<p>neels <strong>submitted</strong> this change.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bsc/+/24635">View Change</a></p><div style="white-space:pre-wrap">Approvals:
Jenkins Builder: Verified
fixeria: Looks good to me, approved
laforge: Looks good to me, but someone else must approve
</div><pre style="font-family: monospace,monospace; white-space: pre-wrap;">implement A5/4 in Ciphering Mode procedure<br><br>Receive and store the Kc128 key from MSC, and use as key sent to BTS if<br>A5/4 is the chosen encryption algorithm.<br><br>(A5/4 in handover will follow in a separate patch)<br><br>Related: SYS#5324<br>Change-Id: I7c458c8a7350f34ff79531b3c891e1b367614469<br>---<br>M include/osmocom/bsc/gsm_data.h<br>M src/osmo-bsc/abis_rsl.c<br>M src/osmo-bsc/osmo_bsc_bssap.c<br>3 files changed, 29 insertions(+), 1 deletion(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmocom/bsc/gsm_data.h b/include/osmocom/bsc/gsm_data.h</span><br><span>index 2a73f46..1755b92 100644</span><br><span>--- a/include/osmocom/bsc/gsm_data.h</span><br><span>+++ b/include/osmocom/bsc/gsm_data.h</span><br><span>@@ -554,6 +554,8 @@</span><br><span> uint8_t alg_id;</span><br><span> uint8_t key_len;</span><br><span> uint8_t key[MAX_A5_KEY_LEN];</span><br><span style="color: hsl(120, 100%, 40%);">+ bool kc128_present;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t kc128[16];</span><br><span> };</span><br><span> </span><br><span> #define LOGPLCHAN(lchan, ss, level, fmt, args...) \</span><br><span>diff --git a/src/osmo-bsc/abis_rsl.c b/src/osmo-bsc/abis_rsl.c</span><br><span>index c844f18..86b1790 100644</span><br><span>--- a/src/osmo-bsc/abis_rsl.c</span><br><span>+++ b/src/osmo-bsc/abis_rsl.c</span><br><span>@@ -178,6 +178,14 @@</span><br><span> memcpy(out, lchan->encr.key, lchan->encr.key_len);</span><br><span> return 1 + lchan->encr.key_len;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ case GSM0808_ALG_ID_A5_4:</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!lchan->encr.kc128_present) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOG_LCHAN(lchan, LOGL_ERROR, "A5/4 encryption chosen, but missing Kc128\n");</span><br><span style="color: hsl(120, 100%, 40%);">+ return -EINVAL;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ memcpy(out, lchan->encr.kc128, sizeof(lchan->encr.kc128));</span><br><span style="color: hsl(120, 100%, 40%);">+ return 1 + sizeof(lchan->encr.kc128);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> default:</span><br><span> LOG_LCHAN(lchan, LOGL_ERROR, "A5/%d encryption not supported\n", lchan->encr.alg_id);</span><br><span> return -EINVAL;</span><br><span>diff --git a/src/osmo-bsc/osmo_bsc_bssap.c b/src/osmo-bsc/osmo_bsc_bssap.c</span><br><span>index 9177e6b..6f0caa7 100644</span><br><span>--- a/src/osmo-bsc/osmo_bsc_bssap.c</span><br><span>+++ b/src/osmo-bsc/osmo_bsc_bssap.c</span><br><span>@@ -466,6 +466,7 @@</span><br><span> uint16_t enc_key_len;</span><br><span> uint8_t enc_bits_msc;</span><br><span> int chosen_cipher;</span><br><span style="color: hsl(120, 100%, 40%);">+ const struct tlv_p_entry *ie_kc128;</span><br><span> </span><br><span> if (!conn || !conn->lchan) {</span><br><span> LOGP(DMSC, LOGL_ERROR, "No lchan/msc_data in cipher mode command.\n");</span><br><span>@@ -544,9 +545,26 @@</span><br><span> conn->lchan->encr.key_len = enc_key_len;</span><br><span> memcpy(conn->lchan->encr.key, enc_key, enc_key_len);</span><br><span> }</span><br><span style="color: hsl(120, 100%, 40%);">+ if ((ie_kc128 = TLVP_GET(&tp, GSM0808_IE_KC_128))) {</span><br><span style="color: hsl(120, 100%, 40%);">+ if (ie_kc128->len != sizeof(conn->lchan->encr.kc128)) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGPFSML(conn->fi, LOGL_ERROR, "Kc128 IE has wrong length: %u (expect %zu)\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ ie_kc128->len, sizeof(conn->lchan->encr.kc128));</span><br><span style="color: hsl(120, 100%, 40%);">+ reject_cause = GSM0808_CAUSE_INFORMATION_ELEMENT_OR_FIELD_MISSING;</span><br><span style="color: hsl(120, 100%, 40%);">+ goto reject;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ memcpy(conn->lchan->encr.kc128, ie_kc128->val, sizeof(conn->lchan->encr.kc128));</span><br><span style="color: hsl(120, 100%, 40%);">+ conn->lchan->encr.kc128_present = true;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- LOGP(DRSL, LOGL_DEBUG, "(subscr %s) Cipher Mode: cipher=%d key=%s include_imeisv=%d\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ if (chosen_cipher == 4 && !conn->lchan->encr.kc128_present) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGPFSML(conn->fi, LOGL_ERROR, "A5/4 encryption selected, but no Kc128\n");</span><br><span style="color: hsl(120, 100%, 40%);">+ reject_cause = GSM0808_CAUSE_INFORMATION_ELEMENT_OR_FIELD_MISSING;</span><br><span style="color: hsl(120, 100%, 40%);">+ goto reject;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DRSL, LOGL_DEBUG, "(subscr %s) Cipher Mode: cipher=%d key=%s kc128=%s include_imeisv=%d\n",</span><br><span> bsc_subscr_name(conn->bsub), chosen_cipher, osmo_hexdump_nospc(enc_key, enc_key_len),</span><br><span style="color: hsl(120, 100%, 40%);">+ ie_kc128? osmo_hexdump_nospc_c(OTC_SELECT, ie_kc128->val, ie_kc128->len) : "-",</span><br><span> include_imeisv);</span><br><span> </span><br><span> if (gsm48_send_rr_ciph_mode(conn->lchan, include_imeisv) < 0) {</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bsc/+/24635">change 24635</a>. 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<div style="display:none"> Gerrit-Project: osmo-bsc </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I7c458c8a7350f34ff79531b3c891e1b367614469 </div>
<div style="display:none"> Gerrit-Change-Number: 24635 </div>
<div style="display:none"> Gerrit-PatchSet: 5 </div>
<div style="display:none"> Gerrit-Owner: Hoernchen <ewild@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: Hoernchen <ewild@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: Jenkins Builder </div>
<div style="display:none"> Gerrit-Reviewer: fixeria <vyanitskiy@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-Reviewer: neels <nhofmeyr@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: merged </div>