/* * X.509 CRL v2 extensions (no extensions parsed yet.) */ static int x509_get_crl_ext( unsigned char **p, const unsigned char *end, x509_buf *ext ) { int ret; size_t len = 0; /* Get explicit tag */ if( ( ret = x509_get_ext( p, end, ext, 0) ) != 0 ) { if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) return( 0 ); return( ret ); } while( *p < end ) { if( ( ret = asn1_get_tag( p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); *p += len; } if( *p != end ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); }
/* * Parse one or more certificates and add them to the chain */ int x509_add_certs( x509_cert *chain, unsigned char *buf, int buflen ) { int ret, len; unsigned char *s1, *s2; unsigned char *p, *end; x509_cert *crt; crt = chain; while( crt->version != 0 ) crt = crt->next; /* * check if the certificate is encoded in base64 */ s1 = (unsigned char *) strstr( (char *) buf, "-----BEGIN CERTIFICATE-----" ); if( s1 != NULL ) { s2 = (unsigned char *) strstr( (char *) buf, "-----END CERTIFICATE-----" ); if( s2 == NULL || s2 <= s1 ) return( ERR_X509_CERT_INVALID_PEM ); s1 += 27; if( *s1 == '\r' ) s1++; if( *s1 == '\n' ) s1++; else return( ERR_X509_CERT_INVALID_PEM ); /* * get the DER data length and decode the buffer */ len = 0; ret = base64_decode( NULL, &len, s1, s2 - s1 ); if( ret == ERR_BASE64_INVALID_CHARACTER ) return( ERR_X509_CERT_INVALID_PEM | ret ); if( ( p = (unsigned char *) malloc( len ) ) == NULL ) return( 1 ); if( ( ret = base64_decode( p, &len, s1, s2 - s1 ) ) != 0 ) { free( p ); return( ERR_X509_CERT_INVALID_PEM | ret ); } /* * update the buffer size and offset */ s2 += 25; if( *s2 == '\r' ) s2++; if( *s2 == '\n' ) s2++; else return( ERR_X509_CERT_INVALID_PEM ); buflen -= s2 - buf; buf = s2; } else { /* * nope, copy the raw DER data */ p = (unsigned char *) malloc( len = buflen ); if( p == NULL ) return( 1 ); memcpy( p, buf, buflen ); buflen = 0; } crt->raw.p = p; crt->raw.len = len; end = p + len; /* * Certificate ::= SEQUENCE { * tbsCertificate TBSCertificate, * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING } */ if( ( ret = asn1_get_tag( &p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) { x509_free_cert( crt ); return( ERR_X509_CERT_INVALID_FORMAT ); } if( len != (int) ( end - p ) ) { x509_free_cert( crt ); return( ERR_X509_CERT_INVALID_FORMAT | ERR_ASN1_LENGTH_MISMATCH ); } /* * TBSCertificate ::= SEQUENCE { */ crt->tbs.p = p; if( ( ret = asn1_get_tag( &p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) { x509_free_cert( crt ); return( ERR_X509_CERT_INVALID_FORMAT | ret ); } end = p + len; crt->tbs.len = end - crt->tbs.p; /* * Version ::= INTEGER { v1(0), v2(1), v3(2) } * * CertificateSerialNumber ::= INTEGER * * signature AlgorithmIdentifier */ if( ( ret = x509_get_version( &p, end, &crt->version ) ) != 0 || ( ret = x509_get_serial( &p, end, &crt->serial ) ) != 0 || ( ret = x509_get_alg( &p, end, &crt->sig_oid1 ) ) != 0 ) { x509_free_cert( crt ); return( ret ); } crt->version++; if( crt->version > 3 ) { x509_free_cert( crt ); return( ERR_X509_CERT_UNKNOWN_VERSION ); } if( crt->sig_oid1.len != 9 || memcmp( crt->sig_oid1.p, OID_PKCS1, 8 ) != 0 ) { x509_free_cert( crt ); return( ERR_X509_CERT_UNKNOWN_SIG_ALG ); } if( crt->sig_oid1.p[8] < 2 || crt->sig_oid1.p[8] > 5 ) { x509_free_cert( crt ); return( ERR_X509_CERT_UNKNOWN_SIG_ALG ); } /* * issuer Name */ crt->issuer_raw.p = p; if( ( ret = asn1_get_tag( &p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) { x509_free_cert( crt ); return( ERR_X509_CERT_INVALID_FORMAT | ret ); } if( ( ret = x509_get_name( &p, p + len, &crt->issuer ) ) != 0 ) { x509_free_cert( crt ); return( ret ); } crt->issuer_raw.len = p - crt->issuer_raw.p; /* * Validity ::= SEQUENCE { * notBefore Time, * notAfter Time } * */ if( ( ret = x509_get_dates( &p, end, &crt->valid_from, &crt->valid_to ) ) != 0 ) { x509_free_cert( crt ); return( ret ); } /* * subject Name */ crt->subject_raw.p = p; if( ( ret = asn1_get_tag( &p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) { x509_free_cert( crt ); return( ERR_X509_CERT_INVALID_FORMAT | ret ); } if( ( ret = x509_get_name( &p, p + len, &crt->subject ) ) != 0 ) { x509_free_cert( crt ); return( ret ); } crt->subject_raw.len = p - crt->subject_raw.p; /* * SubjectPublicKeyInfo ::= SEQUENCE * algorithm AlgorithmIdentifier, * subjectPublicKey BIT STRING } */ if( ( ret = asn1_get_tag( &p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) { x509_free_cert( crt ); return( ERR_X509_CERT_INVALID_FORMAT | ret ); } if( ( ret = x509_get_pubkey( &p, p + len, &crt->pk_oid, &crt->rsa.N, &crt->rsa.E ) ) != 0 ) { x509_free_cert( crt ); return( ret ); } if( ( ret = rsa_check_pubkey( &crt->rsa ) ) != 0 ) { x509_free_cert( crt ); return( ret ); } crt->rsa.len = ( mpi_size( &crt->rsa.N ) + 7 ) >> 3; /* * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version shall be v2 or v3 * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL, * -- If present, version shall be v2 or v3 * extensions [3] EXPLICIT Extensions OPTIONAL * -- If present, version shall be v3 */ if( crt->version == 2 || crt->version == 3 ) { ret = x509_get_uid( &p, end, &crt->issuer_id, 1 ); if( ret != 0 ) { x509_free_cert( crt ); return( ret ); } } if( crt->version == 2 || crt->version == 3 ) { ret = x509_get_uid( &p, end, &crt->subject_id, 2 ); if( ret != 0 ) { x509_free_cert( crt ); return( ret ); } } if( crt->version == 3 ) { ret = x509_get_ext( &p, end, &crt->v3_ext, &crt->ca_istrue, &crt->max_pathlen ); if( ret != 0 ) { x509_free_cert( crt ); return( ret ); } } if( p != end ) { x509_free_cert( crt ); return( ERR_X509_CERT_INVALID_FORMAT | ERR_ASN1_LENGTH_MISMATCH ); } end = crt->raw.p + crt->raw.len; /* * signatureAlgorithm AlgorithmIdentifier, * signatureValue BIT STRING */ if( ( ret = x509_get_alg( &p, end, &crt->sig_oid2 ) ) != 0 ) { x509_free_cert( crt ); return( ret ); } if( memcmp( crt->sig_oid1.p, crt->sig_oid2.p, 9 ) != 0 ) { x509_free_cert( crt ); return( ERR_X509_CERT_SIG_MISMATCH ); } if( ( ret = x509_get_sig( &p, end, &crt->sig ) ) != 0 ) { x509_free_cert( crt ); return( ret ); } if( p != end ) { x509_free_cert( crt ); return( ERR_X509_CERT_INVALID_FORMAT | ERR_ASN1_LENGTH_MISMATCH ); } crt->next = (x509_cert *) malloc( sizeof( x509_cert ) ); if( crt->next == NULL ) { x509_free_cert( crt ); return( 1 ); } crt = crt->next; memset( crt, 0, sizeof( x509_cert ) ); if( buflen > 0 ) return( x509_add_certs( crt, buf, buflen ) ); return( 0 ); }
/* * X.509 v3 extensions * * TODO: Perform all of the basic constraints tests required by the RFC * TODO: Set values for undetected extensions to a sane default? * */ static int x509_get_crt_ext( unsigned char **p, const unsigned char *end, x509_crt *crt ) { int ret; size_t len; unsigned char *end_ext_data, *end_ext_octet; if( ( ret = x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 ) { if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) return( 0 ); return( ret ); } while( *p < end ) { /* * Extension ::= SEQUENCE { * extnID OBJECT IDENTIFIER, * critical BOOLEAN DEFAULT FALSE, * extnValue OCTET STRING } */ x509_buf extn_oid = {0, 0, NULL}; int is_critical = 0; /* DEFAULT FALSE */ int ext_type = 0; if( ( ret = asn1_get_tag( p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); end_ext_data = *p + len; /* Get extension ID */ extn_oid.tag = **p; if( ( ret = asn1_get_tag( p, end, &extn_oid.len, ASN1_OID ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); extn_oid.p = *p; *p += extn_oid.len; if( ( end - *p ) < 1 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_OUT_OF_DATA ); /* Get optional critical */ if( ( ret = asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 && ( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); /* Data should be octet string type */ if( ( ret = asn1_get_tag( p, end_ext_data, &len, ASN1_OCTET_STRING ) ) != 0 ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret ); end_ext_octet = *p + len; if( end_ext_octet != end_ext_data ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); /* * Detect supported extensions */ ret = oid_get_x509_ext_type( &extn_oid, &ext_type ); if( ret != 0 ) { /* No parser found, skip extension */ *p = end_ext_octet; #if !defined(POLARSSL_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION) if( is_critical ) { /* Data is marked as critical: fail */ return ( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_UNEXPECTED_TAG ); } #endif continue; } crt->ext_types |= ext_type; switch( ext_type ) { case EXT_BASIC_CONSTRAINTS: /* Parse basic constraints */ if( ( ret = x509_get_basic_constraints( p, end_ext_octet, &crt->ca_istrue, &crt->max_pathlen ) ) != 0 ) return ( ret ); break; case EXT_KEY_USAGE: /* Parse key usage */ if( ( ret = x509_get_key_usage( p, end_ext_octet, &crt->key_usage ) ) != 0 ) return ( ret ); break; case EXT_EXTENDED_KEY_USAGE: /* Parse extended key usage */ if( ( ret = x509_get_ext_key_usage( p, end_ext_octet, &crt->ext_key_usage ) ) != 0 ) return ( ret ); break; case EXT_SUBJECT_ALT_NAME: /* Parse subject alt name */ if( ( ret = x509_get_subject_alt_name( p, end_ext_octet, &crt->subject_alt_names ) ) != 0 ) return ( ret ); break; case EXT_NS_CERT_TYPE: /* Parse netscape certificate type */ if( ( ret = x509_get_ns_cert_type( p, end_ext_octet, &crt->ns_cert_type ) ) != 0 ) return ( ret ); break; default: return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE ); } } if( *p != end ) return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); }