crypto: Add crypto.DEFAULT_ENCODING (defaults to 'buffer')

This is a flag to make it easier for users to upgrade through the
breaking crypto change, and easier for us to switch it back if it's a
problem.

Explicitly set default encoding to 'buffer' in other tests, in case it
ever changes back.

1 files changed, 189 insertions, 144 deletions

diff --git a/doc/api/crypto.markdown b/doc/api/crypto.markdown
index b17544ea2..5f7265959 100644
--- a/doc/api/crypto.markdown
+++ b/doc/api/crypto.markdown
@@ -5,11 +5,12 @@
 
 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 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.
 
-It also offers a set of wrappers for OpenSSL's hash, hmac, cipher, decipher, sign and verify methods.
+It also offers a set of wrappers for OpenSSL's hash, hmac, cipher,
+decipher, sign and verify methods.
 
 
 ## crypto.getCiphers()
@@ -34,30 +35,38 @@ Example:
 
 ## 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
 
@@ -85,27 +94,29 @@ 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 `'buffer'`, `'utf8'`, `'ascii'` or `'binary'`.
-Defaults to `'buffer'`.
+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 `'buffer'`, `'hex'`, `'binary'` or `'base64'`.
-Defaults to `'buffer'`.
+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 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.
 
-`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
 
@@ -115,38 +126,40 @@ 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 `'buffer'`, `'hex'`, `'binary'` or `'base64'`.
-Defaults to `'buffer'`.
+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).
 
 ## 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
 
@@ -157,38 +170,43 @@ Returned by `crypto.createCipher` and `crypto.createCipheriv`.
 ### cipher.update(data, [input_encoding], [output_encoding])
 
 Updates the cipher with `data`, the encoding of which is given in
-`input_encoding` and can be `'buffer'`, `'utf8'`, `'ascii'` or `'binary'`.
-Defaults to `'buffer'`.
+`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 `'buffer'`, `'binary'`, `'base64'` or `'hex'`. Defaults to
-`'buffer'`.
+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:
-`'buffer'`, `'binary'`, `'base64'` or `'hex'`. Defaults to `'buffer'`.
+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
 
@@ -198,33 +216,36 @@ Returned by `crypto.createDecipher` and `crypto.createDecipheriv`.
 
 ### decipher.update(data, [input_encoding], [output_encoding])
 
-Updates the decipher with `data`, which is encoded in `'buffer'`, `'binary'`,
-`'base64'` or `'hex'`. Defaults to `'buffer'`.
+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: `'buffer'`, `'binary'`, `'ascii'` or `'utf8'`.
-Defaults to `'buffer'`.
+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: `'buffer'`, `'binary'`, `'ascii'` or
-`'utf8'`.
-Defaults to `'buffer'`.
+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
 
@@ -234,18 +255,21 @@ Returned by `crypto.createSign`.
 
 ### signer.update(data)
 
-Updates the signer object with data.
-This can be called many times with new data as it is streamed.
+Updates the signer object with data.  This can be called many times
+with new data as it is streamed.
 
 ### signer.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
+signer.  `private_key` is a string containing the PEM encoded private
+key for signing.
 
-Returns the signature in `output_format` which can be `'buffer'`, `'binary'`,
-`'hex'` or `'base64'`. Defaults to `'buffer'`.
+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: `signer` object can not be used after `sign()` method been
+called.
 
 ## crypto.createVerify(algorithm)
 
@@ -260,32 +284,34 @@ Returned by `crypto.createVerify`.
 
 ### 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 `'buffer'`,
-`'binary'`, `'hex'` or `'base64'`. Defaults to `'buffer'`.
+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 `'buffer'`, `'binary'`, `'hex'`, or
-`'base64'`.
-Defaults to `'buffer'`.
+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
 
@@ -295,65 +321,70 @@ 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 `'buffer'`.
+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 `'buffer'`, `'binary'`, `'hex'`,
-or `'base64'`. The input encoding defaults to `'buffer'`.
-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
-`'buffer'`, `'binary'`, `'hex'`, or `'base64'`. Defaults to `'buffer'`.
+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
-`'buffer'`, `'binary'`, `'hex'`, or `'base64'`. Defaults to `'buffer'`.
+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 `'buffer'`.
+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 `'buffer'`, `'binary'`, `'hex'`, or `'base64'`. Defaults to
-`'buffer'`.
+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 `'buffer', ``'binary'`,
-`'hex'` or `'base64'`. Defaults to `'buffer'`.
+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])
 
-Sets the Diffie-Hellman private key. Key encoding can be `'buffer'`, `'binary'`,
-`'hex'` or `'base64'`. Defaults to `'buffer'`.
+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):
 
@@ -398,32 +429,46 @@ 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.
+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.
 
 Also, a Streaming API will be provided, but this will be done in such
 a way as to preserve the legacy API surface.