diff options
Diffstat (limited to 'openssl-1.1.0h/ssl/statem/statem_lib.c')
| -rw-r--r-- | openssl-1.1.0h/ssl/statem/statem_lib.c | 1083 |
1 files changed, 1083 insertions, 0 deletions
diff --git a/openssl-1.1.0h/ssl/statem/statem_lib.c b/openssl-1.1.0h/ssl/statem/statem_lib.c new file mode 100644 index 0000000..36d410b --- /dev/null +++ b/openssl-1.1.0h/ssl/statem/statem_lib.c @@ -0,0 +1,1083 @@ +/* + * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +/* ==================================================================== + * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. + * ECC cipher suite support in OpenSSL originally developed by + * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project. + */ + +#include <limits.h> +#include <string.h> +#include <stdio.h> +#include "../ssl_locl.h" +#include "statem_locl.h" +#include <openssl/buffer.h> +#include <openssl/objects.h> +#include <openssl/evp.h> +#include <openssl/x509.h> + +/* + * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or + * SSL3_RT_CHANGE_CIPHER_SPEC) + */ +int ssl3_do_write(SSL *s, int type) +{ + int ret; + + ret = ssl3_write_bytes(s, type, &s->init_buf->data[s->init_off], + s->init_num); + if (ret < 0) + return (-1); + if (type == SSL3_RT_HANDSHAKE) + /* + * should not be done for 'Hello Request's, but in that case we'll + * ignore the result anyway + */ + if (!ssl3_finish_mac(s, + (unsigned char *)&s->init_buf->data[s->init_off], + ret)) + return -1; + + if (ret == s->init_num) { + if (s->msg_callback) + s->msg_callback(1, s->version, type, s->init_buf->data, + (size_t)(s->init_off + s->init_num), s, + s->msg_callback_arg); + return (1); + } + s->init_off += ret; + s->init_num -= ret; + return (0); +} + +int tls_construct_finished(SSL *s, const char *sender, int slen) +{ + unsigned char *p; + int i; + unsigned long l; + + p = ssl_handshake_start(s); + + i = s->method->ssl3_enc->final_finish_mac(s, + sender, slen, + s->s3->tmp.finish_md); + if (i <= 0) + return 0; + s->s3->tmp.finish_md_len = i; + memcpy(p, s->s3->tmp.finish_md, i); + l = i; + + /* + * Copy the finished so we can use it for renegotiation checks + */ + if (!s->server) { + OPENSSL_assert(i <= EVP_MAX_MD_SIZE); + memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i); + s->s3->previous_client_finished_len = i; + } else { + OPENSSL_assert(i <= EVP_MAX_MD_SIZE); + memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i); + s->s3->previous_server_finished_len = i; + } + + if (!ssl_set_handshake_header(s, SSL3_MT_FINISHED, l)) { + SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR); + return 0; + } + + return 1; +} + +/* + * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen + * to far. + */ +int ssl3_take_mac(SSL *s) +{ + const char *sender; + int slen; + + if (!s->server) { + sender = s->method->ssl3_enc->server_finished_label; + slen = s->method->ssl3_enc->server_finished_label_len; + } else { + sender = s->method->ssl3_enc->client_finished_label; + slen = s->method->ssl3_enc->client_finished_label_len; + } + + s->s3->tmp.peer_finish_md_len = + s->method->ssl3_enc->final_finish_mac(s, sender, slen, + s->s3->tmp.peer_finish_md); + + if (s->s3->tmp.peer_finish_md_len == 0) { + SSLerr(SSL_F_SSL3_TAKE_MAC, ERR_R_INTERNAL_ERROR); + return 0; + } + + return 1; +} + +MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt) +{ + int al; + long remain; + + remain = PACKET_remaining(pkt); + /* + * 'Change Cipher Spec' is just a single byte, which should already have + * been consumed by ssl_get_message() so there should be no bytes left, + * unless we're using DTLS1_BAD_VER, which has an extra 2 bytes + */ + if (SSL_IS_DTLS(s)) { + if ((s->version == DTLS1_BAD_VER + && remain != DTLS1_CCS_HEADER_LENGTH + 1) + || (s->version != DTLS1_BAD_VER + && remain != DTLS1_CCS_HEADER_LENGTH - 1)) { + al = SSL_AD_ILLEGAL_PARAMETER; + SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, + SSL_R_BAD_CHANGE_CIPHER_SPEC); + goto f_err; + } + } else { + if (remain != 0) { + al = SSL_AD_ILLEGAL_PARAMETER; + SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, + SSL_R_BAD_CHANGE_CIPHER_SPEC); + goto f_err; + } + } + + /* Check we have a cipher to change to */ + if (s->s3->tmp.new_cipher == NULL) { + al = SSL_AD_UNEXPECTED_MESSAGE; + SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY); + goto f_err; + } + + s->s3->change_cipher_spec = 1; + if (!ssl3_do_change_cipher_spec(s)) { + al = SSL_AD_INTERNAL_ERROR; + SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR); + goto f_err; + } + + if (SSL_IS_DTLS(s)) { + dtls1_reset_seq_numbers(s, SSL3_CC_READ); + + if (s->version == DTLS1_BAD_VER) + s->d1->handshake_read_seq++; + +#ifndef OPENSSL_NO_SCTP + /* + * Remember that a CCS has been received, so that an old key of + * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no + * SCTP is used + */ + BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL); +#endif + } + + return MSG_PROCESS_CONTINUE_READING; + f_err: + ssl3_send_alert(s, SSL3_AL_FATAL, al); + ossl_statem_set_error(s); + return MSG_PROCESS_ERROR; +} + +MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt) +{ + int al, i; + + /* If this occurs, we have missed a message */ + if (!s->s3->change_cipher_spec) { + al = SSL_AD_UNEXPECTED_MESSAGE; + SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS); + goto f_err; + } + s->s3->change_cipher_spec = 0; + + i = s->s3->tmp.peer_finish_md_len; + + if ((unsigned long)i != PACKET_remaining(pkt)) { + al = SSL_AD_DECODE_ERROR; + SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_BAD_DIGEST_LENGTH); + goto f_err; + } + + if (CRYPTO_memcmp(PACKET_data(pkt), s->s3->tmp.peer_finish_md, i) != 0) { + al = SSL_AD_DECRYPT_ERROR; + SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_DIGEST_CHECK_FAILED); + goto f_err; + } + + /* + * Copy the finished so we can use it for renegotiation checks + */ + if (s->server) { + OPENSSL_assert(i <= EVP_MAX_MD_SIZE); + memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md, i); + s->s3->previous_client_finished_len = i; + } else { + OPENSSL_assert(i <= EVP_MAX_MD_SIZE); + memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md, i); + s->s3->previous_server_finished_len = i; + } + + return MSG_PROCESS_FINISHED_READING; + f_err: + ssl3_send_alert(s, SSL3_AL_FATAL, al); + ossl_statem_set_error(s); + return MSG_PROCESS_ERROR; +} + +int tls_construct_change_cipher_spec(SSL *s) +{ + unsigned char *p; + + p = (unsigned char *)s->init_buf->data; + *p = SSL3_MT_CCS; + s->init_num = 1; + s->init_off = 0; + + return 1; +} + +unsigned long ssl3_output_cert_chain(SSL *s, CERT_PKEY *cpk) +{ + unsigned char *p; + unsigned long l = 3 + SSL_HM_HEADER_LENGTH(s); + + if (!ssl_add_cert_chain(s, cpk, &l)) + return 0; + + l -= 3 + SSL_HM_HEADER_LENGTH(s); + p = ssl_handshake_start(s); + l2n3(l, p); + l += 3; + + if (!ssl_set_handshake_header(s, SSL3_MT_CERTIFICATE, l)) { + SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR); + return 0; + } + return l + SSL_HM_HEADER_LENGTH(s); +} + +WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst) +{ + void (*cb) (const SSL *ssl, int type, int val) = NULL; + + /* clean a few things up */ + ssl3_cleanup_key_block(s); + + if (!SSL_IS_DTLS(s)) { + /* + * We don't do this in DTLS because we may still need the init_buf + * in case there are any unexpected retransmits + */ + BUF_MEM_free(s->init_buf); + s->init_buf = NULL; + } + + ssl_free_wbio_buffer(s); + + s->init_num = 0; + + if (!s->server || s->renegotiate == 2) { + /* skipped if we just sent a HelloRequest */ + s->renegotiate = 0; + s->new_session = 0; + + if (s->server) { + ssl_update_cache(s, SSL_SESS_CACHE_SERVER); + + s->ctx->stats.sess_accept_good++; + s->handshake_func = ossl_statem_accept; + } else { + ssl_update_cache(s, SSL_SESS_CACHE_CLIENT); + if (s->hit) + s->ctx->stats.sess_hit++; + + s->handshake_func = ossl_statem_connect; + s->ctx->stats.sess_connect_good++; + } + + if (s->info_callback != NULL) + cb = s->info_callback; + else if (s->ctx->info_callback != NULL) + cb = s->ctx->info_callback; + + if (cb != NULL) + cb(s, SSL_CB_HANDSHAKE_DONE, 1); + + if (SSL_IS_DTLS(s)) { + /* done with handshaking */ + s->d1->handshake_read_seq = 0; + s->d1->handshake_write_seq = 0; + s->d1->next_handshake_write_seq = 0; + dtls1_clear_received_buffer(s); + } + } + + return WORK_FINISHED_STOP; +} + +int tls_get_message_header(SSL *s, int *mt) +{ + /* s->init_num < SSL3_HM_HEADER_LENGTH */ + int skip_message, i, recvd_type, al; + unsigned char *p; + unsigned long l; + + p = (unsigned char *)s->init_buf->data; + + do { + while (s->init_num < SSL3_HM_HEADER_LENGTH) { + i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, + &p[s->init_num], + SSL3_HM_HEADER_LENGTH - s->init_num, + 0); + if (i <= 0) { + s->rwstate = SSL_READING; + return 0; + } + if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) { + /* + * A ChangeCipherSpec must be a single byte and may not occur + * in the middle of a handshake message. + */ + if (s->init_num != 0 || i != 1 || p[0] != SSL3_MT_CCS) { + al = SSL_AD_UNEXPECTED_MESSAGE; + SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, + SSL_R_BAD_CHANGE_CIPHER_SPEC); + goto f_err; + } + s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC; + s->init_num = i - 1; + s->init_msg = s->init_buf->data; + s->s3->tmp.message_size = i; + return 1; + } else if (recvd_type != SSL3_RT_HANDSHAKE) { + al = SSL_AD_UNEXPECTED_MESSAGE; + SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY); + goto f_err; + } + s->init_num += i; + } + + skip_message = 0; + if (!s->server) + if (p[0] == SSL3_MT_HELLO_REQUEST) + /* + * The server may always send 'Hello Request' messages -- + * we are doing a handshake anyway now, so ignore them if + * their format is correct. Does not count for 'Finished' + * MAC. + */ + if (p[1] == 0 && p[2] == 0 && p[3] == 0) { + s->init_num = 0; + skip_message = 1; + + if (s->msg_callback) + s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, + p, SSL3_HM_HEADER_LENGTH, s, + s->msg_callback_arg); + } + } while (skip_message); + /* s->init_num == SSL3_HM_HEADER_LENGTH */ + + *mt = *p; + s->s3->tmp.message_type = *(p++); + + if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) { + /* + * Only happens with SSLv3+ in an SSLv2 backward compatible + * ClientHello + * + * Total message size is the remaining record bytes to read + * plus the SSL3_HM_HEADER_LENGTH bytes that we already read + */ + l = RECORD_LAYER_get_rrec_length(&s->rlayer) + + SSL3_HM_HEADER_LENGTH; + s->s3->tmp.message_size = l; + + s->init_msg = s->init_buf->data; + s->init_num = SSL3_HM_HEADER_LENGTH; + } else { + n2l3(p, l); + /* BUF_MEM_grow takes an 'int' parameter */ + if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) { + al = SSL_AD_ILLEGAL_PARAMETER; + SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE); + goto f_err; + } + s->s3->tmp.message_size = l; + + s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH; + s->init_num = 0; + } + + return 1; + f_err: + ssl3_send_alert(s, SSL3_AL_FATAL, al); + return 0; +} + +int tls_get_message_body(SSL *s, unsigned long *len) +{ + long n; + unsigned char *p; + int i; + + if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) { + /* We've already read everything in */ + *len = (unsigned long)s->init_num; + return 1; + } + + p = s->init_msg; + n = s->s3->tmp.message_size - s->init_num; + while (n > 0) { + i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL, + &p[s->init_num], n, 0); + if (i <= 0) { + s->rwstate = SSL_READING; + *len = 0; + return 0; + } + s->init_num += i; + n -= i; + } + + /* + * If receiving Finished, record MAC of prior handshake messages for + * Finished verification. + */ + if (*(s->init_buf->data) == SSL3_MT_FINISHED && !ssl3_take_mac(s)) { + /* SSLfatal() already called */ + *len = 0; + return 0; + } + + /* Feed this message into MAC computation. */ + if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) { + if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, + s->init_num)) { + SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB); + ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); + *len = 0; + return 0; + } + if (s->msg_callback) + s->msg_callback(0, SSL2_VERSION, 0, s->init_buf->data, + (size_t)s->init_num, s, s->msg_callback_arg); + } else { + if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, + s->init_num + SSL3_HM_HEADER_LENGTH)) { + SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB); + ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); + *len = 0; + return 0; + } + if (s->msg_callback) + s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data, + (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s, + s->msg_callback_arg); + } + + /* + * init_num should never be negative...should probably be declared + * unsigned + */ + if (s->init_num < 0) { + SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_INTERNAL_ERROR); + ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); + *len = 0; + return 0; + } + *len = (unsigned long)s->init_num; + return 1; +} + +int ssl_cert_type(const X509 *x, const EVP_PKEY *pk) +{ + if (pk == NULL && (pk = X509_get0_pubkey(x)) == NULL) + return -1; + + switch (EVP_PKEY_id(pk)) { + default: + return -1; + case EVP_PKEY_RSA: + return SSL_PKEY_RSA_ENC; + case EVP_PKEY_DSA: + return SSL_PKEY_DSA_SIGN; +#ifndef OPENSSL_NO_EC + case EVP_PKEY_EC: + return SSL_PKEY_ECC; +#endif +#ifndef OPENSSL_NO_GOST + case NID_id_GostR3410_2001: + return SSL_PKEY_GOST01; + case NID_id_GostR3410_2012_256: + return SSL_PKEY_GOST12_256; + case NID_id_GostR3410_2012_512: + return SSL_PKEY_GOST12_512; +#endif + } +} + +int ssl_verify_alarm_type(long type) +{ + int al; + + switch (type) { + case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: + case X509_V_ERR_UNABLE_TO_GET_CRL: + case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER: + al = SSL_AD_UNKNOWN_CA; + break; + case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: + case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: + case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: + case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: + case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: + case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: + case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: + case X509_V_ERR_CERT_NOT_YET_VALID: + case X509_V_ERR_CRL_NOT_YET_VALID: + case X509_V_ERR_CERT_UNTRUSTED: + case X509_V_ERR_CERT_REJECTED: + case X509_V_ERR_HOSTNAME_MISMATCH: + case X509_V_ERR_EMAIL_MISMATCH: + case X509_V_ERR_IP_ADDRESS_MISMATCH: + case X509_V_ERR_DANE_NO_MATCH: + case X509_V_ERR_EE_KEY_TOO_SMALL: + case X509_V_ERR_CA_KEY_TOO_SMALL: + case X509_V_ERR_CA_MD_TOO_WEAK: + al = SSL_AD_BAD_CERTIFICATE; + break; + case X509_V_ERR_CERT_SIGNATURE_FAILURE: + case X509_V_ERR_CRL_SIGNATURE_FAILURE: + al = SSL_AD_DECRYPT_ERROR; + break; + case X509_V_ERR_CERT_HAS_EXPIRED: + case X509_V_ERR_CRL_HAS_EXPIRED: + al = SSL_AD_CERTIFICATE_EXPIRED; + break; + case X509_V_ERR_CERT_REVOKED: + al = SSL_AD_CERTIFICATE_REVOKED; + break; + case X509_V_ERR_UNSPECIFIED: + case X509_V_ERR_OUT_OF_MEM: + case X509_V_ERR_INVALID_CALL: + case X509_V_ERR_STORE_LOOKUP: + al = SSL_AD_INTERNAL_ERROR; + break; + case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: + case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: + case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: + case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: + case X509_V_ERR_CERT_CHAIN_TOO_LONG: + case X509_V_ERR_PATH_LENGTH_EXCEEDED: + case X509_V_ERR_INVALID_CA: + al = SSL_AD_UNKNOWN_CA; + break; + case X509_V_ERR_APPLICATION_VERIFICATION: + al = SSL_AD_HANDSHAKE_FAILURE; + break; + case X509_V_ERR_INVALID_PURPOSE: + al = SSL_AD_UNSUPPORTED_CERTIFICATE; + break; + default: + al = SSL_AD_CERTIFICATE_UNKNOWN; + break; + } + return (al); +} + +int ssl_allow_compression(SSL *s) +{ + if (s->options & SSL_OP_NO_COMPRESSION) + return 0; + return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL); +} + +static int version_cmp(const SSL *s, int a, int b) +{ + int dtls = SSL_IS_DTLS(s); + + if (a == b) + return 0; + if (!dtls) + return a < b ? -1 : 1; + return DTLS_VERSION_LT(a, b) ? -1 : 1; +} + +typedef struct { + int version; + const SSL_METHOD *(*cmeth) (void); + const SSL_METHOD *(*smeth) (void); +} version_info; + +#if TLS_MAX_VERSION != TLS1_2_VERSION +# error Code needs update for TLS_method() support beyond TLS1_2_VERSION. +#endif + +static const version_info tls_version_table[] = { +#ifndef OPENSSL_NO_TLS1_2 + {TLS1_2_VERSION, tlsv1_2_client_method, tlsv1_2_server_method}, +#else + {TLS1_2_VERSION, NULL, NULL}, +#endif +#ifndef OPENSSL_NO_TLS1_1 + {TLS1_1_VERSION, tlsv1_1_client_method, tlsv1_1_server_method}, +#else + {TLS1_1_VERSION, NULL, NULL}, +#endif +#ifndef OPENSSL_NO_TLS1 + {TLS1_VERSION, tlsv1_client_method, tlsv1_server_method}, +#else + {TLS1_VERSION, NULL, NULL}, +#endif +#ifndef OPENSSL_NO_SSL3 + {SSL3_VERSION, sslv3_client_method, sslv3_server_method}, +#else + {SSL3_VERSION, NULL, NULL}, +#endif + {0, NULL, NULL}, +}; + +#if DTLS_MAX_VERSION != DTLS1_2_VERSION +# error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION. +#endif + +static const version_info dtls_version_table[] = { +#ifndef OPENSSL_NO_DTLS1_2 + {DTLS1_2_VERSION, dtlsv1_2_client_method, dtlsv1_2_server_method}, +#else + {DTLS1_2_VERSION, NULL, NULL}, +#endif +#ifndef OPENSSL_NO_DTLS1 + {DTLS1_VERSION, dtlsv1_client_method, dtlsv1_server_method}, + {DTLS1_BAD_VER, dtls_bad_ver_client_method, NULL}, +#else + {DTLS1_VERSION, NULL, NULL}, + {DTLS1_BAD_VER, NULL, NULL}, +#endif + {0, NULL, NULL}, +}; + +/* + * ssl_method_error - Check whether an SSL_METHOD is enabled. + * + * @s: The SSL handle for the candidate method + * @method: the intended method. + * + * Returns 0 on success, or an SSL error reason on failure. + */ +static int ssl_method_error(const SSL *s, const SSL_METHOD *method) +{ + int version = method->version; + + if ((s->min_proto_version != 0 && + version_cmp(s, version, s->min_proto_version) < 0) || + ssl_security(s, SSL_SECOP_VERSION, 0, version, NULL) == 0) + return SSL_R_VERSION_TOO_LOW; + + if (s->max_proto_version != 0 && + version_cmp(s, version, s->max_proto_version) > 0) + return SSL_R_VERSION_TOO_HIGH; + + if ((s->options & method->mask) != 0) + return SSL_R_UNSUPPORTED_PROTOCOL; + if ((method->flags & SSL_METHOD_NO_SUITEB) != 0 && tls1_suiteb(s)) + return SSL_R_AT_LEAST_TLS_1_2_NEEDED_IN_SUITEB_MODE; + else if ((method->flags & SSL_METHOD_NO_FIPS) != 0 && FIPS_mode()) + return SSL_R_AT_LEAST_TLS_1_0_NEEDED_IN_FIPS_MODE; + + return 0; +} + +/* + * ssl_version_supported - Check that the specified `version` is supported by + * `SSL *` instance + * + * @s: The SSL handle for the candidate method + * @version: Protocol version to test against + * + * Returns 1 when supported, otherwise 0 + */ +int ssl_version_supported(const SSL *s, int version) +{ + const version_info *vent; + const version_info *table; + + switch (s->method->version) { + default: + /* Version should match method version for non-ANY method */ + return version_cmp(s, version, s->version) == 0; + case TLS_ANY_VERSION: + table = tls_version_table; + break; + case DTLS_ANY_VERSION: + table = dtls_version_table; + break; + } + + for (vent = table; + vent->version != 0 && version_cmp(s, version, vent->version) <= 0; + ++vent) { + if (vent->cmeth != NULL && + version_cmp(s, version, vent->version) == 0 && + ssl_method_error(s, vent->cmeth()) == 0) { + return 1; + } + } + return 0; +} + +/* + * ssl_check_version_downgrade - In response to RFC7507 SCSV version + * fallback indication from a client check whether we're using the highest + * supported protocol version. + * + * @s server SSL handle. + * + * Returns 1 when using the highest enabled version, 0 otherwise. + */ +int ssl_check_version_downgrade(SSL *s) +{ + const version_info *vent; + const version_info *table; + + /* + * Check that the current protocol is the highest enabled version + * (according to s->ctx->method, as version negotiation may have changed + * s->method). + */ + if (s->version == s->ctx->method->version) + return 1; + + /* + * Apparently we're using a version-flexible SSL_METHOD (not at its + * highest protocol version). + */ + if (s->ctx->method->version == TLS_method()->version) + table = tls_version_table; + else if (s->ctx->method->version == DTLS_method()->version) + table = dtls_version_table; + else { + /* Unexpected state; fail closed. */ + return 0; + } + + for (vent = table; vent->version != 0; ++vent) { + if (vent->smeth != NULL && ssl_method_error(s, vent->smeth()) == 0) + return s->version == vent->version; + } + return 0; +} + +/* + * ssl_set_version_bound - set an upper or lower bound on the supported (D)TLS + * protocols, provided the initial (D)TLS method is version-flexible. This + * function sanity-checks the proposed value and makes sure the method is + * version-flexible, then sets the limit if all is well. + * + * @method_version: The version of the current SSL_METHOD. + * @version: the intended limit. + * @bound: pointer to limit to be updated. + * + * Returns 1 on success, 0 on failure. + */ +int ssl_set_version_bound(int method_version, int version, int *bound) +{ + if (version == 0) { + *bound = version; + return 1; + } + + /*- + * Restrict TLS methods to TLS protocol versions. + * Restrict DTLS methods to DTLS protocol versions. + * Note, DTLS version numbers are decreasing, use comparison macros. + * + * Note that for both lower-bounds we use explicit versions, not + * (D)TLS_MIN_VERSION. This is because we don't want to break user + * configurations. If the MIN (supported) version ever rises, the user's + * "floor" remains valid even if no longer available. We don't expect the + * MAX ceiling to ever get lower, so making that variable makes sense. + */ + switch (method_version) { + default: + /* + * XXX For fixed version methods, should we always fail and not set any + * bounds, always succeed and not set any bounds, or set the bounds and + * arrange to fail later if they are not met? At present fixed-version + * methods are not subject to controls that disable individual protocol + * versions. + */ + return 0; + + case TLS_ANY_VERSION: + if (version < SSL3_VERSION || version > TLS_MAX_VERSION) + return 0; + break; + + case DTLS_ANY_VERSION: + if (DTLS_VERSION_GT(version, DTLS_MAX_VERSION) || + DTLS_VERSION_LT(version, DTLS1_BAD_VER)) + return 0; + break; + } + + *bound = version; + return 1; +} + +/* + * ssl_choose_server_version - Choose server (D)TLS version. Called when the + * client HELLO is received to select the final server protocol version and + * the version specific method. + * + * @s: server SSL handle. + * + * Returns 0 on success or an SSL error reason number on failure. + */ +int ssl_choose_server_version(SSL *s) +{ + /*- + * With version-flexible methods we have an initial state with: + * + * s->method->version == (D)TLS_ANY_VERSION, + * s->version == (D)TLS_MAX_VERSION. + * + * So we detect version-flexible methods via the method version, not the + * handle version. + */ + int server_version = s->method->version; + int client_version = s->client_version; + const version_info *vent; + const version_info *table; + int disabled = 0; + + switch (server_version) { + default: + if (version_cmp(s, client_version, s->version) < 0) + return SSL_R_WRONG_SSL_VERSION; + /* + * If this SSL handle is not from a version flexible method we don't + * (and never did) check min/max FIPS or Suite B constraints. Hope + * that's OK. It is up to the caller to not choose fixed protocol + * versions they don't want. If not, then easy to fix, just return + * ssl_method_error(s, s->method) + */ + return 0; + case TLS_ANY_VERSION: + table = tls_version_table; + break; + case DTLS_ANY_VERSION: + table = dtls_version_table; + break; + } + + for (vent = table; vent->version != 0; ++vent) { + const SSL_METHOD *method; + + if (vent->smeth == NULL || + version_cmp(s, client_version, vent->version) < 0) + continue; + method = vent->smeth(); + if (ssl_method_error(s, method) == 0) { + s->version = vent->version; + s->method = method; + return 0; + } + disabled = 1; + } + return disabled ? SSL_R_UNSUPPORTED_PROTOCOL : SSL_R_VERSION_TOO_LOW; +} + +/* + * ssl_choose_client_version - Choose client (D)TLS version. Called when the + * server HELLO is received to select the final client protocol version and + * the version specific method. + * + * @s: client SSL handle. + * @version: The proposed version from the server's HELLO. + * + * Returns 0 on success or an SSL error reason number on failure. + */ +int ssl_choose_client_version(SSL *s, int version) +{ + const version_info *vent; + const version_info *table; + + switch (s->method->version) { + default: + if (version != s->version) + return SSL_R_WRONG_SSL_VERSION; + /* + * If this SSL handle is not from a version flexible method we don't + * (and never did) check min/max, FIPS or Suite B constraints. Hope + * that's OK. It is up to the caller to not choose fixed protocol + * versions they don't want. If not, then easy to fix, just return + * ssl_method_error(s, s->method) + */ + return 0; + case TLS_ANY_VERSION: + table = tls_version_table; + break; + case DTLS_ANY_VERSION: + table = dtls_version_table; + break; + } + + for (vent = table; vent->version != 0; ++vent) { + const SSL_METHOD *method; + int err; + + if (version != vent->version) + continue; + if (vent->cmeth == NULL) + break; + method = vent->cmeth(); + err = ssl_method_error(s, method); + if (err != 0) + return err; + s->method = method; + s->version = version; + return 0; + } + + return SSL_R_UNSUPPORTED_PROTOCOL; +} + +/* + * ssl_get_client_min_max_version - get minimum and maximum client version + * @s: The SSL connection + * @min_version: The minimum supported version + * @max_version: The maximum supported version + * + * Work out what version we should be using for the initial ClientHello if the + * version is initially (D)TLS_ANY_VERSION. We apply any explicit SSL_OP_NO_xxx + * options, the MinProtocol and MaxProtocol configuration commands, any Suite B + * or FIPS_mode() constraints and any floor imposed by the security level here, + * so we don't advertise the wrong protocol version to only reject the outcome later. + * + * Computing the right floor matters. If, e.g., TLS 1.0 and 1.2 are enabled, + * TLS 1.1 is disabled, but the security level, Suite-B and/or MinProtocol + * only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1. + * + * Returns 0 on success or an SSL error reason number on failure. On failure + * min_version and max_version will also be set to 0. + */ +int ssl_get_client_min_max_version(const SSL *s, int *min_version, + int *max_version) +{ + int version; + int hole; + const SSL_METHOD *single = NULL; + const SSL_METHOD *method; + const version_info *table; + const version_info *vent; + + switch (s->method->version) { + default: + /* + * If this SSL handle is not from a version flexible method we don't + * (and never did) check min/max FIPS or Suite B constraints. Hope + * that's OK. It is up to the caller to not choose fixed protocol + * versions they don't want. If not, then easy to fix, just return + * ssl_method_error(s, s->method) + */ + *min_version = *max_version = s->version; + return 0; + case TLS_ANY_VERSION: + table = tls_version_table; + break; + case DTLS_ANY_VERSION: + table = dtls_version_table; + break; + } + + /* + * SSL_OP_NO_X disables all protocols above X *if* there are some protocols + * below X enabled. This is required in order to maintain the "version + * capability" vector contiguous. Any versions with a NULL client method + * (protocol version client is disabled at compile-time) is also a "hole". + * + * Our initial state is hole == 1, version == 0. That is, versions above + * the first version in the method table are disabled (a "hole" above + * the valid protocol entries) and we don't have a selected version yet. + * + * Whenever "hole == 1", and we hit an enabled method, its version becomes + * the selected version, and the method becomes a candidate "single" + * method. We're no longer in a hole, so "hole" becomes 0. + * + * If "hole == 0" and we hit an enabled method, then "single" is cleared, + * as we support a contiguous range of at least two methods. If we hit + * a disabled method, then hole becomes true again, but nothing else + * changes yet, because all the remaining methods may be disabled too. + * If we again hit an enabled method after the new hole, it becomes + * selected, as we start from scratch. + */ + *min_version = version = 0; + hole = 1; + for (vent = table; vent->version != 0; ++vent) { + /* + * A table entry with a NULL client method is still a hole in the + * "version capability" vector. + */ + if (vent->cmeth == NULL) { + hole = 1; + continue; + } + method = vent->cmeth(); + if (ssl_method_error(s, method) != 0) { + hole = 1; + } else if (!hole) { + single = NULL; + *min_version = method->version; + } else { + version = (single = method)->version; + *min_version = version; + hole = 0; + } + } + + *max_version = version; + + /* Fail if everything is disabled */ + if (version == 0) + return SSL_R_NO_PROTOCOLS_AVAILABLE; + + return 0; +} + +/* + * ssl_set_client_hello_version - Work out what version we should be using for + * the initial ClientHello. + * + * @s: client SSL handle. + * + * Returns 0 on success or an SSL error reason number on failure. + */ +int ssl_set_client_hello_version(SSL *s) +{ + int ver_min, ver_max, ret; + + ret = ssl_get_client_min_max_version(s, &ver_min, &ver_max); + + if (ret != 0) + return ret; + + s->client_version = s->version = ver_max; + return 0; +} |