* This parses a format loosely based on a DER encoding of the ECPrivateKey type from * section C.4 of SEC 1 , with the following caveats: * * * The octet-length of the SEQUENCE must be encoded as 1 or 2 octets. It is not * required to be encoded as one octet if it is less than 256, as DER would require. * * The octet-length of the SEQUENCE must not be greate
| 33 | * out32 must point to an output buffer of length at least 32 bytes. |
| 34 | */ |
| 35 | static int ec_privkey_import_der(const secp256k1_context* ctx, unsigned char *out32, const unsigned char *privkey, size_t privkeylen) { |
| 36 | const unsigned char *end = privkey + privkeylen; |
| 37 | memset(out32, 0, 32); |
| 38 | /* sequence header */ |
| 39 | if (end - privkey < 1 || *privkey != 0x30u) { |
| 40 | return 0; |
| 41 | } |
| 42 | privkey++; |
| 43 | /* sequence length constructor */ |
| 44 | if (end - privkey < 1 || !(*privkey & 0x80u)) { |
| 45 | return 0; |
| 46 | } |
| 47 | ptrdiff_t lenb = *privkey & ~0x80u; privkey++; |
| 48 | if (lenb < 1 || lenb > 2) { |
| 49 | return 0; |
| 50 | } |
| 51 | if (end - privkey < lenb) { |
| 52 | return 0; |
| 53 | } |
| 54 | /* sequence length */ |
| 55 | ptrdiff_t len = privkey[lenb-1] | (lenb > 1 ? privkey[lenb-2] << 8 : 0u); |
| 56 | privkey += lenb; |
| 57 | if (end - privkey < len) { |
| 58 | return 0; |
| 59 | } |
| 60 | /* sequence element 0: version number (=1) */ |
| 61 | if (end - privkey < 3 || privkey[0] != 0x02u || privkey[1] != 0x01u || privkey[2] != 0x01u) { |
| 62 | return 0; |
| 63 | } |
| 64 | privkey += 3; |
| 65 | /* sequence element 1: octet string, up to 32 bytes */ |
| 66 | if (end - privkey < 2 || privkey[0] != 0x04u) { |
| 67 | return 0; |
| 68 | } |
| 69 | ptrdiff_t oslen = privkey[1]; |
| 70 | privkey += 2; |
| 71 | if (oslen > 32 || end - privkey < oslen) { |
| 72 | return 0; |
| 73 | } |
| 74 | memcpy(out32 + (32 - oslen), privkey, oslen); |
| 75 | if (!secp256k1_ec_seckey_verify(ctx, out32)) { |
| 76 | memset(out32, 0, 32); |
| 77 | return 0; |
| 78 | } |
| 79 | return 1; |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * This serializes to a DER encoding of the ECPrivateKey type from section C.4 of SEC 1 |
no test coverage detected