Algorithms - PKCS7

Functions
int	wc_PKCS7_InitWithCert (PKCS7 *pkcs7, byte *cert, word32 certSz)
	This function initializes a PKCS7 structure with a DER-formatted certificate. To initialize an empty PKCS7 structure, one can pass in a NULL cert and 0 for certSz. More...
void	wc_PKCS7_Free (PKCS7 *pkcs7)
	This function releases any memory allocated by a PKCS7 initializer. More...
int	wc_PKCS7_EncodeData (PKCS7 *pkcs7, byte *output, word32 outputSz)
	This function builds the PKCS7 data content type, encoding the PKCS7 structure into a buffer containing a parsable PKCS7 data packet. More...
int	wc_PKCS7_EncodeSignedData (PKCS7 *pkcs7, byte *output, word32 outputSz)
	This function builds the PKCS7 signed data content type, encoding the PKCS7 structure into a buffer containing a parsable PKCS7 signed data packet. More...
int	wc_PKCS7_EncodeSignedData_ex (PKCS7 *pkcs7, const byte *hashBuf, word32 hashSz, byte *outputHead, word32 *outputHeadSz, byte *outputFoot, word32 *outputFootSz)
	This function builds the PKCS7 signed data content type, encoding the PKCS7 structure into a header and footer buffer containing a parsable PKCS7 signed data packet. This does not include the content. A hash must be computed and provided for the data. More...
int	wc_PKCS7_VerifySignedData (PKCS7 *pkcs7, byte *pkiMsg, word32 pkiMsgSz)
	This function takes in a transmitted PKCS7 signed data message, extracts the certificate list and certificate revocation list, and then verifies the signature. It stores the extracted content in the given PKCS7 structure. More...
int	wc_PKCS7_VerifySignedData_ex (PKCS7 *pkcs7, const byte *hashBuf, word32 hashSz, byte *pkiMsgHead, word32 pkiMsgHeadSz, byte *pkiMsgFoot, word32 pkiMsgFootSz)
	This function takes in a transmitted PKCS7 signed data message as hash/header/footer, then extracts the certificate list and certificate revocation list, and then verifies the signature. It stores the extracted content in the given PKCS7 structure. More...
int	wc_PKCS7_EncodeEnvelopedData (PKCS7 *pkcs7, byte *output, word32 outputSz)
	This function builds the PKCS7 enveloped data content type, encoding the PKCS7 structure into a buffer containing a parsable PKCS7 enveloped data packet. More...
int	wc_PKCS7_DecodeEnvelopedData (PKCS7 *pkcs7, byte *pkiMsg, word32 pkiMsgSz, byte *output, word32 outputSz)
	This function unwraps and decrypts a PKCS7 enveloped data content type, decoding the message into output. It uses the private key of the PKCS7 object passed in to decrypt the message. More...

Detailed Description

Function Documentation

wc_PKCS7_DecodeEnvelopedData()

int wc_PKCS7_DecodeEnvelopedData	(	PKCS7 *	pkcs7,
		byte *	pkiMsg,
		word32	pkiMsgSz,
		byte *	output,
		word32	outputSz
	)

This function unwraps and decrypts a PKCS7 enveloped data content type, decoding the message into output. It uses the private key of the PKCS7 object passed in to decrypt the message.

Returns

On successfully extracting the information from the message, returns the bytes written to output

BAD_FUNC_ARG Returned if one of the input parameters is invalid

ASN_PARSE_E Returned if there is an error parsing from the given pkiMsg

PKCS7_OID_E Returned if the given pkiMsg is not an enveloped data type

ASN_VERSION_E Returned if the PKCS7 signer info is not version 0

MEMORY_E Returned if there is an error allocating memory

ALGO_ID_E Returned if the PKCS7 structure is using an unsupported algorithm type. Currently, only DESb and DES3b are supported for encryption, with RSAk for signature generation

PKCS7_RECIP_E Returned if there is no recipient found in the enveloped data that matches the recipient provided

RSA_BUFFER_E Returned if there is an error during RSA signature verification due to buffer error, output too small or input too large.

MP_INIT_E may be returned if there is an error during signature verification

MP_READ_E may be returned if there is an error during signature verification

MP_CMP_E may be returned if there is an error during signature verification

MP_INVMOD_E may be returned if there is an error during signature verification

MP_EXPTMOD_E may be returned if there is an error during signature verification

MP_MOD_E may be returned if there is an error during signature verification

MP_MUL_E may be returned if there is an error during signature verification

MP_ADD_E may be returned if there is an error during signature verification

MP_MULMOD_E may be returned if there is an error during signature verification

MP_TO_E may be returned if there is an error during signature verification

MP_MEM may be returned if there is an error during signature verification

Parameters

pkcs7	pointer to the PKCS7 structure containing the private key with which to decode the enveloped data package
pkiMsg	pointer to the buffer containing the enveloped data package
pkiMsgSz	size of the enveloped data package
output	pointer to the buffer in which to store the decoded message
outputSz	size available in the output buffer

Example

PKCS7 pkcs7;
byte received[] = { }; // initialize with received enveloped message
byte decoded[FOURK_BUF];
int decodedSz;
 
// initialize pkcs7 with certificate
// update key
pkcs7.privateKey = key;
pkcs7.privateKeySz = keySz;
 
decodedSz = wc_PKCS7_DecodeEnvelopedData(&pkcs7, received,
sizeof(received),decoded, sizeof(decoded));
if ( decodedSz != 0 ) {
    // error decoding message
}

See also

wc_PKCS7_InitWithCert

wc_PKCS7_EncodeEnvelopedData

wc_PKCS7_EncodeData()

int wc_PKCS7_EncodeData	(	PKCS7 *	pkcs7,
		byte *	output,
		word32	outputSz
	)

This function builds the PKCS7 data content type, encoding the PKCS7 structure into a buffer containing a parsable PKCS7 data packet.

Returns

Success On successfully encoding the PKCS7 data into the buffer, returns the index parsed up to in the PKCS7 structure. This index also corresponds to the bytes written to the output buffer.

BUFFER_E Returned if the given buffer is not large enough to hold the encoded certificate

Parameters

pkcs7	pointer to the PKCS7 structure to encode
output	pointer to the buffer in which to store the encoded certificate
outputSz	size available in the output buffer

Example

PKCS7 pkcs7;
int ret;
 
byte derBuff[] = { }; // initialize with DER-encoded certificate
byte pkcs7Buff[FOURK_BUF];
 
wc_PKCS7_InitWithCert(&pkcs7, derBuff, sizeof(derBuff));
// update message and data to encode
pkcs7.privateKey = key;
pkcs7.privateKeySz = keySz;
pkcs7.content = data;
pkcs7.contentSz = dataSz;
... etc.
 
ret = wc_PKCS7_EncodeData(&pkcs7, pkcs7Buff, sizeof(pkcs7Buff));
if ( ret != 0 ) {
    // error encoding into output buffer
}

See also

wc_PKCS7_InitWithCert

wc_PKCS7_EncodeEnvelopedData()

int wc_PKCS7_EncodeEnvelopedData	(	PKCS7 *	pkcs7,
		byte *	output,
		word32	outputSz
	)

This function builds the PKCS7 enveloped data content type, encoding the PKCS7 structure into a buffer containing a parsable PKCS7 enveloped data packet.

Returns

Success Returned on successfully encoding the message in enveloped data format, returns the size written to the output buffer

BAD_FUNC_ARG: Returned if one of the input parameters is invalid, or if the PKCS7 structure is missing required elements

ALGO_ID_E Returned if the PKCS7 structure is using an unsupported algorithm type. Currently, only DESb and DES3b are supported

BUFFER_E Returned if the given output buffer is too small to store the output data

MEMORY_E Returned if there is an error allocating memory

RNG_FAILURE_E Returned if there is an error initializing the random number generator for encryption

DRBG_FAILED Returned if there is an error generating numbers with the random number generator used for encryption

Parameters

pkcs7	pointer to the PKCS7 structure to encode
output	pointer to the buffer in which to store the encoded certificate
outputSz	size available in the output buffer

Example

PKCS7 pkcs7;
int ret;
 
byte derBuff[] = { }; // initialize with DER-encoded certificate
byte pkcs7Buff[FOURK_BUF];
 
wc_PKCS7_InitWithCert(&pkcs7, derBuff, sizeof(derBuff));
// update message and data to encode
pkcs7.privateKey = key;
pkcs7.privateKeySz = keySz;
pkcs7.content = data;
pkcs7.contentSz = dataSz;
... etc.
 
ret = wc_PKCS7_EncodeEnvelopedData(&pkcs7, pkcs7Buff, sizeof(pkcs7Buff));
if ( ret != 0 ) {
    // error encoding into output buffer
}

See also

wc_PKCS7_InitWithCert

wc_PKCS7_DecodeEnvelopedData

wc_PKCS7_EncodeSignedData()

int wc_PKCS7_EncodeSignedData	(	PKCS7 *	pkcs7,
		byte *	output,
		word32	outputSz
	)

This function builds the PKCS7 signed data content type, encoding the PKCS7 structure into a buffer containing a parsable PKCS7 signed data packet.

Returns

Success On successfully encoding the PKCS7 data into the buffer, returns the index parsed up to in the PKCS7 structure. This index also corresponds to the bytes written to the output buffer.

BAD_FUNC_ARG Returned if the PKCS7 structure is missing one or more required elements to generate a signed data packet

MEMORY_E Returned if there is an error allocating memory

PUBLIC_KEY_E Returned if there is an error parsing the public key

RSA_BUFFER_E Returned if buffer error, output too small or input too large

BUFFER_E Returned if the given buffer is not large enough to hold the encoded certificate

MP_INIT_E may be returned if there is an error generating the signature

MP_READ_E may be returned if there is an error generating the signature

MP_CMP_E may be returned if there is an error generating the signature

MP_INVMOD_E may be returned if there is an error generating the signature

MP_EXPTMOD_E may be returned if there is an error generating the signature

MP_MOD_E may be returned if there is an error generating the signature

MP_MUL_E may be returned if there is an error generating the signature

MP_ADD_E may be returned if there is an error generating the signature

MP_MULMOD_E may be returned if there is an error generating the signature

MP_TO_E may be returned if there is an error generating the signature

MP_MEM may be returned if there is an error generating the signature

Parameters

pkcs7	pointer to the PKCS7 structure to encode
output	pointer to the buffer in which to store the encoded certificate
outputSz	size available in the output buffer

Example

PKCS7 pkcs7;
int ret;
 
byte data[] = {}; // initialize with data to sign
byte derBuff[] = { }; // initialize with DER-encoded certificate
byte pkcs7Buff[FOURK_BUF];
 
wc_PKCS7_InitWithCert(&pkcs7, derBuff, sizeof(derBuff));
// update message and data to encode
pkcs7.privateKey = key;
pkcs7.privateKeySz = keySz;
pkcs7.content = data;
pkcs7.contentSz = dataSz;
pkcs7.hashOID = SHAh;
pkcs7.rng = &rng;
... etc.
 
ret = wc_PKCS7_EncodeSignedData(&pkcs7, pkcs7Buff, sizeof(pkcs7Buff));
if ( ret != 0 ) {
    // error encoding into output buffer
}
 
wc_PKCS7_Free(&pkcs7);

See also

wc_PKCS7_InitWithCert

wc_PKCS7_VerifySignedData

wc_PKCS7_EncodeSignedData_ex()

int wc_PKCS7_EncodeSignedData_ex	(	PKCS7 *	pkcs7,
		const byte *	hashBuf,
		word32	hashSz,
		byte *	outputHead,
		word32 *	outputHeadSz,
		byte *	outputFoot,
		word32 *	outputFootSz
	)

This function builds the PKCS7 signed data content type, encoding the PKCS7 structure into a header and footer buffer containing a parsable PKCS7 signed data packet. This does not include the content. A hash must be computed and provided for the data.

Returns

0=Success

BAD_FUNC_ARG Returned if the PKCS7 structure is missing one or more required elements to generate a signed data packet

MEMORY_E Returned if there is an error allocating memory

PUBLIC_KEY_E Returned if there is an error parsing the public key

RSA_BUFFER_E Returned if buffer error, output too small or input too large

BUFFER_E Returned if the given buffer is not large enough to hold the encoded certificate

MP_INIT_E may be returned if there is an error generating the signature

MP_READ_E may be returned if there is an error generating the signature

MP_CMP_E may be returned if there is an error generating the signature

MP_INVMOD_E may be returned if there is an error generating the signature

MP_EXPTMOD_E may be returned if there is an error generating the signature

MP_MOD_E may be returned if there is an error generating the signature

MP_MUL_E may be returned if there is an error generating the signature

MP_ADD_E may be returned if there is an error generating the signature

MP_MULMOD_E may be returned if there is an error generating the signature

MP_TO_E may be returned if there is an error generating the signature

MP_MEM may be returned if there is an error generating the signature

Parameters

pkcs7	pointer to the PKCS7 structure to encode
hashBuf	pointer to computed hash for the content data
hashSz	size of the digest
outputHead	pointer to the buffer in which to store the encoded certificate header
outputHeadSz	pointer populated with size of output header buffer and returns actual size
outputFoot	pointer to the buffer in which to store the encoded certificate footer
outputFootSz	pointer populated with size of output footer buffer and returns actual size

Example

PKCS7 pkcs7;
int ret;
byte derBuff[] = { }; // initialize with DER-encoded certificate
byte data[] = {}; // initialize with data to sign
byte pkcs7HeadBuff[FOURK_BUF/2];
byte pkcs7FootBuff[FOURK_BUF/2];
word32 pkcs7HeadSz = (word32)sizeof(pkcs7HeadBuff);
word32 pkcs7FootSz = (word32)sizeof(pkcs7HeadBuff);
enum wc_HashType hashType = WC_HASH_TYPE_SHA;
byte   hashBuf[WC_MAX_DIGEST_SIZE];
word32 hashSz = wc_HashGetDigestSize(hashType);
 
wc_PKCS7_InitWithCert(&pkcs7, derBuff, sizeof(derBuff));
// update message and data to encode
pkcs7.privateKey = key;
pkcs7.privateKeySz = keySz;
pkcs7.content = NULL;
pkcs7.contentSz = dataSz;
pkcs7.hashOID = SHAh;
pkcs7.rng = &rng;
... etc.
 
// calculate hash for content
ret = wc_HashInit(&hash, hashType);
if (ret == 0) {
    ret = wc_HashUpdate(&hash, hashType, data, sizeof(data));
    if (ret == 0) {
        ret = wc_HashFinal(&hash, hashType, hashBuf);
    }
    wc_HashFree(&hash, hashType);
}
 
ret = wc_PKCS7_EncodeSignedData_ex(&pkcs7, hashBuf, hashSz, pkcs7HeadBuff,
    &pkcs7HeadSz, pkcs7FootBuff, &pkcs7FootSz);
if ( ret != 0 ) {
    // error encoding into output buffer
}
 
wc_PKCS7_Free(&pkcs7);

See also

wc_PKCS7_InitWithCert

wc_PKCS7_VerifySignedData_ex

wc_PKCS7_Free()

void wc_PKCS7_Free

(

PKCS7 *

pkcs7

)

This function releases any memory allocated by a PKCS7 initializer.

Returns

none No returns.

Parameters

pkcs7

pointer to the PKCS7 structure to free

Example

PKCS7 pkcs7;
// initialize and use PKCS7 object
 
wc_PKCS7_Free(pkcs7);

See also

wc_PKCS7_InitWithCert

wc_PKCS7_InitWithCert()

int wc_PKCS7_InitWithCert	(	PKCS7 *	pkcs7,
		byte *	cert,
		word32	certSz
	)

This function initializes a PKCS7 structure with a DER-formatted certificate. To initialize an empty PKCS7 structure, one can pass in a NULL cert and 0 for certSz.

Returns

0 Returned on successfully initializing the PKCS7 structure

MEMORY_E Returned if there is an error allocating memory with XMALLOC

ASN_PARSE_E Returned if there is an error parsing the cert header

ASN_OBJECT_ID_E Returned if there is an error parsing the encryption type from the cert

ASN_EXPECT_0_E Returned if there is a formatting error in the encryption specification of the cert file

ASN_BEFORE_DATE_E Returned if the date is before the certificate start date

ASN_AFTER_DATE_E Returned if the date is after the certificate expiration date

ASN_BITSTR_E Returned if there is an error parsing a bit string from the certificate

ECC_CURVE_OID_E Returned if there is an error parsing the ECC key from the certificate

ASN_UNKNOWN_OID_E Returned if the certificate is using an unknown key object id

ASN_VERSION_E Returned if the ALLOW_V1_EXTENSIONS option is not defined and the certificate is a V1 or V2 certificate

BAD_FUNC_ARG Returned if there is an error processing the certificate extension

ASN_CRIT_EXT_E Returned if an unfamiliar critical extension is encountered in processing the certificate

ASN_SIG_OID_E Returned if the signature encryption type is not the same as the encryption type of the certificate in the provided file

ASN_SIG_CONFIRM_E Returned if confirming the certification signature fails

ASN_NAME_INVALID_E Returned if the certificate’s name is not permitted by the CA name constraints

ASN_NO_SIGNER_E Returned if there is no CA signer to verify the certificate’s authenticity

Parameters

pkcs7	pointer to the PKCS7 structure in which to store the decoded cert
cert	pointer to a buffer containing a DER formatted ASN.1 certificate with which to initialize the PKCS7 structure
certSz	size of the certificate buffer

Example

PKCS7 pkcs7;
byte derBuff[] = { }; // initialize with DER-encoded certificate
if ( wc_PKCS7_InitWithCert(&pkcs7, derBuff, sizeof(derBuff)) != 0 ) {
    // error parsing certificate into pkcs7 format
}

See also

wc_PKCS7_Free

wc_PKCS7_VerifySignedData()

int wc_PKCS7_VerifySignedData	(	PKCS7 *	pkcs7,
		byte *	pkiMsg,
		word32	pkiMsgSz
	)

This function takes in a transmitted PKCS7 signed data message, extracts the certificate list and certificate revocation list, and then verifies the signature. It stores the extracted content in the given PKCS7 structure.

Returns

0 Returned on successfully extracting the information from the message

BAD_FUNC_ARG Returned if one of the input parameters is invalid

ASN_PARSE_E Returned if there is an error parsing from the given pkiMsg

PKCS7_OID_E Returned if the given pkiMsg is not a signed data type

ASN_VERSION_E Returned if the PKCS7 signer info is not version 1

MEMORY_E Returned if there is an error allocating memory

PUBLIC_KEY_E Returned if there is an error parsing the public key

RSA_BUFFER_E Returned if buffer error, output too small or input too large

BUFFER_E Returned if the given buffer is not large enough to hold the encoded certificate

MP_INIT_E may be returned if there is an error generating the signature

MP_READ_E may be returned if there is an error generating the signature

MP_CMP_E may be returned if there is an error generating the signature

MP_INVMOD_E may be returned if there is an error generating the signature

MP_EXPTMOD_E may be returned if there is an error generating the signature

MP_MOD_E may be returned if there is an error generating the signature

MP_MUL_E may be returned if there is an error generating the signature

MP_ADD_E may be returned if there is an error generating the signature

MP_MULMOD_E may be returned if there is an error generating the signature

MP_TO_E may be returned if there is an error generating the signature

MP_MEM may be returned if there is an error generating the signature

Parameters

pkcs7	pointer to the PKCS7 structure in which to store the parsed certificates
pkiMsg	pointer to the buffer containing the signed message to verify and decode
pkiMsgSz	size of the signed message

Example

PKCS7 pkcs7;
int ret;
byte pkcs7Buff[] = {}; // the PKCS7 signature
 
wc_PKCS7_InitWithCert(&pkcs7, NULL, 0);
// update message and data to encode
pkcs7.privateKey = key;
pkcs7.privateKeySz = keySz;
pkcs7.content = data;
pkcs7.contentSz = dataSz;
... etc.
 
ret = wc_PKCS7_VerifySignedData(&pkcs7, pkcs7Buff, sizeof(pkcs7Buff));
if ( ret != 0 ) {
    // error encoding into output buffer
}
 
wc_PKCS7_Free(&pkcs7);

See also

wc_PKCS7_InitWithCert

wc_PKCS7_EncodeSignedData

wc_PKCS7_VerifySignedData_ex()

int wc_PKCS7_VerifySignedData_ex	(	PKCS7 *	pkcs7,
		const byte *	hashBuf,
		word32	hashSz,
		byte *	pkiMsgHead,
		word32	pkiMsgHeadSz,
		byte *	pkiMsgFoot,
		word32	pkiMsgFootSz
	)

This function takes in a transmitted PKCS7 signed data message as hash/header/footer, then extracts the certificate list and certificate revocation list, and then verifies the signature. It stores the extracted content in the given PKCS7 structure.

Returns

0 Returned on successfully extracting the information from the message

BAD_FUNC_ARG Returned if one of the input parameters is invalid

ASN_PARSE_E Returned if there is an error parsing from the given pkiMsg

PKCS7_OID_E Returned if the given pkiMsg is not a signed data type

ASN_VERSION_E Returned if the PKCS7 signer info is not version 1

MEMORY_E Returned if there is an error allocating memory

PUBLIC_KEY_E Returned if there is an error parsing the public key

RSA_BUFFER_E Returned if buffer error, output too small or input too large

BUFFER_E Returned if the given buffer is not large enough to hold the encoded certificate

MP_INIT_E may be returned if there is an error generating the signature

MP_READ_E may be returned if there is an error generating the signature

MP_CMP_E may be returned if there is an error generating the signature

MP_INVMOD_E may be returned if there is an error generating the signature

MP_EXPTMOD_E may be returned if there is an error generating the signature

MP_MOD_E may be returned if there is an error generating the signature

MP_MUL_E may be returned if there is an error generating the signature

MP_ADD_E may be returned if there is an error generating the signature

MP_MULMOD_E may be returned if there is an error generating the signature

MP_TO_E may be returned if there is an error generating the signature

MP_MEM may be returned if there is an error generating the signature

Parameters

pkcs7	pointer to the PKCS7 structure in which to store the parsed certificates
hashBuf	pointer to computed hash for the content data
hashSz	size of the digest
pkiMsgHead	pointer to the buffer containing the signed message header to verify and decode
pkiMsgHeadSz	size of the signed message header
pkiMsgFoot	pointer to the buffer containing the signed message footer to verify and decode
pkiMsgFootSz	size of the signed message footer

Example

PKCS7 pkcs7;
int ret;
byte data[] = {}; // initialize with data to sign
byte pkcs7HeadBuff[] = {}; // initialize with PKCS7 header
byte pkcs7FootBuff[] = {}; // initialize with PKCS7 footer
enum wc_HashType hashType = WC_HASH_TYPE_SHA;
byte   hashBuf[WC_MAX_DIGEST_SIZE];
word32 hashSz = wc_HashGetDigestSize(hashType);
 
wc_PKCS7_InitWithCert(&pkcs7, NULL, 0);
// update message and data to encode
pkcs7.privateKey = key;
pkcs7.privateKeySz = keySz;
pkcs7.content = NULL;
pkcs7.contentSz = dataSz;
pkcs7.rng = &rng;
... etc.
 
// calculate hash for content
ret = wc_HashInit(&hash, hashType);
if (ret == 0) {
    ret = wc_HashUpdate(&hash, hashType, data, sizeof(data));
    if (ret == 0) {
        ret = wc_HashFinal(&hash, hashType, hashBuf);
    }
    wc_HashFree(&hash, hashType);
}
 
ret = wc_PKCS7_VerifySignedData_ex(&pkcs7, hashBuf, hashSz, pkcs7HeadBuff,
    sizeof(pkcs7HeadBuff), pkcs7FootBuff, sizeof(pkcs7FootBuff));
if ( ret != 0 ) {
    // error encoding into output buffer
}
 
wc_PKCS7_Free(&pkcs7);

See also

wc_PKCS7_InitWithCert

wc_PKCS7_EncodeSignedData_ex