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1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #include <openssl/ssl.h>
58 
59 #include <assert.h>
60 #include <limits.h>
61 
62 #include <openssl/ec.h>
63 #include <openssl/ec_key.h>
64 #include <openssl/err.h>
65 #include <openssl/evp.h>
66 #include <openssl/mem.h>
67 
68 #include "internal.h"
69 #include "../crypto/internal.h"
70 
71 
72 BSSL_NAMESPACE_BEGIN
73 
ssl_is_key_type_supported(int key_type)74 bool ssl_is_key_type_supported(int key_type) {
75   return key_type == EVP_PKEY_RSA || key_type == EVP_PKEY_EC ||
76          key_type == EVP_PKEY_ED25519;
77 }
78 
ssl_set_pkey(CERT * cert,EVP_PKEY * pkey)79 static bool ssl_set_pkey(CERT *cert, EVP_PKEY *pkey) {
80   if (!ssl_is_key_type_supported(pkey->type)) {
81     OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CERTIFICATE_TYPE);
82     return false;
83   }
84 
85   if (cert->chain != nullptr &&
86       sk_CRYPTO_BUFFER_value(cert->chain.get(), 0) != nullptr &&
87       // Sanity-check that the private key and the certificate match.
88       !ssl_cert_check_private_key(cert, pkey)) {
89     return false;
90   }
91 
92   cert->privatekey = UpRef(pkey);
93   return true;
94 }
95 
96 typedef struct {
97   uint16_t sigalg;
98   int pkey_type;
99   int curve;
100   const EVP_MD *(*digest_func)(void);
101   bool is_rsa_pss;
102 } SSL_SIGNATURE_ALGORITHM;
103 
104 static const SSL_SIGNATURE_ALGORITHM kSignatureAlgorithms[] = {
105     {SSL_SIGN_RSA_PKCS1_MD5_SHA1, EVP_PKEY_RSA, NID_undef, &EVP_md5_sha1,
106      false},
107     {SSL_SIGN_RSA_PKCS1_SHA1, EVP_PKEY_RSA, NID_undef, &EVP_sha1, false},
108     {SSL_SIGN_RSA_PKCS1_SHA256, EVP_PKEY_RSA, NID_undef, &EVP_sha256, false},
109     {SSL_SIGN_RSA_PKCS1_SHA384, EVP_PKEY_RSA, NID_undef, &EVP_sha384, false},
110     {SSL_SIGN_RSA_PKCS1_SHA512, EVP_PKEY_RSA, NID_undef, &EVP_sha512, false},
111 
112     {SSL_SIGN_RSA_PSS_RSAE_SHA256, EVP_PKEY_RSA, NID_undef, &EVP_sha256, true},
113     {SSL_SIGN_RSA_PSS_RSAE_SHA384, EVP_PKEY_RSA, NID_undef, &EVP_sha384, true},
114     {SSL_SIGN_RSA_PSS_RSAE_SHA512, EVP_PKEY_RSA, NID_undef, &EVP_sha512, true},
115 
116     {SSL_SIGN_ECDSA_SHA1, EVP_PKEY_EC, NID_undef, &EVP_sha1, false},
117     {SSL_SIGN_ECDSA_SECP256R1_SHA256, EVP_PKEY_EC, NID_X9_62_prime256v1,
118      &EVP_sha256, false},
119     {SSL_SIGN_ECDSA_SECP384R1_SHA384, EVP_PKEY_EC, NID_secp384r1, &EVP_sha384,
120      false},
121     {SSL_SIGN_ECDSA_SECP521R1_SHA512, EVP_PKEY_EC, NID_secp521r1, &EVP_sha512,
122      false},
123 
124     {SSL_SIGN_ED25519, EVP_PKEY_ED25519, NID_undef, nullptr, false},
125 };
126 
get_signature_algorithm(uint16_t sigalg)127 static const SSL_SIGNATURE_ALGORITHM *get_signature_algorithm(uint16_t sigalg) {
128   for (size_t i = 0; i < OPENSSL_ARRAY_SIZE(kSignatureAlgorithms); i++) {
129     if (kSignatureAlgorithms[i].sigalg == sigalg) {
130       return &kSignatureAlgorithms[i];
131     }
132   }
133   return NULL;
134 }
135 
ssl_has_private_key(const SSL_HANDSHAKE * hs)136 bool ssl_has_private_key(const SSL_HANDSHAKE *hs) {
137   if (hs->config->cert->privatekey != nullptr ||
138       hs->config->cert->key_method != nullptr ||
139       ssl_signing_with_dc(hs)) {
140     return true;
141   }
142 
143   return false;
144 }
145 
pkey_supports_algorithm(const SSL * ssl,EVP_PKEY * pkey,uint16_t sigalg)146 static bool pkey_supports_algorithm(const SSL *ssl, EVP_PKEY *pkey,
147                                     uint16_t sigalg) {
148   const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
149   if (alg == NULL ||
150       EVP_PKEY_id(pkey) != alg->pkey_type) {
151     return false;
152   }
153 
154   if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
155     // RSA keys may only be used with RSA-PSS.
156     if (alg->pkey_type == EVP_PKEY_RSA && !alg->is_rsa_pss) {
157       return false;
158     }
159 
160     // EC keys have a curve requirement.
161     if (alg->pkey_type == EVP_PKEY_EC &&
162         (alg->curve == NID_undef ||
163          EC_GROUP_get_curve_name(
164              EC_KEY_get0_group(EVP_PKEY_get0_EC_KEY(pkey))) != alg->curve)) {
165       return false;
166     }
167   }
168 
169   return true;
170 }
171 
setup_ctx(SSL * ssl,EVP_MD_CTX * ctx,EVP_PKEY * pkey,uint16_t sigalg,bool is_verify)172 static bool setup_ctx(SSL *ssl, EVP_MD_CTX *ctx, EVP_PKEY *pkey,
173                       uint16_t sigalg, bool is_verify) {
174   if (!pkey_supports_algorithm(ssl, pkey, sigalg)) {
175     OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_SIGNATURE_TYPE);
176     return false;
177   }
178 
179   const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
180   const EVP_MD *digest = alg->digest_func != NULL ? alg->digest_func() : NULL;
181   EVP_PKEY_CTX *pctx;
182   if (is_verify) {
183     if (!EVP_DigestVerifyInit(ctx, &pctx, digest, NULL, pkey)) {
184       return false;
185     }
186   } else if (!EVP_DigestSignInit(ctx, &pctx, digest, NULL, pkey)) {
187     return false;
188   }
189 
190   if (alg->is_rsa_pss) {
191     if (!EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) ||
192         !EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1 /* salt len = hash len */)) {
193       return false;
194     }
195   }
196 
197   return true;
198 }
199 
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)200 enum ssl_private_key_result_t ssl_private_key_sign(
201     SSL_HANDSHAKE *hs, uint8_t *out, size_t *out_len, size_t max_out,
202     uint16_t sigalg, Span<const uint8_t> in) {
203   SSL *const ssl = hs->ssl;
204   const SSL_PRIVATE_KEY_METHOD *key_method = hs->config->cert->key_method;
205   EVP_PKEY *privatekey = hs->config->cert->privatekey.get();
206   assert(!hs->can_release_private_key);
207   if (ssl_signing_with_dc(hs)) {
208     key_method = hs->config->cert->dc_key_method;
209     privatekey = hs->config->cert->dc_privatekey.get();
210   }
211 
212   if (key_method != NULL) {
213     enum ssl_private_key_result_t ret;
214     if (hs->pending_private_key_op) {
215       ret = key_method->complete(ssl, out, out_len, max_out);
216     } else {
217       ret = key_method->sign(ssl, out, out_len, max_out,
218                              sigalg, in.data(), in.size());
219     }
220     if (ret == ssl_private_key_failure) {
221       OPENSSL_PUT_ERROR(SSL, SSL_R_PRIVATE_KEY_OPERATION_FAILED);
222     }
223     hs->pending_private_key_op = ret == ssl_private_key_retry;
224     return ret;
225   }
226 
227   *out_len = max_out;
228   ScopedEVP_MD_CTX ctx;
229   if (!setup_ctx(ssl, ctx.get(), privatekey, sigalg, false /* sign */) ||
230       !EVP_DigestSign(ctx.get(), out, out_len, in.data(), in.size())) {
231     return ssl_private_key_failure;
232   }
233   return ssl_private_key_success;
234 }
235 
ssl_public_key_verify(SSL * ssl,Span<const uint8_t> signature,uint16_t sigalg,EVP_PKEY * pkey,Span<const uint8_t> in)236 bool ssl_public_key_verify(SSL *ssl, Span<const uint8_t> signature,
237                            uint16_t sigalg, EVP_PKEY *pkey,
238                            Span<const uint8_t> in) {
239   ScopedEVP_MD_CTX ctx;
240   if (!setup_ctx(ssl, ctx.get(), pkey, sigalg, true /* verify */)) {
241     return false;
242   }
243   bool ok = EVP_DigestVerify(ctx.get(), signature.data(), signature.size(),
244                              in.data(), in.size());
245 #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
246   ok = true;
247   ERR_clear_error();
248 #endif
249   return ok;
250 }
251 
ssl_private_key_decrypt(SSL_HANDSHAKE * hs,uint8_t * out,size_t * out_len,size_t max_out,Span<const uint8_t> in)252 enum ssl_private_key_result_t ssl_private_key_decrypt(SSL_HANDSHAKE *hs,
253                                                       uint8_t *out,
254                                                       size_t *out_len,
255                                                       size_t max_out,
256                                                       Span<const uint8_t> in) {
257   SSL *const ssl = hs->ssl;
258   assert(!hs->can_release_private_key);
259   if (hs->config->cert->key_method != NULL) {
260     enum ssl_private_key_result_t ret;
261     if (hs->pending_private_key_op) {
262       ret = hs->config->cert->key_method->complete(ssl, out, out_len, max_out);
263     } else {
264       ret = hs->config->cert->key_method->decrypt(ssl, out, out_len, max_out,
265                                                   in.data(), in.size());
266     }
267     if (ret == ssl_private_key_failure) {
268       OPENSSL_PUT_ERROR(SSL, SSL_R_PRIVATE_KEY_OPERATION_FAILED);
269     }
270     hs->pending_private_key_op = ret == ssl_private_key_retry;
271     return ret;
272   }
273 
274   RSA *rsa = EVP_PKEY_get0_RSA(hs->config->cert->privatekey.get());
275   if (rsa == NULL) {
276     // Decrypt operations are only supported for RSA keys.
277     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
278     return ssl_private_key_failure;
279   }
280 
281   // Decrypt with no padding. PKCS#1 padding will be removed as part of the
282   // timing-sensitive code by the caller.
283   if (!RSA_decrypt(rsa, out_len, out, max_out, in.data(), in.size(),
284                    RSA_NO_PADDING)) {
285     return ssl_private_key_failure;
286   }
287   return ssl_private_key_success;
288 }
289 
ssl_private_key_supports_signature_algorithm(SSL_HANDSHAKE * hs,uint16_t sigalg)290 bool ssl_private_key_supports_signature_algorithm(SSL_HANDSHAKE *hs,
291                                                   uint16_t sigalg) {
292   SSL *const ssl = hs->ssl;
293   if (!pkey_supports_algorithm(ssl, hs->local_pubkey.get(), sigalg)) {
294     return false;
295   }
296 
297   // Ensure the RSA key is large enough for the hash. RSASSA-PSS requires that
298   // emLen be at least hLen + sLen + 2. Both hLen and sLen are the size of the
299   // hash in TLS. Reasonable RSA key sizes are large enough for the largest
300   // defined RSASSA-PSS algorithm, but 1024-bit RSA is slightly too small for
301   // SHA-512. 1024-bit RSA is sometimes used for test credentials, so check the
302   // size so that we can fall back to another algorithm in that case.
303   const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
304   if (alg->is_rsa_pss && (size_t)EVP_PKEY_size(hs->local_pubkey.get()) <
305                              2 * EVP_MD_size(alg->digest_func()) + 2) {
306     return false;
307   }
308 
309   return true;
310 }
311 
312 BSSL_NAMESPACE_END
313 
314 using namespace bssl;
315 
SSL_use_RSAPrivateKey(SSL * ssl,RSA * rsa)316 int SSL_use_RSAPrivateKey(SSL *ssl, RSA *rsa) {
317   if (rsa == NULL || ssl->config == NULL) {
318     OPENSSL_PUT_ERROR(SSL, ERR_R_PASSED_NULL_PARAMETER);
319     return 0;
320   }
321 
322   UniquePtr<EVP_PKEY> pkey(EVP_PKEY_new());
323   if (!pkey ||
324       !EVP_PKEY_set1_RSA(pkey.get(), rsa)) {
325     OPENSSL_PUT_ERROR(SSL, ERR_R_EVP_LIB);
326     return 0;
327   }
328 
329   return ssl_set_pkey(ssl->config->cert.get(), pkey.get());
330 }
331 
SSL_use_RSAPrivateKey_ASN1(SSL * ssl,const uint8_t * der,size_t der_len)332 int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der, size_t der_len) {
333   UniquePtr<RSA> rsa(RSA_private_key_from_bytes(der, der_len));
334   if (!rsa) {
335     OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
336     return 0;
337   }
338 
339   return SSL_use_RSAPrivateKey(ssl, rsa.get());
340 }
341 
SSL_use_PrivateKey(SSL * ssl,EVP_PKEY * pkey)342 int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey) {
343   if (pkey == NULL || ssl->config == NULL) {
344     OPENSSL_PUT_ERROR(SSL, ERR_R_PASSED_NULL_PARAMETER);
345     return 0;
346   }
347 
348   return ssl_set_pkey(ssl->config->cert.get(), pkey);
349 }
350 
SSL_use_PrivateKey_ASN1(int type,SSL * ssl,const uint8_t * der,size_t der_len)351 int SSL_use_PrivateKey_ASN1(int type, SSL *ssl, const uint8_t *der,
352                             size_t der_len) {
353   if (der_len > LONG_MAX) {
354     OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
355     return 0;
356   }
357 
358   const uint8_t *p = der;
359   UniquePtr<EVP_PKEY> pkey(d2i_PrivateKey(type, NULL, &p, (long)der_len));
360   if (!pkey || p != der + der_len) {
361     OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
362     return 0;
363   }
364 
365   return SSL_use_PrivateKey(ssl, pkey.get());
366 }
367 
SSL_CTX_use_RSAPrivateKey(SSL_CTX * ctx,RSA * rsa)368 int SSL_CTX_use_RSAPrivateKey(SSL_CTX *ctx, RSA *rsa) {
369   if (rsa == NULL) {
370     OPENSSL_PUT_ERROR(SSL, ERR_R_PASSED_NULL_PARAMETER);
371     return 0;
372   }
373 
374   UniquePtr<EVP_PKEY> pkey(EVP_PKEY_new());
375   if (!pkey ||
376       !EVP_PKEY_set1_RSA(pkey.get(), rsa)) {
377     OPENSSL_PUT_ERROR(SSL, ERR_R_EVP_LIB);
378     return 0;
379   }
380 
381   return ssl_set_pkey(ctx->cert.get(), pkey.get());
382 }
383 
SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX * ctx,const uint8_t * der,size_t der_len)384 int SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX *ctx, const uint8_t *der,
385                                    size_t der_len) {
386   UniquePtr<RSA> rsa(RSA_private_key_from_bytes(der, der_len));
387   if (!rsa) {
388     OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
389     return 0;
390   }
391 
392   return SSL_CTX_use_RSAPrivateKey(ctx, rsa.get());
393 }
394 
SSL_CTX_use_PrivateKey(SSL_CTX * ctx,EVP_PKEY * pkey)395 int SSL_CTX_use_PrivateKey(SSL_CTX *ctx, EVP_PKEY *pkey) {
396   if (pkey == NULL) {
397     OPENSSL_PUT_ERROR(SSL, ERR_R_PASSED_NULL_PARAMETER);
398     return 0;
399   }
400 
401   return ssl_set_pkey(ctx->cert.get(), pkey);
402 }
403 
SSL_CTX_use_PrivateKey_ASN1(int type,SSL_CTX * ctx,const uint8_t * der,size_t der_len)404 int SSL_CTX_use_PrivateKey_ASN1(int type, SSL_CTX *ctx, const uint8_t *der,
405                                 size_t der_len) {
406   if (der_len > LONG_MAX) {
407     OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
408     return 0;
409   }
410 
411   const uint8_t *p = der;
412   UniquePtr<EVP_PKEY> pkey(d2i_PrivateKey(type, NULL, &p, (long)der_len));
413   if (!pkey || p != der + der_len) {
414     OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
415     return 0;
416   }
417 
418   return SSL_CTX_use_PrivateKey(ctx, pkey.get());
419 }
420 
SSL_set_private_key_method(SSL * ssl,const SSL_PRIVATE_KEY_METHOD * key_method)421 void SSL_set_private_key_method(SSL *ssl,
422                                 const SSL_PRIVATE_KEY_METHOD *key_method) {
423   if (!ssl->config) {
424     return;
425   }
426   ssl->config->cert->key_method = key_method;
427 }
428 
SSL_CTX_set_private_key_method(SSL_CTX * ctx,const SSL_PRIVATE_KEY_METHOD * key_method)429 void SSL_CTX_set_private_key_method(SSL_CTX *ctx,
430                                     const SSL_PRIVATE_KEY_METHOD *key_method) {
431   ctx->cert->key_method = key_method;
432 }
433 
434 static constexpr size_t kMaxSignatureAlgorithmNameLen = 23;
435 
436 // This was "constexpr" rather than "const", but that triggered a bug in MSVC
437 // where it didn't pad the strings to the correct length.
438 static const struct {
439   uint16_t signature_algorithm;
440   const char name[kMaxSignatureAlgorithmNameLen];
441 } kSignatureAlgorithmNames[] = {
442     {SSL_SIGN_RSA_PKCS1_MD5_SHA1, "rsa_pkcs1_md5_sha1"},
443     {SSL_SIGN_RSA_PKCS1_SHA1, "rsa_pkcs1_sha1"},
444     {SSL_SIGN_RSA_PKCS1_SHA256, "rsa_pkcs1_sha256"},
445     {SSL_SIGN_RSA_PKCS1_SHA384, "rsa_pkcs1_sha384"},
446     {SSL_SIGN_RSA_PKCS1_SHA512, "rsa_pkcs1_sha512"},
447     {SSL_SIGN_ECDSA_SHA1, "ecdsa_sha1"},
448     {SSL_SIGN_ECDSA_SECP256R1_SHA256, "ecdsa_secp256r1_sha256"},
449     {SSL_SIGN_ECDSA_SECP384R1_SHA384, "ecdsa_secp384r1_sha384"},
450     {SSL_SIGN_ECDSA_SECP521R1_SHA512, "ecdsa_secp521r1_sha512"},
451     {SSL_SIGN_RSA_PSS_RSAE_SHA256, "rsa_pss_rsae_sha256"},
452     {SSL_SIGN_RSA_PSS_RSAE_SHA384, "rsa_pss_rsae_sha384"},
453     {SSL_SIGN_RSA_PSS_RSAE_SHA512, "rsa_pss_rsae_sha512"},
454     {SSL_SIGN_ED25519, "ed25519"},
455 };
456 
SSL_get_signature_algorithm_name(uint16_t sigalg,int include_curve)457 const char *SSL_get_signature_algorithm_name(uint16_t sigalg,
458                                              int include_curve) {
459   if (!include_curve) {
460     switch (sigalg) {
461       case SSL_SIGN_ECDSA_SECP256R1_SHA256:
462         return "ecdsa_sha256";
463       case SSL_SIGN_ECDSA_SECP384R1_SHA384:
464         return "ecdsa_sha384";
465       case SSL_SIGN_ECDSA_SECP521R1_SHA512:
466         return "ecdsa_sha512";
467     }
468   }
469 
470   for (const auto &candidate : kSignatureAlgorithmNames) {
471     if (candidate.signature_algorithm == sigalg) {
472       return candidate.name;
473     }
474   }
475 
476   return NULL;
477 }
478 
SSL_get_signature_algorithm_key_type(uint16_t sigalg)479 int SSL_get_signature_algorithm_key_type(uint16_t sigalg) {
480   const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
481   return alg != nullptr ? alg->pkey_type : EVP_PKEY_NONE;
482 }
483 
SSL_get_signature_algorithm_digest(uint16_t sigalg)484 const EVP_MD *SSL_get_signature_algorithm_digest(uint16_t sigalg) {
485   const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
486   if (alg == nullptr || alg->digest_func == nullptr) {
487     return nullptr;
488   }
489   return alg->digest_func();
490 }
491 
SSL_is_signature_algorithm_rsa_pss(uint16_t sigalg)492 int SSL_is_signature_algorithm_rsa_pss(uint16_t sigalg) {
493   const SSL_SIGNATURE_ALGORITHM *alg = get_signature_algorithm(sigalg);
494   return alg != nullptr && alg->is_rsa_pss;
495 }
496 
SSL_CTX_set_signing_algorithm_prefs(SSL_CTX * ctx,const uint16_t * prefs,size_t num_prefs)497 int SSL_CTX_set_signing_algorithm_prefs(SSL_CTX *ctx, const uint16_t *prefs,
498                                         size_t num_prefs) {
499   return ctx->cert->sigalgs.CopyFrom(MakeConstSpan(prefs, num_prefs));
500 }
501 
SSL_set_signing_algorithm_prefs(SSL * ssl,const uint16_t * prefs,size_t num_prefs)502 int SSL_set_signing_algorithm_prefs(SSL *ssl, const uint16_t *prefs,
503                                     size_t num_prefs) {
504   if (!ssl->config) {
505     return 0;
506   }
507   return ssl->config->cert->sigalgs.CopyFrom(MakeConstSpan(prefs, num_prefs));
508 }
509 
510 static constexpr struct {
511   int pkey_type;
512   int hash_nid;
513   uint16_t signature_algorithm;
514 } kSignatureAlgorithmsMapping[] = {
515     {EVP_PKEY_RSA, NID_sha1, SSL_SIGN_RSA_PKCS1_SHA1},
516     {EVP_PKEY_RSA, NID_sha256, SSL_SIGN_RSA_PKCS1_SHA256},
517     {EVP_PKEY_RSA, NID_sha384, SSL_SIGN_RSA_PKCS1_SHA384},
518     {EVP_PKEY_RSA, NID_sha512, SSL_SIGN_RSA_PKCS1_SHA512},
519     {EVP_PKEY_RSA_PSS, NID_sha256, SSL_SIGN_RSA_PSS_RSAE_SHA256},
520     {EVP_PKEY_RSA_PSS, NID_sha384, SSL_SIGN_RSA_PSS_RSAE_SHA384},
521     {EVP_PKEY_RSA_PSS, NID_sha512, SSL_SIGN_RSA_PSS_RSAE_SHA512},
522     {EVP_PKEY_EC, NID_sha1, SSL_SIGN_ECDSA_SHA1},
523     {EVP_PKEY_EC, NID_sha256, SSL_SIGN_ECDSA_SECP256R1_SHA256},
524     {EVP_PKEY_EC, NID_sha384, SSL_SIGN_ECDSA_SECP384R1_SHA384},
525     {EVP_PKEY_EC, NID_sha512, SSL_SIGN_ECDSA_SECP521R1_SHA512},
526     {EVP_PKEY_ED25519, NID_undef, SSL_SIGN_ED25519},
527 };
528 
parse_sigalg_pairs(Array<uint16_t> * out,const int * values,size_t num_values)529 static bool parse_sigalg_pairs(Array<uint16_t> *out, const int *values,
530                                size_t num_values) {
531   if ((num_values & 1) == 1) {
532     return false;
533   }
534 
535   const size_t num_pairs = num_values / 2;
536   if (!out->Init(num_pairs)) {
537     return false;
538   }
539 
540   for (size_t i = 0; i < num_values; i += 2) {
541     const int hash_nid = values[i];
542     const int pkey_type = values[i+1];
543 
544     bool found = false;
545     for (const auto &candidate : kSignatureAlgorithmsMapping) {
546       if (candidate.pkey_type == pkey_type && candidate.hash_nid == hash_nid) {
547         (*out)[i / 2] = candidate.signature_algorithm;
548         found = true;
549         break;
550       }
551     }
552 
553     if (!found) {
554       OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
555       ERR_add_error_dataf("unknown hash:%d pkey:%d", hash_nid, pkey_type);
556       return false;
557     }
558   }
559 
560   return true;
561 }
562 
compare_uint16_t(const void * p1,const void * p2)563 static int compare_uint16_t(const void *p1, const void *p2) {
564   uint16_t u1 = *((const uint16_t *)p1);
565   uint16_t u2 = *((const uint16_t *)p2);
566   if (u1 < u2) {
567     return -1;
568   } else if (u1 > u2) {
569     return 1;
570   } else {
571     return 0;
572   }
573 }
574 
sigalgs_unique(Span<const uint16_t> in_sigalgs)575 static bool sigalgs_unique(Span<const uint16_t> in_sigalgs) {
576   if (in_sigalgs.size() < 2) {
577     return true;
578   }
579 
580   Array<uint16_t> sigalgs;
581   if (!sigalgs.CopyFrom(in_sigalgs)) {
582     return false;
583   }
584 
585   qsort(sigalgs.data(), sigalgs.size(), sizeof(uint16_t), compare_uint16_t);
586 
587   for (size_t i = 1; i < sigalgs.size(); i++) {
588     if (sigalgs[i - 1] == sigalgs[i]) {
589       OPENSSL_PUT_ERROR(SSL, SSL_R_DUPLICATE_SIGNATURE_ALGORITHM);
590       return false;
591     }
592   }
593 
594   return true;
595 }
596 
SSL_CTX_set1_sigalgs(SSL_CTX * ctx,const int * values,size_t num_values)597 int SSL_CTX_set1_sigalgs(SSL_CTX *ctx, const int *values, size_t num_values) {
598   Array<uint16_t> sigalgs;
599   if (!parse_sigalg_pairs(&sigalgs, values, num_values) ||
600       !sigalgs_unique(sigalgs)) {
601     return 0;
602   }
603 
604   if (!SSL_CTX_set_signing_algorithm_prefs(ctx, sigalgs.data(),
605                                            sigalgs.size()) ||
606       !ctx->verify_sigalgs.CopyFrom(sigalgs)) {
607     return 0;
608   }
609 
610   return 1;
611 }
612 
SSL_set1_sigalgs(SSL * ssl,const int * values,size_t num_values)613 int SSL_set1_sigalgs(SSL *ssl, const int *values, size_t num_values) {
614   if (!ssl->config) {
615     OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
616     return 0;
617   }
618 
619   Array<uint16_t> sigalgs;
620   if (!parse_sigalg_pairs(&sigalgs, values, num_values) ||
621       !sigalgs_unique(sigalgs)) {
622     return 0;
623   }
624 
625   if (!SSL_set_signing_algorithm_prefs(ssl, sigalgs.data(), sigalgs.size()) ||
626       !ssl->config->verify_sigalgs.CopyFrom(sigalgs)) {
627     return 0;
628   }
629 
630   return 1;
631 }
632 
parse_sigalgs_list(Array<uint16_t> * out,const char * str)633 static bool parse_sigalgs_list(Array<uint16_t> *out, const char *str) {
634   // str looks like "RSA+SHA1:ECDSA+SHA256:ecdsa_secp256r1_sha256".
635 
636   // Count colons to give the number of output elements from any successful
637   // parse.
638   size_t num_elements = 1;
639   size_t len = 0;
640   for (const char *p = str; *p; p++) {
641     len++;
642     if (*p == ':') {
643       num_elements++;
644     }
645   }
646 
647   if (!out->Init(num_elements)) {
648     return false;
649   }
650   size_t out_i = 0;
651 
652   enum {
653     pkey_or_name,
654     hash_name,
655   } state = pkey_or_name;
656 
657   char buf[kMaxSignatureAlgorithmNameLen];
658   // buf_used is always < sizeof(buf). I.e. it's always safe to write
659   // buf[buf_used] = 0.
660   size_t buf_used = 0;
661 
662   int pkey_type = 0, hash_nid = 0;
663 
664   // Note that the loop runs to len+1, i.e. it'll process the terminating NUL.
665   for (size_t offset = 0; offset < len+1; offset++) {
666     const unsigned char c = str[offset];
667 
668     switch (c) {
669       case '+':
670         if (state == hash_name) {
671           OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
672           ERR_add_error_dataf("+ found in hash name at offset %zu", offset);
673           return false;
674         }
675         if (buf_used == 0) {
676           OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
677           ERR_add_error_dataf("empty public key type at offset %zu", offset);
678           return false;
679         }
680         buf[buf_used] = 0;
681 
682         if (strcmp(buf, "RSA") == 0) {
683           pkey_type = EVP_PKEY_RSA;
684         } else if (strcmp(buf, "RSA-PSS") == 0 ||
685                    strcmp(buf, "PSS") == 0) {
686           pkey_type = EVP_PKEY_RSA_PSS;
687         } else if (strcmp(buf, "ECDSA") == 0) {
688           pkey_type = EVP_PKEY_EC;
689         } else {
690           OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
691           ERR_add_error_dataf("unknown public key type '%s'", buf);
692           return false;
693         }
694 
695         state = hash_name;
696         buf_used = 0;
697         break;
698 
699       case ':':
700         OPENSSL_FALLTHROUGH;
701       case 0:
702         if (buf_used == 0) {
703           OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
704           ERR_add_error_dataf("empty element at offset %zu", offset);
705           return false;
706         }
707 
708         buf[buf_used] = 0;
709 
710         if (state == pkey_or_name) {
711           // No '+' was seen thus this is a TLS 1.3-style name.
712           bool found = false;
713           for (const auto &candidate : kSignatureAlgorithmNames) {
714             if (strcmp(candidate.name, buf) == 0) {
715               assert(out_i < num_elements);
716               (*out)[out_i++] = candidate.signature_algorithm;
717               found = true;
718               break;
719             }
720           }
721 
722           if (!found) {
723             OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
724             ERR_add_error_dataf("unknown signature algorithm '%s'", buf);
725             return false;
726           }
727         } else {
728           if (strcmp(buf, "SHA1") == 0) {
729             hash_nid = NID_sha1;
730           } else if (strcmp(buf, "SHA256") == 0) {
731             hash_nid = NID_sha256;
732           } else if (strcmp(buf, "SHA384") == 0) {
733             hash_nid = NID_sha384;
734           } else if (strcmp(buf, "SHA512") == 0) {
735             hash_nid = NID_sha512;
736           } else {
737             OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
738             ERR_add_error_dataf("unknown hash function '%s'", buf);
739             return false;
740           }
741 
742           bool found = false;
743           for (const auto &candidate : kSignatureAlgorithmsMapping) {
744             if (candidate.pkey_type == pkey_type &&
745                 candidate.hash_nid == hash_nid) {
746               assert(out_i < num_elements);
747               (*out)[out_i++] = candidate.signature_algorithm;
748               found = true;
749               break;
750             }
751           }
752 
753           if (!found) {
754             OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
755             ERR_add_error_dataf("unknown pkey:%d hash:%s", pkey_type, buf);
756             return false;
757           }
758         }
759 
760         state = pkey_or_name;
761         buf_used = 0;
762         break;
763 
764       default:
765         if (buf_used == sizeof(buf) - 1) {
766           OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
767           ERR_add_error_dataf("substring too long at offset %zu", offset);
768           return false;
769         }
770 
771         if ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') ||
772             (c >= 'A' && c <= 'Z') || c == '-' || c == '_') {
773           buf[buf_used++] = c;
774         } else {
775           OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_SIGNATURE_ALGORITHM);
776           ERR_add_error_dataf("invalid character 0x%02x at offest %zu", c,
777                               offset);
778           return false;
779         }
780     }
781   }
782 
783   assert(out_i == out->size());
784   return true;
785 }
786 
SSL_CTX_set1_sigalgs_list(SSL_CTX * ctx,const char * str)787 int SSL_CTX_set1_sigalgs_list(SSL_CTX *ctx, const char *str) {
788   Array<uint16_t> sigalgs;
789   if (!parse_sigalgs_list(&sigalgs, str) ||
790       !sigalgs_unique(sigalgs)) {
791     return 0;
792   }
793 
794   if (!SSL_CTX_set_signing_algorithm_prefs(ctx, sigalgs.data(),
795                                            sigalgs.size()) ||
796       !SSL_CTX_set_verify_algorithm_prefs(ctx, sigalgs.data(),
797                                           sigalgs.size())) {
798     return 0;
799   }
800 
801   return 1;
802 }
803 
SSL_set1_sigalgs_list(SSL * ssl,const char * str)804 int SSL_set1_sigalgs_list(SSL *ssl, const char *str) {
805   if (!ssl->config) {
806     OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
807     return 0;
808   }
809 
810   Array<uint16_t> sigalgs;
811   if (!parse_sigalgs_list(&sigalgs, str) ||
812       !sigalgs_unique(sigalgs)) {
813     return 0;
814   }
815 
816   if (!SSL_set_signing_algorithm_prefs(ssl, sigalgs.data(), sigalgs.size()) ||
817       !SSL_set_verify_algorithm_prefs(ssl, sigalgs.data(), sigalgs.size())) {
818     return 0;
819   }
820 
821   return 1;
822 }
823 
SSL_CTX_set_verify_algorithm_prefs(SSL_CTX * ctx,const uint16_t * prefs,size_t num_prefs)824 int SSL_CTX_set_verify_algorithm_prefs(SSL_CTX *ctx, const uint16_t *prefs,
825                                        size_t num_prefs) {
826   return ctx->verify_sigalgs.CopyFrom(MakeConstSpan(prefs, num_prefs));
827 }
828 
SSL_set_verify_algorithm_prefs(SSL * ssl,const uint16_t * prefs,size_t num_prefs)829 int SSL_set_verify_algorithm_prefs(SSL *ssl, const uint16_t *prefs,
830                                    size_t num_prefs) {
831   if (!ssl->config) {
832     OPENSSL_PUT_ERROR(SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
833     return 0;
834   }
835 
836   return ssl->config->verify_sigalgs.CopyFrom(MakeConstSpan(prefs, num_prefs));
837 }
838