version 1.18.2.1, 2002/06/26 15:30:39 |
version 1.18.2.2, 2002/10/11 14:51:53 |
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#include "compat.h" |
#include "compat.h" |
#include "ssh.h" |
#include "ssh.h" |
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static int openssh_RSA_verify(int, u_char *, u_int, u_char *, u_int , RSA *); |
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/* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */ |
/* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */ |
int |
int |
ssh_rsa_sign(Key *key, u_char **sigp, u_int *lenp, |
ssh_rsa_sign(Key *key, u_char **sigp, u_int *lenp, |
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{ |
{ |
const EVP_MD *evp_md; |
const EVP_MD *evp_md; |
EVP_MD_CTX md; |
EVP_MD_CTX md; |
u_char digest[EVP_MAX_MD_SIZE], *sig, *ret; |
u_char digest[EVP_MAX_MD_SIZE], *sig; |
u_int slen, dlen, len; |
u_int slen, dlen, len; |
int ok, nid; |
int ok, nid; |
Buffer b; |
Buffer b; |
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return -1; |
return -1; |
} |
} |
if (len < slen) { |
if (len < slen) { |
int diff = slen - len; |
u_int diff = slen - len; |
debug("slen %u > len %u", slen, len); |
debug("slen %u > len %u", slen, len); |
memmove(sig + diff, sig, len); |
memmove(sig + diff, sig, len); |
memset(sig, 0, diff); |
memset(sig, 0, diff); |
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buffer_put_cstring(&b, "ssh-rsa"); |
buffer_put_cstring(&b, "ssh-rsa"); |
buffer_put_string(&b, sig, slen); |
buffer_put_string(&b, sig, slen); |
len = buffer_len(&b); |
len = buffer_len(&b); |
ret = xmalloc(len); |
if (lenp != NULL) |
memcpy(ret, buffer_ptr(&b), len); |
*lenp = len; |
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if (sigp != NULL) { |
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*sigp = xmalloc(len); |
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memcpy(*sigp, buffer_ptr(&b), len); |
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} |
buffer_free(&b); |
buffer_free(&b); |
memset(sig, 's', slen); |
memset(sig, 's', slen); |
xfree(sig); |
xfree(sig); |
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if (lenp != NULL) |
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*lenp = len; |
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if (sigp != NULL) |
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*sigp = ret; |
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return 0; |
return 0; |
} |
} |
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xfree(sigblob); |
xfree(sigblob); |
return -1; |
return -1; |
} else if (len < modlen) { |
} else if (len < modlen) { |
int diff = modlen - len; |
u_int diff = modlen - len; |
debug("ssh_rsa_verify: add padding: modlen %u > len %u", |
debug("ssh_rsa_verify: add padding: modlen %u > len %u", |
modlen, len); |
modlen, len); |
sigblob = xrealloc(sigblob, modlen); |
sigblob = xrealloc(sigblob, modlen); |
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EVP_DigestUpdate(&md, data, datalen); |
EVP_DigestUpdate(&md, data, datalen); |
EVP_DigestFinal(&md, digest, &dlen); |
EVP_DigestFinal(&md, digest, &dlen); |
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ret = RSA_verify(nid, digest, dlen, sigblob, len, key->rsa); |
ret = openssh_RSA_verify(nid, digest, dlen, sigblob, len, key->rsa); |
memset(digest, 'd', sizeof(digest)); |
memset(digest, 'd', sizeof(digest)); |
memset(sigblob, 's', len); |
memset(sigblob, 's', len); |
xfree(sigblob); |
xfree(sigblob); |
if (ret == 0) { |
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int ecode = ERR_get_error(); |
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error("ssh_rsa_verify: RSA_verify failed: %s", |
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ERR_error_string(ecode, NULL)); |
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} |
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debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : ""); |
debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : ""); |
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return ret; |
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} |
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/* |
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* See: |
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* http://www.rsasecurity.com/rsalabs/pkcs/pkcs-1/ |
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* ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1/pkcs-1v2-1.asn |
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*/ |
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/* |
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* id-sha1 OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) |
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* oiw(14) secsig(3) algorithms(2) 26 } |
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*/ |
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static const u_char id_sha1[] = { |
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0x30, 0x21, /* type Sequence, length 0x21 (33) */ |
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0x30, 0x09, /* type Sequence, length 0x09 */ |
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0x06, 0x05, /* type OID, length 0x05 */ |
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0x2b, 0x0e, 0x03, 0x02, 0x1a, /* id-sha1 OID */ |
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0x05, 0x00, /* NULL */ |
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0x04, 0x14 /* Octet string, length 0x14 (20), followed by sha1 hash */ |
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}; |
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/* |
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* id-md5 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) |
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* rsadsi(113549) digestAlgorithm(2) 5 } |
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*/ |
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static const u_char id_md5[] = { |
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0x30, 0x20, /* type Sequence, length 0x20 (32) */ |
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0x30, 0x0c, /* type Sequence, length 0x09 */ |
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0x06, 0x08, /* type OID, length 0x05 */ |
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0x2a, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05, /* id-md5 */ |
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0x05, 0x00, /* NULL */ |
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0x04, 0x10 /* Octet string, length 0x10 (16), followed by md5 hash */ |
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}; |
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static int |
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openssh_RSA_verify(int type, u_char *hash, u_int hashlen, |
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u_char *sigbuf, u_int siglen, RSA *rsa) |
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{ |
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u_int ret, rsasize, oidlen = 0, hlen = 0; |
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int len; |
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const u_char *oid = NULL; |
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u_char *decrypted = NULL; |
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ret = 0; |
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switch (type) { |
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case NID_sha1: |
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oid = id_sha1; |
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oidlen = sizeof(id_sha1); |
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hlen = 20; |
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break; |
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case NID_md5: |
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oid = id_md5; |
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oidlen = sizeof(id_md5); |
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hlen = 16; |
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break; |
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default: |
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goto done; |
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break; |
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} |
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if (hashlen != hlen) { |
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error("bad hashlen"); |
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goto done; |
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} |
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rsasize = RSA_size(rsa); |
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if (siglen == 0 || siglen > rsasize) { |
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error("bad siglen"); |
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goto done; |
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} |
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decrypted = xmalloc(rsasize); |
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if ((len = RSA_public_decrypt(siglen, sigbuf, decrypted, rsa, |
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RSA_PKCS1_PADDING)) < 0) { |
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error("RSA_public_decrypt failed: %s", |
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ERR_error_string(ERR_get_error(), NULL)); |
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goto done; |
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} |
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if (len != hlen + oidlen) { |
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error("bad decrypted len: %d != %d + %d", len, hlen, oidlen); |
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goto done; |
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} |
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if (memcmp(decrypted, oid, oidlen) != 0) { |
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error("oid mismatch"); |
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goto done; |
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} |
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if (memcmp(decrypted + oidlen, hash, hlen) != 0) { |
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error("hash mismatch"); |
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goto done; |
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} |
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ret = 1; |
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done: |
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if (decrypted) |
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xfree(decrypted); |
return ret; |
return ret; |
} |
} |