diff --git a/ChangeLog.d/bugfix_PR_2632.txt b/ChangeLog.d/bugfix_PR_2632.txt new file mode 100644 index 000000000..1d54b4dd2 --- /dev/null +++ b/ChangeLog.d/bugfix_PR_2632.txt @@ -0,0 +1,4 @@ +Bugfix + * Avoid use of statically sized stack buffers for certificate writing. + This previously limited the maximum size of DER encoded certificates + in mbedtls_x509write_crt_der() to 2Kb. Reported by soccerGB in #2631. diff --git a/include/mbedtls/pem.h b/include/mbedtls/pem.h index 16b610141..1d4474110 100644 --- a/include/mbedtls/pem.h +++ b/include/mbedtls/pem.h @@ -139,17 +139,27 @@ void mbedtls_pem_free( mbedtls_pem_context *ctx ); * \brief Write a buffer of PEM information from a DER encoded * buffer. * - * \param header header string to write - * \param footer footer string to write - * \param der_data DER data to write - * \param der_len length of the DER data - * \param buf buffer to write to - * \param buf_len length of output buffer - * \param olen total length written / required (if buf_len is not enough) + * \param header The header string to write. + * \param footer The footer string to write. + * \param der_data The DER data to encode. + * \param der_len The length of the DER data \p der_data in Bytes. + * \param buf The buffer to write to. + * \param buf_len The length of the output buffer \p buf in Bytes. + * \param olen The address at which to store the total length written + * or required (if \p buf_len is not enough). * - * \return 0 on success, or a specific PEM or BASE64 error code. On - * MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL olen is the required - * size. + * \note You may pass \c NULL for \p buf and \c 0 for \p buf_len + * to request the length of the resulting PEM buffer in + * `*olen`. + * + * \note This function may be called with overlapping \p der_data + * and \p buf buffers. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL if \p buf isn't large + * enough to hold the PEM buffer. In this case, `*olen` holds + * the required minimum size of \p buf. + * \return Another PEM or BASE64 error code on other kinds of failure. */ int mbedtls_pem_write_buffer( const char *header, const char *footer, const unsigned char *der_data, size_t der_len, diff --git a/library/x509write_crt.c b/library/x509write_crt.c index 0fc94fed2..c3899807f 100644 --- a/library/x509write_crt.c +++ b/library/x509write_crt.c @@ -101,39 +101,44 @@ void mbedtls_x509write_crt_free( mbedtls_x509write_cert *ctx ) mbedtls_platform_zeroize( ctx, sizeof( mbedtls_x509write_cert ) ); } -void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx, int version ) +void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx, + int version ) { ctx->version = version; } -void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg ) +void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx, + mbedtls_md_type_t md_alg ) { ctx->md_alg = md_alg; } -void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key ) +void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx, + mbedtls_pk_context *key ) { ctx->subject_key = key; } -void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key ) +void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx, + mbedtls_pk_context *key ) { ctx->issuer_key = key; } int mbedtls_x509write_crt_set_subject_name( mbedtls_x509write_cert *ctx, - const char *subject_name ) + const char *subject_name ) { return mbedtls_x509_string_to_names( &ctx->subject, subject_name ); } int mbedtls_x509write_crt_set_issuer_name( mbedtls_x509write_cert *ctx, - const char *issuer_name ) + const char *issuer_name ) { return mbedtls_x509_string_to_names( &ctx->issuer, issuer_name ); } -int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial ) +int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx, + const mbedtls_mpi *serial ) { int ret; @@ -143,8 +148,9 @@ int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx, const mbedtls return( 0 ); } -int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx, const char *not_before, - const char *not_after ) +int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx, + const char *not_before, + const char *not_after ) { if( strlen( not_before ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 || strlen( not_after ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 ) @@ -164,12 +170,12 @@ int mbedtls_x509write_crt_set_extension( mbedtls_x509write_cert *ctx, int critical, const unsigned char *val, size_t val_len ) { - return mbedtls_x509_set_extension( &ctx->extensions, oid, oid_len, - critical, val, val_len ); + return( mbedtls_x509_set_extension( &ctx->extensions, oid, oid_len, + critical, val, val_len ) ); } int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx, - int is_ca, int max_pathlen ) + int is_ca, int max_pathlen ) { int ret; unsigned char buf[9]; @@ -185,18 +191,21 @@ int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx, { if( max_pathlen >= 0 ) { - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, max_pathlen ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, + max_pathlen ) ); } MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_bool( &c, buf, 1 ) ); } MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); - return mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_BASIC_CONSTRAINTS, - MBEDTLS_OID_SIZE( MBEDTLS_OID_BASIC_CONSTRAINTS ), - 0, buf + sizeof(buf) - len, len ); + return( + mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_BASIC_CONSTRAINTS, + MBEDTLS_OID_SIZE( MBEDTLS_OID_BASIC_CONSTRAINTS ), + 0, buf + sizeof(buf) - len, len ) ); } #if defined(MBEDTLS_SHA1_C) @@ -208,7 +217,8 @@ int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ct size_t len = 0; memset( buf, 0, sizeof(buf) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, ctx->subject_key ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_pk_write_pubkey( &c, buf, ctx->subject_key ) ); ret = mbedtls_sha1_ret( buf + sizeof( buf ) - len, len, buf + sizeof( buf ) - 20 ); @@ -218,11 +228,13 @@ int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ct len = 20; MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_OCTET_STRING ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_OCTET_STRING ) ); - return mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER, - MBEDTLS_OID_SIZE( MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER ), - 0, buf + sizeof(buf) - len, len ); + return mbedtls_x509write_crt_set_extension( ctx, + MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER, + MBEDTLS_OID_SIZE( MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER ), + 0, buf + sizeof(buf) - len, len ); } int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx ) @@ -233,7 +245,8 @@ int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert * size_t len = 0; memset( buf, 0, sizeof(buf) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, ctx->issuer_key ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_pk_write_pubkey( &c, buf, ctx->issuer_key ) ); ret = mbedtls_sha1_ret( buf + sizeof( buf ) - len, len, buf + sizeof( buf ) - 20 ); @@ -243,15 +256,19 @@ int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert * len = 20; MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | 0 ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | 0 ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED | - MBEDTLS_ASN1_SEQUENCE ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_tag( &c, buf, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); - return mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER, - MBEDTLS_OID_SIZE( MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER ), - 0, buf + sizeof( buf ) - len, len ); + return mbedtls_x509write_crt_set_extension( + ctx, MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER, + MBEDTLS_OID_SIZE( MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER ), + 0, buf + sizeof( buf ) - len, len ); } #endif /* MBEDTLS_SHA1_C */ @@ -298,8 +315,8 @@ int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx, return( MBEDTLS_ERR_X509_INVALID_FORMAT ); ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_KEY_USAGE, - MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ), - 1, c, (size_t)ret ); + MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ), + 1, c, (size_t)ret ); if( ret != 0 ) return( ret ); @@ -325,8 +342,8 @@ int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx, return( ret ); ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE, - MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ), - 0, c, (size_t)ret ); + MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ), + 0, c, (size_t)ret ); if( ret != 0 ) return( ret ); @@ -348,7 +365,8 @@ static int x509_write_time( unsigned char **p, unsigned char *start, (const unsigned char *) t + 2, size - 2 ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_UTC_TIME ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, + MBEDTLS_ASN1_UTC_TIME ) ); } else { @@ -356,15 +374,17 @@ static int x509_write_time( unsigned char **p, unsigned char *start, (const unsigned char *) t, size ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_GENERALIZED_TIME ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, + MBEDTLS_ASN1_GENERALIZED_TIME ) ); } return( (int) len ); } -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 ) +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 ) { int ret; const char *sig_oid; @@ -372,15 +392,14 @@ int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, unsigned char *c, *c2; unsigned char hash[64]; unsigned char sig[SIGNATURE_MAX_SIZE]; - unsigned char tmp_buf[2048]; size_t sub_len = 0, pub_len = 0, sig_and_oid_len = 0, sig_len; size_t len = 0; mbedtls_pk_type_t pk_alg; /* - * Prepare data to be signed in tmp_buf + * Prepare data to be signed at the end of the target buffer */ - c = tmp_buf + sizeof( tmp_buf ); + c = buf + size; /* Signature algorithm needed in TBS, and later for actual signature */ @@ -406,27 +425,36 @@ int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, /* Only for v3 */ if( ctx->version == MBEDTLS_X509_CRT_VERSION_3 ) { - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_extensions( &c, tmp_buf, ctx->extensions ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | - MBEDTLS_ASN1_SEQUENCE ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | - MBEDTLS_ASN1_CONSTRUCTED | 3 ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_x509_write_extensions( &c, + buf, ctx->extensions ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_tag( &c, buf, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_tag( &c, buf, + MBEDTLS_ASN1_CONTEXT_SPECIFIC | + MBEDTLS_ASN1_CONSTRUCTED | 3 ) ); } /* * SubjectPublicKeyInfo */ - MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_pk_write_pubkey_der( ctx->subject_key, - tmp_buf, c - tmp_buf ) ); + MBEDTLS_ASN1_CHK_ADD( pub_len, + mbedtls_pk_write_pubkey_der( ctx->subject_key, + buf, c - buf ) ); c -= pub_len; len += pub_len; /* * Subject ::= Name */ - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->subject ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_x509_write_names( &c, buf, + ctx->subject ) ); /* * Validity ::= SEQUENCE { @@ -435,32 +463,39 @@ int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, */ sub_len = 0; - MBEDTLS_ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_after, - MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) ); + MBEDTLS_ASN1_CHK_ADD( sub_len, + x509_write_time( &c, buf, ctx->not_after, + MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) ); - MBEDTLS_ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_before, - MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) ); + MBEDTLS_ASN1_CHK_ADD( sub_len, + x509_write_time( &c, buf, ctx->not_before, + MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) ); len += sub_len; - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, sub_len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | - MBEDTLS_ASN1_SEQUENCE ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, sub_len ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_tag( &c, buf, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); /* * Issuer ::= Name */ - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->issuer ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, buf, + ctx->issuer ) ); /* * Signature ::= AlgorithmIdentifier */ - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, tmp_buf, - sig_oid, strlen( sig_oid ), 0 ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_algorithm_identifier( &c, buf, + sig_oid, strlen( sig_oid ), 0 ) ); /* * Serial ::= INTEGER */ - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, tmp_buf, &ctx->serial ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, + &ctx->serial ) ); /* * Version ::= INTEGER { v1(0), v2(1), v3(2) } @@ -470,48 +505,67 @@ int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, if( ctx->version != MBEDTLS_X509_CRT_VERSION_1 ) { sub_len = 0; - MBEDTLS_ASN1_CHK_ADD( sub_len, mbedtls_asn1_write_int( &c, tmp_buf, ctx->version ) ); + MBEDTLS_ASN1_CHK_ADD( sub_len, + mbedtls_asn1_write_int( &c, buf, ctx->version ) ); len += sub_len; - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, sub_len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | - MBEDTLS_ASN1_CONSTRUCTED | 0 ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_len( &c, buf, sub_len ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_tag( &c, buf, + MBEDTLS_ASN1_CONTEXT_SPECIFIC | + MBEDTLS_ASN1_CONSTRUCTED | 0 ) ); } - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | - MBEDTLS_ASN1_SEQUENCE ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, + mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); /* * Make signature */ + + /* Compute hash of CRT. */ if( ( ret = mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c, len, hash ) ) != 0 ) { return( ret ); } - if( ( ret = mbedtls_pk_sign( ctx->issuer_key, ctx->md_alg, hash, 0, sig, &sig_len, - f_rng, p_rng ) ) != 0 ) + if( ( ret = mbedtls_pk_sign( ctx->issuer_key, ctx->md_alg, + hash, 0, sig, &sig_len, + f_rng, p_rng ) ) != 0 ) { return( ret ); } - /* - * Write data to output buffer - */ + /* Move CRT to the front of the buffer to have space + * for the signature. */ + memmove( buf, c, len ); + c = buf + len; + + /* Add signature at the end of the buffer, + * making sure that it doesn't underflow + * into the CRT buffer. */ c2 = buf + size; - MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, buf, + MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, c, sig_oid, sig_oid_len, sig, sig_len ) ); - if( len > (size_t)( c2 - buf ) ) - return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + /* + * Memory layout after this step: + * + * buf c=buf+len c2 buf+size + * [CRT0,...,CRTn, UNUSED, ..., UNUSED, SIG0, ..., SIGm] + */ - c2 -= len; - memcpy( c2, c, len ); + /* Move raw CRT to just before the signature. */ + c = c2 - len; + memmove( c, buf, len ); len += sig_and_oid_len; - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c2, buf, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c2, buf, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); return( (int) len ); @@ -521,23 +575,23 @@ int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, #define PEM_END_CRT "-----END CERTIFICATE-----\n" #if defined(MBEDTLS_PEM_WRITE_C) -int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *crt, unsigned char *buf, size_t size, - int (*f_rng)(void *, unsigned char *, size_t), - void *p_rng ) +int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *crt, + unsigned char *buf, size_t size, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng ) { int ret; - unsigned char output_buf[4096]; - size_t olen = 0; + size_t olen; - if( ( ret = mbedtls_x509write_crt_der( crt, output_buf, sizeof(output_buf), + if( ( ret = mbedtls_x509write_crt_der( crt, buf, size, f_rng, p_rng ) ) < 0 ) { return( ret ); } if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_CRT, PEM_END_CRT, - output_buf + sizeof(output_buf) - ret, - ret, buf, size, &olen ) ) != 0 ) + buf + size - ret, ret, + buf, size, &olen ) ) != 0 ) { return( ret ); }