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pk/rsa: move RSA parse/write private/public key functions to rsa module

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These functions are meant to be used internally, so their prototype
declaration is kept into rsa_internal.h.

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
This commit is contained in:
Valerio Setti 2024-01-23 10:48:45 +01:00
parent 429cd50ac8
commit b328c44932
4 changed files with 422 additions and 382 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

252
library/pkparse.c
View File

@ -28,6 +28,7 @@
/* Key types */
#if defined(MBEDTLS_RSA_C)
#include "mbedtls/rsa.h"
#include "rsa_internal.h"
#endif
/* Extended formats */
@ -757,68 +758,6 @@ static int pk_parse_key_rfc8410_der(mbedtls_pk_context *pk,
#endif /* MBEDTLS_PK_HAVE_ECC_KEYS */
#if defined(MBEDTLS_RSA_C)
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
static int mbedtls_rsa_pubkey_parse(mbedtls_rsa_context *rsa,
unsigned char **p,
const unsigned char *end)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
if ((ret = mbedtls_asn1_get_tag(p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
}
if (*p + len != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
/* Import N */
if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
}
if ((ret = mbedtls_rsa_import_raw(rsa, *p, len, NULL, 0, NULL, 0,
NULL, 0, NULL, 0)) != 0) {
return MBEDTLS_ERR_PK_INVALID_PUBKEY;
}
*p += len;
/* Import E */
if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
}
if ((ret = mbedtls_rsa_import_raw(rsa, NULL, 0, NULL, 0, NULL, 0,
NULL, 0, *p, len)) != 0) {
return MBEDTLS_ERR_PK_INVALID_PUBKEY;
}
*p += len;
if (mbedtls_rsa_complete(rsa) != 0 ||
mbedtls_rsa_check_pubkey(rsa) != 0) {
return MBEDTLS_ERR_PK_INVALID_PUBKEY;
}
if (*p != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
return 0;
}
#endif /* MBEDTLS_RSA_C */
/* Get a PK algorithm identifier
*
* AlgorithmIdentifier ::= SEQUENCE {
@ -944,195 +883,6 @@ int mbedtls_pk_parse_subpubkey(unsigned char **p, const unsigned char *end,
return ret;
}
#if defined(MBEDTLS_RSA_C)
/*
* Wrapper around mbedtls_asn1_get_mpi() that rejects zero.
*
* The value zero is:
* - never a valid value for an RSA parameter
* - interpreted as "omitted, please reconstruct" by mbedtls_rsa_complete().
*
* Since values can't be omitted in PKCS#1, passing a zero value to
* rsa_complete() would be incorrect, so reject zero values early.
*/
static int asn1_get_nonzero_mpi(unsigned char **p,
const unsigned char *end,
mbedtls_mpi *X)
{
int ret;
ret = mbedtls_asn1_get_mpi(p, end, X);
if (ret != 0) {
return ret;
}
if (mbedtls_mpi_cmp_int(X, 0) == 0) {
return MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
}
return 0;
}
/*
* Parse a PKCS#1 encoded private RSA key
*/
static int mbedtls_rsa_key_parse(mbedtls_rsa_context *rsa,
const unsigned char *key,
size_t keylen)
{
int ret, version;
size_t len;
unsigned char *p, *end;
mbedtls_mpi T;
mbedtls_mpi_init(&T);
p = (unsigned char *) key;
end = p + keylen;
/*
* This function parses the RSAPrivateKey (PKCS#1)
*
* RSAPrivateKey ::= SEQUENCE {
* version Version,
* modulus INTEGER, -- n
* publicExponent INTEGER, -- e
* privateExponent INTEGER, -- d
* prime1 INTEGER, -- p
* prime2 INTEGER, -- q
* exponent1 INTEGER, -- d mod (p-1)
* exponent2 INTEGER, -- d mod (q-1)
* coefficient INTEGER, -- (inverse of q) mod p
* otherPrimeInfos OtherPrimeInfos OPTIONAL
* }
*/
if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
}
end = p + len;
if ((ret = mbedtls_asn1_get_int(&p, end, &version)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
}
if (version != 0) {
return MBEDTLS_ERR_PK_KEY_INVALID_VERSION;
}
/* Import N */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, &T, NULL, NULL,
NULL, NULL)) != 0) {
goto cleanup;
}
/* Import E */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
NULL, &T)) != 0) {
goto cleanup;
}
/* Import D */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
&T, NULL)) != 0) {
goto cleanup;
}
/* Import P */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, NULL, &T, NULL,
NULL, NULL)) != 0) {
goto cleanup;
}
/* Import Q */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, NULL, NULL, &T,
NULL, NULL)) != 0) {
goto cleanup;
}
#if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT)
/*
* The RSA CRT parameters DP, DQ and QP are nominally redundant, in
* that they can be easily recomputed from D, P and Q. However by
* parsing them from the PKCS1 structure it is possible to avoid
* recalculating them which both reduces the overhead of loading
* RSA private keys into memory and also avoids side channels which
* can arise when computing those values, since all of D, P, and Q
* are secret. See https://eprint.iacr.org/2020/055 for a
* description of one such attack.
*/
/* Import DP */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_mpi_copy(&rsa->DP, &T)) != 0) {
goto cleanup;
}
/* Import DQ */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_mpi_copy(&rsa->DQ, &T)) != 0) {
goto cleanup;
}
/* Import QP */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_mpi_copy(&rsa->QP, &T)) != 0) {
goto cleanup;
}
#else
/* Verify existence of the CRT params */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0) {
goto cleanup;
}
#endif
/* rsa_complete() doesn't complete anything with the default
* implementation but is still called:
* - for the benefit of alternative implementation that may want to
* pre-compute stuff beyond what's provided (eg Montgomery factors)
* - as is also sanity-checks the key
*
* Furthermore, we also check the public part for consistency with
* mbedtls_pk_parse_pubkey(), as it includes size minima for example.
*/
if ((ret = mbedtls_rsa_complete(rsa)) != 0 ||
(ret = mbedtls_rsa_check_pubkey(rsa)) != 0) {
goto cleanup;
}
if (p != end) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
cleanup:
mbedtls_mpi_free(&T);
if (ret != 0) {
/* Wrap error code if it's coming from a lower level */
if ((ret & 0xff80) == 0) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
} else {
ret = MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
}
mbedtls_rsa_free(rsa);
}
return ret;
}
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
/*
* Parse a SEC1 encoded private EC key

136
library/pkwrite.c
View File

@ -32,6 +32,9 @@
#if defined(MBEDTLS_PEM_WRITE_C)
#include "mbedtls/pem.h"
#endif
#if defined(MBEDTLS_RSA_C)
#include "rsa_internal.h"
#endif
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
@ -56,135 +59,6 @@
* Internal functions for RSA keys.
******************************************************************************/
#if defined(MBEDTLS_RSA_C)
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
static int mbedtls_rsa_pubkey_write(unsigned char **p, unsigned char *start,
const mbedtls_rsa_context *rsa)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
mbedtls_mpi T;
mbedtls_mpi_init(&T);
/* Export E */
if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export N */
if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
end_of_export:
mbedtls_mpi_free(&T);
if (ret < 0) {
return ret;
}
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;
}
static int mbedtls_rsa_key_write(unsigned char **p, unsigned char *start,
const mbedtls_rsa_context *rsa)
{
size_t len = 0;
int ret;
mbedtls_mpi T; /* Temporary holding the exported parameters */
/*
* Export the parameters one after another to avoid simultaneous copies.
*/
mbedtls_mpi_init(&T);
/* Export QP */
if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export DQ */
if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export DP */
if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export Q */
if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, &T, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export P */
if ((ret = mbedtls_rsa_export(rsa, NULL, &T, NULL, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export D */
if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, &T, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export E */
if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export N */
if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
end_of_export:
mbedtls_mpi_free(&T);
if (ret < 0) {
return ret;
}
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, start, 0));
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;
}
static int pk_write_rsa_der(unsigned char **p, unsigned char *buf,
const mbedtls_pk_context *pk)
{
@ -204,7 +78,7 @@ static int pk_write_rsa_der(unsigned char **p, unsigned char *buf,
return (int) len;
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
return mbedtls_rsa_key_write(p, buf, mbedtls_pk_rsa(*pk));
return mbedtls_rsa_key_write(mbedtls_pk_rsa(*pk), buf, p);
}
#endif /* MBEDTLS_RSA_C */
@ -542,7 +416,7 @@ int mbedtls_pk_write_pubkey(unsigned char **p, unsigned char *start,
#if defined(MBEDTLS_RSA_C)
if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_rsa_pubkey_write(p, start, mbedtls_pk_rsa(*key)));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_rsa_pubkey_write(mbedtls_pk_rsa(*key), start, p));
} else
#endif
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)

373
library/rsa.c
View File

@ -31,6 +31,7 @@
#include "rsa_alt_helpers.h"
#include "rsa_internal.h"
#include "mbedtls/oid.h"
#include "mbedtls/asn1write.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
#include "constant_time_internal.h"
@ -659,6 +660,378 @@ size_t mbedtls_rsa_get_len(const mbedtls_rsa_context *ctx)
return ctx->len;
}
/*
* Wrapper around mbedtls_asn1_get_mpi() that rejects zero.
*
* The value zero is:
* - never a valid value for an RSA parameter
* - interpreted as "omitted, please reconstruct" by mbedtls_rsa_complete().
*
* Since values can't be omitted in PKCS#1, passing a zero value to
* rsa_complete() would be incorrect, so reject zero values early.
*/
static int asn1_get_nonzero_mpi(unsigned char **p,
const unsigned char *end,
mbedtls_mpi *X)
{
int ret;
ret = mbedtls_asn1_get_mpi(p, end, X);
if (ret != 0) {
return ret;
}
if (mbedtls_mpi_cmp_int(X, 0) == 0) {
return MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
}
return 0;
}
/*
* Parse a PKCS#1 encoded private RSA key
*/
int mbedtls_rsa_key_parse(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen)
{
int ret, version;
size_t len;
unsigned char *p, *end;
mbedtls_mpi T;
mbedtls_mpi_init(&T);
p = (unsigned char *) key;
end = p + keylen;
/*
* This function parses the RSAPrivateKey (PKCS#1)
*
* RSAPrivateKey ::= SEQUENCE {
* version Version,
* modulus INTEGER, -- n
* publicExponent INTEGER, -- e
* privateExponent INTEGER, -- d
* prime1 INTEGER, -- p
* prime2 INTEGER, -- q
* exponent1 INTEGER, -- d mod (p-1)
* exponent2 INTEGER, -- d mod (q-1)
* coefficient INTEGER, -- (inverse of q) mod p
* otherPrimeInfos OtherPrimeInfos OPTIONAL
* }
*/
if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
}
end = p + len;
if ((ret = mbedtls_asn1_get_int(&p, end, &version)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
}
if (version != 0) {
return MBEDTLS_ERR_PK_KEY_INVALID_VERSION;
}
/* Import N */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, &T, NULL, NULL,
NULL, NULL)) != 0) {
goto cleanup;
}
/* Import E */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
NULL, &T)) != 0) {
goto cleanup;
}
/* Import D */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL,
&T, NULL)) != 0) {
goto cleanup;
}
/* Import P */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, NULL, &T, NULL,
NULL, NULL)) != 0) {
goto cleanup;
}
/* Import Q */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_rsa_import(rsa, NULL, NULL, &T,
NULL, NULL)) != 0) {
goto cleanup;
}
#if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT)
/*
* The RSA CRT parameters DP, DQ and QP are nominally redundant, in
* that they can be easily recomputed from D, P and Q. However by
* parsing them from the PKCS1 structure it is possible to avoid
* recalculating them which both reduces the overhead of loading
* RSA private keys into memory and also avoids side channels which
* can arise when computing those values, since all of D, P, and Q
* are secret. See https://eprint.iacr.org/2020/055 for a
* description of one such attack.
*/
/* Import DP */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_mpi_copy(&rsa->DP, &T)) != 0) {
goto cleanup;
}
/* Import DQ */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_mpi_copy(&rsa->DQ, &T)) != 0) {
goto cleanup;
}
/* Import QP */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = mbedtls_mpi_copy(&rsa->QP, &T)) != 0) {
goto cleanup;
}
#else
/* Verify existence of the CRT params */
if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 ||
(ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0) {
goto cleanup;
}
#endif
/* rsa_complete() doesn't complete anything with the default
* implementation but is still called:
* - for the benefit of alternative implementation that may want to
* pre-compute stuff beyond what's provided (eg Montgomery factors)
* - as is also sanity-checks the key
*
* Furthermore, we also check the public part for consistency with
* mbedtls_pk_parse_pubkey(), as it includes size minima for example.
*/
if ((ret = mbedtls_rsa_complete(rsa)) != 0 ||
(ret = mbedtls_rsa_check_pubkey(rsa)) != 0) {
goto cleanup;
}
if (p != end) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
cleanup:
mbedtls_mpi_free(&T);
if (ret != 0) {
/* Wrap error code if it's coming from a lower level */
if ((ret & 0xff80) == 0) {
ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_KEY_INVALID_FORMAT, ret);
} else {
ret = MBEDTLS_ERR_PK_KEY_INVALID_FORMAT;
}
mbedtls_rsa_free(rsa);
}
return ret;
}
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
int mbedtls_rsa_pubkey_parse(mbedtls_rsa_context *rsa, unsigned char **p,
const unsigned char *end)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len;
if ((ret = mbedtls_asn1_get_tag(p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
}
if (*p + len != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
/* Import N */
if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
}
if ((ret = mbedtls_rsa_import_raw(rsa, *p, len, NULL, 0, NULL, 0,
NULL, 0, NULL, 0)) != 0) {
return MBEDTLS_ERR_PK_INVALID_PUBKEY;
}
*p += len;
/* Import E */
if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY, ret);
}
if ((ret = mbedtls_rsa_import_raw(rsa, NULL, 0, NULL, 0, NULL, 0,
NULL, 0, *p, len)) != 0) {
return MBEDTLS_ERR_PK_INVALID_PUBKEY;
}
*p += len;
if (mbedtls_rsa_complete(rsa) != 0 ||
mbedtls_rsa_check_pubkey(rsa) != 0) {
return MBEDTLS_ERR_PK_INVALID_PUBKEY;
}
if (*p != end) {
return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PK_INVALID_PUBKEY,
MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
}
return 0;
}
int mbedtls_rsa_key_write(const mbedtls_rsa_context *rsa, unsigned char *start,
unsigned char **p)
{
size_t len = 0;
int ret;
mbedtls_mpi T; /* Temporary holding the exported parameters */
/*
* Export the parameters one after another to avoid simultaneous copies.
*/
mbedtls_mpi_init(&T);
/* Export QP */
if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export DQ */
if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export DP */
if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export Q */
if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, &T, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export P */
if ((ret = mbedtls_rsa_export(rsa, NULL, &T, NULL, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export D */
if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, &T, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export E */
if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export N */
if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
end_of_export:
mbedtls_mpi_free(&T);
if (ret < 0) {
return ret;
}
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, start, 0));
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;
}
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
int mbedtls_rsa_pubkey_write(const mbedtls_rsa_context *rsa, unsigned char *start,
unsigned char **p)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
mbedtls_mpi T;
mbedtls_mpi_init(&T);
/* Export E */
if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
/* Export N */
if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
(ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
goto end_of_export;
}
len += ret;
end_of_export:
mbedtls_mpi_free(&T);
if (ret < 0) {
return ret;
}
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;
}
#if defined(MBEDTLS_GENPRIME)

43
library/rsa_internal.h
View File

@ -16,6 +16,49 @@
#include "mbedtls/rsa.h"
/**
* \brief
*
* \param rsa
* \param key
* \param keylen
* \return int
*/
int mbedtls_rsa_key_parse(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen);
/**
* \brief
*
* \param rsa
* \param p
* \param end
* \return int
*/
int mbedtls_rsa_pubkey_parse(mbedtls_rsa_context *rsa, unsigned char **p,
const unsigned char *end);
/**
* \brief
*
* \param p
* \param start
* \param rsa
* \return int
*/
int mbedtls_rsa_key_write(const mbedtls_rsa_context *rsa, unsigned char *start,
unsigned char **p);
/**
* \brief
*
* \param p
* \param start
* \param rsa
* \return int
*/
int mbedtls_rsa_pubkey_write(const mbedtls_rsa_context *rsa, unsigned char *start,
unsigned char **p);
#if defined(MBEDTLS_PKCS1_V21)
/**
* \brief This function is analogue to \c mbedtls_rsa_rsassa_pss_sign().