Operation:
Galois/Counter Mode (GCM) and GMAC [NIST SP 800-38D]
CCM:
Recommendation for Block Cipher Modes of Operation: The CCM Mode
for Authentication and Confidentiality [NIST SP 800-38C]
Asymetric Ciphers - Public Key Techniques:
RSA:
PKCS #1: RSA Cryptography Specifications [RFC 3447]
DSS:
Digital Signature Standard (DSS) [FIPS 186-4]
ECDSA:
Elliptic Curve Digital Signature Algorithm [ECDSA]
SRP:
The SRP Authentication and Key Exchange System [RFC 2945]
Note:
The actual supported algorithms and features depends on their avail-
ability in the actual libcrypto used. See the crypto (App) about depen-
dencies.
Enabling FIPS mode will also disable algorithms and features.
The CRYPTO User's Guide has more information on FIPS, Engines and Algo-
rithm Details like key lengths.
DATA TYPES
Ciphers
cipher() = cipher_no_iv() | cipher_iv() | cipher_aead()
cipher_no_iv() =
aes_128_ecb | aes_192_ecb | aes_256_ecb | aes_ecb |
blowfish_ecb | des_ecb | rc4
cipher_iv() =
aes_128_cbc | aes_192_cbc | aes_256_cbc | aes_cbc |
aes_128_cfb128 | aes_192_cfb128 | aes_256_cfb128 |
aes_cfb128 | aes_128_cfb8 | aes_192_cfb8 | aes_256_cfb8 |
aes_cfb8 | aes_128_ctr | aes_192_ctr | aes_256_ctr | aes_ctr |
blowfish_cbc | blowfish_cfb64 | blowfish_ofb64 | chacha20 |
des_ede3_cbc | des_ede3_cfb | des_cbc | des_cfb | rc2_cbc
cipher_aead() =
aes_128_ccm | aes_192_ccm | aes_256_ccm | aes_ccm |
aes_128_gcm | aes_192_gcm | aes_256_gcm | aes_gcm |
chacha20_poly1305
Ciphers known by the CRYPTO application.
Note that this list might be reduced if the underlying libcrypto
does not support all of them.
crypto_opts() = boolean() | [crypto_opt()]
crypto_opt() = {encrypt, boolean()} | {padding, padding()}
Selects encryption ({encrypt,true}) or decryption
({encrypt,false}).
padding() = cryptolib_padding() | otp_padding()
This option handles padding in the last block. If not set, no
padding is done and any bytes in the last unfilled block is
silently discarded.
cryptolib_padding() = none | pkcs_padding
The cryptolib_padding are paddings that may be present in the
underlying cryptolib linked to the Erlang/OTP crypto app.
For OpenSSL, see the OpenSSL documentation. and find
EVP_CIPHER_CTX_set_padding() in cryptolib for your linked ver-
sion.
otp_padding() = zero | random
Erlang/OTP adds a either padding of zeroes or padding with ran-
dom bytes.
Digests and hash
hash_algorithm() =
sha1() |
sha2() |
sha3() |
blake2() |
ripemd160 |
compatibility_only_hash()
hmac_hash_algorithm() =
sha1() | sha2() | sha3() | compatibility_only_hash()
cmac_cipher_algorithm() =
aes_128_cbc | aes_192_cbc | aes_256_cbc | aes_cbc |
aes_128_cfb128 | aes_192_cfb128 | aes_256_cfb128 |
aes_cfb128 | aes_128_cfb8 | aes_192_cfb8 | aes_256_cfb8 |
aes_cfb8 | blowfish_cbc | des_cbc | des_ede3_cbc | rc2_cbc
rsa_digest_type() = sha1() | sha2() | md5 | ripemd160
dss_digest_type() = sha1() | sha2()
ecdsa_digest_type() = sha1() | sha2()
sha1() = sha
sha2() = sha224 | sha256 | sha384 | sha512
sha3() = sha3_224 | sha3_256 | sha3_384 | sha3_512
blake2() = blake2b | blake2s
compatibility_only_hash() = md5 | md4
The compatibility_only_hash() algorithms are recommended only
for compatibility with existing applications.
Elliptic Curves
ec_named_curve() =
brainpoolP160r1 | brainpoolP160t1 | brainpoolP192r1 |
brainpoolP192t1 | brainpoolP224r1 | brainpoolP224t1 |
brainpoolP256r1 | brainpoolP256t1 | brainpoolP320r1 |
brainpoolP320t1 | brainpoolP384r1 | brainpoolP384t1 |
brainpoolP512r1 | brainpoolP512t1 | c2pnb163v1 | c2pnb163v2 |
c2pnb163v3 | c2pnb176v1 | c2pnb208w1 | c2pnb272w1 |
c2pnb304w1 | c2pnb368w1 | c2tnb191v1 | c2tnb191v2 |
c2tnb191v3 | c2tnb239v1 | c2tnb239v2 | c2tnb239v3 |
c2tnb359v1 | c2tnb431r1 | ipsec3 | ipsec4 | prime192v1 |
prime192v2 | prime192v3 | prime239v1 | prime239v2 |
prime239v3 | prime256v1 | secp112r1 | secp112r2 | secp128r1 |
secp128r2 | secp160k1 | secp160r1 | secp160r2 | secp192k1 |
secp192r1 | secp224k1 | secp224r1 | secp256k1 | secp256r1 |
secp384r1 | secp521r1 | sect113r1 | sect113r2 | sect131r1 |
sect131r2 | sect163k1 | sect163r1 | sect163r2 | sect193r1 |
sect193r2 | sect233k1 | sect233r1 | sect239k1 | sect283k1 |
sect283r1 | sect409k1 | sect409r1 | sect571k1 | sect571r1 |
wtls1 | wtls10 | wtls11 | wtls12 | wtls3 | wtls4 | wtls5 |
wtls6 | wtls7 | wtls8 | wtls9
edwards_curve_dh() = x25519 | x448
edwards_curve_ed() = ed25519 | ed448
Note that some curves are disabled if FIPS is enabled.
ec_explicit_curve() =
{Field :: ec_field(),
Curve :: ec_curve(),
BasePoint :: binary(),
Order :: binary(),
CoFactor :: none | binary()}
ec_field() = ec_prime_field() | ec_characteristic_two_field()
ec_curve() =
{A :: binary(), B :: binary(), Seed :: none | binary()}
Parametric curve definition.
ec_prime_field() = {prime_field, Prime :: integer()}
ec_characteristic_two_field() =
{characteristic_two_field,
M :: integer(),
Basis :: ec_basis()}
ec_basis() =
{tpbasis, K :: integer() >= 0} |
{ppbasis,
K1 :: integer() >= 0,
K2 :: integer() >= 0,
K3 :: integer() >= 0} |
onbasis
Curve definition details.
Keys
key_integer() = integer() | binary()
Always binary() when used as return value
Public/Private Keys
rsa_public() = [key_integer()]
rsa_private() = [key_integer()]
rsa_params() =
{ModulusSizeInBits :: integer(),
PublicExponent :: key_integer()}
rsa_public() = [E, N]
rsa_private() = [E, N, D] | [E, N, D, P1, P2, E1, E2, C]
Where E is the public exponent, N is public modulus and D is the
private exponent. The longer key format contains redundant
information that will make the calculation faster. P1 and P2 are
first and second prime factors. E1 and E2 are first and second
exponents. C is the CRT coefficient. The terminology is taken
from RFC 3447.
dss_public() = [key_integer()]
dss_private() = [key_integer()]
dss_public() = [P, Q, G, Y]
Where P, Q and G are the dss parameters and Y is the public key.
dss_private() = [P, Q, G, X]
Where P, Q and G are the dss parameters and X is the private
key.
ecdsa_public() = key_integer()
ecdsa_private() = key_integer()
ecdsa_params() = ec_named_curve() | ec_explicit_curve()
eddsa_public() = key_integer()
eddsa_private() = key_integer()
eddsa_params() = edwards_curve_ed()
srp_public() = key_integer()
srp_private() = key_integer()
srp_public() = key_integer()
Where is A or B from SRP design
srp_private() = key_integer()
Where is a or b from SRP design
srp_gen_params() =
{user, srp_user_gen_params()} | {host, srp_host_gen_params()}
srp_comp_params() =
{user, srp_user_comp_params()} |
{host, srp_host_comp_params()}
srp_user_gen_params() = [DerivedKey::binary(), Prime::binary(), Generator::binary(), Version::atom()]
srp_host_gen_params() = [Verifier::binary(), Prime::binary(), Version::atom() ]
srp_user_comp_params() = [DerivedKey::binary(), Prime::binary(), Generator::binary(), Version::atom() | ScramblerArg::list()]
srp_host_comp_params() = [Verifier::binary(), Prime::binary(), Version::atom() | ScramblerArg::list()]
Where Verifier is v, Generator is g and Prime is N, DerivedKey
is X, and Scrambler is u (optional will be generated if not pro-
vided) from SRP design Version = '3' | '6' | '6a'
Public Key Ciphers
pk_encrypt_decrypt_algs() = rsa
Algorithms for public key encrypt/decrypt. Only RSA is sup-
ported.
pk_encrypt_decrypt_opts() = [rsa_opt()] | rsa_compat_opts()
rsa_opt() =
{rsa_padding, rsa_padding()} |
{signature_md, atom()} |
{rsa_mgf1_md, sha} |
{rsa_oaep_label, binary()} |
{rsa_oaep_md, sha}
rsa_padding() =
rsa_pkcs1_padding | rsa_pkcs1_oaep_padding |
rsa_sslv23_padding | rsa_x931_padding | rsa_no_padding
Options for public key encrypt/decrypt. Only RSA is supported.
Warning:
The RSA options are experimental.
The exact set of options and there syntax may be changed without
prior notice.
rsa_compat_opts() = [{rsa_pad, rsa_padding()}] | rsa_padding()
Those option forms are kept only for compatibility and should
not be used in new code.
Public Key Sign and Verify
pk_sign_verify_algs() = rsa | dss | ecdsa | eddsa
Algorithms for sign and verify.
pk_sign_verify_opts() = [rsa_sign_verify_opt()]
rsa_sign_verify_opt() =
{rsa_padding, rsa_sign_verify_padding()} |
{rsa_pss_saltlen, integer()} |
{rsa_mgf1_md, sha2()}
rsa_sign_verify_padding() =
rsa_pkcs1_padding | rsa_pkcs1_pss_padding | rsa_x931_padding |
rsa_no_padding
Options for sign and verify.
Warning:
The RSA options are experimental.
The exact set of options and there syntax may be changed without
prior notice.
Diffie-Hellman Keys and parameters
dh_public() = key_integer()
dh_private() = key_integer()
dh_params() = [key_integer()]
dh_params() = [P, G] | [P, G, PrivateKeyBitLength]
ecdh_public() = key_integer()
ecdh_private() = key_integer()
ecdh_params() =
ec_named_curve() | edwards_curve_dh() | ec_explicit_curve()
Types for Engines
engine_key_ref() =
#{engine := engine_ref(),
key_id := key_id(),
password => password(),
term() => term()}
engine_ref() = term()
The result of a call to engine_load/3.
key_id() = string() | binary()
Identifies the key to be used. The format depends on the loaded
engine. It is passed to the ENGINE_load_(private|public)_key
functions in libcrypto.
password() = string() | binary()
The password of the key stored in an engine.
engine_method_type() =
engine_method_rsa | engine_method_dsa | engine_method_dh |
engine_method_rand | engine_method_ecdh |
engine_method_ecdsa | engine_method_ciphers |
engine_method_digests | engine_method_store |
engine_method_pkey_meths | engine_method_pkey_asn1_meths |
engine_method_ec
engine_cmnd() = {unicode:chardata(), unicode:chardata()}
Pre and Post commands for engine_load/3 and /4.
Internal data types
crypto_state()
hash_state()
mac_state()
Contexts with an internal state that should not be manipulated
but passed between function calls.
Error types
run_time_error() = any()
The exception error:badarg signifies that one or more arguments
are of wrong data type, or are otherwise badly formed.
The exception error:notsup signifies that the algorithm is known
but is not supported by current underlying libcrypto or explic-
itly disabled when building that.
For a list of supported algorithms, see supports(ciphers).
descriptive_error() = any()
This is a more developed variant of the older run_time_error().
The exception is:
{Tag, {C_FileName,LineNumber}, Description}
Tag = badarg | notsup | error
C_FileName = string()
LineNumber = integer()
Description = string()
It is like the older type an exception of the error class. In
addition they contain a descriptive text in English. That text
is targeted to a developer. Examples are "Bad key size" or
"Cipher id is not an atom".
The exception tags are:
badarg:
Signifies that one or more arguments are of wrong data type
or are otherwise badly formed.
notsup:
Signifies that the algorithm is known but is not supported
by current underlying libcrypto or explicitly disabled when
building that one.
error:
An error condition that should not occur, for example a mem-
ory allocation failed or the underlying cryptolib returned
an error code, for example "Can't initialize context, step
1". Those text usually needs searching the C-code to be
understood.
To catch the exception, use for example:
try crypto:crypto_init(Ciph, Key, IV, true)
catch
error:{Tag, {C_FileName,LineNumber}, Description} ->
do_something(......)
.....
end
EXPORTS
crypto_init(Cipher, Key, FlagOrOptions) ->
State | descriptive_error()
Types:
Cipher = cipher_no_iv()
Key = iodata()
FlagOrOptions = crypto_opts() | boolean()
State = crypto_state()
Equivalent to the call crypto_init(Cipher, Key, <<>>, FlagOrOp-
tions). It is intended for ciphers without an IV (nounce).
crypto_init(Cipher, Key, IV, FlagOrOptions) ->
State | descriptive_error()
Types:
Cipher = cipher_iv()
Key = IV = iodata()
FlagOrOptions = crypto_opts()
State = crypto_state()
Initializes a series of encryptions or decryptions and creates
an internal state with a reference that is returned.
If IV = <<>>, no IV is used. This is intended for ciphers with-
out an IV (nounce). See crypto_init/3.
If IV = undefined, the IV must be added by calls to
crypto_dyn_iv_update/3. This is intended for cases where the IV
(nounce) need to be changed for each encryption and decryption.
See crypto_dyn_iv_init/3.
The actual encryption or decryption is done by crypto_update/2
(or crypto_dyn_iv_update/3 ).
For encryption, set the FlagOrOptions to true or
[{encrypt,true}]. For decryption, set it to false or
[{encrypt,false}].
Padding could be enabled with the option {padding,Padding}. The
cryptolib_padding enables pkcs_padding or no padding (none). The
paddings zero or random fills the last part of the last block
with zeroes or random bytes. If the last block is already full,
nothing is added.
In decryption, the cryptolib_padding removes such padding, if
present. The otp_padding is not removed - it has to be done
elsewhere.
If padding is {padding,none} or not specifed and the total data
from all subsequent crypto_updates does not fill the last block
fully, that last data is lost. In case of {padding,none} there
will be an error in this case. If padding is not specified, the
bytes of the unfilled block is silently discarded.
The actual padding is performed by crypto_final/1.
For blocksizes call cipher_info/1.
See examples in the User's Guide.
crypto_update(State, Data) -> Result | descriptive_error()
Types:
State = crypto_state()
Data = iodata()
Result = binary()
It does an actual crypto operation on a part of the full text.
If the part is less than a number of full blocks, only the full
blocks (possibly none) are encrypted or decrypted and the
remaining bytes are saved to the next crypto_update operation.
The State should be created with crypto_init/3 or crypto_init/4.
See examples in the User's Guide.
crypto_dyn_iv_init(Cipher, Key, FlagOrOptions) ->
State | descriptive_error()
Types:
Cipher = cipher_iv()
Key = iodata()
FlagOrOptions = crypto_opts() | boolean()
State = crypto_state()
Initializes a series of encryptions or decryptions where the IV
is provided later. The actual encryption or decryption is done
by crypto_dyn_iv_update/3.
The function is equivalent to crypto_init(Cipher, Key, unde-
fined, FlagOrOptions).
crypto_final(State) -> FinalResult | descriptive_error()
Types:
State = crypto_state()
FinalResult = binary()
Finalizes a series of encryptions or decryptions and delivers
the final bytes of the final block. The data returned from this
function may be empty if no padding was enabled in
crypto_init/3,4 or crypto_dyn_iv_init/3.
crypto_get_data(State) -> Result
Types:
State = crypto_state()
Result = map()
Returns information about the State in the argument. The infor-
mation is the form of a map, which currently contains at least:
size:
The number of bytes encrypted or decrypted so far.
padding_size:
After a call to crypto_final/1 it contains the number of
bytes padded. Otherwise 0.
padding_type:
The type of the padding as provided in the call ot
crypto_init/3,4.
encrypt:
Is true if encryption is performed. It is false otherwise.
crypto_dyn_iv_update(State, Data, IV) ->
Result | descriptive_error()
Types:
State = crypto_state()
Data = IV = iodata()
Result = binary()
Do an actual crypto operation on a part of the full text and the
IV is supplied for each part. The State should be created with
crypto_dyn_iv_init/3.
crypto_one_time(Cipher, Key, Data, FlagOrOptions) ->
Result | descriptive_error()
Types:
Cipher = cipher_no_iv()
Key = Data = iodata()
FlagOrOptions = crypto_opts() | boolean()
Result = binary()
As crypto_one_time/5 but for ciphers without IVs.
crypto_one_time(Cipher, Key, IV, Data, FlagOrOptions) ->
Result | descriptive_error()
Types:
Cipher = cipher_iv()
Key = IV = Data = iodata()
FlagOrOptions = crypto_opts() | boolean()
Result = binary()
Do a complete encrypt or decrypt of the full text in the argu-
ment Data.
For encryption, set the FlagOrOptions to true. For decryption,
set it to false. For setting other options, see crypto_init/4.
See examples in the User's Guide.
crypto_one_time_aead(Cipher, Key, IV, InText, AAD,
EncFlag :: true) ->
Result | descriptive_error()
crypto_one_time_aead(Cipher, Key, IV, InText, AAD, TagOrTagLength,
EncFlag) ->
Result | descriptive_error()
Types:
Cipher = cipher_aead()
Key = IV = InText = AAD = iodata()
TagOrTagLength = EncryptTagLength | DecryptTag
EncryptTagLength = integer() >= 0
DecryptTag = iodata()
EncFlag = boolean()
Result = EncryptResult | DecryptResult
EncryptResult = {OutCryptoText, OutTag}
DecryptResult = OutPlainText | error
OutCryptoText = OutTag = OutPlainText = binary()
Do a complete encrypt or decrypt with an AEAD cipher of the full
text.
For encryption, set the EncryptFlag to true and set the TagOrTa-
gLength to the wanted size (in bytes) of the tag, that is, the
tag length. If the default length is wanted, the crypto_aead/6
form may be used.
For decryption, set the EncryptFlag to false and put the tag to
be checked in the argument TagOrTagLength.
See examples in the User's Guide.
supports(Type) -> Support
Types:
Type = hashs | ciphers | public_keys | macs | curves |
rsa_opts
Support = Hashs | Ciphers | PKs | Macs | Curves | RSAopts
Hashs =
[sha1() |
sha2() |
sha3() |
blake2() |
ripemd160 |
compatibility_only_hash()]
Ciphers = [cipher()]
PKs = [rsa | dss | ecdsa | dh | ecdh | eddh | ec_gf2m]
Macs = [hmac | cmac | poly1305]
Curves =
[ec_named_curve() | edwards_curve_dh() |
edwards_curve_ed()]
RSAopts = [rsa_sign_verify_opt() | rsa_opt()]
Can be used to determine which crypto algorithms that are sup-
ported by the underlying libcrypto library
See hash_info/1 and cipher_info/1 for information about the hash
and cipher algorithms.
mac(Type :: poly1305, Key, Data) -> Mac | descriptive_error()
Types:
Key = Data = iodata()
Mac = binary()
Short for mac(Type, undefined, Key, Data).
mac(Type, SubType, Key, Data) -> Mac | descriptive_error()
Types:
Type = hmac | cmac | poly1305
SubType =
hmac_hash_algorithm() | cmac_cipher_algorithm() | unde-
fined
Key = Data = iodata()
Mac = binary()
Computes a MAC (Message Authentication Code) of type Type from
Data.
SubType depends on the MAC Type:
* For hmac it is a hash algorithm, see Algorithm Details in
the User's Guide.
* For cmac it is a cipher suitable for cmac, see Algorithm
Details in the User's Guide.
* For poly1305 it should be set to undefined or the mac/2
function could be used instead, see Algorithm Details in the
User's Guide.
Key is the authentication key with a length according to the
Type and SubType. The key length could be found with the
hash_info/1 (hmac) for and cipher_info/1 (cmac) functions. For
poly1305 the key length is 32 bytes. Note that the cryptographic
quality of the key is not checked.
The Mac result will have a default length depending on the Type
and SubType. To set a shorter length, use macN/4 or macN/5
instead. The default length is documented in Algorithm Details
in the User's Guide.
macN(Type :: poly1305, Key, Data, MacLength) ->
Mac | descriptive_error()
Types:
Key = Data = iodata()
Mac = binary()
MacLength = integer() >= 1
Short for macN(Type, undefined, Key, Data, MacLength).
macN(Type, SubType, Key, Data, MacLength) ->
Mac | descriptive_error()
Types:
Type = hmac | cmac | poly1305
SubType =
hmac_hash_algorithm() | cmac_cipher_algorithm() | unde-
fined
Key = Data = iodata()
Mac = binary()
MacLength = integer() >= 1
Computes a MAC (Message Authentication Code) as mac/3 and mac/4
but MacLength will limit the size of the resultant Mac to at
most MacLength bytes. Note that if MacLength is greater than the
actual number of bytes returned from the underlying hash, the
returned hash will have that shorter length instead.
The max MacLength is documented in Algorithm Details in the
User's Guide.
mac_init(Type :: poly1305, Key) -> State | descriptive_error()
Types:
Key = iodata()
State = mac_state()
Short for mac_init(Type, undefined, Key).
mac_init(Type, SubType, Key) -> State | descriptive_error()
Types:
Type = hmac | cmac | poly1305
SubType =
hmac_hash_algorithm() | cmac_cipher_algorithm() | unde-
fined
Key = iodata()
State = mac_state()
Initializes the context for streaming MAC operations.
Type determines which mac algorithm to use in the MAC operation.
SubType depends on the MAC Type:
* For hmac it is a hash algorithm, see Algorithm Details in
the User's Guide.
* For cmac it is a cipher suitable for cmac, see Algorithm
Details in the User's Guide.
* For poly1305 it should be set to undefined or the mac/2
function could be used instead, see Algorithm Details in the
User's Guide.
Key is the authentication key with a length according to the
Type and SubType. The key length could be found with the
hash_info/1 (hmac) for and cipher_info/1 (cmac) functions. For
poly1305 the key length is 32 bytes. Note that the cryptographic
quality of the key is not checked.
The returned State should be used in one or more subsequent
calls to mac_update/2. The MAC value is finally returned by
calling mac_final/1 or mac_finalN/2.
See examples in the User's Guide.
mac_update(State0, Data) -> State | descriptive_error()
Types:
Data = iodata()
State0 = State = mac_state()
Updates the MAC represented by State0 using the given Data which
could be of any length.
The State0 is the State value originally from a MAC init func-
tion, that is mac_init/2, mac_init/3 or a previous call of
mac_update/2. The value State0 is returned unchanged by the
function as State.
mac_final(State) -> Mac | descriptive_error()
Types:
State = mac_state()
Mac = binary()
Finalizes the MAC operation referenced by State. The Mac result
will have a default length depending on the Type and SubType in
the mac_init/2,3 call. To set a shorter length, use mac_finalN/2
instead. The default length is documented in Algorithm Details
in the User's Guide.
mac_finalN(State, MacLength) -> Mac | descriptive_error()
Types:
State = mac_state()
MacLength = integer() >= 1
Mac = binary()
Finalizes the MAC operation referenced by State.
Mac will be a binary with at most MacLength bytes. Note that if
MacLength is greater than the actual number of bytes returned
from the underlying hash, the returned hash will have that
shorter length instead.
The max MacLength is documented in Algorithm Details in the
User's Guide.
bytes_to_integer(Bin :: binary()) -> integer()
Convert binary representation, of an integer, to an Erlang inte-
ger.
compute_key(Type, OthersPublicKey, MyPrivateKey, Params) ->
SharedSecret
Types:
Type = dh | ecdh | eddh | srp
SharedSecret = binary()
OthersPublicKey = dh_public() | ecdh_public() | srp_public()
MyPrivateKey =
dh_private() | ecdh_private() | {srp_public(), srp_pri-
vate()}
Params = dh_params() | ecdh_params() | srp_comp_params()
Computes the shared secret from the private key and the other
party's public key. See also public_key:compute_key/2
exor(Bin1 :: iodata(), Bin2 :: iodata()) -> binary()
Performs bit-wise XOR (exclusive or) on the data supplied.
generate_key(Type, Params) -> {PublicKey, PrivKeyOut}
generate_key(Type, Params, PrivKeyIn) -> {PublicKey, PrivKeyOut}
Types:
Type = dh | ecdh | eddh | eddsa | rsa | srp
PublicKey =
dh_public() | ecdh_public() | rsa_public() | srp_public()
PrivKeyIn =
undefined |
dh_private() |
ecdh_private() |
rsa_private() |
{srp_public(), srp_private()}
PrivKeyOut =
dh_private() |
ecdh_private() |
rsa_private() |
{srp_public(), srp_private()}
Params =
dh_params() |
ecdh_params() |
eddsa_params() |
rsa_params() |
srp_comp_params()
Generates a public key of type Type. See also public_key:gener-
ate_key/1. May raise exception:
* error:badarg: an argument is of wrong type or has an illegal
value,
* error:low_entropy: the random generator failed due to lack
of secure "randomness",
* error:computation_failed: the computation fails of another
reason than low_entropy.
Note:
RSA key generation is only available if the runtime was built
with dirty scheduler support. Otherwise, attempting to generate
an RSA key will raise exception error:notsup.
hash(Type, Data) -> Digest
Types:
Type = hash_algorithm()
Data = iodata()
Digest = binary()
Computes a message digest of type Type from Data.
May raise exception error:notsup in case the chosen Type is not
supported by the underlying libcrypto implementation.
hash_init(Type) -> State
Types:
Type = hash_algorithm()
State = hash_state()
Initializes the context for streaming hash operations. Type
determines which digest to use. The returned context should be
used as argument to hash_update.
May raise exception error:notsup in case the chosen Type is not
supported by the underlying libcrypto implementation.
hash_update(State, Data) -> NewState
Types:
State = NewState = hash_state()
Data = iodata()
Updates the digest represented by Context using the given Data.
Context must have been generated using hash_init or a previous
call to this function. Data can be any length. NewContext must
be passed into the next call to hash_update or hash_final.
hash_final(State) -> Digest
Types:
State = hash_state()
Digest = binary()
Finalizes the hash operation referenced by Context returned from
a previous call to hash_update. The size of Digest is determined
by the type of hash function used to generate it.
info_fips() -> not_supported | not_enabled | enabled
Provides information about the FIPS operating status of crypto
and the underlying libcrypto library. If crypto was built with
FIPS support this can be either enabled (when running in FIPS
mode) or not_enabled. For other builds this value is always
not_supported.
See enable_fips_mode/1 about how to enable FIPS mode.
Warning:
In FIPS mode all non-FIPS compliant algorithms are disabled and
raise exception error:notsup. Check supports(ciphers) that in
FIPS mode returns the restricted list of available algorithms.
enable_fips_mode(Enable) -> Result
Types:
Enable = Result = boolean()
Enables (Enable = true) or disables (Enable = false) FIPS mode.
Returns true if the operation was successful or false otherwise.
Note that to enable FIPS mode succesfully, OTP must be built
with the configure option --enable-fips, and the underlying
libcrypto must also support FIPS.
See also info_fips/0.
info() ->
#{compile_type := normal | debug | valgrind | asan,
cryptolib_version_compiled => string() | undefined,
cryptolib_version_linked := string(),
link_type := dynamic | static,
otp_crypto_version := string()}
Provides a map with information about the compilation and link-
ing of crypto.
Example:
1> crypto:info().
#{compile_type => normal,
cryptolib_version_compiled => "OpenSSL 3.0.0 7 sep 2021",
cryptolib_version_linked => "OpenSSL 3.0.0 7 sep 2021",
link_type => dynamic,
otp_crypto_version => "5.0.2"}
2>
More association types than documented may be present in the
map.
info_lib() -> [{Name, VerNum, VerStr}]
Types:
Name = binary()
VerNum = integer()
VerStr = binary()
Provides the name and version of the libraries used by crypto.
Name is the name of the library. VerNum is the numeric version
according to the library's own versioning scheme. VerStr con-
tains a text variant of the version.
> info_lib().
[{<<"OpenSSL">>,269484095,<<"OpenSSL 1.1.0c 10 Nov 2016"">>}]
Note:
From OTP R16 the numeric version represents the version of the
OpenSSL header files (openssl/opensslv.h) used when crypto was
compiled. The text variant represents the libcrypto library used
at runtime. In earlier OTP versions both numeric and text was
taken from the library.
hash_info(Type) -> Result | run_time_error()
Types:
Type = hash_algorithm()
Result =
#{size := integer(),
block_size := integer(),
type := integer()}
Provides a map with information about block_size, size and pos-
sibly other properties of the hash algorithm in question.
For a list of supported hash algorithms, see supports(hashs).
cipher_info(Type) -> Result | run_time_error()
Types:
Type = cipher()
Result =
#{key_length := integer(),
iv_length := integer(),
block_size := integer(),
mode := CipherModes,
type := undefined | integer(),
prop_aead := boolean()}
CipherModes =
undefined | cbc_mode | ccm_mode | cfb_mode | ctr_mode |
ecb_mode | gcm_mode | ige_mode | ocb_mode | ofb_mode |
wrap_mode | xts_mode
Provides a map with information about block_size, key_length,
iv_length, aead support and possibly other properties of the
cipher algorithm in question.
Note:
The ciphers aes_cbc, aes_cfb8, aes_cfb128, aes_ctr, aes_ecb,
aes_gcm and aes_ccm has no keylength in the Type as opposed to
for example aes_128_ctr. They adapt to the length of the key
provided in the encrypt and decrypt function. Therefor it is
impossible to return a valid keylength in the map.
Always use a Type with an explicit key length,
For a list of supported cipher algorithms, see sup-
ports(ciphers).
mod_pow(N, P, M) -> Result
Types:
N = P = M = binary() | integer()
Result = binary() | error
Computes the function N^P mod M.
private_decrypt(Algorithm, CipherText, PrivateKey, Options) ->
PlainText
Types:
Algorithm = pk_encrypt_decrypt_algs()
CipherText = binary()
PrivateKey = rsa_private() | engine_key_ref()
Options = pk_encrypt_decrypt_opts()
PlainText = binary()
Decrypts the CipherText, encrypted with public_encrypt/4 (or
equivalent function) using the PrivateKey, and returns the
plaintext (message digest). This is a low level signature veri-
fication operation used for instance by older versions of the
SSL protocol. See also public_key:decrypt_private/[2,3]
private_encrypt(Algorithm, PlainText, PrivateKey, Options) ->
CipherText
Types:
Algorithm = pk_encrypt_decrypt_algs()
PlainText = binary()
PrivateKey = rsa_private() | engine_key_ref()
Options = pk_encrypt_decrypt_opts()
CipherText = binary()
Encrypts the PlainText using the PrivateKey and returns the
ciphertext. This is a low level signature operation used for
instance by older versions of the SSL protocol. See also pub-
lic_key:encrypt_private/[2,3]
public_decrypt(Algorithm, CipherText, PublicKey, Options) ->
PlainText
Types:
Algorithm = pk_encrypt_decrypt_algs()
CipherText = binary()
PublicKey = rsa_public() | engine_key_ref()
Options = pk_encrypt_decrypt_opts()
PlainText = binary()
Decrypts the CipherText, encrypted with private_encrypt/4(or
equivalent function) using the PrivateKey, and returns the
plaintext (message digest). This is a low level signature veri-
fication operation used for instance by older versions of the
SSL protocol. See also public_key:decrypt_public/[2,3]
public_encrypt(Algorithm, PlainText, PublicKey, Options) ->
CipherText
Types:
Algorithm = pk_encrypt_decrypt_algs()
PlainText = binary()
PublicKey = rsa_public() | engine_key_ref()
Options = pk_encrypt_decrypt_opts()
CipherText = binary()
Encrypts the PlainText (message digest) using the PublicKey and
returns the CipherText. This is a low level signature operation
used for instance by older versions of the SSL protocol. See
also public_key:encrypt_public/[2,3]
rand_seed(Seed :: binary()) -> ok
Set the seed for PRNG to the given binary. This calls the
RAND_seed function from openssl. Only use this if the system you
are running on does not have enough "randomness" built in. Nor-
mally this is when strong_rand_bytes/1 raises error:low_entropy
rand_uniform(Lo, Hi) -> N
Types:
Lo, Hi, N = integer()
Generate a random number N, Lo =< N < Hi. Uses the crypto
library pseudo-random number generator. Hi must be larger than
Lo.
start() -> ok | {error, Reason :: term()}
Equivalent to application:start(crypto).
stop() -> ok | {error, Reason :: term()}
Equivalent to application:stop(crypto).
strong_rand_bytes(N :: integer() >= 0) -> binary()
Generates N bytes randomly uniform 0..255, and returns the
result in a binary. Uses a cryptographically secure prng seeded
and periodically mixed with operating system provided entropy.
By default this is the RAND_bytes method from OpenSSL.
May raise exception error:low_entropy in case the random genera-
tor failed due to lack of secure "randomness".
rand_seed() -> rand:state()
Creates state object for random number generation, in order to
generate cryptographically strong random numbers (based on
OpenSSL's BN_rand_range), and saves it in the process dictionary
before returning it as well. See also rand:seed/1 and
rand_seed_s/0.
When using the state object from this function the rand func-
tions using it may raise exception error:low_entropy in case the
random generator failed due to lack of secure "randomness".
Example
_ = crypto:rand_seed(),
_IntegerValue = rand:uniform(42), % [1; 42]
_FloatValue = rand:uniform(). % [0.0; 1.0[
rand_seed_s() -> rand:state()
Creates state object for random number generation, in order to
generate cryptographically strongly random numbers (based on
OpenSSL's BN_rand_range). See also rand:seed_s/1.
When using the state object from this function the rand func-
tions using it may raise exception error:low_entropy in case the
random generator failed due to lack of secure "randomness".
Note:
The state returned from this function cannot be used to get a
reproducable random sequence as from the other rand functions,
since reproducability does not match cryptographically safe.
The only supported usage is to generate one distinct random
sequence from this start state.
rand_seed_alg(Alg) -> rand:state()
Types:
Alg = crypto | crypto_cache
Creates state object for random number generation, in order to
generate cryptographically strong random numbers, and saves it
in the process dictionary before returning it as well. See also
rand:seed/1 and rand_seed_alg_s/1.
When using the state object from this function the rand func-
tions using it may raise exception error:low_entropy in case the
random generator failed due to lack of secure "randomness".
Example
_ = crypto:rand_seed_alg(crypto_cache),
_IntegerValue = rand:uniform(42), % [1; 42]
_FloatValue = rand:uniform(). % [0.0; 1.0[
rand_seed_alg(Alg, Seed) -> rand:state()
Types:
Alg = crypto_aes
Creates a state object for random number generation, in order to
generate cryptographically unpredictable random numbers, and
saves it in the process dictionary before returning it as well.
See also rand_seed_alg_s/2.
Example
_ = crypto:rand_seed_alg(crypto_aes, "my seed"),
IntegerValue = rand:uniform(42), % [1; 42]
FloatValue = rand:uniform(), % [0.0; 1.0[
_ = crypto:rand_seed_alg(crypto_aes, "my seed"),
IntegerValue = rand:uniform(42), % Same values
FloatValue = rand:uniform(). % again
rand_seed_alg_s(Alg) -> rand:state()
Types:
Alg = crypto | crypto_cache
Creates state object for random number generation, in order to
generate cryptographically strongly random numbers. See also
rand:seed_s/1.
If Alg is crypto this function behaves exactly like
rand_seed_s/0.
If Alg is crypto_cache this function fetches random data with
OpenSSL's RAND_bytes and caches it for speed using an internal
word size of 56 bits that makes calculations fast on 64 bit
machines.
When using the state object from this function the rand func-
tions using it may raise exception error:low_entropy in case the
random generator failed due to lack of secure "randomness".
The cache size can be changed from its default value using the
crypto app's configuration parameter rand_cache_size.
When using the state object from this function the rand func-
tions using it may throw exception low_entropy in case the ran-
dom generator failed due to lack of secure "randomness".
Note:
The state returned from this function cannot be used to get a
reproducable random sequence as from the other rand functions,
since reproducability does not match cryptographically safe.
In fact since random data is cached some numbers may get repro-
duced if you try, but this is unpredictable.
The only supported usage is to generate one distinct random
sequence from this start state.
rand_seed_alg_s(Alg, Seed) -> rand:state()
Types:
Alg = crypto_aes
Creates a state object for random number generation, in order to
generate cryptographically unpredictable random numbers. See
also rand_seed_alg/1.
To get a long period the Xoroshiro928 generator from the rand
module is used as a counter (with period 2^928 - 1) and the gen-
erator states are scrambled through AES to create 58-bit pseudo
random values.
The result should be statistically completely unpredictable ran-
dom values, since the scrambling is cryptographically strong and
the period is ridiculously long. But the generated numbers are
not to be regarded as cryptographically strong since there is no
re-keying schedule.
* If you need cryptographically strong random numbers use
rand_seed_alg_s/1 with Alg =:= crypto or Alg =:=
crypto_cache.
* If you need to be able to repeat the sequence use this func-
tion.
* If you do not need the statistical quality of this function,
there are faster algorithms in the rand module.
Thanks to the used generator the state object supports the
rand:jump/0,1 function with distance 2^512.
Numbers are generated in batches and cached for speed reasons.
The cache size can be changed from its default value using the
crypto app's configuration parameter rand_cache_size.
ec_curves() -> [EllipticCurve]
Types:
EllipticCurve =
ec_named_curve() | edwards_curve_dh() |
edwards_curve_ed()
Can be used to determine which named elliptic curves are sup-
ported.
ec_curve(CurveName) -> ExplicitCurve
Types:
CurveName = ec_named_curve()
ExplicitCurve = ec_explicit_curve()
Return the defining parameters of a elliptic curve.
sign(Algorithm, DigestType, Msg, Key) -> Signature
sign(Algorithm, DigestType, Msg, Key, Options) -> Signature
Types:
Algorithm = pk_sign_verify_algs()
DigestType =
rsa_digest_type() |
dss_digest_type() |
ecdsa_digest_type() |
none
Msg = iodata() | {digest, iodata()}
Key =
rsa_private() |
dss_private() |
[ecdsa_private() | ecdsa_params()] |
[eddsa_private() | eddsa_params()] |
engine_key_ref()
Options = pk_sign_verify_opts()
Signature = binary()
Creates a digital signature.
The msg is either the binary "cleartext" data to be signed or it
is the hashed value of "cleartext" i.e. the digest (plaintext).
Algorithm dss can only be used together with digest type sha.
See also public_key:sign/3.
verify(Algorithm, DigestType, Msg, Signature, Key) -> Result
verify(Algorithm, DigestType, Msg, Signature, Key, Options) ->
Result
Types:
Algorithm = pk_sign_verify_algs()
DigestType =
rsa_digest_type() |
dss_digest_type() |
ecdsa_digest_type() |
none
Msg = iodata() | {digest, iodata()}
Signature = binary()
Key =
rsa_public() |
dss_public() |
[ecdsa_public() | ecdsa_params()] |
[eddsa_public() | eddsa_params()] |
engine_key_ref()
Options = pk_sign_verify_opts()
Result = boolean()
Verifies a digital signature
The msg is either the binary "cleartext" data to be signed or it
is the hashed value of "cleartext" i.e. the digest (plaintext).
Algorithm dss can only be used together with digest type sha.
See also public_key:verify/4.
ENGINE API
EXPORTS
privkey_to_pubkey(Type, EnginePrivateKeyRef) -> PublicKey
Types:
Type = rsa | dss
EnginePrivateKeyRef = engine_key_ref()
PublicKey = rsa_public() | dss_public()
Fetches the corresponding public key from a private key stored
in an Engine. The key must be of the type indicated by the Type
parameter.
engine_get_all_methods() -> Result
Types:
Result = [engine_method_type()]
Returns a list of all possible engine methods.
May raise exception error:notsup in case there is no engine sup-
port in the underlying OpenSSL implementation.
See also the chapter Engine Load in the User's Guide.
engine_load(EngineId, PreCmds, PostCmds) -> Result
Types:
EngineId = unicode:chardata()
PreCmds = PostCmds = [engine_cmnd()]
Result =
{ok, Engine :: engine_ref()} | {error, Reason :: term()}
Loads the OpenSSL engine given by EngineId if it is available
and then returns ok and an engine handle. This function is the
same as calling engine_load/4 with EngineMethods set to a list
of all the possible methods. An error tuple is returned if the
engine can't be loaded.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
See also the chapter Engine Load in the User's Guide.
engine_load(EngineId, PreCmds, PostCmds, EngineMethods) -> Result
Types:
EngineId = unicode:chardata()
PreCmds = PostCmds = [engine_cmnd()]
EngineMethods = [engine_method_type()]
Result =
{ok, Engine :: engine_ref()} | {error, Reason :: term()}
Loads the OpenSSL engine given by EngineId if it is available
and then returns ok and an engine handle. An error tuple is
returned if the engine can't be loaded.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
See also the chapter Engine Load in the User's Guide.
engine_unload(Engine) -> Result
Types:
Engine = engine_ref()
Result = ok | {error, Reason :: term()}
Unloads the OpenSSL engine given by Engine. An error tuple is
returned if the engine can't be unloaded.
The function raises a error:badarg if the parameter is in wrong
format. It may also raise the exception error:notsup in case
there is no engine support in the underlying OpenSSL implementa-
tion.
See also the chapter Engine Load in the User's Guide.
engine_by_id(EngineId) -> Result
Types:
EngineId = unicode:chardata()
Result =
{ok, Engine :: engine_ref()} | {error, Reason :: term()}
Get a reference to an already loaded engine with EngineId. An
error tuple is returned if the engine can't be unloaded.
The function raises a error:badarg if the parameter is in wrong
format. It may also raise the exception error:notsup in case
there is no engine support in the underlying OpenSSL implementa-
tion.
See also the chapter Engine Load in the User's Guide.
engine_ctrl_cmd_string(Engine, CmdName, CmdArg) -> Result
Types:
Engine = term()
CmdName = CmdArg = unicode:chardata()
Result = ok | {error, Reason :: term()}
Sends ctrl commands to the OpenSSL engine given by Engine. This
function is the same as calling engine_ctrl_cmd_string/4 with
Optional set to false.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
engine_ctrl_cmd_string(Engine, CmdName, CmdArg, Optional) ->
Result
Types:
Engine = term()
CmdName = CmdArg = unicode:chardata()
Optional = boolean()
Result = ok | {error, Reason :: term()}
Sends ctrl commands to the OpenSSL engine given by Engine.
Optional is a boolean argument that can relax the semantics of
the function. If set to true it will only return failure if the
ENGINE supported the given command name but failed while execut-
ing it, if the ENGINE doesn't support the command name it will
simply return success without doing anything. In this case we
assume the user is only supplying commands specific to the given
ENGINE so we set this to false.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
engine_add(Engine) -> Result
Types:
Engine = engine_ref()
Result = ok | {error, Reason :: term()}
Add the engine to OpenSSL's internal list.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
engine_remove(Engine) -> Result
Types:
Engine = engine_ref()
Result = ok | {error, Reason :: term()}
Remove the engine from OpenSSL's internal list.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
engine_get_id(Engine) -> EngineId
Types:
Engine = engine_ref()
EngineId = unicode:chardata()
Return the ID for the engine, or an empty binary if there is no
id set.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
engine_get_name(Engine) -> EngineName
Types:
Engine = engine_ref()
EngineName = unicode:chardata()
Return the name (eg a description) for the engine, or an empty
binary if there is no name set.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
engine_list() -> Result
Types:
Result = [EngineId :: unicode:chardata()]
List the id's of all engines in OpenSSL's internal list.
It may also raise the exception error:notsup in case there is no
engine support in the underlying OpenSSL implementation.
See also the chapter Engine Load in the User's Guide.
May raise exception error:notsup in case engine functionality is
not supported by the underlying OpenSSL implementation.
ensure_engine_loaded(EngineId, LibPath) -> Result
Types:
EngineId = LibPath = unicode:chardata()
Result =
{ok, Engine :: engine_ref()} | {error, Reason :: term()}
Loads the OpenSSL engine given by EngineId and the path to the
dynamic library implementing the engine. This function is the
same as calling ensure_engine_loaded/3 with EngineMethods set to
a list of all the possible methods. An error tuple is returned
if the engine can't be loaded.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
See also the chapter Engine Load in the User's Guide.
ensure_engine_loaded(EngineId, LibPath, EngineMethods) -> Result
Types:
EngineId = LibPath = unicode:chardata()
EngineMethods = [engine_method_type()]
Result =
{ok, Engine :: engine_ref()} | {error, Reason :: term()}
Loads the OpenSSL engine given by EngineId and the path to the
dynamic library implementing the engine. This function differs
from the normal engine_load in that sense it also add the engine
id to the internal list in OpenSSL. Then in the following calls
to the function it just fetch the reference to the engine
instead of loading it again. An error tuple is returned if the
engine can't be loaded.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
See also the chapter Engine Load in the User's Guide.
ensure_engine_unloaded(Engine) -> Result
Types:
Engine = engine_ref()
Result = ok | {error, Reason :: term()}
Unloads an engine loaded with the ensure_engine_loaded function.
It both removes the label from the OpenSSL internal engine list
and unloads the engine. This function is the same as calling
ensure_engine_unloaded/2 with EngineMethods set to a list of all
the possible methods. An error tuple is returned if the engine
can't be unloaded.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
See also the chapter Engine Load in the User's Guide.
ensure_engine_unloaded(Engine, EngineMethods) -> Result
Types:
Engine = engine_ref()
EngineMethods = [engine_method_type()]
Result = ok | {error, Reason :: term()}
Unloads an engine loaded with the ensure_engine_loaded function.
It both removes the label from the OpenSSL internal engine list
and unloads the engine. An error tuple is returned if the engine
can't be unloaded.
The function raises a error:badarg if the parameters are in
wrong format. It may also raise the exception error:notsup in
case there is no engine support in the underlying OpenSSL imple-
mentation.
See also the chapter Engine Load in the User's Guide.
pbkdf2_hmac(Digest, Pass, Salt, Iter, KeyLen) -> Result
Types:
Digest = sha | sha224 | sha256 | sha384 | sha512
Pass = Salt = binary()
Iter = KeyLen = integer() >= 1
Result = binary()
PKCS #5 PBKDF2 (Password-Based Key Derivation Function 2) in
combination with HMAC.
The function raises a error:badarg if the parameters are in
wrong format.
Ericsson AB crypto 5.0.5 crypto(3)