diff options
Diffstat (limited to 'src/VBox/Runtime/common/asn1/asn1-encode.cpp')
| -rw-r--r-- | src/VBox/Runtime/common/asn1/asn1-encode.cpp | 476 |
1 files changed, 476 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/asn1/asn1-encode.cpp b/src/VBox/Runtime/common/asn1/asn1-encode.cpp new file mode 100644 index 00000000..ce4a4a1f --- /dev/null +++ b/src/VBox/Runtime/common/asn1/asn1-encode.cpp @@ -0,0 +1,476 @@ +/* $Id: asn1-encode.cpp $ */ +/** @file + * IPRT - ASN.1, Encoding. + */ + +/* + * Copyright (C) 2006-2020 Oracle Corporation + * + * This file is part of VirtualBox Open Source Edition (OSE), as + * available from http://www.virtualbox.org. This file is free software; + * you can redistribute it and/or modify it under the terms of the GNU + * General Public License (GPL) as published by the Free Software + * Foundation, in version 2 as it comes in the "COPYING" file of the + * VirtualBox OSE distribution. VirtualBox OSE is distributed in the + * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL) only, as it comes in the "COPYING.CDDL" file of the + * VirtualBox OSE distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include "internal/iprt.h" +#include <iprt/asn1.h> + +#include <iprt/assert.h> +#include <iprt/bignum.h> +#include <iprt/ctype.h> +#include <iprt/err.h> +#include <iprt/string.h> + +#include <iprt/formats/asn1.h> + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +/** + * Argument package for rtAsn1EncodePrepareCallback passed by RTAsn1EncodePrepare. + */ +typedef struct RTASN1ENCODEPREPARGS +{ + /** The size at this level. */ + uint32_t cb; + /** RTASN1ENCODE_F_XXX. */ + uint32_t fFlags; + /** Pointer to the error info. (optional) */ + PRTERRINFO pErrInfo; +} RTASN1ENCODEPREPARGS; + + +/** + * Argument package for rtAsn1EncodeWriteCallback passed by RTAsn1EncodeWrite. + */ +typedef struct RTASN1ENCODEWRITEARGS +{ + /** RTASN1ENCODE_F_XXX. */ + uint32_t fFlags; + /** Pointer to the writer funtion. */ + PFNRTASN1ENCODEWRITER pfnWriter; + /** User argument to the writer function. */ + void *pvUser; + /** Pointer to the error info. (optional) */ + PRTERRINFO pErrInfo; +} RTASN1ENCODEWRITEARGS; + +/** + * Argument package for rtAsn1EncodeToBufferCallback passed by + * RTAsn1EncodeToBuffer. + */ +typedef struct RTASN1ENCODETOBUFARGS +{ + /** The destination buffer position (incremented while writing). */ + uint8_t *pbDst; + /** The size of the destination buffer left (decremented while writing). */ + size_t cbDst; +} RTASN1ENCODETOBUFARGS; + + +RTDECL(int) RTAsn1EncodeRecalcHdrSize(PRTASN1CORE pAsn1Core, uint32_t fFlags, PRTERRINFO pErrInfo) +{ + AssertReturn((fFlags & RTASN1ENCODE_F_RULE_MASK) == RTASN1ENCODE_F_DER, VERR_INVALID_FLAGS); + int rc = VINF_SUCCESS; + + uint8_t cbHdr; + if ((pAsn1Core->fFlags & (RTASN1CORE_F_PRESENT | RTASN1CORE_F_DUMMY | RTASN1CORE_F_DEFAULT)) == RTASN1CORE_F_PRESENT) + { + /* + * The minimum header size is two bytes. + */ + cbHdr = 2; + + /* + * Add additional bytes for encoding the tag. + */ + uint32_t uTag = pAsn1Core->uTag; + if (uTag >= ASN1_TAG_USE_LONG_FORM) + { + AssertReturn(pAsn1Core->uTag != UINT32_MAX, RTErrInfoSet(pErrInfo, VERR_ASN1_DUMMY_OBJECT, "uTag=UINT32_MAX")); + do + { + cbHdr++; + uTag >>= 7; + } while (uTag > 0); + } + + /* + * Add additional bytes for encoding the content length. + */ + uint32_t cb = pAsn1Core->cb; + if (cb >= 0x80) + { + AssertReturn(cb < _1G, RTErrInfoSetF(pErrInfo, VERR_ASN1_TOO_LONG, "cb=%u (%#x)", cb, cb)); + + if (cb <= UINT32_C(0xffff)) + { + if (cb <= UINT32_C(0xff)) + cbHdr += 1; + else + cbHdr += 2; + } + else + { + if (cb <= UINT32_C(0xffffff)) + cbHdr += 3; + else + cbHdr += 4; + } + } + } + /* + * Not present, dummy or otherwise not encoded. + */ + else + { + cbHdr = 0; + if (pAsn1Core->fFlags & RTASN1CORE_F_DEFAULT) + rc = VINF_ASN1_NOT_ENCODED; + else + { + Assert(RTASN1CORE_IS_DUMMY(pAsn1Core)); + Assert(pAsn1Core->pOps && pAsn1Core->pOps->pfnEnum); + rc = VINF_SUCCESS; + } + } + + /* + * Update the header length. + */ + pAsn1Core->cbHdr = cbHdr; + return rc; +} + + +/** + * @callback_method_impl{FNRTASN1ENUMCALLBACK} + */ +static DECLCALLBACK(int) rtAsn1EncodePrepareCallback(PRTASN1CORE pAsn1Core, const char *pszName, uint32_t uDepth, void *pvUser) +{ + RTASN1ENCODEPREPARGS *pArgs = (RTASN1ENCODEPREPARGS *)pvUser; + RT_NOREF_PV(pszName); + if (RTASN1CORE_IS_PRESENT(pAsn1Core)) + { + /* + * Depth first, where relevant. + */ + uint32_t const cbSaved = pArgs->cb; + if (pAsn1Core->pOps) + { + /* + * Use the encoding preparation method when available. + */ + int rc; + if (pAsn1Core->pOps->pfnEncodePrep) + rc = pAsn1Core->pOps->pfnEncodePrep(pAsn1Core, pArgs->fFlags, pArgs->pErrInfo); + else if (pAsn1Core->pOps->pfnEnum) + { + /* + * Recurse to prepare the child objects (if any). + */ + rc = pAsn1Core->pOps->pfnEnum(pAsn1Core, rtAsn1EncodePrepareCallback, uDepth + 1, pArgs); + if (RT_SUCCESS(rc)) + pAsn1Core->cb = pArgs->cb - cbSaved; + } + else + { + /* + * Must be a primitive type if DER. + */ + if ( (pAsn1Core->fClass & ASN1_TAGFLAG_CONSTRUCTED) + && (pArgs->fFlags & RTASN1ENCODE_F_DER) ) + return RTErrInfoSetF(pArgs->pErrInfo, VERR_ASN1_EXPECTED_PRIMITIVE, + "Expected primitive ASN.1 object: uTag=%#x fClass=%#x cb=%u", + RTASN1CORE_GET_TAG(pAsn1Core), pAsn1Core->fClass, pAsn1Core->cb); + rc = VINF_SUCCESS; + } + if (RT_SUCCESS(rc)) + rc = RTAsn1EncodeRecalcHdrSize(pAsn1Core, pArgs->fFlags, pArgs->pErrInfo); + if (RT_FAILURE(rc)) + return rc; + } + else + { + AssertFailed(); + pAsn1Core->cb = 0; + pAsn1Core->cbHdr = 0; + } + + /* + * Recalculate the output size, thus far. Dummy objects propagates the + * content size, but the header size is zero. Other objects with + * header size zero are not encoded and should be omitted entirely. + */ + if (pAsn1Core->cbHdr > 0 || RTASN1CORE_IS_DUMMY(pAsn1Core)) + pArgs->cb = RTASN1CORE_GET_RAW_ASN1_SIZE(pAsn1Core) + cbSaved; + else + pArgs->cb = cbSaved; + } + + return VINF_SUCCESS; +} + + +RTDECL(int) RTAsn1EncodePrepare(PRTASN1CORE pRoot, uint32_t fFlags, uint32_t *pcbEncoded, PRTERRINFO pErrInfo) +{ + AssertReturn((fFlags & RTASN1ENCODE_F_RULE_MASK) == RTASN1ENCODE_F_DER, VERR_INVALID_FLAGS); + + /* + * This is implemented as a recursive enumeration of the ASN.1 object structure. + */ + RTASN1ENCODEPREPARGS Args; + Args.cb = 0; + Args.fFlags = fFlags; + Args.pErrInfo = pErrInfo; + int rc = rtAsn1EncodePrepareCallback(pRoot, "root", 0, &Args); + if (pcbEncoded) + *pcbEncoded = RTASN1CORE_GET_RAW_ASN1_SIZE(pRoot); + return rc; +} + + +RTDECL(int) RTAsn1EncodeWriteHeader(PCRTASN1CORE pAsn1Core, uint32_t fFlags, FNRTASN1ENCODEWRITER pfnWriter, void *pvUser, + PRTERRINFO pErrInfo) +{ + AssertReturn((fFlags & RTASN1ENCODE_F_RULE_MASK) == RTASN1ENCODE_F_DER, VERR_INVALID_FLAGS); + + if ((pAsn1Core->fFlags & (RTASN1CORE_F_PRESENT | RTASN1CORE_F_DUMMY | RTASN1CORE_F_DEFAULT)) == RTASN1CORE_F_PRESENT) + { + uint8_t abHdr[16]; /* 2 + max 5 tag + max 4 length = 11 */ + uint8_t *pbDst = &abHdr[0]; + + /* + * Encode the tag. + */ + uint32_t uTag = pAsn1Core->uTag; + if (uTag < ASN1_TAG_USE_LONG_FORM) + *pbDst++ = (uint8_t)uTag | (pAsn1Core->fClass & ~ASN1_TAG_MASK); + else + { + AssertReturn(pAsn1Core->uTag != UINT32_MAX, RTErrInfoSet(pErrInfo, VERR_ASN1_DUMMY_OBJECT, "uTag=UINT32_MAX")); + + /* In the long form, the tag is encoded MSB style with the 8th bit + of each byte indicating the whether there are more byte. */ + *pbDst++ = ASN1_TAG_USE_LONG_FORM | (pAsn1Core->fClass & ~ASN1_TAG_MASK); + if (uTag <= UINT32_C(0x7f)) + *pbDst++ = uTag; + else if (uTag <= UINT32_C(0x3fff)) /* 2**(7*2) = 0x4000 (16384) */ + { + *pbDst++ = (uTag >> 7) | 0x80; + *pbDst++ = uTag & 0x7f; + } + else if (uTag <= UINT32_C(0x1fffff)) /* 2**(7*3) = 0x200000 (2097152) */ + { + *pbDst++ = (uTag >> 14) | 0x80; + *pbDst++ = ((uTag >> 7) & 0x7f) | 0x80; + *pbDst++ = uTag & 0x7f; + } + else if (uTag <= UINT32_C(0xfffffff)) /* 2**(7*4) = 0x10000000 (268435456) */ + { + *pbDst++ = (uTag >> 21) | 0x80; + *pbDst++ = ((uTag >> 14) & 0x7f) | 0x80; + *pbDst++ = ((uTag >> 7) & 0x7f) | 0x80; + *pbDst++ = uTag & 0x7f; + } + else + { + *pbDst++ = (uTag >> 28) | 0x80; + *pbDst++ = ((uTag >> 21) & 0x7f) | 0x80; + *pbDst++ = ((uTag >> 14) & 0x7f) | 0x80; + *pbDst++ = ((uTag >> 7) & 0x7f) | 0x80; + *pbDst++ = uTag & 0x7f; + } + } + + /* + * Encode the length. + */ + uint32_t cb = pAsn1Core->cb; + if (cb < 0x80) + *pbDst++ = (uint8_t)cb; + else + { + AssertReturn(cb < _1G, RTErrInfoSetF(pErrInfo, VERR_ASN1_TOO_LONG, "cb=%u (%#x)", cb, cb)); + + if (cb <= UINT32_C(0xffff)) + { + if (cb <= UINT32_C(0xff)) + { + pbDst[0] = 0x81; + pbDst[1] = (uint8_t)cb; + pbDst += 2; + } + else + { + pbDst[0] = 0x82; + pbDst[1] = cb >> 8; + pbDst[2] = (uint8_t)cb; + pbDst += 3; + } + } + else + { + if (cb <= UINT32_C(0xffffff)) + { + pbDst[0] = 0x83; + pbDst[1] = (uint8_t)(cb >> 16); + pbDst[2] = (uint8_t)(cb >> 8); + pbDst[3] = (uint8_t)cb; + pbDst += 4; + } + else + { + pbDst[0] = 0x84; + pbDst[1] = (uint8_t)(cb >> 24); + pbDst[2] = (uint8_t)(cb >> 16); + pbDst[3] = (uint8_t)(cb >> 8); + pbDst[4] = (uint8_t)cb; + pbDst += 5; + } + } + } + + size_t const cbHdr = pbDst - &abHdr[0]; + Assert(sizeof(abHdr) >= cbHdr); + Assert(pAsn1Core->cbHdr == cbHdr); + + /* + * Write it. + */ + return pfnWriter(abHdr, cbHdr, pvUser, pErrInfo); + } + + /* + * Not present, dummy or otherwise not encoded. + */ + Assert(pAsn1Core->cbHdr == 0); + if (pAsn1Core->fFlags & RTASN1CORE_F_DEFAULT) + return VINF_ASN1_NOT_ENCODED; + Assert(RTASN1CORE_IS_DUMMY(pAsn1Core)); + Assert(pAsn1Core->pOps && pAsn1Core->pOps->pfnEnum); + return VINF_SUCCESS; +} + + +/** + * @callback_method_impl{FNRTASN1ENUMCALLBACK} + */ +static DECLCALLBACK(int) rtAsn1EncodeWriteCallback(PRTASN1CORE pAsn1Core, const char *pszName, uint32_t uDepth, void *pvUser) +{ + RTASN1ENCODEWRITEARGS *pArgs = (RTASN1ENCODEWRITEARGS *)pvUser; + RT_NOREF_PV(pszName); + int rc; + if (RTASN1CORE_IS_PRESENT(pAsn1Core)) + { + /* + * If there is an write method, use it. + */ + if ( pAsn1Core->pOps + && pAsn1Core->pOps->pfnEncodeWrite) + rc = pAsn1Core->pOps->pfnEncodeWrite(pAsn1Core, pArgs->fFlags, pArgs->pfnWriter, pArgs->pvUser, pArgs->pErrInfo); + else + { + /* + * Generic path. Start by writing the header for this object. + */ + rc = RTAsn1EncodeWriteHeader(pAsn1Core, pArgs->fFlags, pArgs->pfnWriter, pArgs->pvUser, pArgs->pErrInfo); + if (RT_SUCCESS(rc)) + { + /* + * If there is an enum function, call it to assemble the content. + * Otherwise ASSUME the pointer in the header points to the content. + */ + if ( pAsn1Core->pOps + && pAsn1Core->pOps->pfnEnum) + { + if (rc != VINF_ASN1_NOT_ENCODED) + rc = pAsn1Core->pOps->pfnEnum(pAsn1Core, rtAsn1EncodeWriteCallback, uDepth + 1, pArgs); + } + else if (pAsn1Core->cb && rc != VINF_ASN1_NOT_ENCODED) + { + Assert(!RTASN1CORE_IS_DUMMY(pAsn1Core)); + AssertPtrReturn(pAsn1Core->uData.pv, + RTErrInfoSetF(pArgs->pErrInfo, VERR_ASN1_INVALID_DATA_POINTER, + "Invalid uData pointer %p for no pfnEnum object with %#x bytes of content", + pAsn1Core->uData.pv, pAsn1Core->cb)); + rc = pArgs->pfnWriter(pAsn1Core->uData.pv, pAsn1Core->cb, pArgs->pvUser, pArgs->pErrInfo); + } + } + } + if (RT_SUCCESS(rc)) + rc = VINF_SUCCESS; + } + else + rc = VINF_SUCCESS; + return rc; +} + + +RTDECL(int) RTAsn1EncodeWrite(PCRTASN1CORE pRoot, uint32_t fFlags, FNRTASN1ENCODEWRITER pfnWriter, void *pvUser, + PRTERRINFO pErrInfo) +{ + AssertReturn((fFlags & RTASN1ENCODE_F_RULE_MASK) == RTASN1ENCODE_F_DER, VERR_INVALID_FLAGS); + + /* + * This is implemented as a recursive enumeration of the ASN.1 object structure. + */ + RTASN1ENCODEWRITEARGS Args; + Args.fFlags = fFlags; + Args.pfnWriter = pfnWriter; + Args.pvUser = pvUser; + Args.pErrInfo = pErrInfo; + return rtAsn1EncodeWriteCallback((PRTASN1CORE)pRoot, "root", 0, &Args); +} + + +static DECLCALLBACK(int) rtAsn1EncodeToBufferCallback(const void *pvBuf, size_t cbToWrite, void *pvUser, PRTERRINFO pErrInfo) +{ + RTASN1ENCODETOBUFARGS *pArgs = (RTASN1ENCODETOBUFARGS *)pvUser; + if (RT_LIKELY(pArgs->cbDst >= cbToWrite)) + { + memcpy(pArgs->pbDst, pvBuf, cbToWrite); + pArgs->cbDst -= cbToWrite; + pArgs->pbDst += cbToWrite; + return VINF_SUCCESS; + } + + /* + * Overflow. + */ + if (pArgs->cbDst) + { + memcpy(pArgs->pbDst, pvBuf, pArgs->cbDst); + pArgs->pbDst -= pArgs->cbDst; + pArgs->cbDst = 0; + } + RT_NOREF_PV(pErrInfo); + return VERR_BUFFER_OVERFLOW; +} + + +RTDECL(int) RTAsn1EncodeToBuffer(PCRTASN1CORE pRoot, uint32_t fFlags, void *pvBuf, size_t cbBuf, PRTERRINFO pErrInfo) +{ + RTASN1ENCODETOBUFARGS Args; + Args.pbDst = (uint8_t *)pvBuf; + Args.cbDst = cbBuf; + return RTAsn1EncodeWrite(pRoot, fFlags, rtAsn1EncodeToBufferCallback, &Args, pErrInfo); +} + |