diff options
Diffstat (limited to 'roms/skiboot/libstb/crypto/pkcs7/pkcs7.c')
| -rw-r--r-- | roms/skiboot/libstb/crypto/pkcs7/pkcs7.c | 598 |
1 files changed, 598 insertions, 0 deletions
diff --git a/roms/skiboot/libstb/crypto/pkcs7/pkcs7.c b/roms/skiboot/libstb/crypto/pkcs7/pkcs7.c new file mode 100644 index 000000000..a523a9d42 --- /dev/null +++ b/roms/skiboot/libstb/crypto/pkcs7/pkcs7.c @@ -0,0 +1,598 @@ +/* Copyright 2019 IBM Corp. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + * implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#if !defined(MBEDTLS_CONFIG_FILE) +#include "mbedtls/config.h" +#else +#include MBEDTLS_CONFIG_FILE +#endif +#if defined(MBEDTLS_PKCS7_C) + +#include "mbedtls/x509.h" +#include "mbedtls/asn1.h" +#include "pkcs7.h" +#include "mbedtls/x509_crt.h" +#include "mbedtls/x509_crl.h" +#include "mbedtls/oid.h" + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#if defined(MBEDTLS_FS_IO) +#include <sys/types.h> +#include <sys/stat.h> +#endif +#include <unistd.h> + +#if defined(MBEDTLS_PLATFORM_C) +#include "mbedtls/platform.h" +#include "mbedtls/platform_util.h" +#else +#include <stdio.h> +#include <stdlib.h> +#define mbedtls_free free +#define mbedtls_calloc calloc +#define mbedtls_printf printf +#define mbedtls_snprintf snprintf +#endif + +#if defined(MBEDTLS_HAVE_TIME) +#include "mbedtls/platform_time.h" +#endif +#if defined(MBEDTLS_HAVE_TIME_DATE) +#include <time.h> +#endif + +#if defined(MBEDTLS_FS_IO) +/* + * Load all data from a file into a given buffer. + * + * The file is expected to contain DER encoded data. + * A terminating null byte is always appended. + */ +int mbedtls_pkcs7_load_file( const char *path, unsigned char **buf, size_t *n ) +{ + FILE *file; + + if( ( file = fopen( path, "rb" ) ) == NULL ) + return( MBEDTLS_ERR_PKCS7_FILE_IO_ERROR ); + + fseek( file, 0, SEEK_END ); + *n = (size_t) ftell( file ); + fseek( file, 0, SEEK_SET ); + + *buf = mbedtls_calloc( 1, *n + 1 ); + if( *buf == NULL ) + return( MBEDTLS_ERR_PKCS7_ALLOC_FAILED ); + + if( fread( *buf, 1, *n, file ) != *n ) + { + fclose( file ); + + mbedtls_platform_zeroize( *buf, *n + 1 ); + mbedtls_free( *buf ); + + return( MBEDTLS_ERR_PKCS7_FILE_IO_ERROR ); + } + + fclose( file ); + + (*buf)[*n] = '\0'; + + return( 0 ); +} +#endif + +/** + * Initializes the pkcs7 structure. + */ +void mbedtls_pkcs7_init( mbedtls_pkcs7 *pkcs7 ) +{ + memset( pkcs7, 0, sizeof( mbedtls_pkcs7 ) ); +} + +static int pkcs7_get_next_content_len( unsigned char **p, unsigned char *end, + size_t *len ) +{ + int ret; + + if( ( ret = mbedtls_asn1_get_tag( p, end, len, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 ) + { + return( MBEDTLS_ERR_PKCS7_INVALID_FORMAT + ret ); + } + + return( 0 ); +} + +/** + * version Version + * Version ::= INTEGER + **/ +static int pkcs7_get_version( unsigned char **p, unsigned char *end, int *ver ) +{ + int ret; + + if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_FORMAT + ret ); + + /* If version != 1, return invalid version */ + if( *ver != MBEDTLS_PKCS7_SUPPORTED_VERSION ) + return( MBEDTLS_ERR_PKCS7_INVALID_VERSION ); + + return( 0 ); +} + +/** + * ContentInfo ::= SEQUENCE { + * contentType ContentType, + * content + * [0] EXPLICIT ANY DEFINED BY contentType OPTIONAL } + **/ +static int pkcs7_get_content_info_type( unsigned char **p, unsigned char *end, + mbedtls_pkcs7_buf *pkcs7 ) +{ + size_t len = 0; + int ret; + unsigned char *start = *p; + + ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_SEQUENCE ); + if( ret != 0 ) { + *p = start; + return( MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO + ret ); + } + + ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_OID ); + if( ret != 0 ) { + *p = start; + return( MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO + ret ); + } + + pkcs7->tag = MBEDTLS_ASN1_OID; + pkcs7->len = len; + pkcs7->p = *p; + + return( ret ); +} + +/** + * DigestAlgorithmIdentifier ::= AlgorithmIdentifier + * + * This is from x509.h + **/ +static int pkcs7_get_digest_algorithm( unsigned char **p, unsigned char *end, + mbedtls_x509_buf *alg ) +{ + int ret; + + if( ( ret = mbedtls_asn1_get_alg_null( p, end, alg ) ) != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_ALG + ret ); + + return( 0 ); +} + +/** + * DigestAlgorithmIdentifiers :: SET of DigestAlgorithmIdentifier + **/ +static int pkcs7_get_digest_algorithm_set( unsigned char **p, + unsigned char *end, + mbedtls_x509_buf *alg ) +{ + size_t len = 0; + int ret; + + ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_SET ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_ALG + ret ); + + end = *p + len; + + /** For now, it assumes there is only one digest algorithm specified **/ + ret = mbedtls_asn1_get_alg_null( p, end, alg ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_ALG + ret ); + + if (*p != end) + return ( MBEDTLS_ERR_PKCS7_INVALID_FORMAT ); + + return( 0 ); +} + +/** + * certificates :: SET OF ExtendedCertificateOrCertificate, + * ExtendedCertificateOrCertificate ::= CHOICE { + * certificate Certificate -- x509, + * extendedCertificate[0] IMPLICIT ExtendedCertificate } + **/ +static int pkcs7_get_certificates( unsigned char **p, unsigned char *end, + mbedtls_x509_crt *certs ) +{ + int ret; + size_t len1 = 0; + size_t len2 = 0; + unsigned char *end_set, *end_cert; + unsigned char *start = *p; + + if( ( ret = mbedtls_asn1_get_tag( p, end, &len1, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_CONTEXT_SPECIFIC ) ) != 0 ) + { + if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) + return( 0 ); + + return( MBEDTLS_ERR_PKCS7_INVALID_FORMAT + ret ); + } + start = *p; + end_set = *p + len1; + + /* This is to verify that there is only signer certificate, it can + have its chain though. */ + ret = mbedtls_asn1_get_tag( p, end_set, &len2, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_SEQUENCE ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_FORMAT + ret ); + + end_cert = *p + len2; + + if (end_cert != end_set) + return (MBEDTLS_ERR_PKCS7_INVALID_FORMAT); + + /* Since it satisfies the condition of single signer, continue parsing */ + *p = start; + if( ( ret = mbedtls_x509_crt_parse( certs, *p, len1 ) ) < 0 ) + return( ret ); + + *p = *p + len1; + + /** + * Currently we do not check for certificate chain, so we are not handling + * "> 0" case. Return if atleast one certificate in the chain is correctly + * parsed. + **/ + + return( 0 ); +} + +/** + * EncryptedDigest ::= OCTET STRING + **/ +static int pkcs7_get_signature( unsigned char **p, unsigned char *end, + mbedtls_pkcs7_buf *signature ) +{ + int ret; + size_t len = 0; + + ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_OCTET_STRING ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_SIGNATURE + ret ); + + signature->tag = MBEDTLS_ASN1_OCTET_STRING; + signature->len = len; + signature->p = *p; + + *p = *p + len; + + return( 0 ); +} + +/** + * SignerInfos ::= SET of SignerInfo + * SignerInfo ::= SEQUENCE { + * version Version; + * issuerAndSerialNumber IssuerAndSerialNumber, + * digestAlgorithm DigestAlgorithmIdentifier, + * authenticatedAttributes + * [0] IMPLICIT Attributes OPTIONAL, + * digestEncryptionAlgorithm DigestEncryptionAlgorithmIdentifier, + * encryptedDigest EncryptedDigest, + * unauthenticatedAttributes + * [1] IMPLICIT Attributes OPTIONAL, + **/ +static int pkcs7_get_signers_info_set( unsigned char **p, unsigned char *end, + mbedtls_pkcs7_signer_info *signers_set ) +{ + unsigned char *end_set; + int ret; + size_t len = 0; + + ret = mbedtls_asn1_get_tag( p, end, &len, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_SET ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_SIGNER_INFO + ret ); + + end_set = *p + len; + + ret = mbedtls_asn1_get_tag( p, end_set, &len, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_SEQUENCE ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_SIGNER_INFO + ret ); + + end_set = *p + len; + + ret = mbedtls_asn1_get_int( p, end_set, &signers_set->version ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_SIGNER_INFO + ret ); + + ret = mbedtls_asn1_get_tag( p, end_set, &len, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_SEQUENCE ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_SIGNER_INFO + ret ); + + /* Parsing IssuerAndSerialNumber */ + signers_set->issuer_raw.p = *p; + + ret = mbedtls_asn1_get_tag( p, end_set, &len, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_SEQUENCE ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_SIGNER_INFO + ret ); + + ret = mbedtls_x509_get_name( p, *p + len, &signers_set->issuer ); + if( ret != 0 ) + return( ret ); + + signers_set->issuer_raw.len = *p - signers_set->issuer_raw.p; + + ret = mbedtls_x509_get_serial( p, end_set, &signers_set->serial ); + if( ret != 0 ) + return( ret ); + + ret = pkcs7_get_digest_algorithm( p, end_set, + &signers_set->alg_identifier ); + if( ret != 0 ) + return( ret ); + + ret = pkcs7_get_digest_algorithm( p, end_set, + &signers_set->sig_alg_identifier ); + if( ret != 0 ) + return( ret ); + + ret = pkcs7_get_signature( p, end_set, &signers_set->sig ); + if( ret != 0 ) + return( ret ); + + signers_set->next = NULL; + + if (*p != end_set) + return ( MBEDTLS_ERR_PKCS7_INVALID_SIGNER_INFO ); + + return( 0 ); +} + +/** + * SignedData ::= SEQUENCE { + * version Version, + * digestAlgorithms DigestAlgorithmIdentifiers, + * contentInfo ContentInfo, + * certificates + * [0] IMPLICIT ExtendedCertificatesAndCertificates + * OPTIONAL, + * crls + * [0] IMPLICIT CertificateRevocationLists OPTIONAL, + * signerInfos SignerInfos } + */ +static int pkcs7_get_signed_data( unsigned char *buf, size_t buflen, + mbedtls_pkcs7_signed_data *signed_data ) +{ + unsigned char *p = buf; + unsigned char *end = buf + buflen; + unsigned char *end_set; + size_t len = 0; + int ret; + mbedtls_md_type_t md_alg; + + ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_CONSTRUCTED + | MBEDTLS_ASN1_SEQUENCE ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_FORMAT + ret ); + + end_set = p + len; + + /* Get version of signed data */ + ret = pkcs7_get_version( &p, end_set, &signed_data->version ); + if( ret != 0 ) + return( ret ); + + /* Get digest algorithm */ + ret = pkcs7_get_digest_algorithm_set( &p, end_set, + &signed_data->digest_alg_identifiers ); + if( ret != 0 ) + return( ret ); + + ret = mbedtls_oid_get_md_alg( &signed_data->digest_alg_identifiers, &md_alg ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_ALG + ret ); + + /* Do not expect any content */ + ret = pkcs7_get_content_info_type( &p, end_set, &signed_data->content.oid ); + if( ret != 0 ) + return( ret ); + + if( MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS7_DATA, &signed_data->content.oid ) ) + { + return( MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO ) ; + } + + p = p + signed_data->content.oid.len; + + /* Look for certificates, there may or may not be any */ + mbedtls_x509_crt_init( &signed_data->certs ); + ret = pkcs7_get_certificates( &p, end_set, &signed_data->certs ); + if( ret != 0 ) + return( ret ) ; + + /* TODO: optional CRLs go here, currently no CRLs are expected */ + + /* Get signers info */ + ret = pkcs7_get_signers_info_set( &p, end_set, &signed_data->signers ); + if( ret != 0 ) + return( ret ); + + if ( p != end ) + ret = MBEDTLS_ERR_PKCS7_INVALID_FORMAT; + + return( ret ); +} + +int mbedtls_pkcs7_parse_der( const unsigned char *buf, const int buflen, + mbedtls_pkcs7 *pkcs7 ) +{ + unsigned char *start; + unsigned char *end; + size_t len = 0; + int ret; + int isoidset = 0; + + /* use internal buffer for parsing */ + start = (unsigned char *)buf; + end = start + buflen; + + if( !pkcs7 ) + return( MBEDTLS_ERR_PKCS7_BAD_INPUT_DATA ); + + ret = pkcs7_get_content_info_type( &start, end, &pkcs7->content_type_oid ); + if( ret != 0 ) + { + len = buflen; + goto try_data; + } + + if( ! MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS7_DATA, &pkcs7->content_type_oid ) + || ! MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS7_ENCRYPTED_DATA, &pkcs7->content_type_oid ) + || ! MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS7_ENVELOPED_DATA, &pkcs7->content_type_oid ) + || ! MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS7_SIGNED_AND_ENVELOPED_DATA, &pkcs7->content_type_oid ) + || ! MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS7_DIGESTED_DATA, &pkcs7->content_type_oid ) + || ! MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS7_ENCRYPTED_DATA, &pkcs7->content_type_oid ) ) + { + ret = MBEDTLS_ERR_PKCS7_FEATURE_UNAVAILABLE; + goto out; + } + + if( MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS7_SIGNED_DATA, &pkcs7->content_type_oid ) ) + { + ret = MBEDTLS_ERR_PKCS7_BAD_INPUT_DATA; + goto out; + } + + isoidset = 1; + start = start + pkcs7->content_type_oid.len; + + ret = pkcs7_get_next_content_len( &start, end, &len ); + if( ret != 0 ) + goto out; + +try_data: + ret = pkcs7_get_signed_data( start, len, &pkcs7->signed_data ); + if (ret != 0) + goto out; + + if (!isoidset) + { + pkcs7->content_type_oid.tag = MBEDTLS_ASN1_OID; + pkcs7->content_type_oid.len = MBEDTLS_OID_SIZE(MBEDTLS_OID_PKCS7_SIGNED_DATA); + pkcs7->content_type_oid.p = (unsigned char *)MBEDTLS_OID_PKCS7_SIGNED_DATA; + } + + ret = MBEDTLS_PKCS7_SIGNED_DATA; + +out: + if ( ret < 0 ) + mbedtls_pkcs7_free( pkcs7 ); + + return( ret ); +} + +int mbedtls_pkcs7_signed_data_verify( mbedtls_pkcs7 *pkcs7, + mbedtls_x509_crt *cert, + const unsigned char *data, + size_t datalen ) +{ + + int ret; + unsigned char *hash; + mbedtls_pk_context pk_cxt = cert->pk; + const mbedtls_md_info_t *md_info; + mbedtls_md_type_t md_alg; + + ret = mbedtls_oid_get_md_alg( &pkcs7->signed_data.digest_alg_identifiers, &md_alg ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_ALG + ret ); + + md_info = mbedtls_md_info_from_type( md_alg ); + + hash = mbedtls_calloc( mbedtls_md_get_size( md_info ), 1 ); + if( hash == NULL ) { + return( MBEDTLS_ERR_PKCS7_ALLOC_FAILED ); + } + + mbedtls_md( md_info, data, datalen, hash ); + + ret = mbedtls_pk_verify( &pk_cxt, md_alg, hash, sizeof(hash), + pkcs7->signed_data.signers.sig.p, + pkcs7->signed_data.signers.sig.len ); + + mbedtls_free( hash ); + + return( ret ); +} + +int mbedtls_pkcs7_signed_hash_verify( mbedtls_pkcs7 *pkcs7, + mbedtls_x509_crt *cert, + const unsigned char *hash, int hashlen) +{ + int ret; + mbedtls_md_type_t md_alg; + mbedtls_pk_context pk_cxt; + + ret = mbedtls_oid_get_md_alg( &pkcs7->signed_data.digest_alg_identifiers, &md_alg ); + if( ret != 0 ) + return( MBEDTLS_ERR_PKCS7_INVALID_ALG + ret ); + + pk_cxt = cert->pk; + ret = mbedtls_pk_verify( &pk_cxt, md_alg, hash, hashlen, + pkcs7->signed_data.signers.sig.p, + pkcs7->signed_data.signers.sig.len ); + + return ( ret ); +} + +/* + * Unallocate all pkcs7 data + */ +void mbedtls_pkcs7_free( mbedtls_pkcs7 *pkcs7 ) +{ + mbedtls_x509_name *name_cur; + mbedtls_x509_name *name_prv; + + if( pkcs7 == NULL ) + return; + + mbedtls_x509_crt_free( &pkcs7->signed_data.certs ); + mbedtls_x509_crl_free( &pkcs7->signed_data.crl ); + + name_cur = pkcs7->signed_data.signers.issuer.next; + while( name_cur != NULL ) + { + name_prv = name_cur; + name_cur = name_cur->next; + mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) ); + mbedtls_free( name_prv ); + } + + mbedtls_platform_zeroize( pkcs7, sizeof( mbedtls_pkcs7 ) ); +} + +#endif |