* Implemented dynamic loading of an external plug-in shared library to delegate public key authentication
* Moved conditional compilation of the plugin infrastructure into the configure.ac script to be able to add -ldl to dropbear build only when the flag is enabled
* Added tags file to the ignore list
* Updated API to have the constructor to return function pointers in the pliugin instance. Added support for passing user name to the checkpubkey function. Added options to the session returned by the plugin and have dropbear to parse and process them
* Added -rdynamic to the linker flags when EPKA is enabled
* Changed the API to pass a previously created session to the checkPubKey function (created during preauth)
* Added documentation to the API
* Added parameter addrstring to plugin creation function
* Modified the API to retrieve the auth options. Instead of having them as field of the EPKASession struct, they are stored internally (plugin-dependent) in the plugin/session and retrieved through a pointer to a function (in the session)
* Changed option string to be a simple char * instead of unsigned char *
keysizes >= 128 octets will be encoded with a 3 byte header
which must be accounted by the optional-header
Reproduce:
master:~/build/dropbear$ ./dropbearkey -t ecdsa -s 521 -f K
Generating 521 bit ecdsa key, this may take a while...
master:~/build/dropbear$ ./dropbearconvert d o K L
Key is a ecdsa-sha2-nistp521 key
Wrote key to 'L'
master:~/build/dropbear$ openssl ec < L
read EC key
unable to load Key
139769806448384:error:0D07209B:asn1 encoding routines:ASN1_get_object:too long:crypto/asn1/asn1_lib.c:91:
* tweak string size
fix gcc8 warnings
```
svr-agentfwd.c: In function 'bindagent':
svr-agentfwd.c:254:53: warning: '%s' directive output may be truncated writing up to 107 bytes into a region of size between 0 and 107 [-Wformat-truncation=]
snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/%s", path, sockfile);
^~ ~~~~~~~~
svr-agentfwd.c:254:2: note: 'snprintf' output between 2 and 216 bytes into a destination of size 108
snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/%s", path, sockfile);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
* cleanup signed/unsigned comparison
fix gcc8 warnings
```
scp.c: In function 'do_local_cmd':
scp.c:132:17: warning: comparison of integer expressions of different signedness: 'u_int' {aka 'unsigned int'} and 'int' [-Wsign-compare]
for (i = 0; i < a->num; i++)
^
scpmisc.c: In function 'addargs':
scpmisc.c:161:25: warning: comparison of integer expressions of different signedness: 'int' and 'u_int' {aka 'unsigned int'} [-Wsign-compare]
} else if (args->num+2 >= nalloc)
^~
scpmisc.c: In function 'replacearg':
scpmisc.c:183:12: warning: comparison of integer expressions of different signedness: 'u_int' {aka 'unsigned int'} and 'int' [-Wsign-compare]
if (which >= args->num)
^~
scpmisc.c: In function 'freeargs':
scpmisc.c:196:17: warning: comparison of integer expressions of different signedness: 'u_int' {aka 'unsigned int'} and 'int' [-Wsign-compare]
for (i = 0; i < args->num; i++)
^
```
see https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/misc.h.diff?r1=1.16&r2=1.17
This commit introduces fix for scenario:
1. Root login disabled on dropbear
2. PAM authentication model enabled
While login as root user, after prompt for password
user is being notified about login failrue, but
after second attempt of prompt for password within
same session, login becames succesfull.
Signed-off-by: Pawel Rapkiewicz <pawel.rapkiewicz@gmail.com>
