diff options
Diffstat (limited to 'src/libstrongswan/plugins/pem/pem_encoder.c')
| -rw-r--r-- | src/libstrongswan/plugins/pem/pem_encoder.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/pem/pem_encoder.c b/src/libstrongswan/plugins/pem/pem_encoder.c new file mode 100644 index 000000000..13c99a958 --- /dev/null +++ b/src/libstrongswan/plugins/pem/pem_encoder.c @@ -0,0 +1,138 @@ +/* + * Copyright (C) 2010 Andreas Steffen + * Hochschule fuer Technik Rapperswil + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include "pem_encoder.h" + +#define BYTES_PER_LINE 48 + +/** + * See header. + */ +bool pem_encoder_encode(key_encoding_type_t type, chunk_t *encoding, + va_list args) +{ + chunk_t asn1; + char *label; + u_char *pos; + size_t len, written, pem_chars, pem_lines; + chunk_t n, e, d, p, q, exp1, exp2, coeff, to_free = chunk_empty; + + switch (type) + { + case KEY_PUB_PEM: + label ="PUBLIC KEY"; + /* direct PKCS#1 PEM encoding */ + if (key_encoding_args(args, KEY_PART_RSA_PUB_ASN1_DER, + &asn1, KEY_PART_END) || + key_encoding_args(args, KEY_PART_ECDSA_PUB_ASN1_DER, + &asn1, KEY_PART_END)) + { + break; + } + /* indirect PEM encoding from components */ + if (key_encoding_args(args, KEY_PART_RSA_MODULUS, &n, + KEY_PART_RSA_PUB_EXP, &e, KEY_PART_END)) + { + if (lib->encoding->encode(lib->encoding, KEY_PUB_SPKI_ASN1_DER, + NULL, &asn1, KEY_PART_RSA_MODULUS, n, + KEY_PART_RSA_PUB_EXP, e, KEY_PART_END)) + { + to_free = asn1; + break; + } + } + return FALSE; + case KEY_PRIV_PEM: + label ="RSA PRIVATE KEY"; + /* direct PKCS#1 PEM encoding */ + if (key_encoding_args(args, KEY_PART_RSA_PRIV_ASN1_DER, + &asn1, KEY_PART_END)) + { + break; + } + /* indirect PEM encoding from components */ + if (key_encoding_args(args, KEY_PART_RSA_MODULUS, &n, + KEY_PART_RSA_PUB_EXP, &e, KEY_PART_RSA_PRIV_EXP, &d, + KEY_PART_RSA_PRIME1, &p, KEY_PART_RSA_PRIME2, &q, + KEY_PART_RSA_EXP1, &exp1, KEY_PART_RSA_EXP2, &exp2, + KEY_PART_RSA_COEFF, &coeff, KEY_PART_END)) + { + if (lib->encoding->encode(lib->encoding, KEY_PRIV_ASN1_DER, NULL, + &asn1, KEY_PART_RSA_MODULUS, n, + KEY_PART_RSA_PUB_EXP, e, KEY_PART_RSA_PRIV_EXP, d, + KEY_PART_RSA_PRIME1, p, KEY_PART_RSA_PRIME2, q, + KEY_PART_RSA_EXP1, exp1, KEY_PART_RSA_EXP2, exp2, + KEY_PART_RSA_COEFF, coeff, KEY_PART_END)) + { + to_free = asn1; + break; + } + } + if (key_encoding_args(args, KEY_PART_ECDSA_PRIV_ASN1_DER, + &asn1, KEY_PART_END)) + { + label ="EC PRIVATE KEY"; + break; + } + return FALSE; + default: + return FALSE; + } + + /* compute and allocate maximum size of PEM object */ + pem_chars = 4*(asn1.len + 2)/3; + pem_lines = (asn1.len + BYTES_PER_LINE - 1) / BYTES_PER_LINE; + *encoding = chunk_alloc(5 + 2*(6 + strlen(label) + 6) + 3 + pem_chars + pem_lines); + pos = encoding->ptr; + len = encoding->len; + + /* write PEM header */ + written = snprintf(pos, len, "-----BEGIN %s-----\n", label); + pos += written; + len -= written; + + /* write PEM body */ + while (pem_lines--) + { + chunk_t asn1_line, pem_line; + + asn1_line = chunk_create(asn1.ptr, min(asn1.len, BYTES_PER_LINE)); + asn1.ptr += asn1_line.len; + asn1.len -= asn1_line.len; + pem_line = chunk_to_base64(asn1_line, pos); + pos += pem_line.len; + len -= pem_line.len; + *pos = '\n'; + pos++; + len--; + } + + chunk_clear(&to_free); + + /* write PEM trailer */ + written = snprintf(pos, len, "-----END %s-----", label); + pos += written; + len -= written; + + /* replace termination null character with newline */ + *pos = '\n'; + pos++; + len--; + + /* compute effective length of PEM object */ + encoding->len = pos - encoding->ptr; + return TRUE; +} + |