1 /*
2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <openssl/ssl.h>
11
12 #include <assert.h>
13 #include <limits.h>
14
15 #include <algorithm>
16
17 #include <openssl/ec.h>
18 #include <openssl/ec_key.h>
19 #include <openssl/err.h>
20 #include <openssl/evp.h>
21 #include <openssl/mem.h>
22 #include <openssl/span.h>
23
24 #include "../crypto/internal.h"
25 #include "internal.h"
26
27
28 BSSL_NAMESPACE_BEGIN
29
ssl_is_key_type_supported(int key_type)30 bool ssl_is_key_type_supported(int key_type) {
31 return key_type == EVP_PKEY_RSA || key_type == EVP_PKEY_EC ||
32 key_type == EVP_PKEY_ED25519;
33 }
34
35 typedef struct {
36 uint16_t sigalg;
37 int pkey_type;
38 int curve;
39 const EVP_MD *(*digest_func)(void);
40 bool is_rsa_pss;
41 bool tls12_ok;
42 bool tls13_ok;
43 bool client_only;
44 } SSL_SIGNATURE_ALGORITHM;
45
46 static const SSL_SIGNATURE_ALGORITHM kSignatureAlgorithms[] = {
47 // PKCS#1 v1.5 code points are only allowed in TLS 1.2.
48 {SSL_SIGN_RSA_PKCS1_MD5_SHA1, EVP_PKEY_RSA, NID_undef, &EVP_md5_sha1,
49 /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/false,
50 /*client_only=*/false},
51 {SSL_SIGN_RSA_PKCS1_SHA1, EVP_PKEY_RSA, NID_undef, &EVP_sha1,
52 /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/false,
53 /*client_only=*/false},
54 {SSL_SIGN_RSA_PKCS1_SHA256, EVP_PKEY_RSA, NID_undef, &EVP_sha256,
55 /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/false,
56 /*client_only=*/false},
57 {SSL_SIGN_RSA_PKCS1_SHA384, EVP_PKEY_RSA, NID_undef, &EVP_sha384,
58 /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/false,
59 /*client_only=*/false},
60 {SSL_SIGN_RSA_PKCS1_SHA512, EVP_PKEY_RSA, NID_undef, &EVP_sha512,
61 /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/false,
62 /*client_only=*/false},
63
64 // Legacy PKCS#1 v1.5 code points are only allowed in TLS 1.3 and
65 // client-only. See draft-ietf-tls-tls13-pkcs1-00.
66 {SSL_SIGN_RSA_PKCS1_SHA256_LEGACY, EVP_PKEY_RSA, NID_undef, &EVP_sha256,
67 /*is_rsa_pss=*/false, /*tls12_ok=*/false, /*tls13_ok=*/true,
68 /*client_only=*/true},
69
70 {SSL_SIGN_RSA_PSS_RSAE_SHA256, EVP_PKEY_RSA, NID_undef, &EVP_sha256,
71 /*is_rsa_pss=*/true, /*tls12_ok=*/true, /*tls13_ok=*/true,
72 /*client_only=*/false},
73 {SSL_SIGN_RSA_PSS_RSAE_SHA384, EVP_PKEY_RSA, NID_undef, &EVP_sha384,
74 /*is_rsa_pss=*/true, /*tls12_ok=*/true, /*tls13_ok=*/true,
75 /*client_only=*/false},
76 {SSL_SIGN_RSA_PSS_RSAE_SHA512, EVP_PKEY_RSA, NID_undef, &EVP_sha512,
77 /*is_rsa_pss=*/true, /*tls12_ok=*/true, /*tls13_ok=*/true,
78 /*client_only=*/false},
79
80 {SSL_SIGN_ECDSA_SHA1, EVP_PKEY_EC, NID_undef, &EVP_sha1,
81 /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/false,
82 /*client_only=*/false},
83 {SSL_SIGN_ECDSA_SECP256R1_SHA256, EVP_PKEY_EC, NID_X9_62_prime256v1,
84 &EVP_sha256, /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/true,
85 /*client_only=*/false},
86 {SSL_SIGN_ECDSA_SECP384R1_SHA384, EVP_PKEY_EC, NID_secp384r1, &EVP_sha384,
87 /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/true,
88 /*client_only=*/false},
89 {SSL_SIGN_ECDSA_SECP521R1_SHA512, EVP_PKEY_EC, NID_secp521r1, &EVP_sha512,
90 /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/true,
91 /*client_only=*/false},
92
93 {SSL_SIGN_ED25519, EVP_PKEY_ED25519, NID_undef, nullptr,
94 /*is_rsa_pss=*/false, /*tls12_ok=*/true, /*tls13_ok=*/true,
95 /*client_only=*/false},
96 };
97
get_signature_algorithm(uint16_t sigalg)98 static const SSL_SIGNATURE_ALGORITHM *get_signature_algorithm(uint16_t sigalg) {
99 for (size_t i = 0; i < OPENSSL_ARRAY_SIZE(kSignatureAlgorithms); i++) {
100 if (kSignatureAlgorithms[i].sigalg == sigalg) {
101 return &kSignatureAlgorithms[i];
102 }
103 }
104 return NULL;
105 }
106
ssl_pkey_supports_algorithm(const SSL * ssl,EVP_PKEY * pkey,uint16_t sigalg,bool is_verify)107 bool ssl_pkey_supports_algorithm(const SSL *ssl, EVP_PKEY *pkey,
108 uint16_t sigalg, bool is_verify) {
109 const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
110 if (alg == NULL || EVP_PKEY_id(pkey) != alg->pkey_type) {
111 return false;
112 }
113
114 // Ensure the RSA key is large enough for the hash. RSASSA-PSS requires that
115 // emLen be at least hLen + sLen + 2. Both hLen and sLen are the size of the
116 // hash in TLS. Reasonable RSA key sizes are large enough for the largest
117 // defined RSASSA-PSS algorithm, but 1024-bit RSA is slightly too small for
118 // SHA-512. 1024-bit RSA is sometimes used for test credentials, so check the
119 // size so that we can fall back to another algorithm in that case.
120 if (alg->is_rsa_pss &&
121 (size_t)EVP_PKEY_size(pkey) < 2 * EVP_MD_size(alg->digest_func()) + 2) {
122 return false;
123 }
124
125 if (ssl_protocol_version(ssl) < TLS1_2_VERSION) {
126 // TLS 1.0 and 1.1 do not negotiate algorithms and always sign one of two
127 // hardcoded algorithms.
128 return sigalg == SSL_SIGN_RSA_PKCS1_MD5_SHA1 ||
129 sigalg == SSL_SIGN_ECDSA_SHA1;
130 }
131
132 // |SSL_SIGN_RSA_PKCS1_MD5_SHA1| is not a real SignatureScheme for TLS 1.2 and
133 // higher. It is an internal value we use to represent TLS 1.0/1.1's MD5/SHA1
134 // concatenation.
135 if (sigalg == SSL_SIGN_RSA_PKCS1_MD5_SHA1) {
136 return false;
137 }
138
139 if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
140 if (!alg->tls13_ok) {
141 return false;
142 }
143
144 bool is_client_sign = ssl->server == is_verify;
145 if (alg->client_only && !is_client_sign) {
146 return false;
147 }
148
149 // EC keys have a curve requirement.
150 if (alg->pkey_type == EVP_PKEY_EC &&
151 (alg->curve == NID_undef ||
152 EC_GROUP_get_curve_name(
153 EC_KEY_get0_group(EVP_PKEY_get0_EC_KEY(pkey))) != alg->curve)) {
154 return false;
155 }
156 } else if (!alg->tls12_ok) {
157 return false;
158 }
159
160 return true;
161 }
162
setup_ctx(SSL * ssl,EVP_MD_CTX * ctx,EVP_PKEY * pkey,uint16_t sigalg,bool is_verify)163 static bool setup_ctx(SSL *ssl, EVP_MD_CTX *ctx, EVP_PKEY *pkey,
164 uint16_t sigalg, bool is_verify) {
165 if (!ssl_pkey_supports_algorithm(ssl, pkey, sigalg, is_verify)) {
166 OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_SIGNATURE_TYPE);
167 return false;
168 }
169
170 const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
171 const EVP_MD *digest = alg->digest_func != NULL ? alg->digest_func() : NULL;
172 EVP_PKEY_CTX *pctx;
173 if (is_verify) {
174 if (!EVP_DigestVerifyInit(ctx, &pctx, digest, NULL, pkey)) {
175 return false;
176 }
177 } else if (!EVP_DigestSignInit(ctx, &pctx, digest, NULL, pkey)) {
178 return false;
179 }
180
181 if (alg->is_rsa_pss) {
182 if (!EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) ||
183 !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1 /* salt len = hash len */)) {
184 return false;
185 }
186 }
187
188 return true;
189 }
190
ssl_private_key_sign(SSL_HANDSHAKE * hs,uint8_t * out,size_t * out_len,size_t max_out,uint16_t sigalg,Span<const uint8_t> in)191 enum ssl_private_key_result_t ssl_private_key_sign(
192 SSL_HANDSHAKE *hs, uint8_t *out, size_t *out_len, size_t max_out,
193 uint16_t sigalg, Span<const uint8_t> in) {
194 SSL *const ssl = hs->ssl;
195 const SSL_CREDENTIAL *const cred = hs->credential.get();
196 SSL_HANDSHAKE_HINTS *const hints = hs->hints.get();
197 Array<uint8_t> spki;
198 if (hints) {
199 ScopedCBB spki_cbb;
200 if (!CBB_init(spki_cbb.get(), 64) ||
201 !EVP_marshal_public_key(spki_cbb.get(), cred->pubkey.get()) ||
202 !CBBFinishArray(spki_cbb.get(), &spki)) {
203 ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
204 return ssl_private_key_failure;
205 }
206 }
207
208 // Replay the signature from handshake hints if available.
209 if (hints && !hs->hints_requested && //
210 sigalg == hints->signature_algorithm && //
211 in == hints->signature_input && //
212 Span(spki) == hints->signature_spki && //
213 !hints->signature.empty() && //
214 hints->signature.size() <= max_out) {
215 // Signature algorithm and input both match. Reuse the signature from hints.
216 *out_len = hints->signature.size();
217 OPENSSL_memcpy(out, hints->signature.data(), hints->signature.size());
218 return ssl_private_key_success;
219 }
220
221 const SSL_PRIVATE_KEY_METHOD *key_method = cred->key_method;
222 EVP_PKEY *privkey = cred->privkey.get();
223 assert(!hs->can_release_private_key);
224
225 if (key_method != NULL) {
226 enum ssl_private_key_result_t ret;
227 if (hs->pending_private_key_op) {
228 ret = key_method->complete(ssl, out, out_len, max_out);
229 } else {
230 ret = key_method->sign(ssl, out, out_len, max_out, sigalg, in.data(),
231 in.size());
232 }
233 if (ret == ssl_private_key_failure) {
234 OPENSSL_PUT_ERROR(SSL, SSL_R_PRIVATE_KEY_OPERATION_FAILED);
235 }
236 hs->pending_private_key_op = ret == ssl_private_key_retry;
237 if (ret != ssl_private_key_success) {
238 return ret;
239 }
240 } else {
241 *out_len = max_out;
242 ScopedEVP_MD_CTX ctx;
243 if (!setup_ctx(ssl, ctx.get(), privkey, sigalg, false /* sign */) ||
244 !EVP_DigestSign(ctx.get(), out, out_len, in.data(), in.size())) {
245 return ssl_private_key_failure;
246 }
247 }
248
249 // Save the hint if applicable.
250 if (hints && hs->hints_requested) {
251 hints->signature_algorithm = sigalg;
252 hints->signature_spki = std::move(spki);
253 if (!hints->signature_input.CopyFrom(in) ||
254 !hints->signature.CopyFrom(Span(out, *out_len))) {
255 return ssl_private_key_failure;
256 }
257 }
258 return ssl_private_key_success;
259 }
260
ssl_public_key_verify(SSL * ssl,Span<const uint8_t> signature,uint16_t sigalg,EVP_PKEY * pkey,Span<const uint8_t> in)261 bool ssl_public_key_verify(SSL *ssl, Span<const uint8_t> signature,
262 uint16_t sigalg, EVP_PKEY *pkey,
263 Span<const uint8_t> in) {
264 ScopedEVP_MD_CTX ctx;
265 if (!setup_ctx(ssl, ctx.get(), pkey, sigalg, true /* verify */)) {
266 return false;
267 }
268 bool ok = EVP_DigestVerify(ctx.get(), signature.data(), signature.size(),
269 in.data(), in.size());
270 #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
271 ok = true;
272 ERR_clear_error();
273 #endif
274 return ok;
275 }
276
ssl_private_key_decrypt(SSL_HANDSHAKE * hs,uint8_t * out,size_t * out_len,size_t max_out,Span<const uint8_t> in)277 enum ssl_private_key_result_t ssl_private_key_decrypt(SSL_HANDSHAKE *hs,
278 uint8_t *out,
279 size_t *out_len,
280 size_t max_out,
281 Span<const uint8_t> in) {
282 SSL *const ssl = hs->ssl;
283 const SSL_CREDENTIAL *const cred = hs->credential.get();
284 assert(!hs->can_release_private_key);
285 if (cred->key_method != NULL) {
286 enum ssl_private_key_result_t ret;
287 if (hs->pending_private_key_op) {
288 ret = cred->key_method->complete(ssl, out, out_len, max_out);
289 } else {
290 ret = cred->key_method->decrypt(ssl, out, out_len, max_out, in.data(),
291 in.size());
292 }
293 if (ret == ssl_private_key_failure) {
294 OPENSSL_PUT_ERROR(SSL, SSL_R_PRIVATE_KEY_OPERATION_FAILED);
295 }
296 hs->pending_private_key_op = ret == ssl_private_key_retry;
297 return ret;
298 }
299
300 RSA *rsa = EVP_PKEY_get0_RSA(cred->privkey.get());
301 if (rsa == NULL) {
302 // Decrypt operations are only supported for RSA keys.
303 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
304 return ssl_private_key_failure;
305 }
306
307 // Decrypt with no padding. PKCS#1 padding will be removed as part of the
308 // timing-sensitive code by the caller.
309 if (!RSA_decrypt(rsa, out_len, out, max_out, in.data(), in.size(),
310 RSA_NO_PADDING)) {
311 return ssl_private_key_failure;
312 }
313 return ssl_private_key_success;
314 }
315
316 BSSL_NAMESPACE_END
317
318 using namespace bssl;
319
SSL_use_RSAPrivateKey(SSL * ssl,RSA * rsa)320 int SSL_use_RSAPrivateKey(SSL *ssl, RSA *rsa) {
321 if (rsa == NULL || ssl->config == NULL) {
322 OPENSSL_PUT_ERROR(SSL, ERR_R_PASSED_NULL_PARAMETER);
323 return 0;
324 }
325
326 UniquePtr<EVP_PKEY> pkey(EVP_PKEY_new());
327 if (!pkey || //
328 !EVP_PKEY_set1_RSA(pkey.get(), rsa)) {
329 OPENSSL_PUT_ERROR(SSL, ERR_R_EVP_LIB);
330 return 0;
331 }
332
333 return SSL_use_PrivateKey(ssl, pkey.get());
334 }
335
SSL_use_RSAPrivateKey_ASN1(SSL * ssl,const uint8_t * der,size_t der_len)336 int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der, size_t der_len) {
337 UniquePtr<RSA> rsa(RSA_private_key_from_bytes(der, der_len));
338 if (!rsa) {
339 OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
340 return 0;
341 }
342
343 return SSL_use_RSAPrivateKey(ssl, rsa.get());
344 }
345
SSL_use_PrivateKey(SSL * ssl,EVP_PKEY * pkey)346 int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey) {
347 if (pkey == NULL || ssl->config == NULL) {
348 OPENSSL_PUT_ERROR(SSL, ERR_R_PASSED_NULL_PARAMETER);
349 return 0;
350 }
351
352 return SSL_CREDENTIAL_set1_private_key(
353 ssl->config->cert->legacy_credential.get(), pkey);
354 }
355
SSL_use_PrivateKey_ASN1(int type,SSL * ssl,const uint8_t * der,size_t der_len)356 int SSL_use_PrivateKey_ASN1(int type, SSL *ssl, const uint8_t *der,
357 size_t der_len) {
358 if (der_len > LONG_MAX) {
359 OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
360 return 0;
361 }
362
363 const uint8_t *p = der;
364 UniquePtr<EVP_PKEY> pkey(d2i_PrivateKey(type, NULL, &p, (long)der_len));
365 if (!pkey || p != der + der_len) {
366 OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
367 return 0;
368 }
369
370 return SSL_use_PrivateKey(ssl, pkey.get());
371 }
372
SSL_CTX_use_RSAPrivateKey(SSL_CTX * ctx,RSA * rsa)373 int SSL_CTX_use_RSAPrivateKey(SSL_CTX *ctx, RSA *rsa) {
374 if (rsa == NULL) {
375 OPENSSL_PUT_ERROR(SSL, ERR_R_PASSED_NULL_PARAMETER);
376 return 0;
377 }
378
379 UniquePtr<EVP_PKEY> pkey(EVP_PKEY_new());
380 if (!pkey || !EVP_PKEY_set1_RSA(pkey.get(), rsa)) {
381 OPENSSL_PUT_ERROR(SSL, ERR_R_EVP_LIB);
382 return 0;
383 }
384
385 return SSL_CTX_use_PrivateKey(ctx, pkey.get());
386 }
387
SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX * ctx,const uint8_t * der,size_t der_len)388 int SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX *ctx, const uint8_t *der,
389 size_t der_len) {
390 UniquePtr<RSA> rsa(RSA_private_key_from_bytes(der, der_len));
391 if (!rsa) {
392 OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
393 return 0;
394 }
395
396 return SSL_CTX_use_RSAPrivateKey(ctx, rsa.get());
397 }
398
SSL_CTX_use_PrivateKey(SSL_CTX * ctx,EVP_PKEY * pkey)399 int SSL_CTX_use_PrivateKey(SSL_CTX *ctx, EVP_PKEY *pkey) {
400 if (pkey == NULL) {
401 OPENSSL_PUT_ERROR(SSL, ERR_R_PASSED_NULL_PARAMETER);
402 return 0;
403 }
404
405 return SSL_CREDENTIAL_set1_private_key(ctx->cert->legacy_credential.get(),
406 pkey);
407 }
408
SSL_CTX_use_PrivateKey_ASN1(int type,SSL_CTX * ctx,const uint8_t * der,size_t der_len)409 int SSL_CTX_use_PrivateKey_ASN1(int type, SSL_CTX *ctx, const uint8_t *der,
410 size_t der_len) {
411 if (der_len > LONG_MAX) {
412 OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
413 return 0;
414 }
415
416 const uint8_t *p = der;
417 UniquePtr<EVP_PKEY> pkey(d2i_PrivateKey(type, NULL, &p, (long)der_len));
418 if (!pkey || p != der + der_len) {
419 OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
420 return 0;
421 }
422
423 return SSL_CTX_use_PrivateKey(ctx, pkey.get());
424 }
425
SSL_set_private_key_method(SSL * ssl,const SSL_PRIVATE_KEY_METHOD * key_method)426 void SSL_set_private_key_method(SSL *ssl,
427 const SSL_PRIVATE_KEY_METHOD *key_method) {
428 if (!ssl->config) {
429 return;
430 }
431 BSSL_CHECK(SSL_CREDENTIAL_set_private_key_method(
432 ssl->config->cert->legacy_credential.get(), key_method));
433 }
434
SSL_CTX_set_private_key_method(SSL_CTX * ctx,const SSL_PRIVATE_KEY_METHOD * key_method)435 void SSL_CTX_set_private_key_method(SSL_CTX *ctx,
436 const SSL_PRIVATE_KEY_METHOD *key_method) {
437 BSSL_CHECK(SSL_CREDENTIAL_set_private_key_method(
438 ctx->cert->legacy_credential.get(), key_method));
439 }
440
441 static constexpr size_t kMaxSignatureAlgorithmNameLen = 24;
442
443 struct SignatureAlgorithmName {
444 uint16_t signature_algorithm;
445 const char name[kMaxSignatureAlgorithmNameLen];
446 };
447
448 // This was "constexpr" rather than "const", but that triggered a bug in MSVC
449 // where it didn't pad the strings to the correct length.
450 static const SignatureAlgorithmName kSignatureAlgorithmNames[] = {
451 {SSL_SIGN_RSA_PKCS1_MD5_SHA1, "rsa_pkcs1_md5_sha1"},
452 {SSL_SIGN_RSA_PKCS1_SHA1, "rsa_pkcs1_sha1"},
453 {SSL_SIGN_RSA_PKCS1_SHA256, "rsa_pkcs1_sha256"},
454 {SSL_SIGN_RSA_PKCS1_SHA256_LEGACY, "rsa_pkcs1_sha256_legacy"},
455 {SSL_SIGN_RSA_PKCS1_SHA384, "rsa_pkcs1_sha384"},
456 {SSL_SIGN_RSA_PKCS1_SHA512, "rsa_pkcs1_sha512"},
457 {SSL_SIGN_ECDSA_SHA1, "ecdsa_sha1"},
458 {SSL_SIGN_ECDSA_SECP256R1_SHA256, "ecdsa_secp256r1_sha256"},
459 {SSL_SIGN_ECDSA_SECP384R1_SHA384, "ecdsa_secp384r1_sha384"},
460 {SSL_SIGN_ECDSA_SECP521R1_SHA512, "ecdsa_secp521r1_sha512"},
461 {SSL_SIGN_RSA_PSS_RSAE_SHA256, "rsa_pss_rsae_sha256"},
462 {SSL_SIGN_RSA_PSS_RSAE_SHA384, "rsa_pss_rsae_sha384"},
463 {SSL_SIGN_RSA_PSS_RSAE_SHA512, "rsa_pss_rsae_sha512"},
464 {SSL_SIGN_ED25519, "ed25519"},
465 };
466
SSL_get_signature_algorithm_name(uint16_t sigalg,int include_curve)467 const char *SSL_get_signature_algorithm_name(uint16_t sigalg,
468 int include_curve) {
469 if (!include_curve) {
470 switch (sigalg) {
471 case SSL_SIGN_ECDSA_SECP256R1_SHA256:
472 return "ecdsa_sha256";
473 case SSL_SIGN_ECDSA_SECP384R1_SHA384:
474 return "ecdsa_sha384";
475 case SSL_SIGN_ECDSA_SECP521R1_SHA512:
476 return "ecdsa_sha512";
477 // If adding more here, also update
478 // |SSL_get_all_signature_algorithm_names|.
479 }
480 }
481
482 for (const auto &candidate : kSignatureAlgorithmNames) {
483 if (candidate.signature_algorithm == sigalg) {
484 return candidate.name;
485 }
486 }
487
488 return NULL;
489 }
490
SSL_get_all_signature_algorithm_names(const char ** out,size_t max_out)491 size_t SSL_get_all_signature_algorithm_names(const char **out, size_t max_out) {
492 const char *kPredefinedNames[] = {"ecdsa_sha256", "ecdsa_sha384",
493 "ecdsa_sha512"};
494 return GetAllNames(out, max_out, kPredefinedNames,
495 &SignatureAlgorithmName::name,
496 Span(kSignatureAlgorithmNames));
497 }
498
SSL_get_signature_algorithm_key_type(uint16_t sigalg)499 int SSL_get_signature_algorithm_key_type(uint16_t sigalg) {
500 const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
501 return alg != nullptr ? alg->pkey_type : EVP_PKEY_NONE;
502 }
503
SSL_get_signature_algorithm_digest(uint16_t sigalg)504 const EVP_MD *SSL_get_signature_algorithm_digest(uint16_t sigalg) {
505 const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
506 if (alg == nullptr || alg->digest_func == nullptr) {
507 return nullptr;
508 }
509 return alg->digest_func();
510 }
511
SSL_is_signature_algorithm_rsa_pss(uint16_t sigalg)512 int SSL_is_signature_algorithm_rsa_pss(uint16_t sigalg) {
513 const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
514 return alg != nullptr && alg->is_rsa_pss;
515 }
516
compare_uint16_t(const void * p1,const void * p2)517 static int compare_uint16_t(const void *p1, const void *p2) {
518 uint16_t u1 = *((const uint16_t *)p1);
519 uint16_t u2 = *((const uint16_t *)p2);
520 if (u1 < u2) {
521 return -1;
522 } else if (u1 > u2) {
523 return 1;
524 } else {
525 return 0;
526 }
527 }
528
sigalgs_unique(Span<const uint16_t> in_sigalgs)529 static bool sigalgs_unique(Span<const uint16_t> in_sigalgs) {
530 if (in_sigalgs.size() < 2) {
531 return true;
532 }
533
534 Array<uint16_t> sigalgs;
535 if (!sigalgs.CopyFrom(in_sigalgs)) {
536 return false;
537 }
538
539 qsort(sigalgs.data(), sigalgs.size(), sizeof(uint16_t), compare_uint16_t);
540
541 for (size_t i = 1; i < sigalgs.size(); i++) {
542 if (sigalgs[i - 1] == sigalgs[i]) {
543 OPENSSL_PUT_ERROR(SSL, SSL_R_DUPLICATE_SIGNATURE_ALGORITHM);
544 return false;
545 }
546 }
547
548 return true;
549 }
550
set_sigalg_prefs(Array<uint16_t> * out,Span<const uint16_t> prefs)551 static bool set_sigalg_prefs(Array<uint16_t> *out, Span<const uint16_t> prefs) {
552 if (!sigalgs_unique(prefs)) {
553 return false;
554 }
555
556 // Check for invalid algorithms, and filter out |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
557 Array<uint16_t> filtered;
558 if (!filtered.InitForOverwrite(prefs.size())) {
559 return false;
560 }
561 size_t added = 0;
562 for (uint16_t pref : prefs) {
563 if (pref == SSL_SIGN_RSA_PKCS1_MD5_SHA1) {
564 // Though not intended to be used with this API, we treat
565 // |SSL_SIGN_RSA_PKCS1_MD5_SHA1| as a real signature algorithm in
566 // |SSL_PRIVATE_KEY_METHOD|. Not accepting it here makes for a confusing
567 // abstraction.
568 continue;
569 }
570 if (get_signature_algorithm(pref) == nullptr) {
571 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
572 return false;
573 }
574 filtered[added] = pref;
575 added++;
576 }
577 filtered.Shrink(added);
578
579 // This can happen if |prefs| contained only |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
580 // Leaving it empty would revert to the default, so treat this as an error
581 // condition.
582 if (!prefs.empty() && filtered.empty()) {
583 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
584 return false;
585 }
586
587 *out = std::move(filtered);
588 return true;
589 }
590
SSL_CREDENTIAL_set1_signing_algorithm_prefs(SSL_CREDENTIAL * cred,const uint16_t * prefs,size_t num_prefs)591 int SSL_CREDENTIAL_set1_signing_algorithm_prefs(SSL_CREDENTIAL *cred,
592 const uint16_t *prefs,
593 size_t num_prefs) {
594 if (!cred->UsesPrivateKey()) {
595 OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
596 return 0;
597 }
598
599 // Delegated credentials are constrained to a single algorithm, so there is no
600 // need to configure this.
601 if (cred->type == SSLCredentialType::kDelegated) {
602 OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
603 return 0;
604 }
605
606 return set_sigalg_prefs(&cred->sigalgs, Span(prefs, num_prefs));
607 }
608
SSL_CTX_set_signing_algorithm_prefs(SSL_CTX * ctx,const uint16_t * prefs,size_t num_prefs)609 int SSL_CTX_set_signing_algorithm_prefs(SSL_CTX *ctx, const uint16_t *prefs,
610 size_t num_prefs) {
611 return SSL_CREDENTIAL_set1_signing_algorithm_prefs(
612 ctx->cert->legacy_credential.get(), prefs, num_prefs);
613 }
614
SSL_set_signing_algorithm_prefs(SSL * ssl,const uint16_t * prefs,size_t num_prefs)615 int SSL_set_signing_algorithm_prefs(SSL *ssl, const uint16_t *prefs,
616 size_t num_prefs) {
617 if (!ssl->config) {
618 return 0;
619 }
620 return SSL_CREDENTIAL_set1_signing_algorithm_prefs(
621 ssl->config->cert->legacy_credential.get(), prefs, num_prefs);
622 }
623
624 static constexpr struct {
625 int pkey_type;
626 int hash_nid;
627 uint16_t signature_algorithm;
628 } kSignatureAlgorithmsMapping[] = {
629 {EVP_PKEY_RSA, NID_sha1, SSL_SIGN_RSA_PKCS1_SHA1},
630 {EVP_PKEY_RSA, NID_sha256, SSL_SIGN_RSA_PKCS1_SHA256},
631 {EVP_PKEY_RSA, NID_sha384, SSL_SIGN_RSA_PKCS1_SHA384},
632 {EVP_PKEY_RSA, NID_sha512, SSL_SIGN_RSA_PKCS1_SHA512},
633 {EVP_PKEY_RSA_PSS, NID_sha256, SSL_SIGN_RSA_PSS_RSAE_SHA256},
634 {EVP_PKEY_RSA_PSS, NID_sha384, SSL_SIGN_RSA_PSS_RSAE_SHA384},
635 {EVP_PKEY_RSA_PSS, NID_sha512, SSL_SIGN_RSA_PSS_RSAE_SHA512},
636 {EVP_PKEY_EC, NID_sha1, SSL_SIGN_ECDSA_SHA1},
637 {EVP_PKEY_EC, NID_sha256, SSL_SIGN_ECDSA_SECP256R1_SHA256},
638 {EVP_PKEY_EC, NID_sha384, SSL_SIGN_ECDSA_SECP384R1_SHA384},
639 {EVP_PKEY_EC, NID_sha512, SSL_SIGN_ECDSA_SECP521R1_SHA512},
640 {EVP_PKEY_ED25519, NID_undef, SSL_SIGN_ED25519},
641 };
642
parse_sigalg_pairs(Array<uint16_t> * out,const int * values,size_t num_values)643 static bool parse_sigalg_pairs(Array<uint16_t> *out, const int *values,
644 size_t num_values) {
645 if ((num_values & 1) == 1) {
646 return false;
647 }
648
649 const size_t num_pairs = num_values / 2;
650 if (!out->InitForOverwrite(num_pairs)) {
651 return false;
652 }
653
654 for (size_t i = 0; i < num_values; i += 2) {
655 const int hash_nid = values[i];
656 const int pkey_type = values[i + 1];
657
658 bool found = false;
659 for (const auto &candidate : kSignatureAlgorithmsMapping) {
660 if (candidate.pkey_type == pkey_type && candidate.hash_nid == hash_nid) {
661 (*out)[i / 2] = candidate.signature_algorithm;
662 found = true;
663 break;
664 }
665 }
666
667 if (!found) {
668 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
669 ERR_add_error_dataf("unknown hash:%d pkey:%d", hash_nid, pkey_type);
670 return false;
671 }
672 }
673
674 return true;
675 }
676
SSL_CTX_set1_sigalgs(SSL_CTX * ctx,const int * values,size_t num_values)677 int SSL_CTX_set1_sigalgs(SSL_CTX *ctx, const int *values, size_t num_values) {
678 Array<uint16_t> sigalgs;
679 if (!parse_sigalg_pairs(&sigalgs, values, num_values)) {
680 return 0;
681 }
682
683 if (!SSL_CTX_set_signing_algorithm_prefs(ctx, sigalgs.data(),
684 sigalgs.size()) ||
685 !SSL_CTX_set_verify_algorithm_prefs(ctx, sigalgs.data(),
686 sigalgs.size())) {
687 return 0;
688 }
689
690 return 1;
691 }
692
SSL_set1_sigalgs(SSL * ssl,const int * values,size_t num_values)693 int SSL_set1_sigalgs(SSL *ssl, const int *values, size_t num_values) {
694 if (!ssl->config) {
695 OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
696 return 0;
697 }
698
699 Array<uint16_t> sigalgs;
700 if (!parse_sigalg_pairs(&sigalgs, values, num_values)) {
701 return 0;
702 }
703
704 if (!SSL_set_signing_algorithm_prefs(ssl, sigalgs.data(), sigalgs.size()) ||
705 !SSL_set_verify_algorithm_prefs(ssl, sigalgs.data(), sigalgs.size())) {
706 return 0;
707 }
708
709 return 1;
710 }
711
parse_sigalgs_list(Array<uint16_t> * out,const char * str)712 static bool parse_sigalgs_list(Array<uint16_t> *out, const char *str) {
713 // str looks like "RSA+SHA1:ECDSA+SHA256:ecdsa_secp256r1_sha256".
714
715 // Count colons to give the number of output elements from any successful
716 // parse.
717 size_t num_elements = 1;
718 size_t len = 0;
719 for (const char *p = str; *p; p++) {
720 len++;
721 if (*p == ':') {
722 num_elements++;
723 }
724 }
725
726 if (!out->InitForOverwrite(num_elements)) {
727 return false;
728 }
729 size_t out_i = 0;
730
731 enum {
732 pkey_or_name,
733 hash_name,
734 } state = pkey_or_name;
735
736 char buf[kMaxSignatureAlgorithmNameLen];
737 // buf_used is always < sizeof(buf). I.e. it's always safe to write
738 // buf[buf_used] = 0.
739 size_t buf_used = 0;
740
741 int pkey_type = 0, hash_nid = 0;
742
743 // Note that the loop runs to len+1, i.e. it'll process the terminating NUL.
744 for (size_t offset = 0; offset < len + 1; offset++) {
745 const unsigned char c = str[offset];
746
747 switch (c) {
748 case '+':
749 if (state == hash_name) {
750 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
751 ERR_add_error_dataf("+ found in hash name at offset %zu", offset);
752 return false;
753 }
754 if (buf_used == 0) {
755 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
756 ERR_add_error_dataf("empty public key type at offset %zu", offset);
757 return false;
758 }
759 buf[buf_used] = 0;
760
761 if (strcmp(buf, "RSA") == 0) {
762 pkey_type = EVP_PKEY_RSA;
763 } else if (strcmp(buf, "RSA-PSS") == 0 || //
764 strcmp(buf, "PSS") == 0) {
765 pkey_type = EVP_PKEY_RSA_PSS;
766 } else if (strcmp(buf, "ECDSA") == 0) {
767 pkey_type = EVP_PKEY_EC;
768 } else {
769 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
770 ERR_add_error_dataf("unknown public key type '%s'", buf);
771 return false;
772 }
773
774 state = hash_name;
775 buf_used = 0;
776 break;
777
778 case ':':
779 [[fallthrough]];
780 case 0:
781 if (buf_used == 0) {
782 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
783 ERR_add_error_dataf("empty element at offset %zu", offset);
784 return false;
785 }
786
787 buf[buf_used] = 0;
788
789 if (state == pkey_or_name) {
790 // No '+' was seen thus this is a TLS 1.3-style name.
791 bool found = false;
792 for (const auto &candidate : kSignatureAlgorithmNames) {
793 if (strcmp(candidate.name, buf) == 0) {
794 assert(out_i < num_elements);
795 (*out)[out_i++] = candidate.signature_algorithm;
796 found = true;
797 break;
798 }
799 }
800
801 if (!found) {
802 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
803 ERR_add_error_dataf("unknown signature algorithm '%s'", buf);
804 return false;
805 }
806 } else {
807 if (strcmp(buf, "SHA1") == 0) {
808 hash_nid = NID_sha1;
809 } else if (strcmp(buf, "SHA256") == 0) {
810 hash_nid = NID_sha256;
811 } else if (strcmp(buf, "SHA384") == 0) {
812 hash_nid = NID_sha384;
813 } else if (strcmp(buf, "SHA512") == 0) {
814 hash_nid = NID_sha512;
815 } else {
816 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
817 ERR_add_error_dataf("unknown hash function '%s'", buf);
818 return false;
819 }
820
821 bool found = false;
822 for (const auto &candidate : kSignatureAlgorithmsMapping) {
823 if (candidate.pkey_type == pkey_type &&
824 candidate.hash_nid == hash_nid) {
825 assert(out_i < num_elements);
826 (*out)[out_i++] = candidate.signature_algorithm;
827 found = true;
828 break;
829 }
830 }
831
832 if (!found) {
833 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
834 ERR_add_error_dataf("unknown pkey:%d hash:%s", pkey_type, buf);
835 return false;
836 }
837 }
838
839 state = pkey_or_name;
840 buf_used = 0;
841 break;
842
843 default:
844 if (buf_used == sizeof(buf) - 1) {
845 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
846 ERR_add_error_dataf("substring too long at offset %zu", offset);
847 return false;
848 }
849
850 if (OPENSSL_isalnum(c) || c == '-' || c == '_') {
851 buf[buf_used++] = c;
852 } else {
853 OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
854 ERR_add_error_dataf("invalid character 0x%02x at offest %zu", c,
855 offset);
856 return false;
857 }
858 }
859 }
860
861 assert(out_i == out->size());
862 return true;
863 }
864
SSL_CTX_set1_sigalgs_list(SSL_CTX * ctx,const char * str)865 int SSL_CTX_set1_sigalgs_list(SSL_CTX *ctx, const char *str) {
866 Array<uint16_t> sigalgs;
867 if (!parse_sigalgs_list(&sigalgs, str)) {
868 return 0;
869 }
870
871 if (!SSL_CTX_set_signing_algorithm_prefs(ctx, sigalgs.data(),
872 sigalgs.size()) ||
873 !SSL_CTX_set_verify_algorithm_prefs(ctx, sigalgs.data(),
874 sigalgs.size())) {
875 return 0;
876 }
877
878 return 1;
879 }
880
SSL_set1_sigalgs_list(SSL * ssl,const char * str)881 int SSL_set1_sigalgs_list(SSL *ssl, const char *str) {
882 if (!ssl->config) {
883 OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
884 return 0;
885 }
886
887 Array<uint16_t> sigalgs;
888 if (!parse_sigalgs_list(&sigalgs, str)) {
889 return 0;
890 }
891
892 if (!SSL_set_signing_algorithm_prefs(ssl, sigalgs.data(), sigalgs.size()) ||
893 !SSL_set_verify_algorithm_prefs(ssl, sigalgs.data(), sigalgs.size())) {
894 return 0;
895 }
896
897 return 1;
898 }
899
SSL_CTX_set_verify_algorithm_prefs(SSL_CTX * ctx,const uint16_t * prefs,size_t num_prefs)900 int SSL_CTX_set_verify_algorithm_prefs(SSL_CTX *ctx, const uint16_t *prefs,
901 size_t num_prefs) {
902 return set_sigalg_prefs(&ctx->verify_sigalgs, Span(prefs, num_prefs));
903 }
904
SSL_set_verify_algorithm_prefs(SSL * ssl,const uint16_t * prefs,size_t num_prefs)905 int SSL_set_verify_algorithm_prefs(SSL *ssl, const uint16_t *prefs,
906 size_t num_prefs) {
907 if (!ssl->config) {
908 OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
909 return 0;
910 }
911
912 return set_sigalg_prefs(&ssl->config->verify_sigalgs, Span(prefs, num_prefs));
913 }
914