Adding upstream version 3.5.24.upstream/3.5.24upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 781 insertions, 0 deletions

diff --git a/src/tls/tls_certkey.c b/src/tls/tls_certkey.c
new file mode 100644
index 0000000..be8d470
--- /dev/null
+++ b/src/tls/tls_certkey.c
@@ -0,0 +1,781 @@
+/*++
+/* NAME
+/*	tls_certkey 3
+/* SUMMARY
+/*	public key certificate and private key loader
+/* SYNOPSIS
+/*	#define TLS_INTERNAL
+/*	#include <tls.h>
+/*
+/*	int	tls_set_ca_certificate_info(ctx, CAfile, CApath)
+/*	SSL_CTX	*ctx;
+/*	const char *CAfile;
+/*	const char *CApath;
+/*
+/*	int	tls_set_my_certificate_key_info(ctx, chain_files,
+/*						cert_file, key_file,
+/*						dcert_file, dkey_file,
+/*						eccert_file, eckey_file)
+/*	SSL_CTX	*ctx;
+/*	const char *chain_files;
+/*	const char *cert_file;
+/*	const char *key_file;
+/*	const char *dcert_file;
+/*	const char *dkey_file;
+/*	const char *eccert_file;
+/*	const char *eckey_file;
+/*
+/*	int	tls_load_pem_chain(ssl, pem, origin);
+/*	SSL	*ssl;
+/*	const char *pem;
+/*	const char *origin;
+/* DESCRIPTION
+/*	OpenSSL supports two options to specify CA certificates:
+/*	either one file CAfile that contains all CA certificates,
+/*	or a directory CApath with separate files for each
+/*	individual CA, with symbolic links named after the hash
+/*	values of the certificates. The second option is not
+/*	convenient with a chrooted process.
+/*
+/*	tls_set_ca_certificate_info() loads the CA certificate
+/*	information for the specified TLS server or client context.
+/*	The result is -1 on failure, 0 on success.
+/*
+/*	tls_set_my_certificate_key_info() loads the public key
+/*	certificates and private keys for the specified TLS server
+/*	or client context. Up to 3 pairs of key pairs (RSA, DSA and
+/*	ECDSA) may be specified; each certificate and key pair must
+/*	match.  The chain_files argument makes it possible to load
+/*	keys and certificates for more than 3 algorithms, via either
+/*	a single file, or a list of multiple files. The result is -1
+/*	on failure, 0 on success.
+/*
+/*	tls_load_pem_chain() loads one or more (key, cert, [chain])
+/*	triples from an in-memory PEM blob.  The "origin" argument
+/*	is used for error logging, to identify the provenance of the
+/*	PEM blob. "ssl" must be non-zero, and the keys and certificates
+/*	will be loaded into that object.
+/* LICENSE
+/* .ad
+/* .fi
+/*	This software is free. You can do with it whatever you want.
+/*	The original author kindly requests that you acknowledge
+/*	the use of his software.
+/* AUTHOR(S)
+/*	Originally written by:
+/*	Lutz Jaenicke
+/*	BTU Cottbus
+/*	Allgemeine Elektrotechnik
+/*	Universitaetsplatz 3-4
+/*	D-03044 Cottbus, Germany
+/*
+/*	Updated by:
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+
+#ifdef USE_TLS
+
+/* Utility library. */
+
+#include <msg.h>
+
+/* Global library. */
+
+#include <mail_params.h>
+
+/* TLS library. */
+
+#define TLS_INTERNAL
+#include <tls.h>
+
+#define PEM_LOAD_STATE_NOGO	-2	/* Unusable object or sequence */
+#define PEM_LOAD_STATE_FAIL	-1	/* Error in libcrypto */
+#define PEM_LOAD_STATE_DONE	0	/* End of PEM file, return value only */
+#define PEM_LOAD_STATE_INIT	1	/* No PEM objects seen */
+#define PEM_LOAD_STATE_PKEY	2	/* Last object was a private key */
+#define PEM_LOAD_STATE_CERT	3	/* Last object was a certificate */
+#define PEM_LOAD_STATE_BOTH	4	/* Unordered, key + first cert seen */
+
+#define PEM_LOAD_READ_LAST	0	/* Reading last file */
+#define PEM_LOAD_READ_MORE	1	/* More files to be read */
+
+typedef struct pem_load_state_t {
+    const char *origin;			/* PEM chain origin description */
+    const char *source;			/* PEM BIO origin description */
+    const char *keysrc;			/* Source of last key */
+    BIO    *pembio;			/* PEM input stream */
+    SSL_CTX *ctx;			/* SSL connection factory */
+    SSL    *ssl;			/* SSL connection handle */
+    EVP_PKEY *pkey;			/* current key */
+    X509   *cert;			/* current certificate */
+    x509_stack_t *chain;		/* current chain */
+    int     keynum;			/* Index of last key */
+    int     objnum;			/* Index in current source */
+    int     state;			/* Current state, never "DONE" */
+    int     mixed;			/* Single file with key anywhere */
+} pem_load_state_t;
+
+/* init_pem_load_state - fill in initial pem_load_state structure */
+
+static void init_pem_load_state(pem_load_state_t *st, SSL_CTX *ctx, SSL *ssl,
+				        const char *origin)
+{
+    st->origin = origin;
+    st->source = origin;
+    st->keysrc = 0;
+    st->pembio = 0;
+    st->ctx = ctx;
+    st->ssl = ssl;
+    st->pkey = 0;
+    st->cert = 0;
+    st->chain = 0;
+    st->keynum = 0;
+    st->objnum = 0;
+    st->state = PEM_LOAD_STATE_INIT;
+    st->mixed = 0;
+}
+
+/* use_chain - load cert, key and chain into ctx or ssl */
+
+#if OPENSSL_VERSION_NUMBER >= 0x1010100fUL
+static int use_chain(pem_load_state_t *st)
+{
+    int     ret;
+    int     replace = 0;
+
+    /*
+     * With replace == 0, an error is returned if the algorithm slot is
+     * already taken, and a previous key + chain of the same type would be
+     * clobbered.
+     */
+    if (st->ctx)
+	ret = SSL_CTX_use_cert_and_key(st->ctx, st->cert, st->pkey, st->chain,
+				       replace);
+    else
+	ret = SSL_use_cert_and_key(st->ssl, st->cert, st->pkey, st->chain,
+				   replace);
+
+    /*
+     * SSL_[CTX_]_use_cert_key() uprefs all the objects in question, so we
+     * must free ours.
+     */
+    X509_free(st->cert);
+    st->cert = 0;
+    EVP_PKEY_free(st->pkey);
+    st->pkey = 0;
+    sk_X509_pop_free(st->chain, X509_free);
+    st->chain = 0;
+
+    return ret;
+}
+
+#else
+
+/* Legacy OpenSSL 1.0.2 and 1.1.0 interface */
+static int use_chain(pem_load_state_t *st)
+{
+    int     ret = 1;
+
+#define TRY(op, o) \
+    ((st->ctx && SSL_CTX_##op(st->ctx, st->o)) || \
+     (st->ssl && SSL_##op(st->ssl, st->o)))
+
+    /*
+     * This ensures the cert and key have the same type and match. A similar
+     * check is performed in use_PrivateKey(), but only if if the key and
+     * cert are of the same type.
+     */
+    if (!X509_check_private_key(st->cert, st->pkey))
+	ret = 0;
+
+    /*
+     * XXX: With OpenSSL 1.0.2, setting the certificate clears any previous
+     * mismatched key of the same type, so we don't detect conflicting chains
+     * for the same algorithm, and silently use the last one.
+     */
+
+    /* use_certificate() increments the refcount */
+    if (ret && !TRY(use_certificate, cert))
+	ret = 0;
+    X509_free(st->cert);
+    st->cert = 0;
+
+    /* use_PrivateKey() increments the refcount */
+    if (ret && !TRY(use_PrivateKey, pkey))
+	ret = 0;
+    EVP_PKEY_free(st->pkey);
+    st->pkey = 0;
+
+    /* set0_chain() does not increment the refcount */
+    if (!ret || !(ret = TRY(set0_chain, chain)))
+	sk_X509_pop_free(st->chain, X509_free);
+    /* The chain is now owned by the SSL library or freed, zero for next use */
+    st->chain = 0;
+
+    return ret;
+}
+
+#endif
+
+/* load_cert - decode and load a DER-encoded X509 certificate */
+
+static void load_cert(pem_load_state_t *st, unsigned char *buf,
+		              long buflen)
+{
+    const unsigned char *p = buf;
+    X509   *cert = d2i_X509(0, &p, buflen);
+
+    /*
+     * When expecting one or more keys, each key must precede the associated
+     * certificate (chain).
+     */
+    if (!st->mixed && st->state == PEM_LOAD_STATE_INIT) {
+	msg_warn("error loading chain from %s: key not first", st->source);
+	if (cert)
+	    X509_free(cert);
+	st->state = PEM_LOAD_STATE_NOGO;
+	return;
+    }
+    if (!cert) {
+	msg_warn("error loading certificate (PEM object number %d) from %s",
+		 st->objnum, st->source);
+	st->state = PEM_LOAD_STATE_FAIL;
+	return;
+    }
+    if (p - buf != buflen) {
+	msg_warn("error loading certificate (PEM object number %d) from %s:"
+		 " excess data", st->objnum, st->source);
+	X509_free(cert);
+	st->state = PEM_LOAD_STATE_NOGO;
+	return;
+    }
+
+    /*
+     * The first certificate after a new key becomes the leaf certificate for
+     * that key.  Subsequent certificates are added to the issuer chain.
+     * 
+     * In "mixed" mode, the first certificate is either after the key, or else
+     * comes first.
+     */
+    switch (st->state) {
+    case PEM_LOAD_STATE_PKEY:
+	st->cert = cert;
+	st->state = st->mixed ? PEM_LOAD_STATE_BOTH : PEM_LOAD_STATE_CERT;
+	return;
+    case PEM_LOAD_STATE_INIT:
+	st->cert = cert;
+	st->state = PEM_LOAD_STATE_CERT;
+	return;
+    case PEM_LOAD_STATE_CERT:
+    case PEM_LOAD_STATE_BOTH:
+	if ((!st->chain && (st->chain = sk_X509_new_null()) == 0)
+	    || !sk_X509_push(st->chain, cert)) {
+	    X509_free(cert);
+	    st->state = PEM_LOAD_STATE_FAIL;
+	}
+	return;
+    }
+}
+
+/* load_pkey - decode and load a DER-encoded private key */
+
+static void load_pkey(pem_load_state_t *st, int pkey_type,
+		              unsigned char *buf, long buflen)
+{
+    const char *myname = "load_pkey";
+    const unsigned char *p = buf;
+    PKCS8_PRIV_KEY_INFO *p8;
+    EVP_PKEY *pkey = 0;
+
+    /*
+     * Keys are either algorithm-specific, or else (ideally) algorithm
+     * agnostic, in which case they are wrapped as PKCS#8 objects with an
+     * algorithm OID.
+     */
+    if (pkey_type != NID_undef) {
+	pkey = d2i_PrivateKey(pkey_type, 0, &p, buflen);
+    } else {
+	p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, buflen);
+	if (p8) {
+	    pkey = EVP_PKCS82PKEY(p8);
+	    PKCS8_PRIV_KEY_INFO_free(p8);
+	}
+    }
+
+    /*
+     * Except in "mixed" mode, where a single key appears anywhere in a file
+     * with multiple certificates, a given key is either at the first object
+     * we process, or occurs after a previous key and one or more associated
+     * certificates.  Thus, encountering a key in a state other than "INIT"
+     * or "CERT" is an error, except in "mixed" mode where a second key is
+     * ignored with a warning.
+     */
+    switch (st->state) {
+    case PEM_LOAD_STATE_CERT:
+
+	/*
+	 * When processing the key of a "next" chain, we're in the "CERT"
+	 * state, and first complete the processing of the previous chain.
+	 */
+	if (!st->mixed && !use_chain(st)) {
+	    msg_warn("error loading certificate chain: "
+		     "key at index %d in %s does not match the certificate",
+		     st->keynum, st->keysrc);
+	    st->state = PEM_LOAD_STATE_FAIL;
+	    return;
+	}
+	/* FALLTHROUGH */
+    case PEM_LOAD_STATE_INIT:
+
+	if (!pkey) {
+	    msg_warn("error loading private key (PEM object number %d) from %s",
+		     st->objnum, st->source);
+	    st->state = PEM_LOAD_STATE_FAIL;
+	    return;
+	}
+	/* Reject unexpected data beyond the end of the DER-encoded object */
+	if (p - buf != buflen) {
+	    msg_warn("error loading private key (PEM object number %d) from"
+		     " %s: excess data", st->objnum, st->source);
+	    EVP_PKEY_free(pkey);
+	    st->state = PEM_LOAD_STATE_NOGO;
+	    return;
+	}
+	/* All's well, update the state */
+	st->pkey = pkey;
+	if (st->state == PEM_LOAD_STATE_INIT)
+	    st->state = PEM_LOAD_STATE_PKEY;
+	else if (st->mixed)
+	    st->state = PEM_LOAD_STATE_BOTH;
+	else
+	    st->state = PEM_LOAD_STATE_PKEY;
+	return;
+
+    case PEM_LOAD_STATE_PKEY:
+    case PEM_LOAD_STATE_BOTH:
+	if (pkey)
+	    EVP_PKEY_free(pkey);
+
+	/* XXX: Legacy behaviour was silent, should we stay silent? */
+	if (st->mixed) {
+	    msg_warn("ignoring 2nd key at index %d in %s after 1st at %d",
+		     st->objnum, st->source, st->keynum);
+	    return;
+	}
+	/* else back-to-back keys */
+	msg_warn("error loading certificate chain: "
+		 "key at index %d in %s not followed by a certificate",
+		 st->keynum, st->keysrc);
+	st->state = PEM_LOAD_STATE_NOGO;
+	return;
+
+    default:
+	msg_error("%s: internal error: bad state: %d", myname, st->state);
+	st->state = PEM_LOAD_STATE_NOGO;
+	return;
+    }
+}
+
+/* load_pem_object - load next pkey or cert from open BIO */
+
+static int load_pem_object(pem_load_state_t *st)
+{
+    char   *name = 0;
+    char   *header = 0;
+    unsigned char *buf = 0;
+    long    buflen;
+    int     pkey_type = NID_undef;
+
+    if (!PEM_read_bio(st->pembio, &name, &header, &buf, &buflen)) {
+	if (ERR_GET_REASON(ERR_peek_last_error()) != PEM_R_NO_START_LINE)
+	    return (st->state = PEM_LOAD_STATE_FAIL);
+
+	ERR_clear_error();
+	/* Clean EOF, preserve stored state for any next input file */
+	return (PEM_LOAD_STATE_DONE);
+    }
+    if (strcmp(name, PEM_STRING_X509) == 0
+	|| strcmp(name, PEM_STRING_X509_OLD) == 0) {
+	load_cert(st, buf, buflen);
+    } else if (strcmp(name, PEM_STRING_PKCS8INF) == 0
+	       || ((pkey_type = EVP_PKEY_RSA) != NID_undef
+		   && strcmp(name, PEM_STRING_RSA) == 0)
+	       || ((pkey_type = EVP_PKEY_EC) != NID_undef
+		   && strcmp(name, PEM_STRING_ECPRIVATEKEY) == 0)
+	       || ((pkey_type = EVP_PKEY_DSA) != NID_undef
+		   && strcmp(name, PEM_STRING_DSA) == 0)) {
+	load_pkey(st, pkey_type, buf, buflen);
+    } else if (!st->mixed) {
+       msg_warn("loading %s: ignoring PEM type: %s", st->source, name);
+    }
+    OPENSSL_free(name);
+    OPENSSL_free(header);
+    OPENSSL_free(buf);
+    return (st->state);
+}
+
+/* load_pem_bio - load all key/certs from bio and free the bio */
+
+static int load_pem_bio(pem_load_state_t *st, int more)
+{
+    int     state = st->state;
+
+    /* Don't report old news */
+    ERR_clear_error();
+
+    /*
+     * When "more" is PEM_LOAD_READ_MORE, more files will be loaded after the
+     * current file, and final processing for the last key and chain is
+     * deferred.
+     * 
+     * When "more" is PEM_LOAD_READ_LAST, this is the last file in the list, and
+     * we validate the final chain.
+     * 
+     * When st->mixed is true, this is the only file, and its key can occur at
+     * any location.  In this case we load at most one key.
+     */
+    for (st->objnum = 1; state > PEM_LOAD_STATE_DONE; ++st->objnum) {
+	state = load_pem_object(st);
+	if ((st->mixed && st->keynum == 0 &&
+	     (state == PEM_LOAD_STATE_PKEY || state == PEM_LOAD_STATE_BOTH))
+	    || (!st->mixed && state == PEM_LOAD_STATE_PKEY)) {
+	    /* Squirrel-away the current key location */
+	    st->keynum = st->objnum;
+	    st->keysrc = st->source;
+	}
+    }
+    /* We're responsible for unconditionally freeing the BIO */
+    BIO_free(st->pembio);
+
+    /* Success with current file, go back for more? */
+    if (more == PEM_LOAD_READ_MORE && state >= PEM_LOAD_STATE_DONE)
+	return 0;
+
+    /*
+     * If all is well so far, complete processing for the final chain.
+     */
+    switch (st->state) {
+    case PEM_LOAD_STATE_FAIL:
+	tls_print_errors();
+	break;
+    default:
+	break;
+    case PEM_LOAD_STATE_INIT:
+	msg_warn("No PEM data in %s", st->origin);
+	break;
+    case PEM_LOAD_STATE_PKEY:
+	msg_warn("No certs for key at index %d in %s", st->keynum, st->keysrc);
+	break;
+    case PEM_LOAD_STATE_CERT:
+	if (st->mixed) {
+	    msg_warn("No private key found in %s", st->origin);
+	    break;
+	}
+	/* FALLTHROUGH */
+    case PEM_LOAD_STATE_BOTH:
+	/* use_chain() frees the key and certs, and zeroes the pointers */
+	if (use_chain(st))
+	    return (0);
+	msg_warn("key at index %d in %s does not match next certificate",
+		 st->keynum, st->keysrc);
+	tls_print_errors();
+	break;
+    }
+    /* Free any left-over unused keys and certs */
+    EVP_PKEY_free(st->pkey);
+    X509_free(st->cert);
+    sk_X509_pop_free(st->chain, X509_free);
+
+    msg_warn("error loading private keys and certificates from: %s: %s",
+	     st->origin, st->ctx ? "disabling TLS support" :
+	     "aborting TLS handshake");
+    return (-1);
+}
+
+/* load_chain_files - load sequence of (key, cert, [chain]) from files */
+
+static int load_chain_files(SSL_CTX *ctx, const char *chain_files)
+{
+    pem_load_state_t st;
+    ARGV   *files = argv_split(chain_files, CHARS_COMMA_SP);
+    char  **filep;
+    int     ret = 0;
+    int     more;
+
+    init_pem_load_state(&st, ctx, 0, chain_files);
+    for (filep = files->argv; ret == 0 && *filep; ++filep) {
+	st.source = *filep;
+	if ((st.pembio = BIO_new_file(st.source, "r")) == NULL) {
+	    msg_warn("error opening chain file: %s: %m", st.source);
+	    st.state = PEM_LOAD_STATE_NOGO;
+	    break;
+	}
+	more = filep[1] ? PEM_LOAD_READ_MORE : PEM_LOAD_READ_LAST;
+	/* load_pem_bio() frees the BIO */
+	ret = load_pem_bio(&st, more);
+    }
+    argv_free(files);
+    return (ret);
+}
+
+/* load_mixed_file - load certs with single key anywhere in the file */
+
+static int load_mixed_file(SSL_CTX *ctx, const char *file)
+{
+    pem_load_state_t st;
+
+    init_pem_load_state(&st, ctx, 0, file);
+    if ((st.pembio = BIO_new_file(st.source, "r")) == NULL) {
+	msg_warn("error opening chain file: %s: %m", st.source);
+	return (-1);
+    }
+    st.mixed = 1;
+    /* load_pem_bio() frees the BIO */
+    return load_pem_bio(&st, PEM_LOAD_READ_LAST);
+}
+
+/* tls_set_ca_certificate_info - load Certification Authority certificates */
+
+int     tls_set_ca_certificate_info(SSL_CTX *ctx, const char *CAfile,
+				            const char *CApath)
+{
+    if (*CAfile == 0)
+	CAfile = 0;
+    if (*CApath == 0)
+	CApath = 0;
+
+#define CA_PATH_FMT "%s%s%s"
+#define CA_PATH_ARGS(var, nextvar) \
+	var ? #var "=\"" : "", \
+	var ? var : "", \
+	var ? (nextvar ? "\", " : "\"") : ""
+
+    if (CAfile || CApath) {
+	if (!SSL_CTX_load_verify_locations(ctx, CAfile, CApath)) {
+	    msg_info("cannot load Certification Authority data, "
+		     CA_PATH_FMT CA_PATH_FMT ": disabling TLS support",
+		     CA_PATH_ARGS(CAfile, CApath),
+		     CA_PATH_ARGS(CApath, 0));
+	    tls_print_errors();
+	    return (-1);
+	}
+	if (var_tls_append_def_CA && !SSL_CTX_set_default_verify_paths(ctx)) {
+	    msg_info("cannot set default OpenSSL certificate verification "
+		     "paths: disabling TLS support");
+	    tls_print_errors();
+	    return (-1);
+	}
+    }
+    return (0);
+}
+
+/* set_cert_stuff - specify certificate and key information */
+
+static int set_cert_stuff(SSL_CTX *ctx, const char *cert_type,
+			          const char *cert_file,
+			          const char *key_file)
+{
+
+    /*
+     * When the certfile and keyfile are one and the same, load both in a
+     * single pass, avoiding potential race conditions during key rollover.
+     */
+    if (strcmp(cert_file, key_file) == 0)
+	return (load_mixed_file(ctx, cert_file) == 0);
+
+    /*
+     * We need both the private key (in key_file) and the public key
+     * certificate (in cert_file).
+     * 
+     * Code adapted from OpenSSL apps/s_cb.c.
+     */
+    ERR_clear_error();
+    if (SSL_CTX_use_certificate_chain_file(ctx, cert_file) <= 0) {
+	msg_warn("cannot get %s certificate from file \"%s\": "
+		 "disabling TLS support", cert_type, cert_file);
+	tls_print_errors();
+	return (0);
+    }
+    if (SSL_CTX_use_PrivateKey_file(ctx, key_file, SSL_FILETYPE_PEM) <= 0) {
+	msg_warn("cannot get %s private key from file \"%s\": "
+		 "disabling TLS support", cert_type, key_file);
+	tls_print_errors();
+	return (0);
+    }
+
+    /*
+     * Sanity check.
+     */
+    if (!SSL_CTX_check_private_key(ctx)) {
+	msg_warn("%s private key in %s does not match public key in %s: "
+		 "disabling TLS support", cert_type, key_file, cert_file);
+	return (0);
+    }
+    return (1);
+}
+
+/* tls_set_my_certificate_key_info - load client or server certificates/keys */
+
+int     tls_set_my_certificate_key_info(SSL_CTX *ctx, const char *chain_files,
+					        const char *cert_file,
+					        const char *key_file,
+					        const char *dcert_file,
+					        const char *dkey_file,
+					        const char *eccert_file,
+					        const char *eckey_file)
+{
+
+    /* The "chain_files" parameter overrides all the legacy parameters */
+    if (chain_files && *chain_files)
+	return load_chain_files(ctx, chain_files);
+
+    /*
+     * Lack of certificates is fine so long as we are prepared to use
+     * anonymous ciphers.
+     */
+    if (*cert_file && !set_cert_stuff(ctx, "RSA", cert_file, key_file))
+	return (-1);				/* logged */
+    if (*dcert_file && !set_cert_stuff(ctx, "DSA", dcert_file, dkey_file))
+	return (-1);				/* logged */
+#ifndef OPENSSL_NO_ECDH
+    if (*eccert_file && !set_cert_stuff(ctx, "ECDSA", eccert_file, eckey_file))
+	return (-1);				/* logged */
+#else
+    if (*eccert_file)
+	msg_warn("ECDSA not supported. Ignoring ECDSA certificate file \"%s\"",
+		 eccert_file);
+#endif
+    return (0);
+}
+
+/* tls_load_pem_chain - load in-memory PEM client or server chain */
+
+int     tls_load_pem_chain(SSL *ssl, const char *pem, const char *origin)
+{
+    static VSTRING *obuf;
+    pem_load_state_t st;
+
+    if (!obuf)
+	obuf = vstring_alloc(100);
+    vstring_sprintf(obuf, "SNI data for %s", origin);
+    init_pem_load_state(&st, 0, ssl, vstring_str(obuf));
+
+    if ((st.pembio = BIO_new_mem_buf(pem, -1)) == NULL) {
+	msg_warn("error opening memory BIO for %s", st.origin);
+	tls_print_errors();
+	return (-1);
+    }
+    /* load_pem_bio() frees the BIO */
+    return (load_pem_bio(&st, PEM_LOAD_READ_LAST));
+}
+
+#ifdef TEST
+
+static NORETURN usage(void)
+{
+    fprintf(stderr, "usage: tls_certkey [-m] <chainfiles>\n");
+    exit(1);
+}
+
+int     main(int argc, char *argv[])
+{
+    int     ch;
+    int     mixed = 0;
+    int     ret;
+    char   *key_file = 0;
+    SSL_CTX *ctx;
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+
+    /*
+     * Initialize the OpenSSL library by the book! To start with, we must
+     * initialize the algorithms. We want cleartext error messages instead of
+     * just error codes, so we load the error_strings.
+     */
+    SSL_load_error_strings();
+    OpenSSL_add_ssl_algorithms();
+#endif
+
+    if (!(ctx = SSL_CTX_new(TLS_client_method()))) {
+	tls_print_errors();
+	exit(1);
+    }
+    while ((ch = GETOPT(argc, argv, "mk:")) > 0) {
+	switch (ch) {
+	case 'k':
+	    key_file = optarg;
+	    break;
+	case 'm':
+	    mixed = 1;
+	    break;
+	default:
+	    usage();
+	}
+    }
+    argc -= optind;
+    argv += optind;
+
+    if (argc < 1)
+	usage();
+
+    if (key_file)
+	ret = set_cert_stuff(ctx, "any", argv[0], key_file) == 0;
+    else if (mixed)
+	ret = load_mixed_file(ctx, argv[0]);
+    else
+	ret = load_chain_files(ctx, argv[0]);
+
+    if (ret != 0)
+	exit(1);
+
+    if (SSL_CTX_set_current_cert(ctx, SSL_CERT_SET_FIRST) != 1) {
+	fprintf(stderr, "error selecting first certificate\n");
+	tls_print_errors();
+	exit(1);
+    }
+    do {
+	STACK_OF(X509) *chain;
+	int     i;
+
+	if (SSL_CTX_get0_chain_certs(ctx, &chain) != 1) {
+	    fprintf(stderr, "error locating certificate chain\n");
+	    tls_print_errors();
+	    exit(1);
+	}
+	for (i = 0; i <= sk_X509_num(chain); ++i) {
+	    char    buf[CCERT_BUFSIZ];
+	    X509   *cert;
+
+	    if (i > 0)
+		cert = sk_X509_value(chain, i - 1);
+	    else
+		cert = SSL_CTX_get0_certificate(ctx);
+
+	    printf("depth = %d\n", i);
+
+	    X509_NAME_oneline(X509_get_issuer_name(cert), buf, sizeof(buf));
+	    printf("issuer = %s\n", buf);
+
+	    X509_NAME_oneline(X509_get_subject_name(cert), buf, sizeof(buf));
+	    printf("subject = %s\n\n", buf);
+	}
+    } while (SSL_CTX_set_current_cert(ctx, SSL_CERT_SET_NEXT) != 0);
+
+    exit(0);
+}
+
+#endif
+
+#endif