diff options
Diffstat (limited to 'security/nss/lib/util/derenc.c')
| -rw-r--r-- | security/nss/lib/util/derenc.c | 460 |
1 files changed, 460 insertions, 0 deletions
diff --git a/security/nss/lib/util/derenc.c b/security/nss/lib/util/derenc.c new file mode 100644 index 0000000000..da9fc4e649 --- /dev/null +++ b/security/nss/lib/util/derenc.c @@ -0,0 +1,460 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "secder.h" +#include "secerr.h" + +#if 0 +/* + * Generic templates for individual/simple items. + */ + +DERTemplate SECAnyTemplate[] = { + { DER_ANY, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECBitStringTemplate[] = { + { DER_BIT_STRING, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECBooleanTemplate[] = { + { DER_BOOLEAN, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECIA5StringTemplate[] = { + { DER_IA5_STRING, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECIntegerTemplate[] = { + { DER_INTEGER, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECNullTemplate[] = { + { DER_NULL, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECObjectIDTemplate[] = { + { DER_OBJECT_ID, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECOctetStringTemplate[] = { + { DER_OCTET_STRING, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECPrintableStringTemplate[] = { + { DER_PRINTABLE_STRING, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECT61StringTemplate[] = { + { DER_T61_STRING, + 0, NULL, sizeof(SECItem) } +}; + +DERTemplate SECUTCTimeTemplate[] = { + { DER_UTC_TIME, + 0, NULL, sizeof(SECItem) } +}; + +#endif + +static int +header_length(DERTemplate *dtemplate, PRUint32 contents_len) +{ + PRUint32 len; + unsigned long encode_kind, under_kind; + PRBool explicit, optional, universal; + + encode_kind = dtemplate->kind; + + explicit = (encode_kind & DER_EXPLICIT) ? PR_TRUE : PR_FALSE; + optional = (encode_kind & DER_OPTIONAL) ? PR_TRUE : PR_FALSE; + universal = ((encode_kind & DER_CLASS_MASK) == DER_UNIVERSAL) + ? PR_TRUE + : PR_FALSE; + + PORT_Assert(!(explicit && universal)); /* bad templates */ + + if (encode_kind & DER_POINTER) { + if (dtemplate->sub != NULL) { + under_kind = dtemplate->sub->kind; + if (universal) { + encode_kind = under_kind; + } + } else if (universal) { + under_kind = encode_kind & ~DER_POINTER; + } else { + under_kind = dtemplate->arg; + } + } else if (encode_kind & DER_INLINE) { + PORT_Assert(dtemplate->sub != NULL); + under_kind = dtemplate->sub->kind; + if (universal) { + encode_kind = under_kind; + } + } else if (universal) { + under_kind = encode_kind; + } else { + under_kind = dtemplate->arg; + } + + /* This is only used in decoding; it plays no part in encoding. */ + if (under_kind & DER_DERPTR) + return 0; + + /* No header at all for an "empty" optional. */ + if ((contents_len == 0) && optional) + return 0; + + /* And no header for a full DER_ANY. */ + if (encode_kind & DER_ANY) + return 0; + + /* + * The common case: one octet for identifier and as many octets + * as necessary to hold the content length. + */ + len = 1 + DER_LengthLength(contents_len); + + /* Account for the explicit wrapper, if necessary. */ + if (explicit) { +#if 0 /* \ + * Well, I was trying to do something useful, but these \ + * assertions are too restrictive on valid templates. \ + * I wanted to make sure that the top-level "kind" of \ + * a template does not also specify DER_EXPLICIT, which \ + * should only modify a component field. Maybe later \ + * I can figure out a better way to detect such a problem, \ + * but for now I must remove these checks altogether. \ + */ + /* + * This modifier applies only to components of a set or sequence; + * it should never be used on a set/sequence itself -- confirm. + */ + PORT_Assert (under_kind != DER_SEQUENCE); + PORT_Assert (under_kind != DER_SET); +#endif + + len += 1 + DER_LengthLength(len + contents_len); + } + + return len; +} + +static PRUint32 +contents_length(DERTemplate *dtemplate, void *src) +{ + PRUint32 len; + unsigned long encode_kind, under_kind; + PRBool universal; + + PORT_Assert(src != NULL); + + encode_kind = dtemplate->kind; + + universal = ((encode_kind & DER_CLASS_MASK) == DER_UNIVERSAL) + ? PR_TRUE + : PR_FALSE; + encode_kind &= ~DER_OPTIONAL; + + if (encode_kind & DER_POINTER) { + src = *(void **)src; + if (src == NULL) { + return 0; + } + if (dtemplate->sub != NULL) { + dtemplate = dtemplate->sub; + under_kind = dtemplate->kind; + src = (void *)((char *)src + dtemplate->offset); + } else if (universal) { + under_kind = encode_kind & ~DER_POINTER; + } else { + under_kind = dtemplate->arg; + } + } else if (encode_kind & DER_INLINE) { + PORT_Assert(dtemplate->sub != NULL); + dtemplate = dtemplate->sub; + under_kind = dtemplate->kind; + src = (void *)((char *)src + dtemplate->offset); + } else if (universal) { + under_kind = encode_kind; + } else { + under_kind = dtemplate->arg; + } + + /* Having any of these bits is not expected here... */ + PORT_Assert((under_kind & (DER_EXPLICIT | DER_INLINE | DER_OPTIONAL | DER_POINTER | DER_SKIP)) == 0); + + /* This is only used in decoding; it plays no part in encoding. */ + if (under_kind & DER_DERPTR) + return 0; + + if (under_kind & DER_INDEFINITE) { + PRUint32 sub_len; + void **indp = *(void ***)src; + + if (indp == NULL) + return 0; + + len = 0; + under_kind &= ~DER_INDEFINITE; + + if (under_kind == DER_SET || under_kind == DER_SEQUENCE) { + DERTemplate *tmpt = dtemplate->sub; + PORT_Assert(tmpt != NULL); + + for (; *indp != NULL; indp++) { + void *sub_src = (void *)((char *)(*indp) + tmpt->offset); + sub_len = contents_length(tmpt, sub_src); + len += sub_len + header_length(tmpt, sub_len); + } + } else { + /* + * XXX Lisa is not sure this code (for handling, for example, + * DER_INDEFINITE | DER_OCTET_STRING) is right. + */ + for (; *indp != NULL; indp++) { + SECItem *item = (SECItem *)(*indp); + sub_len = item->len; + if (under_kind == DER_BIT_STRING) { + sub_len = (sub_len + 7) >> 3; + /* bit string contents involve an extra octet */ + if (sub_len) + sub_len++; + } + if (under_kind != DER_ANY) + len += 1 + DER_LengthLength(sub_len); + } + } + + return len; + } + + switch (under_kind) { + case DER_SEQUENCE: + case DER_SET: { + DERTemplate *tmpt; + void *sub_src; + PRUint32 sub_len; + + len = 0; + for (tmpt = dtemplate + 1; tmpt->kind; tmpt++) { + sub_src = (void *)((char *)src + tmpt->offset); + sub_len = contents_length(tmpt, sub_src); + len += sub_len + header_length(tmpt, sub_len); + } + } break; + + case DER_BIT_STRING: + len = (((SECItem *)src)->len + 7) >> 3; + /* bit string contents involve an extra octet */ + if (len) + len++; + break; + + default: + len = ((SECItem *)src)->len; + break; + } + + return len; +} + +static unsigned char * +der_encode(unsigned char *buf, DERTemplate *dtemplate, void *src) +{ + int header_len; + PRUint32 contents_len; + unsigned long encode_kind, under_kind; + PRBool explicit, universal; + + /* + * First figure out how long the encoding will be. Do this by + * traversing the template from top to bottom and accumulating + * the length of each leaf item. + */ + contents_len = contents_length(dtemplate, src); + header_len = header_length(dtemplate, contents_len); + + /* + * Enough smarts was involved already, so that if both the + * header and the contents have a length of zero, then we + * are not doing any encoding for this element. + */ + if (header_len == 0 && contents_len == 0) + return buf; + + encode_kind = dtemplate->kind; + + explicit = (encode_kind & DER_EXPLICIT) ? PR_TRUE : PR_FALSE; + encode_kind &= ~DER_OPTIONAL; + universal = ((encode_kind & DER_CLASS_MASK) == DER_UNIVERSAL) + ? PR_TRUE + : PR_FALSE; + + if (encode_kind & DER_POINTER) { + if (contents_len) { + src = *(void **)src; + PORT_Assert(src != NULL); + } + if (dtemplate->sub != NULL) { + dtemplate = dtemplate->sub; + under_kind = dtemplate->kind; + if (universal) { + encode_kind = under_kind; + } + src = (void *)((char *)src + dtemplate->offset); + } else if (universal) { + under_kind = encode_kind & ~DER_POINTER; + } else { + under_kind = dtemplate->arg; + } + } else if (encode_kind & DER_INLINE) { + dtemplate = dtemplate->sub; + under_kind = dtemplate->kind; + if (universal) { + encode_kind = under_kind; + } + src = (void *)((char *)src + dtemplate->offset); + } else if (universal) { + under_kind = encode_kind; + } else { + under_kind = dtemplate->arg; + } + + if (explicit) { + buf = DER_StoreHeader(buf, encode_kind, + (1 + DER_LengthLength(contents_len) + contents_len)); + encode_kind = under_kind; + } + + if ((encode_kind & DER_ANY) == 0) { /* DER_ANY already contains header */ + buf = DER_StoreHeader(buf, encode_kind, contents_len); + } + + /* If no real contents to encode, then we are done. */ + if (contents_len == 0) + return buf; + + if (under_kind & DER_INDEFINITE) { + void **indp; + + indp = *(void ***)src; + PORT_Assert(indp != NULL); + + under_kind &= ~DER_INDEFINITE; + if (under_kind == DER_SET || under_kind == DER_SEQUENCE) { + DERTemplate *tmpt = dtemplate->sub; + PORT_Assert(tmpt != NULL); + for (; *indp != NULL; indp++) { + void *sub_src = (void *)((char *)(*indp) + tmpt->offset); + buf = der_encode(buf, tmpt, sub_src); + } + } else { + for (; *indp != NULL; indp++) { + SECItem *item; + int sub_len; + + item = (SECItem *)(*indp); + sub_len = item->len; + if (under_kind == DER_BIT_STRING) { + if (sub_len) { + int rem; + + sub_len = (sub_len + 7) >> 3; + buf = DER_StoreHeader(buf, under_kind, sub_len + 1); + rem = (sub_len << 3) - item->len; + *buf++ = rem; /* remaining bits */ + } else { + buf = DER_StoreHeader(buf, under_kind, 0); + } + } else if (under_kind != DER_ANY) { + buf = DER_StoreHeader(buf, under_kind, sub_len); + } + PORT_Memcpy(buf, item->data, sub_len); + buf += sub_len; + } + } + return buf; + } + + switch (under_kind) { + case DER_SEQUENCE: + case DER_SET: { + DERTemplate *tmpt; + void *sub_src; + + for (tmpt = dtemplate + 1; tmpt->kind; tmpt++) { + sub_src = (void *)((char *)src + tmpt->offset); + buf = der_encode(buf, tmpt, sub_src); + } + } break; + + case DER_BIT_STRING: { + SECItem *item; + int rem; + + /* + * The contents length includes our extra octet; subtract + * it off so we just have the real string length there. + */ + contents_len--; + item = (SECItem *)src; + PORT_Assert(contents_len == ((item->len + 7) >> 3)); + rem = (contents_len << 3) - item->len; + *buf++ = rem; /* remaining bits */ + PORT_Memcpy(buf, item->data, contents_len); + buf += contents_len; + } break; + + default: { + SECItem *item; + + item = (SECItem *)src; + PORT_Assert(contents_len == item->len); + PORT_Memcpy(buf, item->data, contents_len); + buf += contents_len; + } break; + } + + return buf; +} + +SECStatus +DER_Encode(PLArenaPool *arena, SECItem *dest, DERTemplate *dtemplate, void *src) +{ + unsigned int contents_len, header_len; + + src = (void **)((char *)src + dtemplate->offset); + + /* + * First figure out how long the encoding will be. Do this by + * traversing the template from top to bottom and accumulating + * the length of each leaf item. + */ + contents_len = contents_length(dtemplate, src); + header_len = header_length(dtemplate, contents_len); + + dest->len = contents_len + header_len; + + /* Allocate storage to hold the encoding */ + dest->data = (unsigned char *)PORT_ArenaAlloc(arena, dest->len); + if (dest->data == NULL) { + PORT_SetError(SEC_ERROR_NO_MEMORY); + return SECFailure; + } + + /* Now encode into the buffer */ + (void)der_encode(dest->data, dtemplate, src); + + return SECSuccess; +} |