[[meta title="monkeysphere --gen-subkey seems to fail if no gpg-agent is running"]]

Consider the following transcript of a user who starts with no OpenPGP
key in the first place:
	
	0 wt215@squeak:~$ monkeysphere gen-subkey 
	You have no secret key available.  You should create an OpenPGP
	key before joining the monkeysphere. You can do this with:
	   gpg --gen-key
	255 wt215@squeak:~$ gpg --gen-key
	gpg (GnuPG) 1.4.9; Copyright (C) 2008 Free Software Foundation, Inc.
	This is free software: you are free to change and redistribute it.
	There is NO WARRANTY, to the extent permitted by law.
	
	Please select what kind of key you want:
	   (1) DSA and Elgamal (default)
	   (2) DSA (sign only)
	   (5) RSA (sign only)
	Your selection? 5
	RSA keys may be between 1024 and 4096 bits long.
	What keysize do you want? (2048) 1024
	Requested keysize is 1024 bits
	Please specify how long the key should be valid.
	         0 = key does not expire
	      <n>  = key expires in n days
	      <n>w = key expires in n weeks
	      <n>m = key expires in n months
	      <n>y = key expires in n years
	Key is valid for? (0) 1 
	Key expires at Sat 09 Aug 2008 09:41:34 AM EDT
	Is this correct? (y/N) y
	
	You need a user ID to identify your key; the software constructs the user ID
	from the Real Name, Comment and Email Address in this form:
	    "Heinrich Heine (Der Dichter) <heinrichh@duesseldorf.de>"
	
	Real name: Foo T. Bar
	Email address: monkey@example.org
	Comment: DO NOT USE!
	You selected this USER-ID:
	    "Foo T. Bar (DO NOT USE!) <monkey@example.org>"
	
	Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o
	You need a Passphrase to protect your secret key.
	
	We need to generate a lot of random bytes. It is a good idea to perform
	some other action (type on the keyboard, move the mouse, utilize the
	disks) during the prime generation; this gives the random number
	generator a better chance to gain enough entropy.
	+++++
	gpg: key A09F70B7 marked as ultimately trusted
	public and secret key created and signed.
	
	gpg: checking the trustdb
	gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
	gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
	gpg: next trustdb check due at 2008-08-09
	pub   1024R/A09F70B7 2008-08-08 [expires: 2008-08-09]
	      Key fingerprint = C3D3 1063 7CA1 5809 9EB9  7A63 F4E4 8D01 A09F 70B7
	uid                  Foo T. Bar (DO NOT USE!) <monkey@example.org>
	
	Note that this key cannot be used for encryption.  You may want to use
	the command "--edit-key" to generate a subkey for this purpose.
	0 wt215@squeak:~$ monkeysphere gen-subkey 
	Please specify how long the key should be valid.
	         0 = key does not expire
	      <n>  = key expires in n days
	      <n>w = key expires in n weeks
	      <n>m = key expires in n months
	      <n>y = key expires in n years
	Key is valid for? (0) 2
	ms: generating subkey...
	gpg (GnuPG) 1.4.9; Copyright (C) 2008 Free Software Foundation, Inc.
	This is free software: you are free to change and redistribute it.
	There is NO WARRANTY, to the extent permitted by law.
	
	Secret key is available.
	
	pub  1024R/A09F70B7  created: 2008-08-08  expires: 2008-08-09  usage: SC  
	                     trust: ultimate      validity: ultimate
	[ultimate] (1). Foo T. Bar (DO NOT USE!) <monkey@example.org>
	
	Key is protected.
	
	You need a passphrase to unlock the secret key for
	user: "Foo T. Bar (DO NOT USE!) <monkey@example.org>"
	1024-bit RSA key, ID A09F70B7, created 2008-08-08
	
	             gpg: Invalid passphrase; please try again ...
	
	You need a passphrase to unlock the secret key for
	user: "Foo T. Bar (DO NOT USE!) <monkey@example.org>"
	1024-bit RSA key, ID A09F70B7, created 2008-08-08
	
	             gpg: Invalid passphrase; please try again ...                                
	
	You need a passphrase to unlock the secret key for
	user: "Foo T. Bar (DO NOT USE!) <monkey@example.org>"
	1024-bit RSA key, ID A09F70B7, created 2008-08-08
	
	             gpg: Key generation failed: bad passphrase                                   
	
	
	Invalid command  (try "help")
	
	ms: done.
	0 wt215@squeak:~$ 

This user does not have `use-agent` configured in `~/.gnupg/gpg.conf`.

This problem can be resolved by the user doing:

	echo use-agent >> ~/.gnupg/gpg.conf
	gpg-agent --daemon monkeysphere --gen-subkey

Then they will be prompted for their passphrase during key creation.

If we're OK with relying on `gpg-agent`, we should make make that an
explicit dependency, and ensure that an agent is running (or start one
up specifically for the process).

If we're not OK with relying on the agent, `--gen-subkey` needs
fixing.

---

I think requiring the agent and using it for getting the passphrase is
fine.  That should make this bug fairly easy to fix, so I'll get on
it.

-- BJ (jgr)

---

Alternately, we could use `--passwd-fd` and `ssh-agent`, along the
lines i proposed [for handling passphrase-locked secret
keys](/bugs/handle-passphrase-locked-secret-keys).

--- 

[[bugs/done]] as of 2008-08-15 16:48:26-0400 (to be released in 0.8-1)

I opted to go with the `ssh-askpass` route, and fall back to echoing
stuff to a fifo directly if `ssh-askpass` is not available.