bugfix in encryption key computing, added new feature: derived public keys

tests/key-bobby-pub

@@ -2,35 +2,35 @@
   Generated by: Pretty Curved Privacy Version 0.0.1
         Cipher: CURVE25519-ED25519-SALSA20-POLY1305
          Owner: Bobby
-          Mail: bobby@<EFBFBD>local
-        Key-ID: 0x68832D215AFB2440
-    Public-Key: 1m9SHw3}sw<Ro82?hQ&J[byDA]z(g1.6X$MweEJ95Dz!h
- Creation Time: 2013-10-28T18:48:11
-      Checksum: A8:32:16:EF:9D:38:9A:3C:7D:99:F2:81:D4:42:B3:2D
-                28:13:A9:43:1B:22:C3:71:A8:38:38:10:E3:A3:B9:82
- Serial Number: 0x61FDA3CE
+          Mail: bobby@local
+        Key-ID: 0xCE20289DFB268A3D
+    Public-Key: 18a+&]*cfaPvpGAs*rp=oWkCXnLGe^aUx%^:BtLfv/MGe
+ Creation Time: 2013-11-01T15:53:45
+      Checksum: D6:79:EB:3B:22:CE:77:99:62:58:9A:7D:C5:B7:62:1B
+                F1:2D:2D:FB:C3:D5:B1:9B:D3:B6:DA:9D:89:5B:14:07
+ Serial Number: 0x6F6477D5
    Key Version: 0x00000001
  Random Art ID: +----------------+
+                |      .         |
+                |     o          |
+                |    o .         |
+                |   . = o        |
+                |  o . B .       |
+                |   o + . .      |
+                |    .   o       |
                 |                |
-                |                |
-                |                |
-                |                |
-                |        o .     |
-                |       o o .    |
-                |      . Bo..    |
-                |       +o==.    |
                 +----------------+
 
-1m9SHw3}sw<Ro82?hQ&J[byDA]z(g1.6X$MweEJ95KHzBvTd%QWcl:NlJtTyRdZ>sTc3J1e
-nQ<!<c@^1<(%aF6ks+&}eE%8}zc<Ny@#5&O%GN6ep49slxWhkSe*jox/(JrkVP[zWJ0.wQ8
-RqvuRolF*/(wJ&{+Qpd1dyx&=ERL1c$%bg($]4Fe23!410z/HctdobTD=bs#@]sT[[%d7Z&
-/k:d4>jeJey}hI*S7Pl^8O:i#]wd4}WNR7UYw(=}pBKsHbm^XeFqg^(CtjZG!K4oMPT=bJU
-df/X2F]5iq-bYp:EC82YBJ<[NP*BDW?r-L..!As*CWddicuvsp^AQ20O-$+a@K<}6OPd*Hb
-jex#UvSbZ+C%Gt+z!0i(0j#I6?xftr.eqpicnf]DWfiqE:*?/%(slD9QQU[7t4{J>hyLRkC
-s=uT0HwrFIz6f9C!&=Nf$(jE*(3RFhA>SM5MiFq&8TqUn:^2xzxa70=]T*J[g}vVl8:-Zqq
-N%{=qe7rScb.M4{Ld4j[HDIV(YZZWZ4}At*x.NT5E[/5p/3{SbNK7wjj[1yA2d]ZlE[I4-Z
-11m*e^vcdRz+(xlU=:cXwV2<E1jGb5N/rmsW}O*DM/lG^lEi*+ahIvln>A+463^RQHyN77/
->fdtrPLE^lGYGTc(=FosgPggLZmqU)FTG6g.][KFAi5&YHl]3FOk$jf@g=c(^t3E+tqucW%
-009610m4wrvfsIuoY5m{QWy!7fuih0^e@NMCINT@TYUeV/h:L8WNE3YBh]kQ{UG3qf*4Ql9
-}&1i2de}$URN7GD6yTb/8L^J
+18a+&]*cfaPvpGAs*rp=oWkCXnLGe^aUx%^:BtLfv)U9yvTd$l]THd!tuMEjzY(YpATNQ[=
++9O9^D(VP+S/a@hLz<>u{Y]esh$8duOcR0iu]e*D%*)/F/JBwGFEOY/Sy.dtBJ:a1C7003$
+APnZE=KcH[2z+=R]?R?[}M!t@g+p2.UI!HL$?7.5v.w>3}B>dB[l#p7e<7{<I=x8vBCX-+Z
++^4{FLkgm=2C2XtC{&RQ$vTD*[GO5edJOJz==3oO+dHiI^tFHJF9th-!zV:rRoe7a]Bf2c4
+6?KlfIOU$[tib4@ae2gxwErN!nlyFyCjK#fq(nhLdXZnaBZPJH?2<3i.AGbhcn2^REv^wgp
+nf^T<vSbZ+C%Dg:v{%fN5jnkID*#%SsF3#*<Gl53B[s3T/u&/u1X+^Xf2H5x@j+Vr!1eAkO
+]*qlLlFNsx+ha/b9Nbn2T.A[{n!PClH%bE{Ou>i)Jl<){nb:RRPgWu/uw8l<tSqoh^L4s-D
+.s+A?7V*0%}2J[XV/XX[L5A8ydsrlSvei+eLs@Eo.#@wENxEYwb+FAAYJ7=ax}ZiXgn(Yy7
+VF7osPjBku4f+P[M^<9V5>a@FBi{i@3y8]O6/l:NF0P7nsx4xKueAjuVY1h5e*K+3RwcZdD
+Gviumba.%%uk*Ve3k39UMAPWa70-7xS7[SeaoyYtQmkuLLi5%w@lnyCUk@g[elv3v/qucW%
+009610m=p7zV.nxQrk[Mw!!mbV1F[Nd(efiPTr+pd=QNgCQ>-k?#=T)<X%@VePW62>XM7A[
+jSQW]2+-gx<+-p(4+#H8#]%s
 ------ END PCP PUBLICKEY ------