diff --git a/README.md b/README.md index 0cca8bb..17c2c94 100644 --- a/README.md +++ b/README.md @@ -160,7 +160,7 @@ PCSCF=2001:db8::105 | `STATE_FILE` | `/var/lib/imsd/imsreg.state` (root) / `$XDG_STATE_HOME/imsd/imsreg.state` | persisted registration context for warm resume | | `RESUME` | `auto` | `0` forces a fresh registration (ignores a warm SA) | | `REFRESH_INTERVAL` | *(auto)* | keepalive re-REGISTER period in s; default = half the granted expiry, clamped to [120, 1800] | -| `EALG` | `aes-cbc` | offered ESP cipher (`aes-cbc`, `des-ede3-cbc`, `null`) | +| `EALG` | `aes-cbc` | offered ESP cipher (`aes-cbc`, `des-ede3-cbc`, `null`). From the 401's `Security-Server` list imsd selects the highest-preference `ipsec-3gpp` mechanism that matches this offer (RFC 3329 §2.3.1) and takes the SPIs/ports from the entry carrying them (some cores list every mechanism they support and put the SPIs on the one they applied); when no entry matches, the P-CSCF's SPI-carrying entry is installed as listed (`hmac-md5-96`, an absent `ealg` = null) and the journal says so. The line, the selection and the SA parameters are logged at every fresh registration | | `SIP_TRANSPORT` | `auto` | transport of the protected leg (the second REGISTER and everything after it): `tcp`, `udp`, or `auto` = TCP, falling back to a fresh registration over UDP when the P-CSCF leaves two TCP connects unanswered — but only on a phone that has never registered over TCP: once the state file (`/var/lib/imsd/imsreg.state`) records a TCP registration, a silent connect is treated as an outage, not a policy (delete the file or set `udp` to override, e.g. after a SIM change). The challenge (first REGISTER) is always UDP. Over UDP a REGISTER or INVITE larger than ~1.2 KB leaves as IPv6 fragments at the ims PDN's 1280-byte MTU (the journal says so once per flow); there are no SIP retransmission timers over UDP yet, so a lost datagram costs a timeout. The SAs, the listener and the firewall rule cover both transports | | `EMERGENCY_NUMBERS` | *(empty)* | comma-separated additions to the builtin 112/911 emergency numbers (e.g. a private test core's short code). SIM `EF_ECC` is not read yet | | `RTP_PORT` | `50004` | local RTP port advertised in SDP | diff --git a/implementations/main.cpp b/implementations/main.cpp index 701f623..2821468 100644 --- a/implementations/main.cpp +++ b/implementations/main.cpp @@ -96,6 +96,16 @@ ProcResult RunCapture(const std::vector& argv) { // Run argv, discard output, return exit code. int RunCmd(const std::vector& argv) { return RunCapture(argv).rc; } +// argv as one journal line with key material (the "0x…" tokens) masked. +std::string RedactKeys(const std::vector& argv) { + std::string s; + for (const auto& a : argv) { + if (!s.empty()) s += ' '; + s += a.starts_with("0x") ? "" : a; + } + return s; +} + // ---- small text extractors (401 header params, qmicli "completed:") ------- std::optional QuotedAfter(std::string_view text, std::string_view key) { @@ -119,16 +129,6 @@ std::optional IntAfter(std::string_view text, std::string_view key) { return v; } -std::string EalgAfter(std::string_view ss) { - std::size_t at = ss.find("ealg="); - if (at == std::string_view::npos) return "null"; - std::size_t i = at + 5; - std::size_t start = i; - auto ok = [](char c) { return (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '-'; }; - while (i < ss.size() && ok(ss[i])) i++; - return std::string(ss.substr(start, i - start)); -} - // value after "completed:" — integer or the hex ("AB:CD:..") token std::optional CompletedInt(std::string_view out) { return IntAfter(out, "completed: "); @@ -1038,15 +1038,41 @@ private: if (!raw || raw->size() < 32) throw std::runtime_error("bad nonce"); std::vector rand16(raw->begin(), raw->begin() + 16); std::vector autn16(raw->begin() + 16, raw->begin() + 32); - auto ssv = imsd::sip::Header(resp, "Security-Server"); - if (!ssv) throw std::runtime_error("no Security-Server"); - ss_ = std::string(*ssv); - int portPs = static_cast(IntAfter(ss_, "port-s=").value_or(0)); - int portPc = static_cast(IntAfter(ss_, "port-c=").value_or(0)); - std::uint32_t spiPs = static_cast(IntAfter(ss_, "spi-s=").value_or(0)); - std::uint32_t spiPc = static_cast(IntAfter(ss_, "spi-c=").value_or(0)); - std::string ealg = EalgAfter(ss_); - if (spiPs == 0) throw ThrottledError("fresh-SA throttle active (spi-s=0)"); + // Every Security-Server instance is one comma-list (RFC 3261 + // §7.3.1); the joined value is what Security-Verify echoes — RFC + // 3329 §2.2 wants the whole list back, not the chosen entry. + auto ssLines = imsd::sip::Headers(resp, "Security-Server"); + if (ssLines.empty()) throw std::runtime_error("no Security-Server"); + ss_.clear(); + for (std::string_view line : ssLines) { + if (!ss_.empty()) ss_ += ','; + ss_ += line; + } + Log(std::format("Security-Server: {}", ss_)); + // Algorithms from the mechanism we select against our offer (RFC + // 3329 §2.3.1), SPIs/ports from the entry carrying them (O2 lists + // six and marks one; ims ledger F11). An answer we cannot use is a + // deferral on the throttle schedule, not a fatal: a fatal restarts + // imsd every RestartSec, an initial REGISTER each time. + auto ss = imsd::ipsec::ParseSecurityServer(ss_, "hmac-sha-1-96", ealgOffer_); + if (!ss) throw ThrottledError("Security-Server has no ipsec-3gpp mechanism"); + const imsd::ipsec::SecurityMechanism& mech = ss->Selected(); + const imsd::ipsec::SecurityMechanism& carrier = ss->Carrier(); + Log(std::format("selected mechanism {} of {}{}: {}", ss->selected + 1, ss->mechanisms.size(), ss->offerMatched ? "" : " (none matches our offer; taking the P-CSCF's)", mech.text)); + if (ss->carrier != ss->selected) Log(std::format("SPIs/ports from mechanism {}: {}", ss->carrier + 1, carrier.text)); + if (carrier.spiPs == 0u) throw ThrottledError("fresh-SA throttle active (spi-s=0)"); + if (!carrier.spiPs || !carrier.spiPc || !carrier.portPs || !carrier.portPc) throw ThrottledError("Security-Server carries no spi-c/spi-s/port-c/port-s"); + std::string alg = mech.alg.empty() ? "hmac-sha-1-96" : mech.alg; // absent: what we offered + std::string ealg = imsd::ipsec::NormalizeEalg(mech.ealg); // absent: the null cipher (RFC 3329) + if (!imsd::ipsec::KernelAuth(alg)) throw ThrottledError(std::format("Security-Server alg={} unsupported", alg)); + if (!imsd::ipsec::KnownEalg(ealg)) throw ThrottledError(std::format("Security-Server ealg={} unsupported", ealg)); + if (!mech.prot.empty() && mech.prot != "esp") throw ThrottledError(std::format("Security-Server prot={} unsupported", mech.prot)); + if (!mech.mod.empty() && mech.mod != "trans") throw ThrottledError(std::format("Security-Server mod={} unsupported", mech.mod)); + std::uint32_t spiPs = *carrier.spiPs; + std::uint32_t spiPc = *carrier.spiPc; + int portPs = *carrier.portPs; + int portPc = *carrier.portPc; + Log(std::format("SA: alg={} ealg={}{} spi-c={} spi-s={} port-c={} port-s={}", alg, ealg, mech.ealg.empty() ? " (absent)" : "", spiPc, spiPs, portPc, portPs)); auto aka = Authenticate(rand16, autn16); if (!aka) throw std::runtime_error("USIM AKA failed"); @@ -1057,9 +1083,12 @@ private: sp.ik = aka->ik; sp.ck = aka->ck; sp.spiUc = spiUc; sp.spiUs = spiUs; sp.spiPc = spiPc; sp.spiPs = spiPs; sp.portUc = PortUc; sp.portUs = PortUs; sp.portPs = portPs; sp.portPc = portPc; + sp.alg = alg; sp.ealg = ealg; - for (auto& cmd : imsd::ipsec::BuildSetupCommands(sp)) - RunCmd(cmd); + for (auto& cmd : imsd::ipsec::BuildSetupCommands(sp)) { + int rc = RunCmd(cmd); + if (rc != 0) Log(std::format("{} -> rc {}", RedactKeys(cmd), rc)); + } ctx_.securityServer = ss_; portPs_ = portPs; diff --git a/interfaces/Imsd-Ipsec.cppm b/interfaces/Imsd-Ipsec.cppm index 6aa7d40..fbbd514 100644 --- a/interfaces/Imsd-Ipsec.cppm +++ b/interfaces/Imsd-Ipsec.cppm @@ -8,12 +8,14 @@ lines, plus a reader for an SA already installed in the kernel. A registered IMS UE keeps two ESP SA pairs with the P-CSCF (TS 33.203): reqid 1 carries the UE-initiated client flow (protected client port ⇄ P-CSCF -server port), reqid 2 the terminating server flow. Integrity is HMAC-SHA1-96 -keyed with IK; confidentiality is the negotiated ealg keyed with CK. This -module turns the negotiated SPIs/ports/keys into the exact argv lists the -daemon shell hands to `ip`, and — for a warm resume — reconstructs the SPIs, -ports, and Security-Server value back out of `ip xfrm state`/`policy` text so -a refresh re-REGISTER can advertise the SPIs actually in use. +server port), reqid 2 the terminating server flow. Integrity is the negotiated +alg (HMAC-SHA-1-96 or HMAC-MD5-96) keyed with IK; confidentiality is the +negotiated ealg keyed with CK. Both come from the Security-Server mechanism +the P-CSCF selected in its 401 (parsed here), and this module turns the +negotiated SPIs/ports/keys into the exact argv lists the daemon shell hands to +`ip`; for a warm resume it reconstructs the SPIs, ports, and Security-Server +value back out of `ip xfrm state`/`policy` text so a refresh re-REGISTER can +advertise the SPIs actually in use. Pure std C++ (the shell runs the commands and captures the text). Command shapes and the parser are pinned by tests/Ipsec. @@ -40,9 +42,36 @@ export namespace imsd::ipsec { int portUs = imsd::util::PortUs; // UE protected server port int portPs = 0; // P-CSCF server port (UE connects its TCP here) int portPc = 0; // P-CSCF client port + std::string alg = "hmac-sha-1-96"; // hmac-sha-1-96 | hmac-md5-96 std::string ealg = "aes-cbc"; // aes-cbc | des-ede3-cbc/3des | null }; + // Kernel name of a TS 33.203 ESP integrity algorithm; nullopt for one we + // cannot install. Both take IK itself as the key: HMAC zero-pads a key + // shorter than its block, so the IK||0x00000000 the spec writes for + // SHA-1 hashes identically to the 128-bit IK handed to the kernel. + std::optional KernelAuth(std::string_view alg) { + if (alg == "hmac-sha-1-96") return "hmac(sha1)"; + if (alg == "hmac-md5-96") return "hmac(md5)"; + return std::nullopt; + } + + // Canonical ealg name: absent is the null cipher (RFC 3329 §2.2), "3des" + // (imsd's EALG alias) is des-ede3-cbc. Used on both sides of the + // offer/answer comparison. + std::string NormalizeEalg(std::string_view ealg) { + if (ealg.empty()) return "null"; + if (ealg == "3des") return "des-ede3-cbc"; + return std::string(ealg); + } + + // The ESP ciphers EncArgs can key from CK (canonical names). A P-CSCF + // selecting anything else must be refused by the caller, never + // installed as a silent null. + bool KnownEalg(std::string_view ealg) { + return ealg == "null" || ealg == "aes-cbc" || ealg == "des-ede3-cbc"; + } + namespace detail { // ESP cipher argv triple for `ip xfrm state add ... `, matching // imscall.setup_sa: aes-cbc keyed with CK; 3DES uses CK||CK[:8] to @@ -57,13 +86,13 @@ export namespace imsd::ipsec { return {"enc", "cipher_null", ""}; } - inline std::vector StateAdd(std::string_view src, std::string_view dst, std::uint32_t spi, int reqid, std::string_view ikx, const std::vector& enc) { + inline std::vector StateAdd(std::string_view src, std::string_view dst, std::uint32_t spi, int reqid, std::string_view auth, std::string_view ikx, const std::vector& enc) { std::vector a = { "ip", "xfrm", "state", "add", "src", std::string(src), "dst", std::string(dst), "proto", "esp", "spi", std::to_string(spi), "mode", "transport", "reqid", std::to_string(reqid), - "auth-trunc", "hmac(sha1)", std::string(ikx), "96"}; + "auth-trunc", std::string(auth), std::string(ikx), "96"}; a.insert(a.end(), enc.begin(), enc.end()); return a; } @@ -83,20 +112,23 @@ export namespace imsd::ipsec { // The full `ip xfrm` argv sequence to install a fresh SA pair: flush // state+policy, add the four ESP states, add the four transport policies. - // Order matches imscall.setup_sa exactly. + // Order matches imscall.setup_sa exactly. Callers validate p.alg with + // KernelAuth() first; an unknown alg goes to the kernel by its own name + // and is rejected there, never mapped to a default. std::vector> BuildSetupCommands(const SaParams& p) { const std::string& local = p.local; const std::string& pcscf = p.pcscf; std::string ikx = std::format("0x{}", imsd::util::ToHex(p.ik)); + std::string auth = KernelAuth(p.alg).value_or(p.alg); std::vector enc = detail::EncArgs(p); int plen = imsd::util::Is6(local) ? 128 : 32; std::vector> cmds; cmds.push_back({"ip", "xfrm", "state", "flush"}); cmds.push_back({"ip", "xfrm", "policy", "flush"}); - cmds.push_back(detail::StateAdd(local, pcscf, p.spiPs, 1, ikx, enc)); - cmds.push_back(detail::StateAdd(pcscf, local, p.spiUc, 1, ikx, enc)); - cmds.push_back(detail::StateAdd(local, pcscf, p.spiPc, 2, ikx, enc)); - cmds.push_back(detail::StateAdd(pcscf, local, p.spiUs, 2, ikx, enc)); + cmds.push_back(detail::StateAdd(local, pcscf, p.spiPs, 1, auth, ikx, enc)); + cmds.push_back(detail::StateAdd(pcscf, local, p.spiUc, 1, auth, ikx, enc)); + cmds.push_back(detail::StateAdd(local, pcscf, p.spiPc, 2, auth, ikx, enc)); + cmds.push_back(detail::StateAdd(pcscf, local, p.spiUs, 2, auth, ikx, enc)); cmds.push_back(detail::PolicyAdd(local, pcscf, plen, p.portUc, p.portPs, "out", local, pcscf, 1)); cmds.push_back(detail::PolicyAdd(pcscf, local, plen, p.portPs, p.portUc, "in", pcscf, local, 1)); cmds.push_back(detail::PolicyAdd(local, pcscf, plen, p.portUs, p.portPc, "out", local, pcscf, 2)); @@ -108,6 +140,169 @@ export namespace imsd::ipsec { return {{"ip", "xfrm", "state", "flush"}, {"ip", "xfrm", "policy", "flush"}}; } + // ---- Security-Server (RFC 3329 §2.2) ----------------------------------- + // + // The P-CSCF answers the challenge with the mechanisms it supports, each + // with a preference, plus the SPIs and ports it assigned to this + // registration. The UE takes the highest-preference mechanism that is + // in that list AND that it offered (RFC 3329 §2.3.1, TS 24.229 + // §5.1.1.5.1, TS 33.203 §7.2); imsd offers exactly one combination + // (hmac-sha-1-96 + EALG). The SPIs/ports are per registration, not per + // mechanism: they come from whichever entry carries them (O2 UK's + // Mavenir core lists six entries and puts them on the one it applied). + // imsd ≤ 0.3.5 took the first `ealg=` anywhere in the header and + // installed 3DES against a P-CSCF expecting the null cipher: every + // protected packet was undecryptable to it (alyx, 2026-09-17; journal/ims + // ledger F11). + + struct SecurityMechanism { + std::string text; // the mechanism verbatim (trimmed) + std::string name; // mechanism-name, lower-case ("ipsec-3gpp") + std::optional qMilli; // q in thousandths (q=0.94 -> 940) + std::string alg; // lower-case; empty when absent + std::string ealg; // lower-case; empty when absent (= null cipher) + std::string prot; // lower-case; empty when absent (= esp) + std::string mod; // lower-case; empty when absent (= trans) + std::optional spiPc; + std::optional spiPs; + std::optional portPc; + std::optional portPs; + }; + + struct SecurityServer { + std::vector mechanisms; // in header order + std::size_t selected = 0; // algorithms: the ipsec-3gpp entry the UE selects + std::size_t carrier = 0; // SPIs/ports: the entry carrying spi-s (== selected when it does) + bool offerMatched = false; // selected is what we offered; false = the fallback below + const SecurityMechanism& Selected() const { return mechanisms[selected]; } + const SecurityMechanism& Carrier() const { return mechanisms[carrier]; } + }; + + namespace detail { + inline std::string_view TrimWs(std::string_view s) { + auto ws = [](char c) { return c == ' ' || c == '\t' || c == '\r' || c == '\n'; }; + while (!s.empty() && ws(s.front())) s.remove_prefix(1); + while (!s.empty() && ws(s.back())) s.remove_suffix(1); + return s; + } + + inline std::string Lower(std::string_view s) { + std::string out(s); + for (char& c : out) if (c >= 'A' && c <= 'Z') c = static_cast(c - 'A' + 'a'); + return out; + } + + // Split on `sep` outside double quotes: a d-qop="auth,auth-int" + // value must not split the mechanism list. + inline std::vector SplitUnquoted(std::string_view s, char sep) { + std::vector out; + bool quoted = false; + std::size_t start = 0; + for (std::size_t i = 0; i < s.size(); i++) { + if (s[i] == '"') quoted = !quoted; + else if (s[i] == sep && !quoted) { out.push_back(s.substr(start, i - start)); start = i + 1; } + } + out.push_back(s.substr(start)); + return out; + } + + // RFC 3261 qvalue ("0" ["." 0*3DIGIT] / "1" ["." 0*3("0")]) in thousandths. + inline std::optional ParseQMilli(std::string_view v) { + std::size_t dot = v.find('.'); + std::string_view whole = v.substr(0, dot); + std::string_view frac = dot == std::string_view::npos ? std::string_view{} : v.substr(dot + 1); + if ((whole.empty() && frac.empty()) || whole.size() > 1 || frac.size() > 3) return std::nullopt; + int q = 0; + for (char c : whole) { if (c < '0' || c > '9') return std::nullopt; q = (c - '0') * 1000; } + int scale = 100; + for (char c : frac) { if (c < '0' || c > '9') return std::nullopt; q += (c - '0') * scale; scale /= 10; } + return q; + } + + template + inline std::optional ParseWhole(std::string_view v) { + if (v.empty()) return std::nullopt; + T out{}; + auto [p, ec] = std::from_chars(v.data(), v.data() + v.size(), out); + if (ec != std::errc{} || p != v.data() + v.size()) return std::nullopt; + return out; + } + + inline std::optional ParsePort(std::string_view v) { + auto p = ParseWhole(v); + if (!p || *p < 1 || *p > 65535) return std::nullopt; + return p; + } + + // Index of the highest-q mechanism satisfying `pred` (absent q loses + // to any q; ties keep the earlier entry); nullopt when none does. + template + inline std::optional Best(const std::vector& ms, Pred pred) { + std::optional b; + for (std::size_t i = 0; i < ms.size(); i++) { + if (!pred(ms[i])) continue; + if (!b || ms[i].qMilli.value_or(-1) > ms[*b].qMilli.value_or(-1)) b = i; + } + return b; + } + } + + // Parse a Security-Server value and select against our offer. Names, + // parameter names and alg/ealg/prot/mod values are tokens + // (case-insensitive) and come back lower-case. `selected` = the + // highest-q ipsec-3gpp mechanism whose alg (absent = the offered one) + // and ealg (absent = null) equal what we offered; when none matches, + // the highest-q ipsec-3gpp entry carrying spi-s, else port-s, else the + // first ipsec-3gpp entry, with offerMatched = false so the caller can + // say so. `carrier` = selected when it carries spi-s, else the highest-q + // ipsec-3gpp entry that does. nullopt when the value holds no ipsec-3gpp + // mechanism at all. + std::optional ParseSecurityServer(std::string_view value, std::string_view offeredAlg, std::string_view offeredEalg) { + SecurityServer ss; + for (std::string_view part : detail::SplitUnquoted(value, ',')) { + part = detail::TrimWs(part); + if (part.empty()) continue; + SecurityMechanism m; + m.text = std::string(part); + bool first = true; + for (std::string_view tok : detail::SplitUnquoted(part, ';')) { + tok = detail::TrimWs(tok); + if (first) { m.name = detail::Lower(tok); first = false; continue; } + if (tok.empty()) continue; + std::size_t eq = tok.find('='); + std::string key = detail::Lower(detail::TrimWs(tok.substr(0, eq))); + std::string_view val = eq == std::string_view::npos ? std::string_view{} : detail::TrimWs(tok.substr(eq + 1)); + if (val.size() >= 2 && val.front() == '"' && val.back() == '"') val = val.substr(1, val.size() - 2); + if (key == "q") m.qMilli = detail::ParseQMilli(val); + else if (key == "alg") m.alg = detail::Lower(val); + else if (key == "ealg") m.ealg = detail::Lower(val); + else if (key == "prot") m.prot = detail::Lower(val); + else if (key == "mod") m.mod = detail::Lower(val); + else if (key == "spi-c") m.spiPc = detail::ParseWhole(val); + else if (key == "spi-s") m.spiPs = detail::ParseWhole(val); + else if (key == "port-c") m.portPc = detail::ParsePort(val); + else if (key == "port-s") m.portPs = detail::ParsePort(val); + } + ss.mechanisms.push_back(std::move(m)); + } + auto ipsec = [](const SecurityMechanism& m) { return m.name == "ipsec-3gpp"; }; + auto carries = [&](const SecurityMechanism& m) { return ipsec(m) && m.spiPs.has_value(); }; + std::string wantAlg = detail::Lower(offeredAlg); + std::string wantEalg = NormalizeEalg(detail::Lower(offeredEalg)); + auto offered = [&](const SecurityMechanism& m) { + return ipsec(m) && (m.alg.empty() || m.alg == wantAlg) && NormalizeEalg(m.ealg) == wantEalg; + }; + auto firstIpsec = std::ranges::find_if(ss.mechanisms, ipsec); + if (firstIpsec == ss.mechanisms.end()) return std::nullopt; + if (auto i = detail::Best(ss.mechanisms, offered)) { ss.selected = *i; ss.offerMatched = true; } + else if (auto i = detail::Best(ss.mechanisms, carries)) ss.selected = *i; + else if (auto i = detail::Best(ss.mechanisms, [&](const SecurityMechanism& m) { return ipsec(m) && m.portPs.has_value(); })) ss.selected = *i; + else ss.selected = static_cast(firstIpsec - ss.mechanisms.begin()); + ss.carrier = ss.selected; + if (!ss.Selected().spiPs) if (auto i = detail::Best(ss.mechanisms, carries)) ss.carrier = *i; + return ss; + } + // What a warm SA in the kernel tells us — enough for a refresh re-REGISTER // to re-bind without re-authenticating. struct ExistingSa { diff --git a/tests/Ipsec/main.cpp b/tests/Ipsec/main.cpp index 92f85d6..4132a3d 100644 --- a/tests/Ipsec/main.cpp +++ b/tests/Ipsec/main.cpp @@ -3,8 +3,10 @@ // lint-disable-file fixed-width-types // Imsd:Ipsec unit tests — the `ip xfrm` setup command sequence (byte-exact -// argv) and the warm-SA reader, fed `ip xfrm state`/`policy` output in the -// exact shape captured from a registered FP6 (addresses/keys synthetic). +// argv), the warm-SA reader, fed `ip xfrm state`/`policy` output in the +// exact shape captured from a registered FP6 (addresses/keys synthetic), and +// the Security-Server parser, fed the operator lines as captured (O2 UK's +// six-mechanism Mavenir shape verbatim, KPN's single mechanism). import std; import Imsd; @@ -119,6 +121,114 @@ int main() { Check(st[st.size() - 3] == "enc" && st[st.size() - 2] == "cipher_null" && st[st.size() - 1].empty(), "null cipher: cipher_null + empty key"); } + // md5 integrity as the P-CSCF selected it: hmac(md5), IK as the key + { + SaParams p; + p.local = "::2"; p.pcscf = "::1"; + p.ik = std::vector(16, 0x01); + p.ck = {}; + p.alg = "hmac-md5-96"; p.ealg = "null"; + auto cmds = BuildSetupCommands(p); + Check(cmds[2][17] == "hmac(md5)" && cmds[2][18] == "0x01010101010101010101010101010101" && cmds[2][19] == "96", "md5: auth-trunc hmac(md5) IK 96"); + Check(KernelAuth("hmac-sha-1-96") == "hmac(sha1)" && KernelAuth("hmac-md5-96") == "hmac(md5)" && !KernelAuth("hmac-sha-256-128"), "KernelAuth names"); + Check(KnownEalg("null") && KnownEalg("aes-cbc") && KnownEalg("des-ede3-cbc") && !KnownEalg("aes-gcm") && !KnownEalg("") && !KnownEalg("3des"), "KnownEalg set (canonical names only)"); + } + + // ---- Security-Server: O2 UK (alyx report 11, 2026-09-17) verbatim — + // six mechanisms, the SPIs/ports on the fourth (sha1, no ealg); the + // first `ealg=` in the header is the unselected 3DES entry. + constexpr std::string_view O2 = + "ipsec-3gpp;q=0.88;alg=hmac-md5-96;mod=trans," + "ipsec-3gpp;q=0.9;alg=hmac-md5-96;mod=trans;ealg=des-ede3-cbc," + "ipsec-3gpp;q=0.92;alg=hmac-md5-96;mod=trans;ealg=aes-cbc," + "ipsec-3gpp;q=0.94;alg=hmac-sha-1-96;mod=trans;spi-c=129427852;spi-s=133937015;port-c=6051;port-s=6060," + "ipsec-3gpp;q=0.96;alg=hmac-sha-1-96;mod=trans;ealg=des-ede3-cbc," + "ipsec-3gpp;q=0.98;alg=hmac-sha-1-96;mod=trans;ealg=aes-cbc"; + { + // alyx's offer (EALG=null): the entry O2 marked is also the only one matching the offer + auto ss = ParseSecurityServer(O2, "hmac-sha-1-96", "null"); + Check(ss.has_value() && ss->mechanisms.size() == 6, "O2/null: six mechanisms"); + Check(ss && ss->selected == 3 && ss->carrier == 3 && ss->offerMatched, "O2/null: the fourth mechanism (sha1, no ealg, the SPIs) selected, offer matched"); + if (ss) { + const auto& m = ss->Selected(); + Check(m.name == "ipsec-3gpp" && m.mod == "trans" && m.prot.empty(), "O2/null: name, mod=trans, prot absent"); + Check(m.qMilli == 940, "O2/null: q=0.94"); + Check(m.alg == "hmac-sha-1-96", "O2/null: alg from the selected mechanism"); + Check(m.ealg.empty(), "O2/null: ealg absent on the selected mechanism (null), NOT the header's first ealg= (3DES)"); + Check(m.spiPc == 129427852u && m.spiPs == 133937015u, "O2/null: SPIs"); + Check(m.portPc == 6051 && m.portPs == 6060, "O2/null: ports"); + Check(m.text == "ipsec-3gpp;q=0.94;alg=hmac-sha-1-96;mod=trans;spi-c=129427852;spi-s=133937015;port-c=6051;port-s=6060", "O2/null: selected text verbatim"); + Check(ss->mechanisms[1].ealg == "des-ede3-cbc" && !ss->mechanisms[1].spiPs, "O2/null: the 3DES entry is parsed but carries no SPIs"); + } + // the default offer (EALG=aes-cbc): the spec picks sha1+aes (q=0.98); the SPIs stay with the marked entry + auto sa = ParseSecurityServer(O2, "hmac-sha-1-96", "aes-cbc"); + Check(sa && sa->selected == 5 && sa->offerMatched, "O2/aes: sha1+aes-cbc (q=0.98) selected for the aes offer"); + Check(sa && sa->carrier == 3 && sa->Carrier().spiPs == 133937015u && sa->Carrier().portPs == 6060, "O2/aes: SPIs/ports from the entry carrying them"); + Check(sa && sa->Selected().ealg == "aes-cbc" && sa->Selected().alg == "hmac-sha-1-96", "O2/aes: algorithms from the selected entry"); + // an offer O2 does not list (3des alias -> des-ede3-cbc): sha1+3des (q=0.96) + auto s3 = ParseSecurityServer(O2, "hmac-sha-1-96", "3des"); + Check(s3 && s3->selected == 4 && s3->offerMatched && s3->carrier == 3, "O2/3des: the alias matches des-ede3-cbc (q=0.96), SPIs from the marked entry"); + } + // ---- KPN: one mechanism, spaces after the separators, explicit ealg + { + auto ss = ParseSecurityServer("ipsec-3gpp; q=0.1; alg=hmac-sha-1-96; ealg=aes-cbc; spi-c=49889723; spi-s=49889722; port-c=33142; port-s=6000", "hmac-sha-1-96", "aes-cbc"); + Check(ss && ss->mechanisms.size() == 1 && ss->selected == 0 && ss->carrier == 0 && ss->offerMatched, "KPN: single mechanism selected, offer matched"); + Check(ss && ss->Selected().alg == "hmac-sha-1-96" && ss->Selected().ealg == "aes-cbc", "KPN: alg + ealg"); + Check(ss && ss->Selected().spiPc == 49889723u && ss->Selected().spiPs == 49889722u && ss->Selected().portPc == 33142 && ss->Selected().portPs == 6000, "KPN: SPIs + ports"); + Check(ss && ss->Selected().qMilli == 100, "KPN: q=0.1"); + auto nul = ParseSecurityServer("ipsec-3gpp; q=0.1; alg=hmac-sha-1-96; ealg=null; spi-c=33998503; spi-s=33998502; port-c=33021; port-s=6000", "hmac-sha-1-96", "null"); + Check(nul && nul->Selected().ealg == "null" && nul->offerMatched, "KPN: explicit ealg=null matches the null offer"); + // the P-CSCF answers a cipher we did not offer: still the only entry, installed as answered, flagged + auto other = ParseSecurityServer("ipsec-3gpp; q=0.1; alg=hmac-sha-1-96; ealg=null; spi-c=33998503; spi-s=33998502; port-c=33021; port-s=6000", "hmac-sha-1-96", "aes-cbc"); + Check(other && other->selected == 0 && other->carrier == 0 && !other->offerMatched, "single entry not matching the offer: selected via the spi-s fallback, offerMatched=false"); + // the fresh-SA throttle answer: spi-s present and zero + auto thr = ParseSecurityServer("ipsec-3gpp; q=0.1; alg=hmac-sha-1-96; ealg=aes-cbc; spi-c=1; spi-s=0; port-c=33102; port-s=6000", "hmac-sha-1-96", "aes-cbc"); + Check(thr && thr->Carrier().spiPs.has_value() && *thr->Carrier().spiPs == 0, "KPN throttle: spi-s=0 is present, not absent"); + // no SPIs anywhere: parsed, nothing to build from + auto bare = ParseSecurityServer("ipsec-3gpp; q=0.1; alg=hmac-sha-1-96; ealg=null;", "hmac-sha-1-96", "null"); + Check(bare && bare->mechanisms.size() == 1 && bare->offerMatched && !bare->Carrier().spiPs && !bare->Carrier().portPs, "no spi-s: absent, not zero"); + } + // ---- selection rules and syntax corners + { + // spec-shaped list: every entry carries the SPI set, md5 preferred by q — we offered sha1, so sha1 wins (audit A1) + auto a1 = ParseSecurityServer("ipsec-3gpp;q=0.1;alg=hmac-sha-1-96;ealg=aes-cbc;spi-c=11;spi-s=12;port-c=13;port-s=14,ipsec-3gpp;q=0.2;alg=hmac-md5-96;ealg=aes-cbc;spi-c=11;spi-s=12;port-c=13;port-s=14", "hmac-sha-1-96", "aes-cbc"); + Check(a1 && a1->selected == 0 && a1->offerMatched && a1->Selected().alg == "hmac-sha-1-96", "every entry carries SPIs, md5 preferred: the offered sha1 is selected, not the highest q"); + // two sha1 entries with different ciphers, both carrying SPIs: the offered cipher wins over q (audit A3) + auto a3 = ParseSecurityServer("ipsec-3gpp;q=0.9;alg=hmac-sha-1-96;ealg=des-ede3-cbc;spi-c=1;spi-s=2;port-c=3;port-s=4,ipsec-3gpp;q=0.8;alg=hmac-sha-1-96;ealg=aes-cbc;spi-c=5;spi-s=6;port-c=7;port-s=8", "hmac-sha-1-96", "aes-cbc"); + Check(a3 && a3->selected == 1 && a3->Carrier().spiPs == 6u, "offered cipher wins over a higher-q cipher we did not offer"); + // two matching entries: the higher q + auto two = ParseSecurityServer("ipsec-3gpp;q=0.5;alg=hmac-sha-1-96;ealg=aes-cbc;spi-c=1;spi-s=2;port-c=3;port-s=4,ipsec-3gpp;q=0.9;alg=hmac-sha-1-96;ealg=aes-cbc;spi-c=5;spi-s=6;port-c=7;port-s=8", "hmac-sha-1-96", "aes-cbc"); + Check(two && two->selected == 1 && two->Selected().spiPs == 6u, "two matching entries: highest q selected"); + // nothing matches the offer (md5-only list): fallback = the highest-q carrier, flagged + auto md5 = ParseSecurityServer("ipsec-3gpp;q=0.5;alg=hmac-md5-96;spi-c=1;spi-s=2;port-c=3;port-s=4,ipsec-3gpp;q=0.9;alg=hmac-md5-96;ealg=aes-cbc;spi-c=5;spi-s=6;port-c=7;port-s=8", "hmac-sha-1-96", "aes-cbc"); + Check(md5 && md5->selected == 1 && !md5->offerMatched && md5->carrier == 1, "no match: highest-q carrier, offerMatched=false"); + // no q at all, nothing matching: the first carrier + auto noq = ParseSecurityServer("ipsec-3gpp;alg=hmac-md5-96;spi-c=1;spi-s=2;port-c=3;port-s=4,ipsec-3gpp;alg=hmac-md5-96;ealg=aes-cbc;spi-c=5;spi-s=6;port-c=7;port-s=8", "hmac-sha-1-96", "aes-cbc"); + Check(noq && noq->selected == 0 && !noq->offerMatched, "no q, no match: first carrier"); + // absent alg on the entry counts as the offered one + auto noalg = ParseSecurityServer("ipsec-3gpp;ealg=aes-cbc;spi-c=1;spi-s=2;port-c=3;port-s=4", "hmac-sha-1-96", "aes-cbc"); + Check(noalg && noalg->offerMatched, "absent alg matches the offer"); + // only non-ipsec mechanisms: nothing for us + Check(!ParseSecurityServer("tls;q=0.2,digest;d-alg=MD5", "hmac-sha-1-96", "aes-cbc").has_value(), "tls/digest only -> nullopt"); + // a quoted comma must not split the list; tokens are case-insensitive + auto q = ParseSecurityServer("digest;d-alg=MD5;d-qop=\"auth,auth-int\",IPSEC-3GPP; ALG=HMAC-SHA-1-96; EALG=AES-CBC; SPI-C=11; SPI-S=12; PORT-C=13; PORT-S=14", "HMAC-SHA-1-96", "AES-CBC"); + Check(q && q->mechanisms.size() == 2 && q->mechanisms[0].name == "digest", "quoted comma stays inside the digest mechanism"); + Check(q && q->selected == 1 && q->offerMatched && q->Selected().name == "ipsec-3gpp" && q->Selected().alg == "hmac-sha-1-96" && q->Selected().ealg == "aes-cbc" && q->Selected().spiPs == 12u && q->Selected().portPs == 14, "case-insensitive names and values, lower-cased; offer compared case-insensitively"); + // prot/mod parsed for the caller to refuse + auto tun = ParseSecurityServer("ipsec-3gpp;alg=hmac-sha-1-96;ealg=aes-cbc;prot=ah;mod=tun;spi-c=1;spi-s=2;port-c=3;port-s=4", "hmac-sha-1-96", "aes-cbc"); + Check(tun && tun->Selected().prot == "ah" && tun->Selected().mod == "tun", "prot/mod parsed"); + // spi-s beyond 32 bits, a port beyond 16 bits or zero: absent, not garbage + auto bad = ParseSecurityServer("ipsec-3gpp;alg=hmac-sha-1-96;ealg=aes-cbc;spi-c=1;spi-s=4294967296;port-c=0;port-s=70000", "hmac-sha-1-96", "aes-cbc"); + Check(bad && !bad->Selected().spiPs && !bad->Selected().portPs && !bad->Selected().portPc && bad->Selected().spiPc == 1u, "out-of-range spi-s/port-s and port 0 are absent"); + // q syntax + auto q1 = ParseSecurityServer("ipsec-3gpp;q=1;spi-s=1", "hmac-sha-1-96", "null"); + Check(q1 && q1->Selected().qMilli == 1000, "q=1 -> 1000"); + auto qx = ParseSecurityServer("ipsec-3gpp;q=x;spi-s=1", "hmac-sha-1-96", "null"); + Check(qx && !qx->Selected().qMilli, "q=x -> no q"); + Check(!ParseSecurityServer("", "hmac-sha-1-96", "null").has_value() && !ParseSecurityServer(" , ", "hmac-sha-1-96", "null").has_value(), "empty value -> nullopt"); + Check(NormalizeEalg("") == "null" && NormalizeEalg("3des") == "des-ede3-cbc" && NormalizeEalg("aes-cbc") == "aes-cbc", "NormalizeEalg"); + } + if (Failures == 0) std::println("Ipsec: all tests passed"); return Failures; }