tests: add len2elen.sh

Check plaintext file name length -> encrypted file name length relation

Example output:

0 22
2 22
3 22
4 22
5 22
6 22
7 22
8 22
9 22
10 22
11 22
12 22
13 22
14 22
15 22
16 43
17 43
18 43
19 43
20 43
21 43
22 43
23 43
24 43
25 43
26 43
27 43
28 43
29 43
30 43
31 43
32 64
33 64
34 64
35 64
36 64
37 64
38 64
39 64
40 64
41 64
42 64
43 64
44 64
45 64
46 64
47 64
48 86
49 86
50 86
51 86
52 86
53 86
54 86
55 86
56 86
57 86
58 86
59 86
60 86
61 86
62 86
63 86
64 107
65 107
66 107
67 107
68 107
69 107
70 107
71 107
72 107
73 107
74 107
75 107
76 107
77 107
78 107
79 107
80 128
81 128
82 128
83 128
84 128
85 128
86 128
87 128
88 128
89 128
90 128
91 128
92 128
93 128
94 128
95 128
96 150
97 150
98 150
99 150
100 150
101 150
102 150
103 150
104 150
105 150
106 150
107 150
108 150
109 150
110 150
111 150
112 171
113 171
114 171
115 171
116 171
117 171
118 171
119 171
120 171
121 171
122 171
123 171
124 171
125 171
126 171
127 171
128 192
129 192
130 192
131 192
132 192
133 192
134 192
135 192
136 192
137 192
138 192
139 192
140 192
141 192
142 192
143 192
144 214
145 214
146 214
147 214
148 214
149 214
150 214
151 214
152 214
153 214
154 214
155 214
156 214
157 214
158 214
159 214
160 235
161 235
162 235
163 235
164 235
165 235
166 235
167 235
168 235
169 235
170 235
171 235
172 235
173 235
174 235
175 235
176 67
177 67
178 67
179 67
180 67
181 67
182 67
183 67
184 67
185 67
186 67
187 67
188 67
189 67
190 67
191 67
192 67
193 67
194 67
195 67
196 67
197 67
198 67
199 67
200 67
201 67
202 67
203 67
204 67
205 67
206 67
207 67
208 67
209 67
210 67
211 67
212 67
213 67
214 67
215 67
216 67
217 67
218 67
219 67
220 67
221 67
222 67
223 67
224 67
225 67
226 67
227 67
228 67
229 67
230 67
231 67
232 67
233 67
234 67
235 67
236 67
237 67
238 67
239 67
240 67
241 67
242 67
243 67
244 67
245 67
246 67
247 67
248 67
249 67
250 67
251 67
252 67
253 67
254 67
255 67

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/len2elen.sh b/tests/len2elen.sh
new file mode 100755
index 0000000..e101277
--- /dev/null
+++ b/tests/len2elen.sh
@@ -0,0 +1,29 @@
+#!/bin/bash -eu
+#
+# Check plaintext file name length -> encrypted file name length relation
+#
+# Part of the gocryptfs test suite
+# https://nuetzlich.net/gocryptfs/
+
+NAME="x"
+LEN=0
+
+if [[ ! -f a/gocryptfs.conf ]] ; then
+	echo "fatal: must have gocryptfs dir 'a' mounted at 'b'"
+	exit 1
+fi
+if ! mountpoint b > /dev/null ; then
+	echo "fatal: must have gocryptfs dir 'a' mounted at 'b'"
+	exit 1
+fi
+
+rm -f b/*
+
+while [[ $LEN -le 255 ]]; do
+	touch b/$NAME || break
+	ELEN=$(ls a | wc -L)
+	echo $LEN $ELEN
+	rm b/$NAME
+	NAME="${NAME}x"
+	LEN=${#NAME}
+done