diff options
Diffstat (limited to 'crypto/der.c')
| -rw-r--r-- | crypto/der.c | 307 |
1 files changed, 285 insertions, 22 deletions
diff --git a/crypto/der.c b/crypto/der.c index f877390bbb..dab3fe4f24 100644 --- a/crypto/der.c +++ b/crypto/der.c @@ -22,20 +22,93 @@ #include "qemu/osdep.h" #include "crypto/der.h" +typedef struct QCryptoDerEncodeNode { + uint8_t tag; + struct QCryptoDerEncodeNode *parent; + struct QCryptoDerEncodeNode *next; + /* for constructed type, data is null */ + const uint8_t *data; + size_t dlen; +} QCryptoDerEncodeNode; + +typedef struct QCryptoEncodeContext { + QCryptoDerEncodeNode root; + QCryptoDerEncodeNode *current_parent; + QCryptoDerEncodeNode *tail; +} QCryptoEncodeContext; + enum QCryptoDERTypeTag { QCRYPTO_DER_TYPE_TAG_BOOL = 0x1, QCRYPTO_DER_TYPE_TAG_INT = 0x2, QCRYPTO_DER_TYPE_TAG_BIT_STR = 0x3, QCRYPTO_DER_TYPE_TAG_OCT_STR = 0x4, - QCRYPTO_DER_TYPE_TAG_OCT_NULL = 0x5, - QCRYPTO_DER_TYPE_TAG_OCT_OID = 0x6, + QCRYPTO_DER_TYPE_TAG_NULL = 0x5, + QCRYPTO_DER_TYPE_TAG_OID = 0x6, QCRYPTO_DER_TYPE_TAG_SEQ = 0x10, QCRYPTO_DER_TYPE_TAG_SET = 0x11, }; -#define QCRYPTO_DER_CONSTRUCTED_MASK 0x20 +enum QCryptoDERTagClass { + QCRYPTO_DER_TAG_CLASS_UNIV = 0x0, + QCRYPTO_DER_TAG_CLASS_APPL = 0x1, + QCRYPTO_DER_TAG_CLASS_CONT = 0x2, + QCRYPTO_DER_TAG_CLASS_PRIV = 0x3, +}; + +enum QCryptoDERTagEnc { + QCRYPTO_DER_TAG_ENC_PRIM = 0x0, + QCRYPTO_DER_TAG_ENC_CONS = 0x1, +}; + +#define QCRYPTO_DER_TAG_ENC_MASK 0x20 +#define QCRYPTO_DER_TAG_ENC_SHIFT 5 + +#define QCRYPTO_DER_TAG_CLASS_MASK 0xc0 +#define QCRYPTO_DER_TAG_CLASS_SHIFT 6 + +#define QCRYPTO_DER_TAG_VAL_MASK 0x1f #define QCRYPTO_DER_SHORT_LEN_MASK 0x80 +#define QCRYPTO_DER_TAG(class, enc, val) \ + (((class) << QCRYPTO_DER_TAG_CLASS_SHIFT) | \ + ((enc) << QCRYPTO_DER_TAG_ENC_SHIFT) | (val)) + +/** + * qcrypto_der_encode_length: + * @src_len: the length of source data + * @dst: distination to save the encoded 'length', if dst is NULL, only compute + * the expected buffer size in bytes. + * @dst_len: output parameter, indicates how many bytes wrote. + * + * Encode the 'length' part of TLV tuple. + */ +static void qcrypto_der_encode_length(size_t src_len, + uint8_t *dst, size_t *dst_len) +{ + size_t max_length = 0xFF; + uint8_t length_bytes = 0, header_byte; + + if (src_len < QCRYPTO_DER_SHORT_LEN_MASK) { + header_byte = src_len; + *dst_len = 1; + } else { + for (length_bytes = 1; max_length < src_len; length_bytes++) { + max_length = (max_length << 8) + max_length; + } + header_byte = length_bytes; + header_byte |= QCRYPTO_DER_SHORT_LEN_MASK; + *dst_len = length_bytes + 1; + } + if (!dst) { + return; + } + *dst++ = header_byte; + /* Bigendian length bytes */ + for (; length_bytes > 0; length_bytes--) { + *dst++ = ((src_len >> (length_bytes - 1) * 8) & 0xFF); + } +} + static uint8_t qcrypto_der_peek_byte(const uint8_t **data, size_t *dlen) { return **data; @@ -150,40 +223,230 @@ static int qcrypto_der_extract_data(const uint8_t **data, size_t *dlen, return qcrypto_der_extract_definite_data(data, dlen, cb, ctx, errp); } -int qcrypto_der_decode_int(const uint8_t **data, size_t *dlen, - QCryptoDERDecodeCb cb, void *ctx, Error **errp) +static int qcrypto_der_decode_tlv(const uint8_t expected_tag, + const uint8_t **data, size_t *dlen, + QCryptoDERDecodeCb cb, + void *ctx, Error **errp) { + const uint8_t *saved_data = *data; + size_t saved_dlen = *dlen; uint8_t tag; + int data_length; + if (*dlen < 1) { error_setg(errp, "Need more data"); return -1; } tag = qcrypto_der_cut_byte(data, dlen); + if (tag != expected_tag) { + error_setg(errp, "Unexpected tag: expected: %u, actual: %u", + expected_tag, tag); + goto error; + } - /* INTEGER must encoded in primitive-form */ - if (tag != QCRYPTO_DER_TYPE_TAG_INT) { - error_setg(errp, "Invalid integer type tag: %u", tag); - return -1; + data_length = qcrypto_der_extract_data(data, dlen, cb, ctx, errp); + if (data_length < 0) { + goto error; } + return data_length; - return qcrypto_der_extract_data(data, dlen, cb, ctx, errp); +error: + *data = saved_data; + *dlen = saved_dlen; + return -1; +} + +int qcrypto_der_decode_int(const uint8_t **data, size_t *dlen, + QCryptoDERDecodeCb cb, void *ctx, Error **errp) +{ + const uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_PRIM, + QCRYPTO_DER_TYPE_TAG_INT); + return qcrypto_der_decode_tlv(tag, data, dlen, cb, ctx, errp); } int qcrypto_der_decode_seq(const uint8_t **data, size_t *dlen, QCryptoDERDecodeCb cb, void *ctx, Error **errp) { - uint8_t tag; - if (*dlen < 1) { - error_setg(errp, "Need more data"); - return -1; - } - tag = qcrypto_der_cut_byte(data, dlen); + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_CONS, + QCRYPTO_DER_TYPE_TAG_SEQ); + return qcrypto_der_decode_tlv(tag, data, dlen, cb, ctx, errp); +} - /* SEQUENCE must use constructed form */ - if (tag != (QCRYPTO_DER_TYPE_TAG_SEQ | QCRYPTO_DER_CONSTRUCTED_MASK)) { - error_setg(errp, "Invalid type sequence tag: %u", tag); - return -1; - } +int qcrypto_der_decode_octet_str(const uint8_t **data, size_t *dlen, + QCryptoDERDecodeCb cb, void *ctx, Error **errp) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_PRIM, + QCRYPTO_DER_TYPE_TAG_OCT_STR); + return qcrypto_der_decode_tlv(tag, data, dlen, cb, ctx, errp); +} + +int qcrypto_der_decode_bit_str(const uint8_t **data, size_t *dlen, + QCryptoDERDecodeCb cb, void *ctx, Error **errp) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_PRIM, + QCRYPTO_DER_TYPE_TAG_BIT_STR); + return qcrypto_der_decode_tlv(tag, data, dlen, cb, ctx, errp); +} + +int qcrypto_der_decode_oid(const uint8_t **data, size_t *dlen, + QCryptoDERDecodeCb cb, void *ctx, Error **errp) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_PRIM, + QCRYPTO_DER_TYPE_TAG_OID); + return qcrypto_der_decode_tlv(tag, data, dlen, cb, ctx, errp); +} + +int qcrypto_der_decode_ctx_tag(const uint8_t **data, size_t *dlen, int tag_id, + QCryptoDERDecodeCb cb, void *ctx, Error **errp) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_CONT, + QCRYPTO_DER_TAG_ENC_CONS, + tag_id); + return qcrypto_der_decode_tlv(tag, data, dlen, cb, ctx, errp); +} - return qcrypto_der_extract_data(data, dlen, cb, ctx, errp); +static void qcrypto_der_encode_prim(QCryptoEncodeContext *ctx, uint8_t tag, + const uint8_t *data, size_t dlen) +{ + QCryptoDerEncodeNode *node = g_new0(QCryptoDerEncodeNode, 1); + size_t nbytes_len; + + node->tag = tag; + node->data = data; + node->dlen = dlen; + node->parent = ctx->current_parent; + + qcrypto_der_encode_length(dlen, NULL, &nbytes_len); + /* 1 byte for Tag, nbyte_len for Length, and dlen for Value */ + node->parent->dlen += 1 + nbytes_len + dlen; + + ctx->tail->next = node; + ctx->tail = node; +} + +QCryptoEncodeContext *qcrypto_der_encode_ctx_new(void) +{ + QCryptoEncodeContext *ctx = g_new0(QCryptoEncodeContext, 1); + ctx->current_parent = &ctx->root; + ctx->tail = &ctx->root; + return ctx; +} + +static void qcrypto_der_encode_cons_begin(QCryptoEncodeContext *ctx, + uint8_t tag) +{ + QCryptoDerEncodeNode *node = g_new0(QCryptoDerEncodeNode, 1); + + node->tag = tag; + node->parent = ctx->current_parent; + ctx->current_parent = node; + ctx->tail->next = node; + ctx->tail = node; +} + +static void qcrypto_der_encode_cons_end(QCryptoEncodeContext *ctx) +{ + QCryptoDerEncodeNode *cons_node = ctx->current_parent; + size_t nbytes_len; + + qcrypto_der_encode_length(cons_node->dlen, NULL, &nbytes_len); + /* 1 byte for Tag, nbyte_len for Length, and dlen for Value */ + cons_node->parent->dlen += 1 + nbytes_len + cons_node->dlen; + ctx->current_parent = cons_node->parent; +} + +void qcrypto_der_encode_seq_begin(QCryptoEncodeContext *ctx) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_CONS, + QCRYPTO_DER_TYPE_TAG_SEQ); + qcrypto_der_encode_cons_begin(ctx, tag); +} + +void qcrypto_der_encode_seq_end(QCryptoEncodeContext *ctx) +{ + qcrypto_der_encode_cons_end(ctx); +} + +void qcrypto_der_encode_oid(QCryptoEncodeContext *ctx, + const uint8_t *src, size_t src_len) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_PRIM, + QCRYPTO_DER_TYPE_TAG_OID); + qcrypto_der_encode_prim(ctx, tag, src, src_len); +} + +void qcrypto_der_encode_int(QCryptoEncodeContext *ctx, + const uint8_t *src, size_t src_len) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_PRIM, + QCRYPTO_DER_TYPE_TAG_INT); + qcrypto_der_encode_prim(ctx, tag, src, src_len); +} + +void qcrypto_der_encode_null(QCryptoEncodeContext *ctx) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_PRIM, + QCRYPTO_DER_TYPE_TAG_NULL); + qcrypto_der_encode_prim(ctx, tag, NULL, 0); +} + +void qcrypto_der_encode_octet_str(QCryptoEncodeContext *ctx, + const uint8_t *src, size_t src_len) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_PRIM, + QCRYPTO_DER_TYPE_TAG_OCT_STR); + qcrypto_der_encode_prim(ctx, tag, src, src_len); +} + +void qcrypto_der_encode_octet_str_begin(QCryptoEncodeContext *ctx) +{ + uint8_t tag = QCRYPTO_DER_TAG(QCRYPTO_DER_TAG_CLASS_UNIV, + QCRYPTO_DER_TAG_ENC_PRIM, + QCRYPTO_DER_TYPE_TAG_OCT_STR); + qcrypto_der_encode_cons_begin(ctx, tag); +} + +void qcrypto_der_encode_octet_str_end(QCryptoEncodeContext *ctx) +{ + qcrypto_der_encode_cons_end(ctx); +} + +size_t qcrypto_der_encode_ctx_buffer_len(QCryptoEncodeContext *ctx) +{ + return ctx->root.dlen; +} + +void qcrypto_der_encode_ctx_flush_and_free(QCryptoEncodeContext *ctx, + uint8_t *dst) +{ + QCryptoDerEncodeNode *node, *prev; + size_t len; + + for (prev = &ctx->root; + (node = prev->next) && (prev->next = node->next, 1);) { + /* Tag */ + *dst++ = node->tag; + + /* Length */ + qcrypto_der_encode_length(node->dlen, dst, &len); + dst += len; + + /* Value */ + if (node->data) { + memcpy(dst, node->data, node->dlen); + dst += node->dlen; + } + g_free(node); + } + g_free(ctx); } |