properly read IMSI as Mobile Identity (3GPP TS 24.008)
diff --git a/sim-applet/src/org/osmocom/IMSIPseudo/IMSIPseudo.java b/sim-applet/src/org/osmocom/IMSIPseudo/IMSIPseudo.java
index bd3a9ec..3107030 100755
--- a/sim-applet/src/org/osmocom/IMSIPseudo/IMSIPseudo.java
+++ b/sim-applet/src/org/osmocom/IMSIPseudo/IMSIPseudo.java
@@ -99,11 +99,101 @@
showMsg(msg);
}
+ /* Convert BCD-encoded digit into printable character
+ * \param[in] bcd A single BCD-encoded digit
+ * \returns single printable character
+ */
+ private byte bcd2char(byte bcd)
+ {
+ if (bcd < 0xa)
+ return (byte)('0' + bcd);
+ else
+ return (byte)('A' + (bcd - 0xa));
+ }
+
+ /* Convert BCD to string.
+ * The given nibble offsets are interpreted in BCD order, i.e. nibble 0 is bcd[0] & 0xf, nibble 1 is bcd[0] >> 4, nibble
+ * 3 is bcd[1] & 0xf, etc..
+ * \param[out] dst Output byte array.
+ * \param[in] dst_ofs Where to start writing in dst.
+ * \param[in] dst_len How many bytes are available at dst_ofs.
+ * \param[in] bcd Binary coded data buffer.
+ * \param[in] start_nibble Offset to start from, in nibbles.
+ * \param[in] end_nibble Offset to stop before, in nibbles.
+ * \param[in] allow_hex If false, return false if there are digits other than 0-9.
+ * \returns true on success, false otherwise
+ */
+ private boolean bcd2str(byte dst[], byte dst_ofs, byte dst_len,
+ byte bcd[], byte start_nibble, byte end_nibble, boolean allow_hex)
+ {
+ byte nibble_i;
+ byte dst_i = dst_ofs;
+ byte dst_end = (byte)(dst_ofs + dst_len);
+ boolean rc = true;
+
+ for (nibble_i = start_nibble; nibble_i < end_nibble && dst_i < dst_end; nibble_i++, dst_i++) {
+ byte nibble = bcd[(byte)nibble_i >> 1];
+ if ((nibble_i & 1) != 0)
+ nibble >>= 4;
+ nibble &= 0xf;
+
+ if (!allow_hex && nibble > 9)
+ rc = false;
+
+ dst[dst_i] = bcd2char(nibble);
+ }
+
+ return rc;
+ }
+
+ private boolean mi2str(byte dst[], byte dst_ofs, byte dst_len,
+ byte mi[], boolean allow_hex)
+ {
+ /* The IMSI byte array by example:
+ * 08 99 10 07 00 00 10 74 90
+ *
+ * This is encoded according to 3GPP TS 24.008 10.5.1.4 Mobile
+ * Identity, short the Mobile Identity IEI:
+ *
+ * 08 length for the following MI, in bytes.
+ * 9 = 0b1001
+ * 1 = odd nr of digits
+ * 001 = MI type = IMSI
+ * 9 first IMSI digit (BCD)
+ * 0 second digit
+ * 1 third
+ * ...
+ * 0 14th digit
+ * 9 15th and last digit
+ *
+ * If the IMSI had an even number of digits:
+ *
+ * 08 98 10 07 00 00 10 74 f0
+ *
+ * 08 length for the following MI, in bytes.
+ * 8 = 0b0001
+ * 0 = even nr of digits
+ * 001 = MI type = IMSI
+ * 9 first IMSI digit
+ * 0 second digit
+ * 1 third
+ * ...
+ * 0 14th and last digit
+ * f filler
+ */
+ byte bytelen = mi[0];
+ byte mi_type = (byte)(mi[1] & 0xf);
+ boolean odd_nr_of_digits = ((mi_type & 0x08) != 0);
+ byte start_nibble = 2 + 1; // 2 to skip the bytelen, 1 to skip the mi_type
+ byte end_nibble = (byte)(2 + bytelen * 2 - (odd_nr_of_digits ? 0 : 1));
+ return bcd2str(dst, dst_ofs, dst_len, mi, start_nibble, end_nibble, allow_hex);
+ }
+
private void showIMSI() {
/* 3GPP TS 31.102 4.2.2: IMSI */
byte[] IMSI = new byte[9];
byte[] msg = {'C', 'u', 'r', 'r', 'e', 'n', 't', ' ', 'I', 'M', 'S', 'I', ':', ' ',
- '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_', '_'};
+ ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '};
gsmFile.select((short) SIMView.FID_DF_GSM);
gsmFile.select((short) SIMView.FID_EF_IMSI);
@@ -114,19 +204,8 @@
showError(e.getReason());
return;
}
- byte len = (byte) (IMSI[0] * 2);
- for (byte i = (byte)0; i < (byte)18; i++) {
- byte msg_i = (byte)(14 + i);
- if (i >= len) {
- msg[msg_i] = ' ';
- } else if (i % (byte)2 == (byte)0) {
- msg[msg_i] = (byte)('0' + (IMSI[i / (byte)2] & 0x0f));
- } else {
- msg[msg_i] = (byte)('0' + (IMSI[i / (byte)2] >>> 4));
- }
- showMsg(msg); /* DEBUG */
- }
+ mi2str(msg, (byte)14, (byte)16, IMSI, false);
showMsg(msg);
}