1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314
// Copyright 2015 Brian Smith. // // Permission to use, copy, modify, and/or distribute this software for any // purpose with or without fee is hereby granted, provided that the above // copyright notice and this permission notice appear in all copies. // // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR // ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN // ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF // OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. //! webpki: Web PKI X.509 Certificate Validation. //! //! <code>git clone https://github.com/briansmith/webpki</code> //! //! See `EndEntityCert`'s documentation for a description of the certificate //! processing steps necessary for a TLS connection. #![doc(html_root_url="https://briansmith.org/rustdoc/")] #![no_std] // TODO: Deny `unused_qualifications` after // https://github.com/rust-lang/rust/issues/37345 is fixed. #![allow( missing_copy_implementations, missing_debug_implementations, unused_qualifications, )] #![deny( const_err, dead_code, deprecated, exceeding_bitshifts, fat_ptr_transmutes, improper_ctypes, missing_docs, mutable_transmutes, no_mangle_const_items, non_camel_case_types, non_shorthand_field_patterns, non_snake_case, non_upper_case_globals, overflowing_literals, path_statements, plugin_as_library, private_no_mangle_fns, private_no_mangle_statics, stable_features, trivial_casts, trivial_numeric_casts, unconditional_recursion, unknown_crate_types, unknown_lints, unreachable_code, unsafe_code, unstable_features, unused_allocation, unused_assignments, unused_attributes, unused_comparisons, unused_extern_crates, unused_features, unused_imports, unused_import_braces, unused_must_use, unused_mut, unused_parens, unused_results, unused_unsafe, unused_variables, variant_size_differences, warnings, while_true, )] #[cfg(any(test, feature = "trust_anchor_util"))] #[macro_use(format)] extern crate std; extern crate ring; extern crate time; #[cfg(test)] extern crate rustc_serialize; extern crate untrusted; #[macro_use] mod der; mod cert; mod name; mod signed_data; #[cfg(feature = "trust_anchor_util")] pub mod trust_anchor_util; mod verify_cert; pub use signed_data::{ SignatureAlgorithm, ECDSA_P256_SHA256, ECDSA_P256_SHA384, ECDSA_P384_SHA256, ECDSA_P384_SHA384, RSA_PKCS1_2048_8192_SHA1, RSA_PKCS1_2048_8192_SHA256, RSA_PKCS1_2048_8192_SHA384, RSA_PKCS1_2048_8192_SHA512, RSA_PKCS1_3072_8192_SHA384, RSA_PSS_2048_8192_SHA256_LEGACY_KEY, RSA_PSS_2048_8192_SHA384_LEGACY_KEY, RSA_PSS_2048_8192_SHA512_LEGACY_KEY, }; /// An end-entity certificate. /// /// Server certificate processing in a TLS connection consists of several /// steps. All of these steps are necessary: /// /// * `EndEntityCert.verify_is_valid_tls_server_cert`: Verify that the server's /// certificate is currently valid. /// * `EndEntityCert.verify_is_valid_for_dns_name`: Verify that the server's /// certificate is valid for the host that is being connected to. /// * `EndEntityCert.verify_signature`: Verify that the signature of server's /// `ServerKeyExchange` message is valid for the server's certificate. /// /// Although it would be less error-prone to combine all these steps into a /// single function call, some significant optimizations are possible if the /// three steps are processed separately (in parallel). It does not matter much /// which order the steps are done in, but **all of these steps must completed /// before application data is sent and before received application data is /// processed**. `EndEntityCert::from` is an inexpensive operation and is /// deterministic, so if these tasks are done in multiple threads, it is /// probably best to just call `EndEntityCert::from` multiple times (before each /// operation) for the same DER-encoded ASN.1 certificate bytes. pub struct EndEntityCert<'a> { inner: cert::Cert<'a>, } impl <'a> EndEntityCert<'a> { /// Parse the ASN.1 DER-encoded X.509 encoding of the certificate /// `cert_der`. pub fn from(cert_der: untrusted::Input<'a>) -> Result<EndEntityCert<'a>, Error> { Ok(EndEntityCert { inner: try!(cert::parse_cert(cert_der, cert::EndEntityOrCA::EndEntity)) }) } /// Verifies that the end-entity certificate is valid for use by a TLS /// server. /// /// `supported_sig_algs` is the list of signature algorithms that are /// trusted for use in certificate signatures; the end-entity certificate's /// public key is not validated against this list. `trust_anchors` is the /// list of root CAs to trust. `intermediate_certs` is the sequence of /// intermediate certificates that the server sent in the TLS handshake. /// `cert` is the purported end-entity certificate of the server. `time` is /// the time for which the validation is effective (usually the current /// time). pub fn verify_is_valid_tls_server_cert( &self, supported_sig_algs: &[&SignatureAlgorithm], trust_anchors: &[TrustAnchor], intermediate_certs: &[untrusted::Input], time: time::Timespec) -> Result<(), Error> { verify_cert::build_chain(verify_cert::EKU_SERVER_AUTH, supported_sig_algs, trust_anchors, intermediate_certs, &self.inner, time, 0) } /// Verifies that the certificate is valid for the given DNS host name. /// /// `dns_name` is assumed to a normalized ASCII (punycode if non-ASCII) DNS /// name. pub fn verify_is_valid_for_dns_name(&self, dns_name: untrusted::Input) -> Result<(), Error> { name::verify_cert_dns_name(&self, dns_name) } /// Verifies the signature `signature` of message `msg` using the /// certificate's public key. /// /// `signature_alg` is the algorithm to use to /// verify the signature; the certificate's public key is verified to be /// compatible with this algorithm. /// /// For TLS 1.2, `signature` corresponds to TLS's /// `DigitallySigned.signature` and `signature_alg` corresponds to TLS's /// `DigitallySigned.algorithm` of TLS type `SignatureAndHashAlgorithm`. In /// TLS 1.2 a single `SignatureAndHashAlgorithm` may map to multiple /// `SignatureAlgorithm`s. For example, a TLS 1.2 /// `ignatureAndHashAlgorithm` of (ECDSA, SHA-256) may map to any or all /// of {`ECDSA_P256_SHA256`, `ECDSA_P384_SHA256`}, depending on how the TLS /// implementation is configured. /// /// For current TLS 1.3 drafts, `signature_alg` corresponds to TLS's /// `algorithm` fields of type `SignatureScheme`. There is (currently) a /// one-to-one correspondence between TLS 1.3's `SignatureScheme` and /// `SignatureAlgorithm`. pub fn verify_signature(&self, signature_alg: &SignatureAlgorithm, msg: untrusted::Input, signature: untrusted::Input) -> Result<(), Error> { signed_data::verify_signature(signature_alg, self.inner.spki, msg, signature) } } /// An error that occurs during certificate validation or name validation. #[derive(Clone, Copy, Debug, PartialEq)] pub enum Error { /// The encoding of some ASN.1 DER-encoded item is invalid. BadDER, /// The encoding of an ASN.1 DER-encoded time is invalid. BadDERTime, /// A CA certificate is veing used as an end-entity certificate. CAUsedAsEndEntity, /// The certificate is expired; i.e. the time it is being validated for is /// later than the certificate's notAfter time. CertExpired, /// The certificate is not valid for the name it is being validated for. CertNotValidForName, /// The certificate is not valid yet; i.e. the time it is being validated /// for is earlier than the certificate's notBefore time. CertNotValidYet, /// An end-entity certificate is being used as a CA certificate. EndEntityUsedAsCA, /// An X.509 extension is invalid. ExtensionValueInvalid, /// The certificate validity period (notBefore, notAfter) is invalid; e.g. /// the notAfter time is earlier than the notBefore time. InvalidCertValidity, /// The name that a certificate is being validated for is malformed. This /// is not a problem with the certificate, but with the name it is being /// validated for. InvalidReferenceName, /// The signature is invalid for the given public key. InvalidSignatureForPublicKey, /// The certificate violates one or more name constraints. NameConstraintViolation, /// The certificate violates one or more path length constraints. PathLenConstraintViolated, /// The algorithm in the TBSCertificate "signature" field of a certificate /// does not match the algorithm in the signature of the certificate. SignatureAlgorithmMismatch, /// The certificate is not valid for the Extended Key Usage for which it is /// being validated. RequiredEKUNotFound, /// A valid issuer for the certificate could not be found. UnknownIssuer, /// The certificate is not a v3 X.509 certificate. UnsupportedCertVersion, /// The certificate contains an unsupported critical extension. UnsupportedCriticalExtension, /// The signature's algorithm does not match the algorithm of the public /// key it is being validated for. This may be because the public key /// algorithm's OID isn't recognized (e.g. DSA), or the public key /// algorithm's parameters don't match the supported parameters for that /// algorithm (e.g. ECC keys for unsupported curves), or the public key /// algorithm and the signature algorithm simply don't match (e.g. /// verifying an RSA signature with an ECC public key). UnsupportedSignatureAlgorithmForPublicKey, /// The signature algorithm for a signature is not in the set of supported /// signature algorithms given. UnsupportedSignatureAlgorithm, } /// A trust anchor (a.k.a. root CA). /// /// Traditionally, certificate verification libraries have represented trust /// anchors as full X.509 root certificates. However, those certificates /// contain a lot more data than is needed for verifying certificates. The /// `TrustAnchor` representation allows an application to store just the /// essential elements of trust anchors. The `webpki::trust_anchor_util` module /// provides functions for converting X.509 certificates to to the minimized /// `TrustAnchor` representation, either at runtime or in a build script. #[derive(Debug)] pub struct TrustAnchor<'a> { /// The value of the `subject` field of the trust anchor. pub subject: &'a [u8], /// The value of the `subjectPublicKeyInfo` field of the trust anchor. pub spki: &'a [u8], /// The value of a DER-encoded NameConstraints, containing name /// constraints to apply to the trust anchor, if any. pub name_constraints: Option<&'a [u8]> }