diff options
Diffstat (limited to 'src/crypto/bytestring/cbs.c')
| -rw-r--r-- | src/crypto/bytestring/cbs.c | 61 |
1 files changed, 30 insertions, 31 deletions
diff --git a/src/crypto/bytestring/cbs.c b/src/crypto/bytestring/cbs.c index 8328b7fe..ec495d21 100644 --- a/src/crypto/bytestring/cbs.c +++ b/src/crypto/bytestring/cbs.c @@ -190,13 +190,13 @@ static int cbs_get_any_asn1_element(CBS *cbs, CBS *out, unsigned *out_tag, return 0; } - /* ITU-T X.690 section 8.1.2.3 specifies the format for identifiers with a tag - * number no greater than 30. - * - * If the number portion is 31 (0x1f, the largest value that fits in the - * allotted bits), then the tag is more than one byte long and the - * continuation bytes contain the tag number. This parser only supports tag - * numbers less than 31 (and thus single-byte tags). */ + // ITU-T X.690 section 8.1.2.3 specifies the format for identifiers with a tag + // number no greater than 30. + // + // If the number portion is 31 (0x1f, the largest value that fits in the + // allotted bits), then the tag is more than one byte long and the + // continuation bytes contain the tag number. This parser only supports tag + // numbers less than 31 (and thus single-byte tags). if ((tag & 0x1f) == 0x1f) { return 0; } @@ -206,52 +206,51 @@ static int cbs_get_any_asn1_element(CBS *cbs, CBS *out, unsigned *out_tag, } size_t len; - /* The format for the length encoding is specified in ITU-T X.690 section - * 8.1.3. */ + // The format for the length encoding is specified in ITU-T X.690 section + // 8.1.3. if ((length_byte & 0x80) == 0) { - /* Short form length. */ + // Short form length. len = ((size_t) length_byte) + 2; if (out_header_len != NULL) { *out_header_len = 2; } } else { - /* The high bit indicate that this is the long form, while the next 7 bits - * encode the number of subsequent octets used to encode the length (ITU-T - * X.690 clause 8.1.3.5.b). */ + // The high bit indicate that this is the long form, while the next 7 bits + // encode the number of subsequent octets used to encode the length (ITU-T + // X.690 clause 8.1.3.5.b). const size_t num_bytes = length_byte & 0x7f; uint32_t len32; if (ber_ok && (tag & CBS_ASN1_CONSTRUCTED) != 0 && num_bytes == 0) { - /* indefinite length */ + // indefinite length if (out_header_len != NULL) { *out_header_len = 2; } return CBS_get_bytes(cbs, out, 2); } - /* ITU-T X.690 clause 8.1.3.5.c specifies that the value 0xff shall not be - * used as the first byte of the length. If this parser encounters that - * value, num_bytes will be parsed as 127, which will fail the check below. - */ + // ITU-T X.690 clause 8.1.3.5.c specifies that the value 0xff shall not be + // used as the first byte of the length. If this parser encounters that + // value, num_bytes will be parsed as 127, which will fail the check below. if (num_bytes == 0 || num_bytes > 4) { return 0; } if (!cbs_get_u(&header, &len32, num_bytes)) { return 0; } - /* ITU-T X.690 section 10.1 (DER length forms) requires encoding the length - * with the minimum number of octets. */ + // ITU-T X.690 section 10.1 (DER length forms) requires encoding the length + // with the minimum number of octets. if (len32 < 128) { - /* Length should have used short-form encoding. */ + // Length should have used short-form encoding. return 0; } if ((len32 >> ((num_bytes-1)*8)) == 0) { - /* Length should have been at least one byte shorter. */ + // Length should have been at least one byte shorter. return 0; } len = len32; if (len + 2 + num_bytes < len) { - /* Overflow. */ + // Overflow. return 0; } len += 2 + num_bytes; @@ -338,23 +337,23 @@ int CBS_get_asn1_uint64(CBS *cbs, uint64_t *out) { size_t len = CBS_len(&bytes); if (len == 0) { - /* An INTEGER is encoded with at least one octet. */ + // An INTEGER is encoded with at least one octet. return 0; } if ((data[0] & 0x80) != 0) { - /* Negative number. */ + // Negative number. return 0; } if (data[0] == 0 && len > 1 && (data[1] & 0x80) == 0) { - /* Extra leading zeros. */ + // Extra leading zeros. return 0; } for (size_t i = 0; i < len; i++) { if ((*out >> 56) != 0) { - /* Too large to represent as a uint64_t. */ + // Too large to represent as a uint64_t. return 0; } *out <<= 8; @@ -462,7 +461,7 @@ int CBS_is_valid_asn1_bitstring(const CBS *cbs) { return 1; } - /* All num_unused_bits bits must exist and be zeros. */ + // All num_unused_bits bits must exist and be zeros. uint8_t last; if (!CBS_get_last_u8(&in, &last) || (last & ((1 << num_unused_bits) - 1)) != 0) { @@ -480,9 +479,9 @@ int CBS_asn1_bitstring_has_bit(const CBS *cbs, unsigned bit) { const unsigned byte_num = (bit >> 3) + 1; const unsigned bit_num = 7 - (bit & 7); - /* Unused bits are zero, and this function does not distinguish between - * missing and unset bits. Thus it is sufficient to do a byte-level length - * check. */ + // Unused bits are zero, and this function does not distinguish between + // missing and unset bits. Thus it is sufficient to do a byte-level length + // check. return byte_num < CBS_len(cbs) && (CBS_data(cbs)[byte_num] & (1 << bit_num)) != 0; } |