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diff --git a/doc/api/crypto.markdown b/doc/api/crypto.markdown index e6cff32ab..de574bc37 100644 --- a/doc/api/crypto.markdown +++ b/doc/api/crypto.markdown @@ -5,38 +5,67 @@ Use `require('crypto')` to access this module. -The crypto module requires OpenSSL to be available on the underlying platform. -It offers a way of encapsulating secure credentials to be used as part -of a secure HTTPS net or http connection. +The crypto module offers a way of encapsulating secure credentials to be +used as part of a secure HTTPS net or http connection. + +It also offers a set of wrappers for OpenSSL's hash, hmac, cipher, +decipher, sign and verify methods. + + +## crypto.getCiphers() + +Returns an array with the names of the supported ciphers. + +Example: + + var ciphers = crypto.getCiphers(); + console.log(ciphers); // ['AES128-SHA', 'AES256-SHA', ...] + + +## crypto.getHashes() + +Returns an array with the names of the supported hash algorithms. + +Example: + + var hashes = crypto.getHashes(); + console.log(hashes); // ['sha', 'sha1', 'sha1WithRSAEncryption', ...] -It also offers a set of wrappers for OpenSSL's hash, hmac, cipher, decipher, sign and verify methods. ## crypto.createCredentials(details) -Creates a credentials object, with the optional details being a dictionary with keys: +Creates a credentials object, with the optional details being a +dictionary with keys: -* `pfx` : A string or buffer holding the PFX or PKCS12 encoded private key, certificate and CA certificates +* `pfx` : A string or buffer holding the PFX or PKCS12 encoded private + key, certificate and CA certificates * `key` : A string holding the PEM encoded private key * `passphrase` : A string of passphrase for the private key or pfx * `cert` : A string holding the PEM encoded certificate -* `ca` : Either a string or list of strings of PEM encoded CA certificates to trust. -* `crl` : Either a string or list of strings of PEM encoded CRLs (Certificate Revocation List) -* `ciphers`: A string describing the ciphers to use or exclude. Consult - <http://www.openssl.org/docs/apps/ciphers.html#CIPHER_LIST_FORMAT> for details - on the format. - -If no 'ca' details are given, then node.js will use the default publicly trusted list of CAs as given in +* `ca` : Either a string or list of strings of PEM encoded CA + certificates to trust. +* `crl` : Either a string or list of strings of PEM encoded CRLs + (Certificate Revocation List) +* `ciphers`: A string describing the ciphers to use or exclude. + Consult + <http://www.openssl.org/docs/apps/ciphers.html#CIPHER_LIST_FORMAT> + for details on the format. + +If no 'ca' details are given, then node.js will use the default +publicly trusted list of CAs as given in <http://mxr.mozilla.org/mozilla/source/security/nss/lib/ckfw/builtins/certdata.txt>. ## crypto.createHash(algorithm) -Creates and returns a hash object, a cryptographic hash with the given algorithm -which can be used to generate hash digests. +Creates and returns a hash object, a cryptographic hash with the given +algorithm which can be used to generate hash digests. -`algorithm` is dependent on the available algorithms supported by the version -of OpenSSL on the platform. Examples are `'sha1'`, `'md5'`, `'sha256'`, `'sha512'`, etc. -On recent releases, `openssl list-message-digest-algorithms` will display the available digest algorithms. +`algorithm` is dependent on the available algorithms supported by the +version of OpenSSL on the platform. Examples are `'sha1'`, `'md5'`, +`'sha256'`, `'sha512'`, etc. On recent releases, `openssl +list-message-digest-algorithms` will display the available digest +algorithms. Example: this program that takes the sha1 sum of a file @@ -60,30 +89,43 @@ Example: this program that takes the sha1 sum of a file The class for creating hash digests of data. +It is a [stream](stream.html) that is both readable and writable. The +written data is used to compute the hash. Once the writable side of +the stream is ended, use the `read()` method to get the computed hash +digest. The legacy `update` and `digest` methods are also supported. + Returned by `crypto.createHash`. ### hash.update(data, [input_encoding]) -Updates the hash content with the given `data`, the encoding of which is given -in `input_encoding` and can be `'utf8'`, `'ascii'` or `'binary'`. -Defaults to `'binary'`. +Updates the hash content with the given `data`, the encoding of which +is given in `input_encoding` and can be `'utf8'`, `'ascii'` or +`'binary'`. If no encoding is provided, then a buffer is expected. + This can be called many times with new data as it is streamed. ### hash.digest([encoding]) -Calculates the digest of all of the passed data to be hashed. -The `encoding` can be `'hex'`, `'binary'` or `'base64'`. -Defaults to `'binary'`. +Calculates the digest of all of the passed data to be hashed. The +`encoding` can be `'hex'`, `'binary'` or `'base64'`. If no encoding +is provided, then a buffer is returned. -Note: `hash` object can not be used after `digest()` method has been called. +Note: `hash` object can not be used after `digest()` method been +called. ## crypto.createHmac(algorithm, key) -Creates and returns a hmac object, a cryptographic hmac with the given algorithm and key. +Creates and returns a hmac object, a cryptographic hmac with the given +algorithm and key. + +It is a [stream](stream.html) that is both readable and writable. The +written data is used to compute the hmac. Once the writable side of +the stream is ended, use the `read()` method to get the computed +digest. The legacy `update` and `digest` methods are also supported. -`algorithm` is dependent on the available algorithms supported by OpenSSL - see createHash above. -`key` is the hmac key to be used. +`algorithm` is dependent on the available algorithms supported by +OpenSSL - see createHash above. `key` is the hmac key to be used. ## Class: Hmac @@ -93,38 +135,45 @@ Returned by `crypto.createHmac`. ### hmac.update(data) -Update the hmac content with the given `data`. -This can be called many times with new data as it is streamed. +Update the hmac content with the given `data`. This can be called +many times with new data as it is streamed. ### hmac.digest([encoding]) -Calculates the digest of all of the passed data to the hmac. -The `encoding` can be `'hex'`, `'binary'` or `'base64'`. -Defaults to `'binary'`. +Calculates the digest of all of the passed data to the hmac. The +`encoding` can be `'hex'`, `'binary'` or `'base64'`. If no encoding +is provided, then a buffer is returned. -Note: `hmac` object can not be used after `digest()` method been called. +Note: `hmac` object can not be used after `digest()` method been +called. ## crypto.createCipher(algorithm, password) -Creates and returns a cipher object, with the given algorithm and password. +Creates and returns a cipher object, with the given algorithm and +password. + +`algorithm` is dependent on OpenSSL, examples are `'aes192'`, etc. On +recent releases, `openssl list-cipher-algorithms` will display the +available cipher algorithms. `password` is used to derive key and IV, +which must be a `'binary'` encoded string or a [buffer](buffer.html). -`algorithm` is dependent on OpenSSL, examples are `'aes192'`, etc. -On recent releases, `openssl list-cipher-algorithms` will display the -available cipher algorithms. -`password` is used to derive key and IV, which must be a `'binary'` encoded -string or a [buffer](buffer.html). +It is a [stream](stream.html) that is both readable and writable. The +written data is used to compute the hash. Once the writable side of +the stream is ended, use the `read()` method to get the computed hash +digest. The legacy `update` and `digest` methods are also supported. ## crypto.createCipheriv(algorithm, key, iv) -Creates and returns a cipher object, with the given algorithm, key and iv. +Creates and returns a cipher object, with the given algorithm, key and +iv. -`algorithm` is the same as the argument to `createCipher()`. -`key` is the raw key used by the algorithm. -`iv` is an [initialization +`algorithm` is the same as the argument to `createCipher()`. `key` is +the raw key used by the algorithm. `iv` is an [initialization vector](http://en.wikipedia.org/wiki/Initialization_vector). -`key` and `iv` must be `'binary'` encoded strings or [buffers](buffer.html). +`key` and `iv` must be `'binary'` encoded strings or +[buffers](buffer.html). ## Class: Cipher @@ -132,40 +181,51 @@ Class for encrypting data. Returned by `crypto.createCipher` and `crypto.createCipheriv`. +Cipher objects are [streams](stream.html) that are both readable and +writable. The written plain text data is used to produce the +encrypted data on the the readable side. The legacy `update` and +`final` methods are also supported. + ### cipher.update(data, [input_encoding], [output_encoding]) Updates the cipher with `data`, the encoding of which is given in -`input_encoding` and can be `'utf8'`, `'ascii'` or `'binary'`. -Defaults to `'binary'`. +`input_encoding` and can be `'utf8'`, `'ascii'` or `'binary'`. If no +encoding is provided, then a buffer is expected. -The `output_encoding` specifies the output format of the enciphered data, -and can be `'binary'`, `'base64'` or `'hex'`. Defaults to `'binary'`. +The `output_encoding` specifies the output format of the enciphered +data, and can be `'binary'`, `'base64'` or `'hex'`. If no encoding is +provided, then a buffer iis returned. -Returns the enciphered contents, and can be called many times with new data as it is streamed. +Returns the enciphered contents, and can be called many times with new +data as it is streamed. ### cipher.final([output_encoding]) -Returns any remaining enciphered contents, with `output_encoding` being one of: -`'binary'`, `'base64'` or `'hex'`. Defaults to `'binary'`. +Returns any remaining enciphered contents, with `output_encoding` +being one of: `'binary'`, `'base64'` or `'hex'`. If no encoding is +provided, then a buffer is returned. -Note: `cipher` object can not be used after `final()` method been called. +Note: `cipher` object can not be used after `final()` method been +called. ### cipher.setAutoPadding(auto_padding=true) -You can disable automatic padding of the input data to block size. If `auto_padding` is false, -the length of the entire input data must be a multiple of the cipher's block size or `final` will fail. -Useful for non-standard padding, e.g. using `0x0` instead of PKCS padding. You must call this before `cipher.final`. +You can disable automatic padding of the input data to block size. If +`auto_padding` is false, the length of the entire input data must be a +multiple of the cipher's block size or `final` will fail. Useful for +non-standard padding, e.g. using `0x0` instead of PKCS padding. You +must call this before `cipher.final`. ## crypto.createDecipher(algorithm, password) -Creates and returns a decipher object, with the given algorithm and key. -This is the mirror of the [createCipher()][] above. +Creates and returns a decipher object, with the given algorithm and +key. This is the mirror of the [createCipher()][] above. ## crypto.createDecipheriv(algorithm, key, iv) -Creates and returns a decipher object, with the given algorithm, key and iv. -This is the mirror of the [createCipheriv()][] above. +Creates and returns a decipher object, with the given algorithm, key +and iv. This is the mirror of the [createCipheriv()][] above. ## Class: Decipher @@ -173,54 +233,72 @@ Class for decrypting data. Returned by `crypto.createDecipher` and `crypto.createDecipheriv`. +Decipher objects are [streams](stream.html) that are both readable and +writable. The written enciphered data is used to produce the +plain-text data on the the readable side. The legacy `update` and +`final` methods are also supported. + ### decipher.update(data, [input_encoding], [output_encoding]) -Updates the decipher with `data`, which is encoded in `'binary'`, `'base64'` -or `'hex'`. Defaults to `'binary'`. +Updates the decipher with `data`, which is encoded in `'binary'`, +`'base64'` or `'hex'`. If no encoding is provided, then a buffer is +expected. -The `output_decoding` specifies in what format to return the deciphered -plaintext: `'binary'`, `'ascii'` or `'utf8'`. Defaults to `'binary'`. +The `output_decoding` specifies in what format to return the +deciphered plaintext: `'binary'`, `'ascii'` or `'utf8'`. If no +encoding is provided, then a buffer is returned. ### decipher.final([output_encoding]) -Returns any remaining plaintext which is deciphered, -with `output_encoding` being one of: `'binary'`, `'ascii'` or `'utf8'`. -Defaults to `'binary'`. +Returns any remaining plaintext which is deciphered, with +`output_encoding` being one of: `'binary'`, `'ascii'` or `'utf8'`. If +no encoding is provided, then a buffer is returned. -Note: `decipher` object can not be used after `final()` method been called. +Note: `decipher` object can not be used after `final()` method been +called. ### decipher.setAutoPadding(auto_padding=true) -You can disable auto padding if the data has been encrypted without standard block padding to prevent -`decipher.final` from checking and removing it. Can only work if the input data's length is a multiple of the -ciphers block size. You must call this before streaming data to `decipher.update`. +You can disable auto padding if the data has been encrypted without +standard block padding to prevent `decipher.final` from checking and +removing it. Can only work if the input data's length is a multiple of +the ciphers block size. You must call this before streaming data to +`decipher.update`. ## crypto.createSign(algorithm) -Creates and returns a signing object, with the given algorithm. -On recent OpenSSL releases, `openssl list-public-key-algorithms` will display -the available signing algorithms. Examples are `'RSA-SHA256'`. +Creates and returns a signing object, with the given algorithm. On +recent OpenSSL releases, `openssl list-public-key-algorithms` will +display the available signing algorithms. Examples are `'RSA-SHA256'`. -## Class: Signer +## Class: Sign Class for generating signatures. Returned by `crypto.createSign`. -### signer.update(data) +Sign objects are writable [streams](stream.html). The written data is +used to generate the signature. Once all of the data has been +written, the `sign` method will return the signature. The legacy +`update` method is also supported. -Updates the signer object with data. -This can be called many times with new data as it is streamed. +### sign.update(data) + +Updates the sign object with data. This can be called many times +with new data as it is streamed. -### signer.sign(private_key, [output_format]) +### sign.sign(private_key, [output_format]) -Calculates the signature on all the updated data passed through the signer. -`private_key` is a string containing the PEM encoded private key for signing. +Calculates the signature on all the updated data passed through the +sign. `private_key` is a string containing the PEM encoded private +key for signing. -Returns the signature in `output_format` which can be `'binary'`, `'hex'` or -`'base64'`. Defaults to `'binary'`. +Returns the signature in `output_format` which can be `'binary'`, +`'hex'` or `'base64'`. If no encoding is provided, then a buffer is +returned. -Note: `signer` object can not be used after `sign()` method been called. +Note: `sign` object can not be used after `sign()` method been +called. ## crypto.createVerify(algorithm) @@ -233,33 +311,42 @@ Class for verifying signatures. Returned by `crypto.createVerify`. +Verify objects are writable [streams](stream.html). The written data +is used to validate against the supplied signature. Once all of the +data has been written, the `verify` method will return true if the +supplied signature is valid. The legacy `update` method is also +supported. + ### verifier.update(data) -Updates the verifier object with data. -This can be called many times with new data as it is streamed. +Updates the verifier object with data. This can be called many times +with new data as it is streamed. ### verifier.verify(object, signature, [signature_format]) -Verifies the signed data by using the `object` and `signature`. `object` is a -string containing a PEM encoded object, which can be one of RSA public key, -DSA public key, or X.509 certificate. `signature` is the previously calculated -signature for the data, in the `signature_format` which can be `'binary'`, -`'hex'` or `'base64'`. Defaults to `'binary'`. +Verifies the signed data by using the `object` and `signature`. +`object` is a string containing a PEM encoded object, which can be +one of RSA public key, DSA public key, or X.509 certificate. +`signature` is the previously calculated signature for the data, in +the `signature_format` which can be `'binary'`, `'hex'` or `'base64'`. +If no encoding is specified, then a buffer is expected. -Returns true or false depending on the validity of the signature for the data and public key. +Returns true or false depending on the validity of the signature for +the data and public key. -Note: `verifier` object can not be used after `verify()` method been called. +Note: `verifier` object can not be used after `verify()` method been +called. ## crypto.createDiffieHellman(prime_length) -Creates a Diffie-Hellman key exchange object and generates a prime of the -given bit length. The generator used is `2`. +Creates a Diffie-Hellman key exchange object and generates a prime of +the given bit length. The generator used is `2`. ## crypto.createDiffieHellman(prime, [encoding]) -Creates a Diffie-Hellman key exchange object using the supplied prime. The -generator used is `2`. Encoding can be `'binary'`, `'hex'`, or `'base64'`. -Defaults to `'binary'`. +Creates a Diffie-Hellman key exchange object using the supplied prime. +The generator used is `2`. Encoding can be `'binary'`, `'hex'`, or +`'base64'`. If no encoding is specified, then a buffer is expected. ## Class: DiffieHellman @@ -269,64 +356,70 @@ Returned by `crypto.createDiffieHellman`. ### diffieHellman.generateKeys([encoding]) -Generates private and public Diffie-Hellman key values, and returns the -public key in the specified encoding. This key should be transferred to the -other party. Encoding can be `'binary'`, `'hex'`, or `'base64'`. -Defaults to `'binary'`. +Generates private and public Diffie-Hellman key values, and returns +the public key in the specified encoding. This key should be +transferred to the other party. Encoding can be `'binary'`, `'hex'`, +or `'base64'`. If no encoding is provided, then a buffer is returned. ### diffieHellman.computeSecret(other_public_key, [input_encoding], [output_encoding]) -Computes the shared secret using `other_public_key` as the other party's -public key and returns the computed shared secret. Supplied key is -interpreted using specified `input_encoding`, and secret is encoded using -specified `output_encoding`. Encodings can be `'binary'`, `'hex'`, or -`'base64'`. The input encoding defaults to `'binary'`. -If no output encoding is given, the input encoding is used as output encoding. +Computes the shared secret using `other_public_key` as the other +party's public key and returns the computed shared secret. Supplied +key is interpreted using specified `input_encoding`, and secret is +encoded using specified `output_encoding`. Encodings can be +`'binary'`, `'hex'`, or `'base64'`. If the input encoding is not +provided, then a buffer is expected. + +If no output encoding is given, then a buffer is returned. ### diffieHellman.getPrime([encoding]) -Returns the Diffie-Hellman prime in the specified encoding, which can be -`'binary'`, `'hex'`, or `'base64'`. Defaults to `'binary'`. +Returns the Diffie-Hellman prime in the specified encoding, which can +be `'binary'`, `'hex'`, or `'base64'`. If no encoding is provided, +then a buffer is returned. ### diffieHellman.getGenerator([encoding]) -Returns the Diffie-Hellman prime in the specified encoding, which can be -`'binary'`, `'hex'`, or `'base64'`. Defaults to `'binary'`. +Returns the Diffie-Hellman prime in the specified encoding, which can +be `'binary'`, `'hex'`, or `'base64'`. If no encoding is provided, +then a buffer is returned. ### diffieHellman.getPublicKey([encoding]) -Returns the Diffie-Hellman public key in the specified encoding, which can -be `'binary'`, `'hex'`, or `'base64'`. Defaults to `'binary'`. +Returns the Diffie-Hellman public key in the specified encoding, which +can be `'binary'`, `'hex'`, or `'base64'`. If no encoding is provided, +then a buffer is returned. ### diffieHellman.getPrivateKey([encoding]) -Returns the Diffie-Hellman private key in the specified encoding, which can -be `'binary'`, `'hex'`, or `'base64'`. Defaults to `'binary'`. +Returns the Diffie-Hellman private key in the specified encoding, +which can be `'binary'`, `'hex'`, or `'base64'`. If no encoding is +provided, then a buffer is returned. ### diffieHellman.setPublicKey(public_key, [encoding]) -Sets the Diffie-Hellman public key. Key encoding can be `'binary'`, `'hex'`, -or `'base64'`. Defaults to `'binary'`. +Sets the Diffie-Hellman public key. Key encoding can be `'binary'`, +`'hex'` or `'base64'`. If no encoding is provided, then a buffer is +expected. -### diffieHellman.setPrivateKey(public_key, [encoding]) +### diffieHellman.setPrivateKey(private_key, [encoding]) -Sets the Diffie-Hellman private key. Key encoding can be `'binary'`, `'hex'`, -or `'base64'`. Defaults to `'binary'`. +Sets the Diffie-Hellman private key. Key encoding can be `'binary'`, +`'hex'` or `'base64'`. If no encoding is provided, then a buffer is +expected. ## crypto.getDiffieHellman(group_name) -Creates a predefined Diffie-Hellman key exchange object. -The supported groups are: `'modp1'`, `'modp2'`, `'modp5'` -(defined in [RFC 2412][]) -and `'modp14'`, `'modp15'`, `'modp16'`, `'modp17'`, `'modp18'` -(defined in [RFC 3526][]). -The returned object mimics the interface of objects created by -[crypto.createDiffieHellman()][] above, but -will not allow to change the keys (with -[diffieHellman.setPublicKey()][] for example). -The advantage of using this routine is that the parties don't have to -generate nor exchange group modulus beforehand, saving both processor and -communication time. +Creates a predefined Diffie-Hellman key exchange object. The +supported groups are: `'modp1'`, `'modp2'`, `'modp5'` (defined in [RFC +2412][]) and `'modp14'`, `'modp15'`, `'modp16'`, `'modp17'`, +`'modp18'` (defined in [RFC 3526][]). The returned object mimics the +interface of objects created by [crypto.createDiffieHellman()][] +above, but will not allow to change the keys (with +[diffieHellman.setPublicKey()][] for example). The advantage of using +this routine is that the parties don't have to generate nor exchange +group modulus beforehand, saving both processor and communication +time. Example (obtaining a shared secret): @@ -337,8 +430,8 @@ Example (obtaining a shared secret): alice.generateKeys(); bob.generateKeys(); - var alice_secret = alice.computeSecret(bob.getPublicKey(), 'binary', 'hex'); - var bob_secret = bob.computeSecret(alice.getPublicKey(), 'binary', 'hex'); + var alice_secret = alice.computeSecret(bob.getPublicKey(), null, 'hex'); + var bob_secret = bob.computeSecret(alice.getPublicKey(), null, 'hex'); /* alice_secret and bob_secret should be the same */ console.log(alice_secret == bob_secret); @@ -349,6 +442,10 @@ Asynchronous PBKDF2 applies pseudorandom function HMAC-SHA1 to derive a key of given length from the given password, salt and iterations. The callback gets two arguments `(err, derivedKey)`. +## crypto.pbkdf2Sync(password, salt, iterations, keylen) + +Synchronous PBKDF2 function. Returns derivedKey or throws error. + ## crypto.randomBytes(size, [callback]) Generates cryptographically strong pseudo-random data. Usage: @@ -367,35 +464,46 @@ Generates cryptographically strong pseudo-random data. Usage: // handle error } -## Proposed API Changes in Future Versions of Node +## crypto.DEFAULT_ENCODING + +The default encoding to use for functions that can take either strings +or buffers. The default value is `'buffer'`, which makes it default +to using Buffer objects. This is here to make the crypto module more +easily compatible with legacy programs that expected `'binary'` to be +the default encoding. + +Note that new programs will probably expect buffers, so only use this +as a temporary measure. + +## Recent API Changes The Crypto module was added to Node before there was the concept of a unified Stream API, and before there were Buffer objects for handling binary data. As such, the streaming classes don't have the typical methods found on -other Node classes, and many methods accept and return Binary-encoded -strings by default rather than Buffers. +other Node classes, and many methods accepted and returned +Binary-encoded strings by default rather than Buffers. This was +changed to use Buffers by default instead. -A future version of node will make Buffers the default data type. -This will be a breaking change for some use cases, but not all. +This is a breaking change for some use cases, but not all. For example, if you currently use the default arguments to the Sign class, and then pass the results to the Verify class, without ever inspecting the data, then it will continue to work as before. Where -you now get a binary string and then present the binary string to the -Verify object, you'll get a Buffer, and present the Buffer to the -Verify object. +you once got a binary string and then presented the binary string to +the Verify object, you'll now get a Buffer, and present the Buffer to +the Verify object. -However, if you are doing things with the string data that will not +However, if you were doing things with the string data that will not work properly on Buffers (such as, concatenating them, storing in databases, etc.), or you are passing binary strings to the crypto functions without an encoding argument, then you will need to start providing encoding arguments to specify which encoding you'd like to -use. - -Also, a Streaming API will be provided, but this will be done in such -a way as to preserve the legacy API surface. +use. To switch to the previous style of using binary strings by +default, set the `crypto.DEFAULT_ENCODING` field to 'binary'. Note +that new programs will probably expect buffers, so only use this as a +temporary measure. [createCipher()]: #crypto_crypto_createcipher_algorithm_password |