diff --git a/library/pk_wrap.c b/library/pk_wrap.c index 5e3580ec60..095b132c84 100644 --- a/library/pk_wrap.c +++ b/library/pk_wrap.c @@ -741,8 +741,87 @@ static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg, #endif /* MBEDTLS_USE_PSA_CRYPTO */ #if defined(MBEDTLS_USE_PSA_CRYPTO) +/* + * Simultaneously convert and move raw MPI from the beginning of a buffer + * to an ASN.1 MPI at the end of the buffer. + * See also mbedtls_asn1_write_mpi(). + * + * p: pointer to the end of the output buffer + * start: start of the output buffer, and also of the mpi to write at the end + * n_len: length of the mpi to read from start + */ +static int asn1_write_mpibuf( unsigned char **p, unsigned char *start, + size_t n_len ) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t len = 0; + + if( (size_t)( *p - start ) < n_len ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + len = n_len; + *p -= len; + memmove( *p, start, len ); + + /* ASN.1 DER encoding requires minimal length, so skip leading 0s. + * Neither r nor s should be 0, but as a failsafe measure, still detect + * that rather than overflowing the buffer in case of a PSA error. */ + while( len > 0 && **p == 0x00 ) + { + ++(*p); + --len; + } + + /* this is only reached if the signature was invalid */ + if( len == 0 ) + return( MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED ); + + /* if the msb is 1, ASN.1 requires that we prepend a 0. + * Neither r nor s can be 0, so we can assume len > 0 at all times. */ + if( **p & 0x80 ) + { + if( *p - start < 1 ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + *--(*p) = 0x00; + len += 1; + } + + 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_INTEGER ) ); + + return( (int) len ); +} + +/* Transcode signature from PSA format to ASN.1 sequence. + * See ecdsa_signature_to_asn1 in ecdsa.c, but with byte buffers instead of + * MPIs, and in-place. + * + * [in/out] sig: the signature pre- and post-transcoding + * [in/out] sig_len: signature length pre- and post-transcoding + * [int] buf_len: the available size the in/out buffer + */ static int pk_ecdsa_sig_asn1_from_psa( unsigned char *sig, size_t *sig_len, - size_t buf_len ); + size_t buf_len ) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t len = 0; + const size_t rs_len = *sig_len / 2; + unsigned char *p = sig + buf_len; + + MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig + rs_len, rs_len ) ); + MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig, rs_len ) ); + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, sig, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, sig, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); + + memmove( sig, p, len ); + *sig_len = len; + + return( 0 ); +} static int find_ecdsa_private_key( unsigned char **buf, unsigned char *end, size_t *key_len ) { @@ -1118,92 +1197,6 @@ static int pk_opaque_can_do( mbedtls_pk_type_t type ) type == MBEDTLS_PK_ECDSA ); } -#if defined(MBEDTLS_ECDSA_C) - -/* - * Simultaneously convert and move raw MPI from the beginning of a buffer - * to an ASN.1 MPI at the end of the buffer. - * See also mbedtls_asn1_write_mpi(). - * - * p: pointer to the end of the output buffer - * start: start of the output buffer, and also of the mpi to write at the end - * n_len: length of the mpi to read from start - */ -static int asn1_write_mpibuf( unsigned char **p, unsigned char *start, - size_t n_len ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t len = 0; - - if( (size_t)( *p - start ) < n_len ) - return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); - - len = n_len; - *p -= len; - memmove( *p, start, len ); - - /* ASN.1 DER encoding requires minimal length, so skip leading 0s. - * Neither r nor s should be 0, but as a failsafe measure, still detect - * that rather than overflowing the buffer in case of a PSA error. */ - while( len > 0 && **p == 0x00 ) - { - ++(*p); - --len; - } - - /* this is only reached if the signature was invalid */ - if( len == 0 ) - return( MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED ); - - /* if the msb is 1, ASN.1 requires that we prepend a 0. - * Neither r nor s can be 0, so we can assume len > 0 at all times. */ - if( **p & 0x80 ) - { - if( *p - start < 1 ) - return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); - - *--(*p) = 0x00; - len += 1; - } - - 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_INTEGER ) ); - - return( (int) len ); -} - -/* Transcode signature from PSA format to ASN.1 sequence. - * See ecdsa_signature_to_asn1 in ecdsa.c, but with byte buffers instead of - * MPIs, and in-place. - * - * [in/out] sig: the signature pre- and post-transcoding - * [in/out] sig_len: signature length pre- and post-transcoding - * [int] buf_len: the available size the in/out buffer - */ -static int pk_ecdsa_sig_asn1_from_psa( unsigned char *sig, size_t *sig_len, - size_t buf_len ) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t len = 0; - const size_t rs_len = *sig_len / 2; - unsigned char *p = sig + buf_len; - - MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig + rs_len, rs_len ) ); - MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig, rs_len ) ); - - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, sig, len ) ); - MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, sig, - MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ); - - memmove( sig, p, len ); - *sig_len = len; - - return( 0 ); -} - -#endif /* MBEDTLS_ECDSA_C */ - static int pk_opaque_sign_wrap( void *ctx, mbedtls_md_type_t md_alg, const unsigned char *hash, size_t hash_len, unsigned char *sig, size_t sig_size, size_t *sig_len,