/* * RSAPublicKey ::= SEQUENCE { * modulus INTEGER, -- n * publicExponent INTEGER -- e * } */ static int pk_write_rsa_pubkey( unsigned char **p, unsigned char *start, mbedtls_rsa_context *rsa ) { int ret; size_t len = 0; MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( p, start, &rsa->E ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( p, start, &rsa->N ) ); 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_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); return( (int) len ); }
/* * Convert a signature (given by context) to ASN.1 */ static int ecdsa_signature_to_asn1( const mbedtls_mpi *r, const mbedtls_mpi *s, unsigned char *sig, size_t *slen ) { int ret; unsigned char buf[MBEDTLS_ECDSA_MAX_LEN]; unsigned char *p = buf + sizeof( buf ); size_t len = 0; MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, s ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, r ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, buf, len ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, buf, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); memcpy( sig, p, len ); *slen = len; return( 0 ); }
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; size_t sig_oid_len = 0; unsigned char *c, *c2; unsigned char hash[64]; unsigned char sig[MBEDTLS_MPI_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 */ c = tmp_buf + sizeof( tmp_buf ); /* Signature algorithm needed in TBS, and later for actual signature */ pk_alg = mbedtls_pk_get_type( ctx->issuer_key ); if( pk_alg == MBEDTLS_PK_ECKEY ) pk_alg = MBEDTLS_PK_ECDSA; if( ( ret = mbedtls_oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg, &sig_oid, &sig_oid_len ) ) != 0 ) { return( ret ); } /* * Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension */ 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 ) ); /* * SubjectPublicKeyInfo */ MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_pk_write_pubkey_der( ctx->subject_key, tmp_buf, c - tmp_buf ) ); c -= pub_len; len += pub_len; /* * Subject ::= Name */ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->subject ) ); /* * Validity ::= SEQUENCE { * notBefore Time, * notAfter Time } */ 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, tmp_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 ) ); /* * Issuer ::= Name */ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->issuer ) ); /* * Signature ::= AlgorithmIdentifier */ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, tmp_buf, sig_oid, strlen( sig_oid ), 0 ) ); /* * Serial ::= INTEGER */ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, tmp_buf, &ctx->serial ) ); /* * Version ::= INTEGER { v1(0), v2(1), v3(2) } */ sub_len = 0; MBEDTLS_ASN1_CHK_ADD( sub_len, mbedtls_asn1_write_int( &c, tmp_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, tmp_buf, len ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); /* * Make signature */ mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c, len, hash ); 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 */ c2 = buf + size; MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, buf, sig_oid, sig_oid_len, sig, sig_len ) ); if( len > (size_t)( c2 - buf ) ) return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); c2 -= len; memcpy( c2, c, 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_SEQUENCE ) ); return( (int) len ); }
int mbedtls_pk_write_key_der( mbedtls_pk_context *key, unsigned char *buf, size_t size ) { int ret; unsigned char *c = buf + size; size_t len = 0; #if defined(MBEDTLS_RSA_C) if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA ) { mbedtls_rsa_context *rsa = mbedtls_pk_rsa( *key ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->QP ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->DQ ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->DP ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->Q ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->P ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->D ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->E ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->N ) ); MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 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 ) ); } else #endif /* MBEDTLS_RSA_C */ #if defined(MBEDTLS_ECP_C) if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY ) { mbedtls_ecp_keypair *ec = mbedtls_pk_ec( *key ); size_t pub_len = 0, par_len = 0; /* * RFC 5915, or SEC1 Appendix C.4 * * ECPrivateKey ::= SEQUENCE { * version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1), * privateKey OCTET STRING, * parameters [0] ECParameters {{ NamedCurve }} OPTIONAL, * publicKey [1] BIT STRING OPTIONAL * } */ /* publicKey */ MBEDTLS_ASN1_CHK_ADD( pub_len, pk_write_ec_pubkey( &c, buf, ec ) ); if( c - buf < 1 ) return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); *--c = 0; pub_len += 1; MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) ); MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) ); MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) ); MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) ); len += pub_len; /* parameters */ MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, ec ) ); MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_len( &c, buf, par_len ) ); MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ); len += par_len; /* privateKey: write as MPI then fix tag */ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &ec->d ) ); *c = MBEDTLS_ASN1_OCTET_STRING; /* version */ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &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_SEQUENCE ) ); } else #endif /* MBEDTLS_ECP_C */ return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE ); return( (int) len ); }