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IABSD.fr/src/lib/libssl/t1_lib.c
jsing
- lib/libssl/t1_lib.c
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/* $OpenBSD: t1_lib.c,v 1.165 2020/03/10 17:02:21 jsing Exp $ */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ /* ==================================================================== * Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * openssl-core@openssl.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.openssl.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #include <stdio.h> #include <openssl/evp.h> #include <openssl/hmac.h> #include <openssl/objects.h> #include <openssl/ocsp.h> #include "ssl_locl.h" #include "bytestring.h" #include "ssl_sigalgs.h" #include "ssl_tlsext.h" static int tls_decrypt_ticket(SSL *s, CBS *session_id, CBS *ticket, SSL_SESSION **psess); SSL3_ENC_METHOD TLSv1_enc_data = { .enc_flags = 0, }; SSL3_ENC_METHOD TLSv1_1_enc_data = { .enc_flags = SSL_ENC_FLAG_EXPLICIT_IV, }; SSL3_ENC_METHOD TLSv1_2_enc_data = { .enc_flags = SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS| SSL_ENC_FLAG_SHA256_PRF|SSL_ENC_FLAG_TLS1_2_CIPHERS, }; long tls1_default_timeout(void) { /* 2 hours, the 24 hours mentioned in the TLSv1 spec * is way too long for http, the cache would over fill */ return (60 * 60 * 2); } int tls1_new(SSL *s) { if (!ssl3_new(s)) return (0); s->method->internal->ssl_clear(s); return (1); } void tls1_free(SSL *s) { if (s == NULL) return; free(s->internal->tlsext_session_ticket); ssl3_free(s); } void tls1_clear(SSL *s) { ssl3_clear(s); s->version = s->method->internal->version; } static int nid_list[] = { NID_sect163k1, /* sect163k1 (1) */ NID_sect163r1, /* sect163r1 (2) */ NID_sect163r2, /* sect163r2 (3) */ NID_sect193r1, /* sect193r1 (4) */ NID_sect193r2, /* sect193r2 (5) */ NID_sect233k1, /* sect233k1 (6) */ NID_sect233r1, /* sect233r1 (7) */ NID_sect239k1, /* sect239k1 (8) */ NID_sect283k1, /* sect283k1 (9) */ NID_sect283r1, /* sect283r1 (10) */ NID_sect409k1, /* sect409k1 (11) */ NID_sect409r1, /* sect409r1 (12) */ NID_sect571k1, /* sect571k1 (13) */ NID_sect571r1, /* sect571r1 (14) */ NID_secp160k1, /* secp160k1 (15) */ NID_secp160r1, /* secp160r1 (16) */ NID_secp160r2, /* secp160r2 (17) */ NID_secp192k1, /* secp192k1 (18) */ NID_X9_62_prime192v1, /* secp192r1 (19) */ NID_secp224k1, /* secp224k1 (20) */ NID_secp224r1, /* secp224r1 (21) */ NID_secp256k1, /* secp256k1 (22) */ NID_X9_62_prime256v1, /* secp256r1 (23) */ NID_secp384r1, /* secp384r1 (24) */ NID_secp521r1, /* secp521r1 (25) */ NID_brainpoolP256r1, /* brainpoolP256r1 (26) */ NID_brainpoolP384r1, /* brainpoolP384r1 (27) */ NID_brainpoolP512r1, /* brainpoolP512r1 (28) */ NID_X25519, /* X25519 (29) */ }; #if 0 static const uint8_t ecformats_list[] = { TLSEXT_ECPOINTFORMAT_uncompressed, TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime, TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2 }; #endif static const uint8_t ecformats_default[] = { TLSEXT_ECPOINTFORMAT_uncompressed, }; #if 0 static const uint16_t eccurves_list[] = { 29, /* X25519 (29) */ 14, /* sect571r1 (14) */ 13, /* sect571k1 (13) */ 25, /* secp521r1 (25) */ 28, /* brainpoolP512r1 (28) */ 11, /* sect409k1 (11) */ 12, /* sect409r1 (12) */ 27, /* brainpoolP384r1 (27) */ 24, /* secp384r1 (24) */ 9, /* sect283k1 (9) */ 10, /* sect283r1 (10) */ 26, /* brainpoolP256r1 (26) */ 22, /* secp256k1 (22) */ 23, /* secp256r1 (23) */ 8, /* sect239k1 (8) */ 6, /* sect233k1 (6) */ 7, /* sect233r1 (7) */ 20, /* secp224k1 (20) */ 21, /* secp224r1 (21) */ 4, /* sect193r1 (4) */ 5, /* sect193r2 (5) */ 18, /* secp192k1 (18) */ 19, /* secp192r1 (19) */ 1, /* sect163k1 (1) */ 2, /* sect163r1 (2) */ 3, /* sect163r2 (3) */ 15, /* secp160k1 (15) */ 16, /* secp160r1 (16) */ 17, /* secp160r2 (17) */ }; #endif static const uint16_t eccurves_default[] = { 29, /* X25519 (29) */ 23, /* secp256r1 (23) */ 24, /* secp384r1 (24) */ }; int tls1_ec_curve_id2nid(const uint16_t curve_id) { /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */ if ((curve_id < 1) || ((unsigned int)curve_id > sizeof(nid_list) / sizeof(nid_list[0]))) return 0; return nid_list[curve_id - 1]; } uint16_t tls1_ec_nid2curve_id(const int nid) { /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */ switch (nid) { case NID_sect163k1: /* sect163k1 (1) */ return 1; case NID_sect163r1: /* sect163r1 (2) */ return 2; case NID_sect163r2: /* sect163r2 (3) */ return 3; case NID_sect193r1: /* sect193r1 (4) */ return 4; case NID_sect193r2: /* sect193r2 (5) */ return 5; case NID_sect233k1: /* sect233k1 (6) */ return 6; case NID_sect233r1: /* sect233r1 (7) */ return 7; case NID_sect239k1: /* sect239k1 (8) */ return 8; case NID_sect283k1: /* sect283k1 (9) */ return 9; case NID_sect283r1: /* sect283r1 (10) */ return 10; case NID_sect409k1: /* sect409k1 (11) */ return 11; case NID_sect409r1: /* sect409r1 (12) */ return 12; case NID_sect571k1: /* sect571k1 (13) */ return 13; case NID_sect571r1: /* sect571r1 (14) */ return 14; case NID_secp160k1: /* secp160k1 (15) */ return 15; case NID_secp160r1: /* secp160r1 (16) */ return 16; case NID_secp160r2: /* secp160r2 (17) */ return 17; case NID_secp192k1: /* secp192k1 (18) */ return 18; case NID_X9_62_prime192v1: /* secp192r1 (19) */ return 19; case NID_secp224k1: /* secp224k1 (20) */ return 20; case NID_secp224r1: /* secp224r1 (21) */ return 21; case NID_secp256k1: /* secp256k1 (22) */ return 22; case NID_X9_62_prime256v1: /* secp256r1 (23) */ return 23; case NID_secp384r1: /* secp384r1 (24) */ return 24; case NID_secp521r1: /* secp521r1 (25) */ return 25; case NID_brainpoolP256r1: /* brainpoolP256r1 (26) */ return 26; case NID_brainpoolP384r1: /* brainpoolP384r1 (27) */ return 27; case NID_brainpoolP512r1: /* brainpoolP512r1 (28) */ return 28; case NID_X25519: /* X25519 (29) */ return 29; default: return 0; } } /* * Return the appropriate format list. If client_formats is non-zero, return * the client/session formats. Otherwise return the custom format list if one * exists, or the default formats if a custom list has not been specified. */ void tls1_get_formatlist(SSL *s, int client_formats, const uint8_t **pformats, size_t *pformatslen) { if (client_formats != 0) { *pformats = SSI(s)->tlsext_ecpointformatlist; *pformatslen = SSI(s)->tlsext_ecpointformatlist_length; return; } *pformats = s->internal->tlsext_ecpointformatlist; *pformatslen = s->internal->tlsext_ecpointformatlist_length; if (*pformats == NULL) { *pformats = ecformats_default; *pformatslen = sizeof(ecformats_default); } } /* * Return the appropriate group list. If client_groups is non-zero, return * the client/session groups. Otherwise return the custom group list if one * exists, or the default groups if a custom list has not been specified. */ void tls1_get_group_list(SSL *s, int client_groups, const uint16_t **pgroups, size_t *pgroupslen) { if (client_groups != 0) { *pgroups = SSI(s)->tlsext_supportedgroups; *pgroupslen = SSI(s)->tlsext_supportedgroups_length; return; } *pgroups = s->internal->tlsext_supportedgroups; *pgroupslen = s->internal->tlsext_supportedgroups_length; if (*pgroups == NULL) { *pgroups = eccurves_default; *pgroupslen = sizeof(eccurves_default) / 2; } } int tls1_set_groups(uint16_t **out_group_ids, size_t *out_group_ids_len, const int *groups, size_t ngroups) { uint16_t *group_ids; size_t i; group_ids = calloc(ngroups, sizeof(uint16_t)); if (group_ids == NULL) return 0; for (i = 0; i < ngroups; i++) { group_ids[i] = tls1_ec_nid2curve_id(groups[i]); if (group_ids[i] == 0) { free(group_ids); return 0; } } free(*out_group_ids); *out_group_ids = group_ids; *out_group_ids_len = ngroups; return 1; } int tls1_set_group_list(uint16_t **out_group_ids, size_t *out_group_ids_len, const char *groups) { uint16_t *new_group_ids, *group_ids = NULL; size_t ngroups = 0; char *gs, *p, *q; int nid; if ((gs = strdup(groups)) == NULL) return 0; q = gs; while ((p = strsep(&q, ":")) != NULL) { nid = OBJ_sn2nid(p); if (nid == NID_undef) nid = OBJ_ln2nid(p); if (nid == NID_undef) nid = EC_curve_nist2nid(p); if (nid == NID_undef) goto err; if ((new_group_ids = reallocarray(group_ids, ngroups + 1, sizeof(uint16_t))) == NULL) goto err; group_ids = new_group_ids; group_ids[ngroups] = tls1_ec_nid2curve_id(nid); if (group_ids[ngroups] == 0) goto err; ngroups++; } free(gs); free(*out_group_ids); *out_group_ids = group_ids; *out_group_ids_len = ngroups; return 1; err: free(gs); free(group_ids); return 0; } /* Check that a curve is one of our preferences. */ int tls1_check_curve(SSL *s, const uint16_t curve_id) { const uint16_t *groups; size_t groupslen, i; tls1_get_group_list(s, 0, &groups, &groupslen); for (i = 0; i < groupslen; i++) { if (groups[i] == curve_id) return (1); } return (0); } int tls1_get_shared_curve(SSL *s) { size_t preflen, supplen, i, j; const uint16_t *pref, *supp; unsigned long server_pref; /* Cannot do anything on the client side. */ if (s->server == 0) return (NID_undef); /* Return first preference shared curve. */ server_pref = (s->internal->options & SSL_OP_CIPHER_SERVER_PREFERENCE); tls1_get_group_list(s, (server_pref == 0), &pref, &preflen); tls1_get_group_list(s, (server_pref != 0), &supp, &supplen); for (i = 0; i < preflen; i++) { for (j = 0; j < supplen; j++) { if (pref[i] == supp[j]) return (tls1_ec_curve_id2nid(pref[i])); } } return (NID_undef); } /* For an EC key set TLS ID and required compression based on parameters. */ static int tls1_set_ec_id(uint16_t *curve_id, uint8_t *comp_id, EC_KEY *ec) { const EC_GROUP *grp; const EC_METHOD *meth; int is_prime = 0; int nid, id; if (ec == NULL) return (0); /* Determine if it is a prime field. */ if ((grp = EC_KEY_get0_group(ec)) == NULL) return (0); if ((meth = EC_GROUP_method_of(grp)) == NULL) return (0); if (EC_METHOD_get_field_type(meth) == NID_X9_62_prime_field) is_prime = 1; /* Determine curve ID. */ nid = EC_GROUP_get_curve_name(grp); id = tls1_ec_nid2curve_id(nid); /* If we have an ID set it, otherwise set arbitrary explicit curve. */ if (id != 0) *curve_id = id; else *curve_id = is_prime ? 0xff01 : 0xff02; /* Specify the compression identifier. */ if (comp_id != NULL) { if (EC_KEY_get0_public_key(ec) == NULL) return (0); if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED) { *comp_id = is_prime ? TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime : TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2; } else { *comp_id = TLSEXT_ECPOINTFORMAT_uncompressed; } } return (1); } /* Check that an EC key is compatible with extensions. */ static int tls1_check_ec_key(SSL *s, const uint16_t *curve_id, const uint8_t *comp_id) { size_t groupslen, formatslen, i; const uint16_t *groups; const uint8_t *formats; /* * Check point formats extension if present, otherwise everything * is supported (see RFC4492). */ tls1_get_formatlist(s, 1, &formats, &formatslen); if (comp_id != NULL && formats != NULL) { for (i = 0; i < formatslen; i++) { if (formats[i] == *comp_id) break; } if (i == formatslen) return (0); } /* * Check curve list if present, otherwise everything is supported. */ tls1_get_group_list(s, 1, &groups, &groupslen); if (curve_id != NULL && groups != NULL) { for (i = 0; i < groupslen; i++) { if (groups[i] == *curve_id) break; } if (i == groupslen) return (0); } return (1); } /* Check EC server key is compatible with client extensions. */ int tls1_check_ec_server_key(SSL *s) { CERT_PKEY *cpk = s->cert->pkeys + SSL_PKEY_ECC; uint16_t curve_id; uint8_t comp_id; EVP_PKEY *pkey; int rv; if (cpk->x509 == NULL || cpk->privatekey == NULL) return (0); if ((pkey = X509_get_pubkey(cpk->x509)) == NULL) return (0); rv = tls1_set_ec_id(&curve_id, &comp_id, pkey->pkey.ec); EVP_PKEY_free(pkey); if (rv != 1) return (0); return tls1_check_ec_key(s, &curve_id, &comp_id); } int ssl_check_clienthello_tlsext_early(SSL *s) { int ret = SSL_TLSEXT_ERR_NOACK; int al = SSL_AD_UNRECOGNIZED_NAME; /* The handling of the ECPointFormats extension is done elsewhere, namely in * ssl3_choose_cipher in s3_lib.c. */ /* The handling of the EllipticCurves extension is done elsewhere, namely in * ssl3_choose_cipher in s3_lib.c. */ if (s->ctx != NULL && s->ctx->internal->tlsext_servername_callback != 0) ret = s->ctx->internal->tlsext_servername_callback(s, &al, s->ctx->internal->tlsext_servername_arg); else if (s->initial_ctx != NULL && s->initial_ctx->internal->tlsext_servername_callback != 0) ret = s->initial_ctx->internal->tlsext_servername_callback(s, &al, s->initial_ctx->internal->tlsext_servername_arg); switch (ret) { case SSL_TLSEXT_ERR_ALERT_FATAL: ssl3_send_alert(s, SSL3_AL_FATAL, al); return -1; case SSL_TLSEXT_ERR_ALERT_WARNING: ssl3_send_alert(s, SSL3_AL_WARNING, al); return 1; case SSL_TLSEXT_ERR_NOACK: s->internal->servername_done = 0; default: return 1; } } int ssl_check_clienthello_tlsext_late(SSL *s) { int ret = SSL_TLSEXT_ERR_OK; int al = 0; /* XXX gcc3 */ /* If status request then ask callback what to do. * Note: this must be called after servername callbacks in case * the certificate has changed, and must be called after the cipher * has been chosen because this may influence which certificate is sent */ if ((s->tlsext_status_type != -1) && s->ctx && s->ctx->internal->tlsext_status_cb) { int r; CERT_PKEY *certpkey; certpkey = ssl_get_server_send_pkey(s); /* If no certificate can't return certificate status */ if (certpkey == NULL) { s->internal->tlsext_status_expected = 0; return 1; } /* Set current certificate to one we will use so * SSL_get_certificate et al can pick it up. */ s->cert->key = certpkey; r = s->ctx->internal->tlsext_status_cb(s, s->ctx->internal->tlsext_status_arg); switch (r) { /* We don't want to send a status request response */ case SSL_TLSEXT_ERR_NOACK: s->internal->tlsext_status_expected = 0; break; /* status request response should be sent */ case SSL_TLSEXT_ERR_OK: if (s->internal->tlsext_ocsp_resp) s->internal->tlsext_status_expected = 1; else s->internal->tlsext_status_expected = 0; break; /* something bad happened */ case SSL_TLSEXT_ERR_ALERT_FATAL: ret = SSL_TLSEXT_ERR_ALERT_FATAL; al = SSL_AD_INTERNAL_ERROR; goto err; } } else s->internal->tlsext_status_expected = 0; err: switch (ret) { case SSL_TLSEXT_ERR_ALERT_FATAL: ssl3_send_alert(s, SSL3_AL_FATAL, al); return -1; case SSL_TLSEXT_ERR_ALERT_WARNING: ssl3_send_alert(s, SSL3_AL_WARNING, al); return 1; default: return 1; } } int ssl_check_serverhello_tlsext(SSL *s) { int ret = SSL_TLSEXT_ERR_NOACK; int al = SSL_AD_UNRECOGNIZED_NAME; ret = SSL_TLSEXT_ERR_OK; if (s->ctx != NULL && s->ctx->internal->tlsext_servername_callback != 0) ret = s->ctx->internal->tlsext_servername_callback(s, &al, s->ctx->internal->tlsext_servername_arg); else if (s->initial_ctx != NULL && s->initial_ctx->internal->tlsext_servername_callback != 0) ret = s->initial_ctx->internal->tlsext_servername_callback(s, &al, s->initial_ctx->internal->tlsext_servername_arg); /* If we've requested certificate status and we wont get one * tell the callback */ if ((s->tlsext_status_type != -1) && !(s->internal->tlsext_status_expected) && s->ctx && s->ctx->internal->tlsext_status_cb) { int r; /* Set resp to NULL, resplen to -1 so callback knows * there is no response. */ free(s->internal->tlsext_ocsp_resp); s->internal->tlsext_ocsp_resp = NULL; s->internal->tlsext_ocsp_resplen = -1; r = s->ctx->internal->tlsext_status_cb(s, s->ctx->internal->tlsext_status_arg); if (r == 0) { al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE; ret = SSL_TLSEXT_ERR_ALERT_FATAL; } if (r < 0) { al = SSL_AD_INTERNAL_ERROR; ret = SSL_TLSEXT_ERR_ALERT_FATAL; } } switch (ret) { case SSL_TLSEXT_ERR_ALERT_FATAL: ssl3_send_alert(s, SSL3_AL_FATAL, al); return -1; case SSL_TLSEXT_ERR_ALERT_WARNING: ssl3_send_alert(s, SSL3_AL_WARNING, al); return 1; case SSL_TLSEXT_ERR_NOACK: s->internal->servername_done = 0; default: return 1; } } /* Since the server cache lookup is done early on in the processing of the * ClientHello, and other operations depend on the result, we need to handle * any TLS session ticket extension at the same time. * * session_id: a CBS containing the session ID. * ext_block: a CBS for the ClientHello extensions block. * ret: (output) on return, if a ticket was decrypted, then this is set to * point to the resulting session. * * If s->internal->tls_session_secret_cb is set then we are expecting a pre-shared key * ciphersuite, in which case we have no use for session tickets and one will * never be decrypted, nor will s->internal->tlsext_ticket_expected be set to 1. * * Returns: * -1: fatal error, either from parsing or decrypting the ticket. * 0: no ticket was found (or was ignored, based on settings). * 1: a zero length extension was found, indicating that the client supports * session tickets but doesn't currently have one to offer. * 2: either s->internal->tls_session_secret_cb was set, or a ticket was offered but * couldn't be decrypted because of a non-fatal error. * 3: a ticket was successfully decrypted and *ret was set. * * Side effects: * Sets s->internal->tlsext_ticket_expected to 1 if the server will have to issue * a new session ticket to the client because the client indicated support * (and s->internal->tls_session_secret_cb is NULL) but the client either doesn't have * a session ticket or we couldn't use the one it gave us, or if * s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket. * Otherwise, s->internal->tlsext_ticket_expected is set to 0. */ int tls1_process_ticket(SSL *s, CBS *session_id, CBS *ext_block, SSL_SESSION **ret) { CBS extensions, ext_data; uint16_t ext_type = 0; int r; s->internal->tlsext_ticket_expected = 0; *ret = NULL; /* * If tickets disabled behave as if no ticket present to permit stateful * resumption. */ if (SSL_get_options(s) & SSL_OP_NO_TICKET) return 0; /* * An empty extensions block is valid, but obviously does not contain * a session ticket. */ if (CBS_len(ext_block) == 0) return 0; if (!CBS_get_u16_length_prefixed(ext_block, &extensions)) return -1; while (CBS_len(&extensions) > 0) { if (!CBS_get_u16(&extensions, &ext_type) || !CBS_get_u16_length_prefixed(&extensions, &ext_data)) return -1; if (ext_type == TLSEXT_TYPE_session_ticket) break; } if (ext_type != TLSEXT_TYPE_session_ticket) return 0; if (CBS_len(&ext_data) == 0) { /* * The client will accept a ticket but does not currently * have one. */ s->internal->tlsext_ticket_expected = 1; return 1; } if (s->internal->tls_session_secret_cb != NULL) { /* * Indicate that the ticket could not be decrypted rather than * generating the session from ticket now, trigger abbreviated * handshake based on external mechanism to calculate the master * secret later. */ return 2; } r = tls_decrypt_ticket(s, session_id, &ext_data, ret); switch (r) { case 2: /* ticket couldn't be decrypted */ s->internal->tlsext_ticket_expected = 1; return 2; case 3: /* ticket was decrypted */ return r; case 4: /* ticket decrypted but need to renew */ s->internal->tlsext_ticket_expected = 1; return 3; default: /* fatal error */ return -1; } } /* tls_decrypt_ticket attempts to decrypt a session ticket. * * session_id: a CBS containing the session ID. * ticket: a CBS containing the body of the session ticket extension. * psess: (output) on return, if a ticket was decrypted, then this is set to * point to the resulting session. * * Returns: * -1: fatal error, either from parsing or decrypting the ticket. * 2: the ticket couldn't be decrypted. * 3: a ticket was successfully decrypted and *psess was set. * 4: same as 3, but the ticket needs to be renewed. */ static int tls_decrypt_ticket(SSL *s, CBS *session_id, CBS *ticket, SSL_SESSION **psess) { CBS ticket_name, ticket_iv, ticket_encdata, ticket_hmac; SSL_SESSION *sess = NULL; unsigned char *sdec = NULL; size_t sdec_len = 0; size_t session_id_len; const unsigned char *p; unsigned char hmac[EVP_MAX_MD_SIZE]; HMAC_CTX *hctx = NULL; EVP_CIPHER_CTX *cctx = NULL; SSL_CTX *tctx = s->initial_ctx; int slen, hlen; int renew_ticket = 0; int ret = -1; *psess = NULL; if (!CBS_get_bytes(ticket, &ticket_name, 16)) goto derr; /* * Initialize session ticket encryption and HMAC contexts. */ if ((cctx = EVP_CIPHER_CTX_new()) == NULL) goto err; if ((hctx = HMAC_CTX_new()) == NULL) goto err; if (tctx->internal->tlsext_ticket_key_cb != NULL) { int rv; /* * The API guarantees EVP_MAX_IV_LENGTH bytes of space for * the iv to tlsext_ticket_key_cb(). Since the total space * required for a session cookie is never less than this, * this check isn't too strict. The exact check comes later. */ if (CBS_len(ticket) < EVP_MAX_IV_LENGTH) goto derr; if ((rv = tctx->internal->tlsext_ticket_key_cb(s, (unsigned char *)CBS_data(&ticket_name), (unsigned char *)CBS_data(ticket), cctx, hctx, 0)) < 0) goto err; if (rv == 0) goto derr; if (rv == 2) renew_ticket = 1; /* * Now that the cipher context is initialised, we can extract * the IV since its length is known. */ if (!CBS_get_bytes(ticket, &ticket_iv, EVP_CIPHER_CTX_iv_length(cctx))) goto derr; } else { /* Check that the key name matches. */ if (!CBS_mem_equal(&ticket_name, tctx->internal->tlsext_tick_key_name, sizeof(tctx->internal->tlsext_tick_key_name))) goto derr; if (!CBS_get_bytes(ticket, &ticket_iv, EVP_CIPHER_iv_length(EVP_aes_128_cbc()))) goto derr; if (!EVP_DecryptInit_ex(cctx, EVP_aes_128_cbc(), NULL, tctx->internal->tlsext_tick_aes_key, CBS_data(&ticket_iv))) goto err; if (!HMAC_Init_ex(hctx, tctx->internal->tlsext_tick_hmac_key, sizeof(tctx->internal->tlsext_tick_hmac_key), EVP_sha256(), NULL)) goto err; } /* * Attempt to process session ticket. */ if ((hlen = HMAC_size(hctx)) < 0) goto err; if (hlen > CBS_len(ticket)) goto derr; if (!CBS_get_bytes(ticket, &ticket_encdata, CBS_len(ticket) - hlen)) goto derr; if (!CBS_get_bytes(ticket, &ticket_hmac, hlen)) goto derr; if (CBS_len(ticket) != 0) goto err; /* Check HMAC of encrypted ticket. */ if (HMAC_Update(hctx, CBS_data(&ticket_name), CBS_len(&ticket_name)) <= 0) goto err; if (HMAC_Update(hctx, CBS_data(&ticket_iv), CBS_len(&ticket_iv)) <= 0) goto err; if (HMAC_Update(hctx, CBS_data(&ticket_encdata), CBS_len(&ticket_encdata)) <= 0) goto err; if (HMAC_Final(hctx, hmac, &hlen) <= 0) goto err; if (!CBS_mem_equal(&ticket_hmac, hmac, hlen)) goto derr; /* Attempt to decrypt session data. */ sdec_len = CBS_len(&ticket_encdata); if ((sdec = calloc(1, sdec_len)) == NULL) goto err; if (EVP_DecryptUpdate(cctx, sdec, &slen, CBS_data(&ticket_encdata), CBS_len(&ticket_encdata)) <= 0) goto derr; if (EVP_DecryptFinal_ex(cctx, sdec + slen, &hlen) <= 0) goto derr; slen += hlen; /* * For session parse failures, indicate that we need to send a new * ticket. */ p = sdec; if ((sess = d2i_SSL_SESSION(NULL, &p, slen)) == NULL) goto derr; /* * The session ID, if non-empty, is used by some clients to detect that * the ticket has been accepted. So we copy it to the session structure. * If it is empty set length to zero as required by standard. */ if (!CBS_write_bytes(session_id, sess->session_id, sizeof(sess->session_id), &session_id_len)) goto err; sess->session_id_length = (unsigned int)session_id_len; *psess = sess; sess = NULL; if (renew_ticket) ret = 4; else ret = 3; goto done; derr: ret = 2; goto done; err: ret = -1; goto done; done: freezero(sdec, sdec_len); EVP_CIPHER_CTX_free(cctx); HMAC_CTX_free(hctx); SSL_SESSION_free(sess); if (ret == 2) ERR_clear_error(); return ret; }