Crypto: Align PSA headers entirely to Mbed TLS 3.6.0
This also simplifies the client attributes translation between
client view and service view and reorganized how the Mbed TLS
config files are handled between NS/S (client/service) sides.
At the same time, perform a CMake targets refactoring to allow
exporting a client side view of the config files.
Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>
Change-Id: I9a715f9ef40fc223992575ecbac5cf23d162a326
diff --git a/interface/include/mbedtls/x509_crt.h b/interface/include/mbedtls/x509_crt.h
new file mode 100644
index 0000000..1ce0d23
--- /dev/null
+++ b/interface/include/mbedtls/x509_crt.h
@@ -0,0 +1,1208 @@
+/**
+ * \file x509_crt.h
+ *
+ * \brief X.509 certificate parsing and writing
+ */
+/*
+ * Copyright The Mbed TLS Contributors
+ * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+#ifndef MBEDTLS_X509_CRT_H
+#define MBEDTLS_X509_CRT_H
+#include "mbedtls/private_access.h"
+
+#include "mbedtls/build_info.h"
+
+#include "mbedtls/x509.h"
+#include "mbedtls/x509_crl.h"
+#include "mbedtls/bignum.h"
+
+/**
+ * \addtogroup x509_module
+ * \{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \name Structures and functions for parsing and writing X.509 certificates
+ * \{
+ */
+
+/**
+ * Container for an X.509 certificate. The certificate may be chained.
+ *
+ * Some fields of this structure are publicly readable. Do not modify
+ * them except via Mbed TLS library functions: the effect of modifying
+ * those fields or the data that those fields points to is unspecified.
+ */
+typedef struct mbedtls_x509_crt {
+ int MBEDTLS_PRIVATE(own_buffer); /**< Indicates if \c raw is owned
+ * by the structure or not. */
+ mbedtls_x509_buf raw; /**< The raw certificate data (DER). */
+ mbedtls_x509_buf tbs; /**< The raw certificate body (DER). The part that is To Be Signed. */
+
+ int version; /**< The X.509 version. (1=v1, 2=v2, 3=v3) */
+ mbedtls_x509_buf serial; /**< Unique id for certificate issued by a specific CA. */
+ mbedtls_x509_buf sig_oid; /**< Signature algorithm, e.g. sha1RSA */
+
+ mbedtls_x509_buf issuer_raw; /**< The raw issuer data (DER). Used for quick comparison. */
+ mbedtls_x509_buf subject_raw; /**< The raw subject data (DER). Used for quick comparison. */
+
+ mbedtls_x509_name issuer; /**< The parsed issuer data (named information object). */
+ mbedtls_x509_name subject; /**< The parsed subject data (named information object). */
+
+ mbedtls_x509_time valid_from; /**< Start time of certificate validity. */
+ mbedtls_x509_time valid_to; /**< End time of certificate validity. */
+
+ mbedtls_x509_buf pk_raw;
+ mbedtls_pk_context pk; /**< Container for the public key context. */
+
+ mbedtls_x509_buf issuer_id; /**< Optional X.509 v2/v3 issuer unique identifier. */
+ mbedtls_x509_buf subject_id; /**< Optional X.509 v2/v3 subject unique identifier. */
+ mbedtls_x509_buf v3_ext; /**< Optional X.509 v3 extensions. */
+ mbedtls_x509_sequence subject_alt_names; /**< Optional list of raw entries of Subject Alternative Names extension. These can be later parsed by mbedtls_x509_parse_subject_alt_name. */
+ mbedtls_x509_buf subject_key_id; /**< Optional X.509 v3 extension subject key identifier. */
+ mbedtls_x509_authority authority_key_id; /**< Optional X.509 v3 extension authority key identifier. */
+
+ mbedtls_x509_sequence certificate_policies; /**< Optional list of certificate policies (Only anyPolicy is printed and enforced, however the rest of the policies are still listed). */
+
+ int MBEDTLS_PRIVATE(ext_types); /**< Bit string containing detected and parsed extensions */
+ int MBEDTLS_PRIVATE(ca_istrue); /**< Optional Basic Constraint extension value: 1 if this certificate belongs to a CA, 0 otherwise. */
+ int MBEDTLS_PRIVATE(max_pathlen); /**< Optional Basic Constraint extension value: The maximum path length to the root certificate. Path length is 1 higher than RFC 5280 'meaning', so 1+ */
+
+ unsigned int MBEDTLS_PRIVATE(key_usage); /**< Optional key usage extension value: See the values in x509.h */
+
+ mbedtls_x509_sequence ext_key_usage; /**< Optional list of extended key usage OIDs. */
+
+ unsigned char MBEDTLS_PRIVATE(ns_cert_type); /**< Optional Netscape certificate type extension value: See the values in x509.h */
+
+ mbedtls_x509_buf MBEDTLS_PRIVATE(sig); /**< Signature: hash of the tbs part signed with the private key. */
+ mbedtls_md_type_t MBEDTLS_PRIVATE(sig_md); /**< Internal representation of the MD algorithm of the signature algorithm, e.g. MBEDTLS_MD_SHA256 */
+ mbedtls_pk_type_t MBEDTLS_PRIVATE(sig_pk); /**< Internal representation of the Public Key algorithm of the signature algorithm, e.g. MBEDTLS_PK_RSA */
+ void *MBEDTLS_PRIVATE(sig_opts); /**< Signature options to be passed to mbedtls_pk_verify_ext(), e.g. for RSASSA-PSS */
+
+ /** Next certificate in the linked list that constitutes the CA chain.
+ * \p NULL indicates the end of the list.
+ * Do not modify this field directly. */
+ struct mbedtls_x509_crt *next;
+}
+mbedtls_x509_crt;
+
+/**
+ * Build flag from an algorithm/curve identifier (pk, md, ecp)
+ * Since 0 is always XXX_NONE, ignore it.
+ */
+#define MBEDTLS_X509_ID_FLAG(id) (1 << ((id) - 1))
+
+/**
+ * Security profile for certificate verification.
+ *
+ * All lists are bitfields, built by ORing flags from MBEDTLS_X509_ID_FLAG().
+ *
+ * The fields of this structure are part of the public API and can be
+ * manipulated directly by applications. Future versions of the library may
+ * add extra fields or reorder existing fields.
+ *
+ * You can create custom profiles by starting from a copy of
+ * an existing profile, such as mbedtls_x509_crt_profile_default or
+ * mbedtls_x509_ctr_profile_none and then tune it to your needs.
+ *
+ * For example to allow SHA-224 in addition to the default:
+ *
+ * mbedtls_x509_crt_profile my_profile = mbedtls_x509_crt_profile_default;
+ * my_profile.allowed_mds |= MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 );
+ *
+ * Or to allow only RSA-3072+ with SHA-256:
+ *
+ * mbedtls_x509_crt_profile my_profile = mbedtls_x509_crt_profile_none;
+ * my_profile.allowed_mds = MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 );
+ * my_profile.allowed_pks = MBEDTLS_X509_ID_FLAG( MBEDTLS_PK_RSA );
+ * my_profile.rsa_min_bitlen = 3072;
+ */
+typedef struct mbedtls_x509_crt_profile {
+ uint32_t allowed_mds; /**< MDs for signatures */
+ uint32_t allowed_pks; /**< PK algs for public keys;
+ * this applies to all certificates
+ * in the provided chain. */
+ uint32_t allowed_curves; /**< Elliptic curves for ECDSA */
+ uint32_t rsa_min_bitlen; /**< Minimum size for RSA keys */
+}
+mbedtls_x509_crt_profile;
+
+#define MBEDTLS_X509_CRT_VERSION_1 0
+#define MBEDTLS_X509_CRT_VERSION_2 1
+#define MBEDTLS_X509_CRT_VERSION_3 2
+
+#define MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN 20
+#define MBEDTLS_X509_RFC5280_UTC_TIME_LEN 15
+
+#if !defined(MBEDTLS_X509_MAX_FILE_PATH_LEN)
+#define MBEDTLS_X509_MAX_FILE_PATH_LEN 512
+#endif
+
+/* This macro unfolds to the concatenation of macro invocations
+ * X509_CRT_ERROR_INFO( error code,
+ * error code as string,
+ * human readable description )
+ * where X509_CRT_ERROR_INFO is defined by the user.
+ * See x509_crt.c for an example of how to use this. */
+#define MBEDTLS_X509_CRT_ERROR_INFO_LIST \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_EXPIRED, \
+ "MBEDTLS_X509_BADCERT_EXPIRED", \
+ "The certificate validity has expired") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_REVOKED, \
+ "MBEDTLS_X509_BADCERT_REVOKED", \
+ "The certificate has been revoked (is on a CRL)") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_CN_MISMATCH, \
+ "MBEDTLS_X509_BADCERT_CN_MISMATCH", \
+ "The certificate Common Name (CN) does not match with the expected CN") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_NOT_TRUSTED, \
+ "MBEDTLS_X509_BADCERT_NOT_TRUSTED", \
+ "The certificate is not correctly signed by the trusted CA") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_NOT_TRUSTED, \
+ "MBEDTLS_X509_BADCRL_NOT_TRUSTED", \
+ "The CRL is not correctly signed by the trusted CA") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_EXPIRED, \
+ "MBEDTLS_X509_BADCRL_EXPIRED", \
+ "The CRL is expired") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_MISSING, \
+ "MBEDTLS_X509_BADCERT_MISSING", \
+ "Certificate was missing") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_SKIP_VERIFY, \
+ "MBEDTLS_X509_BADCERT_SKIP_VERIFY", \
+ "Certificate verification was skipped") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_OTHER, \
+ "MBEDTLS_X509_BADCERT_OTHER", \
+ "Other reason (can be used by verify callback)") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_FUTURE, \
+ "MBEDTLS_X509_BADCERT_FUTURE", \
+ "The certificate validity starts in the future") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_FUTURE, \
+ "MBEDTLS_X509_BADCRL_FUTURE", \
+ "The CRL is from the future") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_KEY_USAGE, \
+ "MBEDTLS_X509_BADCERT_KEY_USAGE", \
+ "Usage does not match the keyUsage extension") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_EXT_KEY_USAGE, \
+ "MBEDTLS_X509_BADCERT_EXT_KEY_USAGE", \
+ "Usage does not match the extendedKeyUsage extension") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_NS_CERT_TYPE, \
+ "MBEDTLS_X509_BADCERT_NS_CERT_TYPE", \
+ "Usage does not match the nsCertType extension") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_BAD_MD, \
+ "MBEDTLS_X509_BADCERT_BAD_MD", \
+ "The certificate is signed with an unacceptable hash.") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_BAD_PK, \
+ "MBEDTLS_X509_BADCERT_BAD_PK", \
+ "The certificate is signed with an unacceptable PK alg (eg RSA vs ECDSA).") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCERT_BAD_KEY, \
+ "MBEDTLS_X509_BADCERT_BAD_KEY", \
+ "The certificate is signed with an unacceptable key (eg bad curve, RSA too short).") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_BAD_MD, \
+ "MBEDTLS_X509_BADCRL_BAD_MD", \
+ "The CRL is signed with an unacceptable hash.") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_BAD_PK, \
+ "MBEDTLS_X509_BADCRL_BAD_PK", \
+ "The CRL is signed with an unacceptable PK alg (eg RSA vs ECDSA).") \
+ X509_CRT_ERROR_INFO(MBEDTLS_X509_BADCRL_BAD_KEY, \
+ "MBEDTLS_X509_BADCRL_BAD_KEY", \
+ "The CRL is signed with an unacceptable key (eg bad curve, RSA too short).")
+
+/**
+ * Container for writing a certificate (CRT)
+ */
+typedef struct mbedtls_x509write_cert {
+ int MBEDTLS_PRIVATE(version);
+ unsigned char MBEDTLS_PRIVATE(serial)[MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN];
+ size_t MBEDTLS_PRIVATE(serial_len);
+ mbedtls_pk_context *MBEDTLS_PRIVATE(subject_key);
+ mbedtls_pk_context *MBEDTLS_PRIVATE(issuer_key);
+ mbedtls_asn1_named_data *MBEDTLS_PRIVATE(subject);
+ mbedtls_asn1_named_data *MBEDTLS_PRIVATE(issuer);
+ mbedtls_md_type_t MBEDTLS_PRIVATE(md_alg);
+ char MBEDTLS_PRIVATE(not_before)[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
+ char MBEDTLS_PRIVATE(not_after)[MBEDTLS_X509_RFC5280_UTC_TIME_LEN + 1];
+ mbedtls_asn1_named_data *MBEDTLS_PRIVATE(extensions);
+}
+mbedtls_x509write_cert;
+
+/**
+ * \brief Set Subject Alternative Name
+ *
+ * \param ctx Certificate context to use
+ * \param san_list List of SAN values
+ *
+ * \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
+ *
+ * \note "dnsName", "uniformResourceIdentifier", "IP address",
+ * "otherName", and "DirectoryName", as defined in RFC 5280,
+ * are supported.
+ */
+int mbedtls_x509write_crt_set_subject_alternative_name(mbedtls_x509write_cert *ctx,
+ const mbedtls_x509_san_list *san_list);
+
+/**
+ * Item in a verification chain: cert and flags for it
+ */
+typedef struct {
+ mbedtls_x509_crt *MBEDTLS_PRIVATE(crt);
+ uint32_t MBEDTLS_PRIVATE(flags);
+} mbedtls_x509_crt_verify_chain_item;
+
+/**
+ * Max size of verification chain: end-entity + intermediates + trusted root
+ */
+#define MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE (MBEDTLS_X509_MAX_INTERMEDIATE_CA + 2)
+
+/**
+ * Verification chain as built by \c mbedtls_crt_verify_chain()
+ */
+typedef struct {
+ mbedtls_x509_crt_verify_chain_item MBEDTLS_PRIVATE(items)[MBEDTLS_X509_MAX_VERIFY_CHAIN_SIZE];
+ unsigned MBEDTLS_PRIVATE(len);
+
+#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
+ /* This stores the list of potential trusted signers obtained from
+ * the CA callback used for the CRT verification, if configured.
+ * We must track it somewhere because the callback passes its
+ * ownership to the caller. */
+ mbedtls_x509_crt *MBEDTLS_PRIVATE(trust_ca_cb_result);
+#endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
+} mbedtls_x509_crt_verify_chain;
+
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+
+/**
+ * \brief Context for resuming X.509 verify operations
+ */
+typedef struct {
+ /* for check_signature() */
+ mbedtls_pk_restart_ctx MBEDTLS_PRIVATE(pk);
+
+ /* for find_parent_in() */
+ mbedtls_x509_crt *MBEDTLS_PRIVATE(parent); /* non-null iff parent_in in progress */
+ mbedtls_x509_crt *MBEDTLS_PRIVATE(fallback_parent);
+ int MBEDTLS_PRIVATE(fallback_signature_is_good);
+
+ /* for find_parent() */
+ int MBEDTLS_PRIVATE(parent_is_trusted); /* -1 if find_parent is not in progress */
+
+ /* for verify_chain() */
+ enum {
+ x509_crt_rs_none,
+ x509_crt_rs_find_parent,
+ } MBEDTLS_PRIVATE(in_progress); /* none if no operation is in progress */
+ int MBEDTLS_PRIVATE(self_cnt);
+ mbedtls_x509_crt_verify_chain MBEDTLS_PRIVATE(ver_chain);
+
+} mbedtls_x509_crt_restart_ctx;
+
+#else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
+
+/* Now we can declare functions that take a pointer to that */
+typedef void mbedtls_x509_crt_restart_ctx;
+
+#endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
+
+#if defined(MBEDTLS_X509_CRT_PARSE_C)
+/**
+ * Default security profile. Should provide a good balance between security
+ * and compatibility with current deployments.
+ *
+ * This profile permits:
+ * - SHA2 hashes with at least 256 bits: SHA-256, SHA-384, SHA-512.
+ * - Elliptic curves with 255 bits and above except secp256k1.
+ * - RSA with 2048 bits and above.
+ *
+ * New minor versions of Mbed TLS may extend this profile, for example if
+ * new algorithms are added to the library. New minor versions of Mbed TLS will
+ * not reduce this profile unless serious security concerns require it.
+ */
+extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default;
+
+/**
+ * Expected next default profile. Recommended for new deployments.
+ * Currently targets a 128-bit security level, except for allowing RSA-2048.
+ * This profile may change at any time.
+ */
+extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_next;
+
+/**
+ * NSA Suite B profile.
+ */
+extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_suiteb;
+
+/**
+ * Empty profile that allows nothing. Useful as a basis for constructing
+ * custom profiles.
+ */
+extern const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_none;
+
+/**
+ * \brief Parse a single DER formatted certificate and add it
+ * to the end of the provided chained list.
+ *
+ * \note If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ * subsystem must have been initialized by calling
+ * psa_crypto_init() before calling this function.
+ *
+ * \param chain The pointer to the start of the CRT chain to attach to.
+ * When parsing the first CRT in a chain, this should point
+ * to an instance of ::mbedtls_x509_crt initialized through
+ * mbedtls_x509_crt_init().
+ * \param buf The buffer holding the DER encoded certificate.
+ * \param buflen The size in Bytes of \p buf.
+ *
+ * \note This function makes an internal copy of the CRT buffer
+ * \p buf. In particular, \p buf may be destroyed or reused
+ * after this call returns. To avoid duplicating the CRT
+ * buffer (at the cost of stricter lifetime constraints),
+ * use mbedtls_x509_crt_parse_der_nocopy() instead.
+ *
+ * \return \c 0 if successful.
+ * \return A negative error code on failure.
+ */
+int mbedtls_x509_crt_parse_der(mbedtls_x509_crt *chain,
+ const unsigned char *buf,
+ size_t buflen);
+
+/**
+ * \brief The type of certificate extension callbacks.
+ *
+ * Callbacks of this type are passed to and used by the
+ * mbedtls_x509_crt_parse_der_with_ext_cb() routine when
+ * it encounters either an unsupported extension or a
+ * "certificate policies" extension containing any
+ * unsupported certificate policies.
+ * Future versions of the library may invoke the callback
+ * in other cases, if and when the need arises.
+ *
+ * \param p_ctx An opaque context passed to the callback.
+ * \param crt The certificate being parsed.
+ * \param oid The OID of the extension.
+ * \param critical Whether the extension is critical.
+ * \param p Pointer to the start of the extension value
+ * (the content of the OCTET STRING).
+ * \param end End of extension value.
+ *
+ * \note The callback must fail and return a negative error code
+ * if it can not parse or does not support the extension.
+ * When the callback fails to parse a critical extension
+ * mbedtls_x509_crt_parse_der_with_ext_cb() also fails.
+ * When the callback fails to parse a non critical extension
+ * mbedtls_x509_crt_parse_der_with_ext_cb() simply skips
+ * the extension and continues parsing.
+ *
+ * \return \c 0 on success.
+ * \return A negative error code on failure.
+ */
+typedef int (*mbedtls_x509_crt_ext_cb_t)(void *p_ctx,
+ mbedtls_x509_crt const *crt,
+ mbedtls_x509_buf const *oid,
+ int critical,
+ const unsigned char *p,
+ const unsigned char *end);
+
+/**
+ * \brief Parse a single DER formatted certificate and add it
+ * to the end of the provided chained list.
+ *
+ * \note If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ * subsystem must have been initialized by calling
+ * psa_crypto_init() before calling this function.
+ *
+ * \param chain The pointer to the start of the CRT chain to attach to.
+ * When parsing the first CRT in a chain, this should point
+ * to an instance of ::mbedtls_x509_crt initialized through
+ * mbedtls_x509_crt_init().
+ * \param buf The buffer holding the DER encoded certificate.
+ * \param buflen The size in Bytes of \p buf.
+ * \param make_copy When not zero this function makes an internal copy of the
+ * CRT buffer \p buf. In particular, \p buf may be destroyed
+ * or reused after this call returns.
+ * When zero this function avoids duplicating the CRT buffer
+ * by taking temporary ownership thereof until the CRT
+ * is destroyed (like mbedtls_x509_crt_parse_der_nocopy())
+ * \param cb A callback invoked for every unsupported certificate
+ * extension.
+ * \param p_ctx An opaque context passed to the callback.
+ *
+ * \note This call is functionally equivalent to
+ * mbedtls_x509_crt_parse_der(), and/or
+ * mbedtls_x509_crt_parse_der_nocopy()
+ * but it calls the callback with every unsupported
+ * certificate extension and additionally the
+ * "certificate policies" extension if it contains any
+ * unsupported certificate policies.
+ * The callback must return a negative error code if it
+ * does not know how to handle such an extension.
+ * When the callback fails to parse a critical extension
+ * mbedtls_x509_crt_parse_der_with_ext_cb() also fails.
+ * When the callback fails to parse a non critical extension
+ * mbedtls_x509_crt_parse_der_with_ext_cb() simply skips
+ * the extension and continues parsing.
+ * Future versions of the library may invoke the callback
+ * in other cases, if and when the need arises.
+ *
+ * \return \c 0 if successful.
+ * \return A negative error code on failure.
+ */
+int mbedtls_x509_crt_parse_der_with_ext_cb(mbedtls_x509_crt *chain,
+ const unsigned char *buf,
+ size_t buflen,
+ int make_copy,
+ mbedtls_x509_crt_ext_cb_t cb,
+ void *p_ctx);
+
+/**
+ * \brief Parse a single DER formatted certificate and add it
+ * to the end of the provided chained list. This is a
+ * variant of mbedtls_x509_crt_parse_der() which takes
+ * temporary ownership of the CRT buffer until the CRT
+ * is destroyed.
+ *
+ * \note If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ * subsystem must have been initialized by calling
+ * psa_crypto_init() before calling this function.
+ *
+ * \param chain The pointer to the start of the CRT chain to attach to.
+ * When parsing the first CRT in a chain, this should point
+ * to an instance of ::mbedtls_x509_crt initialized through
+ * mbedtls_x509_crt_init().
+ * \param buf The address of the readable buffer holding the DER encoded
+ * certificate to use. On success, this buffer must be
+ * retained and not be changed for the lifetime of the
+ * CRT chain \p chain, that is, until \p chain is destroyed
+ * through a call to mbedtls_x509_crt_free().
+ * \param buflen The size in Bytes of \p buf.
+ *
+ * \note This call is functionally equivalent to
+ * mbedtls_x509_crt_parse_der(), but it avoids creating a
+ * copy of the input buffer at the cost of stronger lifetime
+ * constraints. This is useful in constrained environments
+ * where duplication of the CRT cannot be tolerated.
+ *
+ * \return \c 0 if successful.
+ * \return A negative error code on failure.
+ */
+int mbedtls_x509_crt_parse_der_nocopy(mbedtls_x509_crt *chain,
+ const unsigned char *buf,
+ size_t buflen);
+
+/**
+ * \brief Parse one DER-encoded or one or more concatenated PEM-encoded
+ * certificates and add them to the chained list.
+ *
+ * For CRTs in PEM encoding, the function parses permissively:
+ * if at least one certificate can be parsed, the function
+ * returns the number of certificates for which parsing failed
+ * (hence \c 0 if all certificates were parsed successfully).
+ * If no certificate could be parsed, the function returns
+ * the first (negative) error encountered during parsing.
+ *
+ * PEM encoded certificates may be interleaved by other data
+ * such as human readable descriptions of their content, as
+ * long as the certificates are enclosed in the PEM specific
+ * '-----{BEGIN/END} CERTIFICATE-----' delimiters.
+ *
+ * \note If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ * subsystem must have been initialized by calling
+ * psa_crypto_init() before calling this function.
+ *
+ * \param chain The chain to which to add the parsed certificates.
+ * \param buf The buffer holding the certificate data in PEM or DER format.
+ * For certificates in PEM encoding, this may be a concatenation
+ * of multiple certificates; for DER encoding, the buffer must
+ * comprise exactly one certificate.
+ * \param buflen The size of \p buf, including the terminating \c NULL byte
+ * in case of PEM encoded data.
+ *
+ * \return \c 0 if all certificates were parsed successfully.
+ * \return The (positive) number of certificates that couldn't
+ * be parsed if parsing was partly successful (see above).
+ * \return A negative X509 or PEM error code otherwise.
+ *
+ */
+int mbedtls_x509_crt_parse(mbedtls_x509_crt *chain, const unsigned char *buf, size_t buflen);
+
+#if defined(MBEDTLS_FS_IO)
+/**
+ * \brief Load one or more certificates and add them
+ * to the chained list. Parses permissively. If some
+ * certificates can be parsed, the result is the number
+ * of failed certificates it encountered. If none complete
+ * correctly, the first error is returned.
+ *
+ * \note If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
+ * subsystem must have been initialized by calling
+ * psa_crypto_init() before calling this function.
+ *
+ * \param chain points to the start of the chain
+ * \param path filename to read the certificates from
+ *
+ * \return 0 if all certificates parsed successfully, a positive number
+ * if partly successful or a specific X509 or PEM error code
+ */
+int mbedtls_x509_crt_parse_file(mbedtls_x509_crt *chain, const char *path);
+
+/**
+ * \brief Load one or more certificate files from a path and add them
+ * to the chained list. Parses permissively. If some
+ * certificates can be parsed, the result is the number
+ * of failed certificates it encountered. If none complete
+ * correctly, the first error is returned.
+ *
+ * \param chain points to the start of the chain
+ * \param path directory / folder to read the certificate files from
+ *
+ * \return 0 if all certificates parsed successfully, a positive number
+ * if partly successful or a specific X509 or PEM error code
+ */
+int mbedtls_x509_crt_parse_path(mbedtls_x509_crt *chain, const char *path);
+
+#endif /* MBEDTLS_FS_IO */
+
+#if !defined(MBEDTLS_X509_REMOVE_INFO)
+/**
+ * \brief Returns an informational string about the
+ * certificate.
+ *
+ * \param buf Buffer to write to
+ * \param size Maximum size of buffer
+ * \param prefix A line prefix
+ * \param crt The X509 certificate to represent
+ *
+ * \return The length of the string written (not including the
+ * terminated nul byte), or a negative error code.
+ */
+int mbedtls_x509_crt_info(char *buf, size_t size, const char *prefix,
+ const mbedtls_x509_crt *crt);
+
+/**
+ * \brief Returns an informational string about the
+ * verification status of a certificate.
+ *
+ * \param buf Buffer to write to
+ * \param size Maximum size of buffer
+ * \param prefix A line prefix
+ * \param flags Verification flags created by mbedtls_x509_crt_verify()
+ *
+ * \return The length of the string written (not including the
+ * terminated nul byte), or a negative error code.
+ */
+int mbedtls_x509_crt_verify_info(char *buf, size_t size, const char *prefix,
+ uint32_t flags);
+#endif /* !MBEDTLS_X509_REMOVE_INFO */
+
+/**
+ * \brief Verify a chain of certificates.
+ *
+ * The verify callback is a user-supplied callback that
+ * can clear / modify / add flags for a certificate. If set,
+ * the verification callback is called for each
+ * certificate in the chain (from the trust-ca down to the
+ * presented crt). The parameters for the callback are:
+ * (void *parameter, mbedtls_x509_crt *crt, int certificate_depth,
+ * int *flags). With the flags representing current flags for
+ * that specific certificate and the certificate depth from
+ * the bottom (Peer cert depth = 0).
+ *
+ * All flags left after returning from the callback
+ * are also returned to the application. The function should
+ * return 0 for anything (including invalid certificates)
+ * other than fatal error, as a non-zero return code
+ * immediately aborts the verification process. For fatal
+ * errors, a specific error code should be used (different
+ * from MBEDTLS_ERR_X509_CERT_VERIFY_FAILED which should not
+ * be returned at this point), or MBEDTLS_ERR_X509_FATAL_ERROR
+ * can be used if no better code is available.
+ *
+ * \note In case verification failed, the results can be displayed
+ * using \c mbedtls_x509_crt_verify_info()
+ *
+ * \note Same as \c mbedtls_x509_crt_verify_with_profile() with the
+ * default security profile.
+ *
+ * \note It is your responsibility to provide up-to-date CRLs for
+ * all trusted CAs. If no CRL is provided for the CA that was
+ * used to sign the certificate, CRL verification is skipped
+ * silently, that is *without* setting any flag.
+ *
+ * \note The \c trust_ca list can contain two types of certificates:
+ * (1) those of trusted root CAs, so that certificates
+ * chaining up to those CAs will be trusted, and (2)
+ * self-signed end-entity certificates to be trusted (for
+ * specific peers you know) - in that case, the self-signed
+ * certificate doesn't need to have the CA bit set.
+ *
+ * \param crt The certificate chain to be verified.
+ * \param trust_ca The list of trusted CAs.
+ * \param ca_crl The list of CRLs for trusted CAs.
+ * \param cn The expected Common Name. This will be checked to be
+ * present in the certificate's subjectAltNames extension or,
+ * if this extension is absent, as a CN component in its
+ * Subject name. DNS names and IP addresses are fully
+ * supported, while the URI subtype is partially supported:
+ * only exact matching, without any normalization procedures
+ * described in 7.4 of RFC5280, will result in a positive
+ * URI verification.
+ * This may be \c NULL if the CN need not be verified.
+ * \param flags The address at which to store the result of the verification.
+ * If the verification couldn't be completed, the flag value is
+ * set to (uint32_t) -1.
+ * \param f_vrfy The verification callback to use. See the documentation
+ * of mbedtls_x509_crt_verify() for more information.
+ * \param p_vrfy The context to be passed to \p f_vrfy.
+ *
+ * \return \c 0 if the chain is valid with respect to the
+ * passed CN, CAs, CRLs and security profile.
+ * \return #MBEDTLS_ERR_X509_CERT_VERIFY_FAILED in case the
+ * certificate chain verification failed. In this case,
+ * \c *flags will have one or more
+ * \c MBEDTLS_X509_BADCERT_XXX or \c MBEDTLS_X509_BADCRL_XXX
+ * flags set.
+ * \return Another negative error code in case of a fatal error
+ * encountered during the verification process.
+ */
+int mbedtls_x509_crt_verify(mbedtls_x509_crt *crt,
+ mbedtls_x509_crt *trust_ca,
+ mbedtls_x509_crl *ca_crl,
+ const char *cn, uint32_t *flags,
+ int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
+ void *p_vrfy);
+
+/**
+ * \brief Verify a chain of certificates with respect to
+ * a configurable security profile.
+ *
+ * \note Same as \c mbedtls_x509_crt_verify(), but with explicit
+ * security profile.
+ *
+ * \note The restrictions on keys (RSA minimum size, allowed curves
+ * for ECDSA) apply to all certificates: trusted root,
+ * intermediate CAs if any, and end entity certificate.
+ *
+ * \param crt The certificate chain to be verified.
+ * \param trust_ca The list of trusted CAs.
+ * \param ca_crl The list of CRLs for trusted CAs.
+ * \param profile The security profile to use for the verification.
+ * \param cn The expected Common Name. This may be \c NULL if the
+ * CN need not be verified.
+ * \param flags The address at which to store the result of the verification.
+ * If the verification couldn't be completed, the flag value is
+ * set to (uint32_t) -1.
+ * \param f_vrfy The verification callback to use. See the documentation
+ * of mbedtls_x509_crt_verify() for more information.
+ * \param p_vrfy The context to be passed to \p f_vrfy.
+ *
+ * \return \c 0 if the chain is valid with respect to the
+ * passed CN, CAs, CRLs and security profile.
+ * \return #MBEDTLS_ERR_X509_CERT_VERIFY_FAILED in case the
+ * certificate chain verification failed. In this case,
+ * \c *flags will have one or more
+ * \c MBEDTLS_X509_BADCERT_XXX or \c MBEDTLS_X509_BADCRL_XXX
+ * flags set.
+ * \return Another negative error code in case of a fatal error
+ * encountered during the verification process.
+ */
+int mbedtls_x509_crt_verify_with_profile(mbedtls_x509_crt *crt,
+ mbedtls_x509_crt *trust_ca,
+ mbedtls_x509_crl *ca_crl,
+ const mbedtls_x509_crt_profile *profile,
+ const char *cn, uint32_t *flags,
+ int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
+ void *p_vrfy);
+
+/**
+ * \brief Restartable version of \c mbedtls_crt_verify_with_profile()
+ *
+ * \note Performs the same job as \c mbedtls_crt_verify_with_profile()
+ * but can return early and restart according to the limit
+ * set with \c mbedtls_ecp_set_max_ops() to reduce blocking.
+ *
+ * \param crt The certificate chain to be verified.
+ * \param trust_ca The list of trusted CAs.
+ * \param ca_crl The list of CRLs for trusted CAs.
+ * \param profile The security profile to use for the verification.
+ * \param cn The expected Common Name. This may be \c NULL if the
+ * CN need not be verified.
+ * \param flags The address at which to store the result of the verification.
+ * If the verification couldn't be completed, the flag value is
+ * set to (uint32_t) -1.
+ * \param f_vrfy The verification callback to use. See the documentation
+ * of mbedtls_x509_crt_verify() for more information.
+ * \param p_vrfy The context to be passed to \p f_vrfy.
+ * \param rs_ctx The restart context to use. This may be set to \c NULL
+ * to disable restartable ECC.
+ *
+ * \return See \c mbedtls_crt_verify_with_profile(), or
+ * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
+ * operations was reached: see \c mbedtls_ecp_set_max_ops().
+ */
+int mbedtls_x509_crt_verify_restartable(mbedtls_x509_crt *crt,
+ mbedtls_x509_crt *trust_ca,
+ mbedtls_x509_crl *ca_crl,
+ const mbedtls_x509_crt_profile *profile,
+ const char *cn, uint32_t *flags,
+ int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
+ void *p_vrfy,
+ mbedtls_x509_crt_restart_ctx *rs_ctx);
+
+/**
+ * \brief The type of trusted certificate callbacks.
+ *
+ * Callbacks of this type are passed to and used by the CRT
+ * verification routine mbedtls_x509_crt_verify_with_ca_cb()
+ * when looking for trusted signers of a given certificate.
+ *
+ * On success, the callback returns a list of trusted
+ * certificates to be considered as potential signers
+ * for the input certificate.
+ *
+ * \param p_ctx An opaque context passed to the callback.
+ * \param child The certificate for which to search a potential signer.
+ * This will point to a readable certificate.
+ * \param candidate_cas The address at which to store the address of the first
+ * entry in the generated linked list of candidate signers.
+ * This will not be \c NULL.
+ *
+ * \note The callback must only return a non-zero value on a
+ * fatal error. If, in contrast, the search for a potential
+ * signer completes without a single candidate, the
+ * callback must return \c 0 and set \c *candidate_cas
+ * to \c NULL.
+ *
+ * \return \c 0 on success. In this case, \c *candidate_cas points
+ * to a heap-allocated linked list of instances of
+ * ::mbedtls_x509_crt, and ownership of this list is passed
+ * to the caller.
+ * \return A negative error code on failure.
+ */
+typedef int (*mbedtls_x509_crt_ca_cb_t)(void *p_ctx,
+ mbedtls_x509_crt const *child,
+ mbedtls_x509_crt **candidate_cas);
+
+#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
+/**
+ * \brief Version of \c mbedtls_x509_crt_verify_with_profile() which
+ * uses a callback to acquire the list of trusted CA
+ * certificates.
+ *
+ * \param crt The certificate chain to be verified.
+ * \param f_ca_cb The callback to be used to query for potential signers
+ * of a given child certificate. See the documentation of
+ * ::mbedtls_x509_crt_ca_cb_t for more information.
+ * \param p_ca_cb The opaque context to be passed to \p f_ca_cb.
+ * \param profile The security profile for the verification.
+ * \param cn The expected Common Name. This may be \c NULL if the
+ * CN need not be verified.
+ * \param flags The address at which to store the result of the verification.
+ * If the verification couldn't be completed, the flag value is
+ * set to (uint32_t) -1.
+ * \param f_vrfy The verification callback to use. See the documentation
+ * of mbedtls_x509_crt_verify() for more information.
+ * \param p_vrfy The context to be passed to \p f_vrfy.
+ *
+ * \return See \c mbedtls_crt_verify_with_profile().
+ */
+int mbedtls_x509_crt_verify_with_ca_cb(mbedtls_x509_crt *crt,
+ mbedtls_x509_crt_ca_cb_t f_ca_cb,
+ void *p_ca_cb,
+ const mbedtls_x509_crt_profile *profile,
+ const char *cn, uint32_t *flags,
+ int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
+ void *p_vrfy);
+
+#endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
+
+/**
+ * \brief Check usage of certificate against keyUsage extension.
+ *
+ * \param crt Leaf certificate used.
+ * \param usage Intended usage(s) (eg MBEDTLS_X509_KU_KEY_ENCIPHERMENT
+ * before using the certificate to perform an RSA key
+ * exchange).
+ *
+ * \note Except for decipherOnly and encipherOnly, a bit set in the
+ * usage argument means this bit MUST be set in the
+ * certificate. For decipherOnly and encipherOnly, it means
+ * that bit MAY be set.
+ *
+ * \return 0 is these uses of the certificate are allowed,
+ * MBEDTLS_ERR_X509_BAD_INPUT_DATA if the keyUsage extension
+ * is present but does not match the usage argument.
+ *
+ * \note You should only call this function on leaf certificates, on
+ * (intermediate) CAs the keyUsage extension is automatically
+ * checked by \c mbedtls_x509_crt_verify().
+ */
+int mbedtls_x509_crt_check_key_usage(const mbedtls_x509_crt *crt,
+ unsigned int usage);
+
+/**
+ * \brief Check usage of certificate against extendedKeyUsage.
+ *
+ * \param crt Leaf certificate used.
+ * \param usage_oid Intended usage (eg MBEDTLS_OID_SERVER_AUTH or
+ * MBEDTLS_OID_CLIENT_AUTH).
+ * \param usage_len Length of usage_oid (eg given by MBEDTLS_OID_SIZE()).
+ *
+ * \return 0 if this use of the certificate is allowed,
+ * MBEDTLS_ERR_X509_BAD_INPUT_DATA if not.
+ *
+ * \note Usually only makes sense on leaf certificates.
+ */
+int mbedtls_x509_crt_check_extended_key_usage(const mbedtls_x509_crt *crt,
+ const char *usage_oid,
+ size_t usage_len);
+
+#if defined(MBEDTLS_X509_CRL_PARSE_C)
+/**
+ * \brief Verify the certificate revocation status
+ *
+ * \param crt a certificate to be verified
+ * \param crl the CRL to verify against
+ *
+ * \return 1 if the certificate is revoked, 0 otherwise
+ *
+ */
+int mbedtls_x509_crt_is_revoked(const mbedtls_x509_crt *crt, const mbedtls_x509_crl *crl);
+#endif /* MBEDTLS_X509_CRL_PARSE_C */
+
+/**
+ * \brief Initialize a certificate (chain)
+ *
+ * \param crt Certificate chain to initialize
+ */
+void mbedtls_x509_crt_init(mbedtls_x509_crt *crt);
+
+/**
+ * \brief Unallocate all certificate data
+ *
+ * \param crt Certificate chain to free
+ */
+void mbedtls_x509_crt_free(mbedtls_x509_crt *crt);
+
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+/**
+ * \brief Initialize a restart context
+ */
+void mbedtls_x509_crt_restart_init(mbedtls_x509_crt_restart_ctx *ctx);
+
+/**
+ * \brief Free the components of a restart context
+ */
+void mbedtls_x509_crt_restart_free(mbedtls_x509_crt_restart_ctx *ctx);
+#endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
+#endif /* MBEDTLS_X509_CRT_PARSE_C */
+
+/**
+ * \brief Query certificate for given extension type
+ *
+ * \param[in] ctx Certificate context to be queried, must not be \c NULL
+ * \param ext_type Extension type being queried for, must be a valid
+ * extension type. Must be one of the MBEDTLS_X509_EXT_XXX
+ * values
+ *
+ * \return 0 if the given extension type is not present,
+ * non-zero otherwise
+ */
+static inline int mbedtls_x509_crt_has_ext_type(const mbedtls_x509_crt *ctx,
+ int ext_type)
+{
+ return ctx->MBEDTLS_PRIVATE(ext_types) & ext_type;
+}
+
+/**
+ * \brief Access the ca_istrue field
+ *
+ * \param[in] crt Certificate to be queried, must not be \c NULL
+ *
+ * \return \c 1 if this a CA certificate \c 0 otherwise.
+ * \return MBEDTLS_ERR_X509_INVALID_EXTENSIONS if the certificate does not contain
+ * the Optional Basic Constraint extension.
+ *
+ */
+int mbedtls_x509_crt_get_ca_istrue(const mbedtls_x509_crt *crt);
+
+/** \} name Structures and functions for parsing and writing X.509 certificates */
+
+#if defined(MBEDTLS_X509_CRT_WRITE_C)
+/**
+ * \brief Initialize a CRT writing context
+ *
+ * \param ctx CRT context to initialize
+ */
+void mbedtls_x509write_crt_init(mbedtls_x509write_cert *ctx);
+
+/**
+ * \brief Set the version for a Certificate
+ * Default: MBEDTLS_X509_CRT_VERSION_3
+ *
+ * \param ctx CRT context to use
+ * \param version version to set (MBEDTLS_X509_CRT_VERSION_1, MBEDTLS_X509_CRT_VERSION_2 or
+ * MBEDTLS_X509_CRT_VERSION_3)
+ */
+void mbedtls_x509write_crt_set_version(mbedtls_x509write_cert *ctx, int version);
+
+#if defined(MBEDTLS_BIGNUM_C) && !defined(MBEDTLS_DEPRECATED_REMOVED)
+/**
+ * \brief Set the serial number for a Certificate.
+ *
+ * \deprecated This function is deprecated and will be removed in a
+ * future version of the library. Please use
+ * mbedtls_x509write_crt_set_serial_raw() instead.
+ *
+ * \note Even though the MBEDTLS_BIGNUM_C guard looks redundant since
+ * X509 depends on PK and PK depends on BIGNUM, this emphasizes
+ * a direct dependency between X509 and BIGNUM which is going
+ * to be deprecated in the future.
+ *
+ * \param ctx CRT context to use
+ * \param serial serial number to set
+ *
+ * \return 0 if successful
+ */
+int MBEDTLS_DEPRECATED mbedtls_x509write_crt_set_serial(
+ mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial);
+#endif // MBEDTLS_BIGNUM_C && !MBEDTLS_DEPRECATED_REMOVED
+
+/**
+ * \brief Set the serial number for a Certificate.
+ *
+ * \param ctx CRT context to use
+ * \param serial A raw array of bytes containing the serial number in big
+ * endian format
+ * \param serial_len Length of valid bytes (expressed in bytes) in \p serial
+ * input buffer
+ *
+ * \return 0 if successful, or
+ * MBEDTLS_ERR_X509_BAD_INPUT_DATA if the provided input buffer
+ * is too big (longer than MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN)
+ */
+int mbedtls_x509write_crt_set_serial_raw(mbedtls_x509write_cert *ctx,
+ unsigned char *serial, size_t serial_len);
+
+/**
+ * \brief Set the validity period for a Certificate
+ * Timestamps should be in string format for UTC timezone
+ * i.e. "YYYYMMDDhhmmss"
+ * e.g. "20131231235959" for December 31st 2013
+ * at 23:59:59
+ *
+ * \param ctx CRT context to use
+ * \param not_before not_before timestamp
+ * \param not_after not_after timestamp
+ *
+ * \return 0 if timestamp was parsed successfully, or
+ * a specific error code
+ */
+int mbedtls_x509write_crt_set_validity(mbedtls_x509write_cert *ctx, const char *not_before,
+ const char *not_after);
+
+/**
+ * \brief Set the issuer name for a Certificate
+ * Issuer names should contain a comma-separated list
+ * of OID types and values:
+ * e.g. "C=UK,O=ARM,CN=Mbed TLS CA"
+ *
+ * \param ctx CRT context to use
+ * \param issuer_name issuer name to set
+ *
+ * \return 0 if issuer name was parsed successfully, or
+ * a specific error code
+ */
+int mbedtls_x509write_crt_set_issuer_name(mbedtls_x509write_cert *ctx,
+ const char *issuer_name);
+
+/**
+ * \brief Set the subject name for a Certificate
+ * Subject names should contain a comma-separated list
+ * of OID types and values:
+ * e.g. "C=UK,O=ARM,CN=Mbed TLS Server 1"
+ *
+ * \param ctx CRT context to use
+ * \param subject_name subject name to set
+ *
+ * \return 0 if subject name was parsed successfully, or
+ * a specific error code
+ */
+int mbedtls_x509write_crt_set_subject_name(mbedtls_x509write_cert *ctx,
+ const char *subject_name);
+
+/**
+ * \brief Set the subject public key for the certificate
+ *
+ * \param ctx CRT context to use
+ * \param key public key to include
+ */
+void mbedtls_x509write_crt_set_subject_key(mbedtls_x509write_cert *ctx, mbedtls_pk_context *key);
+
+/**
+ * \brief Set the issuer key used for signing the certificate
+ *
+ * \param ctx CRT context to use
+ * \param key private key to sign with
+ */
+void mbedtls_x509write_crt_set_issuer_key(mbedtls_x509write_cert *ctx, mbedtls_pk_context *key);
+
+/**
+ * \brief Set the MD algorithm to use for the signature
+ * (e.g. MBEDTLS_MD_SHA1)
+ *
+ * \param ctx CRT context to use
+ * \param md_alg MD algorithm to use
+ */
+void mbedtls_x509write_crt_set_md_alg(mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg);
+
+/**
+ * \brief Generic function to add to or replace an extension in the
+ * CRT
+ *
+ * \param ctx CRT context to use
+ * \param oid OID of the extension
+ * \param oid_len length of the OID
+ * \param critical if the extension is critical (per the RFC's definition)
+ * \param val value of the extension OCTET STRING
+ * \param val_len length of the value data
+ *
+ * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
+ */
+int mbedtls_x509write_crt_set_extension(mbedtls_x509write_cert *ctx,
+ const char *oid, size_t oid_len,
+ int critical,
+ const unsigned char *val, size_t val_len);
+
+/**
+ * \brief Set the basicConstraints extension for a CRT
+ *
+ * \param ctx CRT context to use
+ * \param is_ca is this a CA certificate
+ * \param max_pathlen maximum length of certificate chains below this
+ * certificate (only for CA certificates, -1 is
+ * unlimited)
+ *
+ * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
+ */
+int mbedtls_x509write_crt_set_basic_constraints(mbedtls_x509write_cert *ctx,
+ int is_ca, int max_pathlen);
+
+#if defined(MBEDTLS_MD_CAN_SHA1)
+/**
+ * \brief Set the subjectKeyIdentifier extension for a CRT
+ * Requires that mbedtls_x509write_crt_set_subject_key() has been
+ * called before
+ *
+ * \param ctx CRT context to use
+ *
+ * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
+ */
+int mbedtls_x509write_crt_set_subject_key_identifier(mbedtls_x509write_cert *ctx);
+
+/**
+ * \brief Set the authorityKeyIdentifier extension for a CRT
+ * Requires that mbedtls_x509write_crt_set_issuer_key() has been
+ * called before
+ *
+ * \param ctx CRT context to use
+ *
+ * \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
+ */
+int mbedtls_x509write_crt_set_authority_key_identifier(mbedtls_x509write_cert *ctx);
+#endif /* MBEDTLS_MD_CAN_SHA1 */
+
+/**
+ * \brief Set the Key Usage Extension flags
+ * (e.g. MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_KEY_CERT_SIGN)
+ *
+ * \param ctx CRT context to use
+ * \param key_usage key usage flags to set
+ *
+ * \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
+ */
+int mbedtls_x509write_crt_set_key_usage(mbedtls_x509write_cert *ctx,
+ unsigned int key_usage);
+
+/**
+ * \brief Set the Extended Key Usage Extension
+ * (e.g. MBEDTLS_OID_SERVER_AUTH)
+ *
+ * \param ctx CRT context to use
+ * \param exts extended key usage extensions to set, a sequence of
+ * MBEDTLS_ASN1_OID objects
+ *
+ * \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
+ */
+int mbedtls_x509write_crt_set_ext_key_usage(mbedtls_x509write_cert *ctx,
+ const mbedtls_asn1_sequence *exts);
+
+/**
+ * \brief Set the Netscape Cert Type flags
+ * (e.g. MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT | MBEDTLS_X509_NS_CERT_TYPE_EMAIL)
+ *
+ * \param ctx CRT context to use
+ * \param ns_cert_type Netscape Cert Type flags to set
+ *
+ * \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
+ */
+int mbedtls_x509write_crt_set_ns_cert_type(mbedtls_x509write_cert *ctx,
+ unsigned char ns_cert_type);
+
+/**
+ * \brief Free the contents of a CRT write context
+ *
+ * \param ctx CRT context to free
+ */
+void mbedtls_x509write_crt_free(mbedtls_x509write_cert *ctx);
+
+/**
+ * \brief Write a built up certificate to a X509 DER structure
+ * Note: data is written at the end of the buffer! Use the
+ * return value to determine where you should start
+ * using the buffer
+ *
+ * \param ctx certificate to write away
+ * \param buf buffer to write to
+ * \param size size of the buffer
+ * \param f_rng RNG function. This must not be \c NULL.
+ * \param p_rng RNG parameter
+ *
+ * \return length of data written if successful, or a specific
+ * error code
+ *
+ * \note \p f_rng is used for the signature operation.
+ */
+int mbedtls_x509write_crt_der(mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
+ int (*f_rng)(void *, unsigned char *, size_t),
+ void *p_rng);
+
+#if defined(MBEDTLS_PEM_WRITE_C)
+/**
+ * \brief Write a built up certificate to a X509 PEM string
+ *
+ * \param ctx certificate to write away
+ * \param buf buffer to write to
+ * \param size size of the buffer
+ * \param f_rng RNG function. This must not be \c NULL.
+ * \param p_rng RNG parameter
+ *
+ * \return 0 if successful, or a specific error code
+ *
+ * \note \p f_rng is used for the signature operation.
+ */
+int mbedtls_x509write_crt_pem(mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size,
+ int (*f_rng)(void *, unsigned char *, size_t),
+ void *p_rng);
+#endif /* MBEDTLS_PEM_WRITE_C */
+#endif /* MBEDTLS_X509_CRT_WRITE_C */
+
+/** \} addtogroup x509_module */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* mbedtls_x509_crt.h */